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Roose S, Vande Velde F, Vlaminck J, Geldhof P, Levecke B. Serological diagnosis of soil-transmitted helminth (Ascaris, Trichuris and hookworm) infections: A scoping review. PLoS Negl Trop Dis 2024; 18:e0012049. [PMID: 38574166 PMCID: PMC10994556 DOI: 10.1371/journal.pntd.0012049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Accepted: 03/05/2024] [Indexed: 04/06/2024] Open
Abstract
BACKGROUND The World Health Organization emphasizes the importance of integrated monitoring and evaluation in neglected tropical disease (NTD) control programs. Serological assays offer a potential solution for integrated diagnosis of NTDs, particularly for those requiring mass drug administration (MDA) as primary control and elimination strategy. This scoping review aims (i) to provide an overview of assays using serum or plasma to detect infections with soil-transmitted helminths (STHs) in both humans and animals, (ii) to examine the methodologies used in this research field and (iii) to discuss advancements in serological diagnosis of STHs to guide prevention and control programs in veterinary and human medicine. METHODOLOGY We conducted a systematic search in the Ovid MEDLINE, Embase and Cochrane Library databases, supplemented by a Google search using predefined keywords to identify commercially available serological assays. Additionally, we performed a patent search through Espacenet. PRINCIPAL FINDINGS We identified 85 relevant literature records spanning over 50 years, with a notable increased interest in serological assay development in recent years. Most of the research efforts concentrated on diagnosing Ascaris infections in both humans and pigs, primarily using ELISA and western blot technologies. Almost all records targeted antibodies as analytes, employing proteins and peptides as analyte detection agents. Approximately 60% of sample sets described pertained to human samples. No commercially available tests for Trichuris or hookworms were identified, while for Ascaris, there are at least seven different ELISAs on the market. CONCLUSIONS While a substantial number of assays are employed in epidemiological research, the current state of serological diagnosis for guiding STH prevention and control programs is limited. Only two assays designed for pigs are used to inform efficient deworming practices in pig populations. Regarding human diagnosis, none of the existing assays has undergone extensive large-scale validation or integration into routine diagnostics for MDA programs.
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Affiliation(s)
- Sara Roose
- Department of Translational Physiology, Infectiology and Public Health, Ghent University, Merelbeke, Belgium
| | - Fiona Vande Velde
- Department of Translational Physiology, Infectiology and Public Health, Ghent University, Merelbeke, Belgium
| | - Johnny Vlaminck
- Department of Translational Physiology, Infectiology and Public Health, Ghent University, Merelbeke, Belgium
| | - Peter Geldhof
- Department of Translational Physiology, Infectiology and Public Health, Ghent University, Merelbeke, Belgium
| | - Bruno Levecke
- Department of Translational Physiology, Infectiology and Public Health, Ghent University, Merelbeke, Belgium
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Agrawal R, Pattnaik S, Kshatri JS, Kanungo S, Mandal N, Palo SK, Pati S. Prevalence and correlates of soil-transmitted helminths in schoolchildren aged 5 to 18 years in low- and middle-income countries: a systematic review and meta-analysis. Front Public Health 2024; 12:1283054. [PMID: 38577281 PMCID: PMC10991833 DOI: 10.3389/fpubh.2024.1283054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Accepted: 02/01/2024] [Indexed: 04/06/2024] Open
Abstract
Background According to the Global Burden of Disease (GBD) 2019 report, up to 1.5 million disability-adjusted life years (DALYs) are lost due to soil-transmitted helminths (STHs), and 5.9 million people are at risk of acquiring STHs. Regions with the highest prevalence of STH infections include Sub-Saharan Africa, China, South America, and Asia. While there are numerous fragmented studies on STH, comprehensive information on the prevalence and geographic distribution of different species, as well as their regional variations in the context of STHs is limited. The present systematic review and meta-analysis study attempts to provide a summary of the prevalence, geographical variation, and determinants of STHs among schoolchildren aged 5 to 18 years. Methods An extensive literature search was carried out using PubMed, Embase, Cinhal, and Psychinfo for studies published between 1999 and 2022 that reported the rate of STH infection in school-going children aged 5-18 years. A random effects model was employed in this meta-analysis due to expected heterogeneity. Subgroup analysis was carried out based on sex and STH species because of expected geographical variation. Results A total of 19,725 of the 49,630 children examined were infected with STH, yielding an overall pooled prevalence of 37.16% (95% CI: 29.74-44.89). The prevalence was highest in the Western Pacific region at 50.41% (95% CI: 33.74-67.04) followed by Europe at 39.74% (95% CI: 20.40-61.0) and Africa at 37.10% (95% CI: 26.84-47.95). Ascaris lumbricoides was found to be the most prevalent helminth with a prevalence of 24.07% (95% CI: 17.07-31.83). Conclusion The Western Pacific region is classified as a High-risk Zone (HRZ), while Southeast Asia, Africa, Europe, and the Eastern Mediterranean are classified as moderate-risk zones (MRZs). We found a 12% reduction in the pooled prevalence of STH infection from 1999 to 2012. Ascaris lumbricoides was the predominant species among schoolchildren. Mass Drug Administration (MDA) of Albendazole tablets and improved water, sanitation, and hygiene (WASH) practices are effective in controlling and preventing STH. Ensuring their implementation and access is crucial to addressing the problem. Systematic review registration https://www.crd.york.ac.uk/prospero/#loginpage, CRD42022333341.
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Kołodziej P, Szostakowska B, Lass A, Sulima M, Sikorska K, Kocki J, Krupski W, Starownik D, Bojar P, Szumiło J, Kasztelan-Szczerbińska B, Cichoż-Lach H, Bogucki J, Szymańska M, Fota-Markowska H, Bogucka-Kocka A. Chronic intestinal schistosomiasis caused by co-infection with Schistosoma intercalatum and Schistosoma mansoni. THE LANCET. INFECTIOUS DISEASES 2024; 24:e196-e205. [PMID: 37783223 DOI: 10.1016/s1473-3099(23)00486-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 06/23/2023] [Accepted: 07/19/2023] [Indexed: 10/04/2023]
Abstract
The Grand Round concerns a 24-year-old man from Zimbabwe who was studying and living in Poland. The patient had been complaining of abdominal pain, fatigue, alternating diarrhoea and constipation, and presence of blood in his stool for 3 years. The patient had the following diagnostic tests: colonoscopy, CT scan, histopathology, and parasitological and molecular tests. Results of the examinations showed that the cause of the patient's complaints was chronic intestinal schistosomiasis due to the co-infection with Schistosoma intercalatum and Schistosoma mansoni. The patient had two cycles of praziquantel therapy (Biltricide) and responded well to the treatment. In the Grand Round, we describe full diagnostics as well as clinical and therapeutic management in the patient with S intercalatum and S mansoni co-infection. This case allows us to draw attention to cases of forgotten chronic tropical diseases (including rare ones) in patients from regions with a high endemic index staying in non-endemic regions of the world for a long time. Co-infection with S intercalatum and S mansoni should be considered as a very rare clinical case.
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Affiliation(s)
- Przemysław Kołodziej
- Department of Biology and Genetics, Medical University of Lublin, Lublin, Poland.
| | - Beata Szostakowska
- Department of Tropical Parasitology, Medical University of Gdańsk, Gdańsk, Poland.
| | - Anna Lass
- Department of Tropical Parasitology, Medical University of Gdańsk, Gdańsk, Poland
| | - Małgorzata Sulima
- Division of Tropical and Parasitic Diseases, Medical University of Gdańsk, Gdańsk, Poland
| | - Katarzyna Sikorska
- Division of Tropical and Parasitic Diseases, Medical University of Gdańsk, Gdańsk, Poland
| | - Janusz Kocki
- Department of Clinical Genetics, Medical University of Lublin, Lublin, Poland
| | - Witold Krupski
- Department of Medical Radiology, Medical University of Lublin, Lublin, Poland
| | - Dorota Starownik
- Independent Public Clinical Hospital No. 4 in Lublin, Medical University of Lublin, Lublin, Poland
| | - Paweł Bojar
- Department of Pathomorphology, Beskid Oncology Centre-John Paul II Memorial City Hospital in Bielsko-Biala, Bielsko-Biała, Poland
| | - Justyna Szumiło
- Department of Clinical Pathomorphology, Medical University of Lublin, Lublin, Poland
| | | | - Halina Cichoż-Lach
- Department of Gastroenterology with Endoscopy Unit, Medical University of Lublin, Lublin, Poland
| | - Jacek Bogucki
- Department of Organic Chemistry, Medical University of Lublin, Lublin, Poland
| | - Magdalena Szymańska
- Department of Biology and Genetics, Medical University of Lublin, Lublin, Poland
| | | | - Anna Bogucka-Kocka
- Department of Biology and Genetics, Medical University of Lublin, Lublin, Poland
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Wepnje GB, Peters MK, Green AE, Nkuizin TE, Kenko DBN, Dzekashu FF, Kimbi HK, Anchang-Kimbi JK. Seasonal and environmental dynamics of intra-urban freshwater habitats and their influence on the abundance of Bulinus snail host of Schistosoma haematobium in the Tiko endemic focus, Mount Cameroon region. PLoS One 2023; 18:e0292943. [PMID: 37856526 PMCID: PMC10586688 DOI: 10.1371/journal.pone.0292943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Accepted: 10/02/2023] [Indexed: 10/21/2023] Open
Abstract
Urogenital schistosomiasis (UGS) caused by Schistosoma haematobium is endemic in the South West Region of Cameroon. An understanding of the abundance and distribution of the Bulinus snail, intermediate host can inform strategic snail control programmes at a local scale. This study investigated seasonal dynamics and environmental factors influencing occurrence and abundance of freshwater snail intermediate hosts in Tiko, a semi-urban endemic focus in the Mount Cameroon area. A longitudinal malacological field survey was conducted between December 2019 and December 2020 in the Tiko municipality. Snails were collected for one year monthly at 12 different human water contact sites along a stretch of the Ndongo stream using a standardized sampling technique. Freshwater snails were identified using shell morphological features. In addition, water temperature, pH, electrical conductivity, total dissolved solutes, salinity, water depth, width and flow velocity were measured, and vegetation cover as well as substrate type were determined. Bayesian regression models were used to identify the main environmental factors affecting the occurrence and abundance of Bulinus intermediate host. In total, 2129 fresh water snails were collected during the study period. Physa (51.4%) was the most abundant genus followed by Melanoides (28.6%) then, Bulinus (15.5%), Lymnaea (4.2%), Indoplanorbis (0.2%) and Potadoma (0.1%). Seasonality in abundance was significant in Bulinus sp as well as other genera, with greater numbers in the dry season (peaks between December and February). Water temperature, a rocky or sandy substrate type associated positively with Bulinus sp, meanwhile a higher water flow rate and medium vegetation negatively influenced the snail intermediate host population. These findings underscore the importance of timing behavioural and snail control interventions against schistosomiasis as well as increase vigilance of other trematode diseases in the study area. The continuous spread of planorbid snail hosts is a major concern.
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Affiliation(s)
- Godlove Bunda Wepnje
- Department of Animal Biology and Conservation, Faculty of Science, University of Buea, Buea, Cameroon
| | - Marcell K. Peters
- Department of Animal Ecology and Tropical Biology, Biocenter, University of Würzburg, Würzburg, Germany
| | - Adeline Enjema Green
- Department of Animal Biology and Conservation, Faculty of Science, University of Buea, Buea, Cameroon
| | - Tingmi Emparo Nkuizin
- Department of Animal Biology and Conservation, Faculty of Science, University of Buea, Buea, Cameroon
| | | | - Fairo F. Dzekashu
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
- Department of Biological Sciences, University of Lethbridge, Lethbridge, AB, Canada
| | - Helen Kuokuo Kimbi
- Department of Animal Biology and Conservation, Faculty of Science, University of Buea, Buea, Cameroon
- Department of Biomedical Sciences, Faculty of Health Sciences, University of Bamenda, Bambili, Cameroon
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, United States of America
| | - Judith Kuoh Anchang-Kimbi
- Department of Animal Biology and Conservation, Faculty of Science, University of Buea, Buea, Cameroon
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Nkemngo FN, W G Raissa L, Nebangwa DN, Nkeng AM, Kengne A, Mugenzi LMJ, Fotso-Toguem YG, Wondji MJ, Shey RA, Nguiffo-Nguete D, Fru-Cho J, Ndo C, Njiokou F, Webster JP, Wanji S, Wondji CS. Epidemiology of malaria, schistosomiasis, and geohelminthiasis amongst children 3-15 years of age during the dry season in Northern Cameroon. PLoS One 2023; 18:e0288560. [PMID: 37523402 PMCID: PMC10389741 DOI: 10.1371/journal.pone.0288560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Accepted: 06/29/2023] [Indexed: 08/02/2023] Open
Abstract
BACKGROUND The double burden of malaria and helminthiasis in children poses an obvious public health challenge, particularly in terms of anemia morbidity. While both diseases frequently geographically overlap, most studies focus on mono-infection and general prevalence surveys without molecular analysis. The current study investigated the epidemiological determinants of malaria, schistosomiasis, and geohelminthiasis transmission among children in the North Region of Cameroon. METHODOLOGY School and pre-school children aged 3-15 year-of-age were enrolled from three communities in March 2021 using a community cross-sectional design. Capillary-blood samples were obtained, and each was examined for malaria parasites using rapid-diagnostic-test (RDT), microscopy, and PCR while hemoglobin level was measured using a hemoglobinometer. Stool samples were analyzed for Schistosoma mansoni, S. guineensis, and soil-transmitted-helminthiasis (STH) infections using the Kato Katz method, and urine samples were assessed for the presence of S. haematobium eggs (including hybrids) using the standard urine filtration technique. RESULT A malaria prevalence of 56% (277/495) was recorded by PCR as opposed to 31.5% (156/495) by microscopy and 37.8% (186/495) by RDT. Similarly, schistosomiasis was observed at prevalence levels of up to 13.3% (66/495) overall [S. haematobium (8.7%); S. mansoni (3.8%); mixed Sh/Sm (0.6%); mixed Sh/Sm/Sg (0.2%). Both infections were higher in males and the 3-9 year-of-age groups. A high frequency of PCR reported P. falciparum mono-infection of 81.9% (227/277) and mixed P. falciparum/P. malariae infection of 17.3% (48/277) was observed. Malaria-helminths co-infections were observed at 13.1% (65/495) with marked variation between P. falciparum/S. haematobium (50.8%, 33/65); P. falciparum/S. mansoni (16.9%, 11/65) and P. falciparum/Ascaris (9.2%, 6/65) (χ2 = 17.5, p = 0.00003). Anemia prevalence was 32.9% (163/495), categorically associated with P. falciparum (45.8%, 104/227), Pf/Sh (11.5%, 26/227), and Pf/Sm (3.9%, 9/227) polyparasitism. CONCLUSION Polyparasitism with malaria and helminth infections is common in school-aged children despite periodic long-lasting insecticide-treated nets (LLINs) distribution and regular school-based praziquantel (for schistosomiasis) and albendazole (for STH) campaigns. Co-existence of Plasmodium parasites and helminths infections notably Schistosoma species among children may concurrently lead to an increase in Plasmodium infection with an enhanced risk of anemia, highlighting the necessity of an integrated approach for disease control interventions.
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Affiliation(s)
- Francis N Nkemngo
- Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon
- Department of Microbiology and Parasitology, Faculty of Science, University of Buea, Buea, Cameroon
| | - Lymen W G Raissa
- Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon
| | - Derrick N Nebangwa
- Faculty of Life Science and Medicine, King's College London, New Hunt's House, London, United Kingdom
| | - Asongha M Nkeng
- Centre for Infection Biology and Translational Research (CIBiT), Forzi Institute, Buea, Cameroon
- Department of Sociology & Anthropology, Faculty of Social and Management Sciences, University of Buea, Buea, Cameroon
| | - Alvine Kengne
- Department of Animal Biology and Physiology, Parasitology and Ecology Laboratory, Faculty of Science, University of Yaoundé I, Yaoundé, Cameroon
| | - Leon M J Mugenzi
- Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon
| | | | - Murielle J Wondji
- Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon
- Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, United Kingdom
| | - Robert A Shey
- Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, Buea, Cameroon
| | | | - Jerome Fru-Cho
- Department of Microbiology and Parasitology, Faculty of Science, University of Buea, Buea, Cameroon
- Research Foundation in Tropical Diseases and Environment (REFOTDE), Buea, Cameroon
| | - Cyrille Ndo
- Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon
- Department of Biological Sciences, Faculty of Medicine and Pharmaceutical Sciences, University of Douala, Douala, Cameroon
| | - Flobert Njiokou
- Department of Animal Biology and Physiology, Parasitology and Ecology Laboratory, Faculty of Science, University of Yaoundé I, Yaoundé, Cameroon
| | - Joanne P Webster
- Department of Pathobiology and Population Sciences, Royal Veterinary College, University of London, Herts, United Kingdom
| | - Samuel Wanji
- Department of Microbiology and Parasitology, Faculty of Science, University of Buea, Buea, Cameroon
- Research Foundation in Tropical Diseases and Environment (REFOTDE), Buea, Cameroon
| | - Charles S Wondji
- Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon
- Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, United Kingdom
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Association between polymorphisms of IL4, IL13, IL10, STAT6 and IFNG genes, cytokines and immunoglobulin E levels with high burden of Schistosoma mansoni in children from schistosomiasis endemic areas of Cameroon. INFECTION, GENETICS AND EVOLUTION : JOURNAL OF MOLECULAR EPIDEMIOLOGY AND EVOLUTIONARY GENETICS IN INFECTIOUS DISEASES 2023; 111:105416. [PMID: 36889485 PMCID: PMC10167540 DOI: 10.1016/j.meegid.2023.105416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 02/02/2023] [Accepted: 02/08/2023] [Indexed: 03/08/2023]
Abstract
Eliminating schistosomiasis as a public health problem by 2030 requires a better understanding of the disease transmission, especially the asymmetric distribution of worm burden in individuals living and sharing the same environment. It is in this light that this study was designed to identify human genetic determinants associated with high burden of S. mansoni and also with the plasma concentrations of IgE and four cytokines in children from two schistosomiasis endemic areas of Cameroon. In school-aged children of schistosomiasis endemic areas of Makenene and Nom-Kandi of Cameroon, S. mansoni infections and their infection intensities were evaluated in urine and stool samples using respectively the Point-of-care Circulating Cathodic Antigen test (POC-CCA) and the Kato Katz (KK) test. Thereafter, blood samples were collected in children harbouring high burden of schistosome infections as well as in their parents and siblings. DNA extracts and plasma were obtained from blood. Polymorphisms at 14 loci of five genes were assessed using PCR-restriction fragment length polymorphism and amplification-refractory mutation system. The ELISA test enabled to determine the plasma concentrations of IgE, IL-13, IL-10, IL-4 and IFN-γ. The prevalence of S. mansoni infections was significantly higher (P < 0.0001 for POC-CCA; P = 0.001 for KK) in Makenene (48.6% for POC-CCA and 7.9% for KK) compared to Nom-Kandi (31% for POC-CCA and 4.3% for KK). The infection intensities were also higher (P < 0.0001 for POC-CCA; P = 0.001 for KK) in children from Makenene than those from Nom-Kandi. The allele C of SNP rs3024974 of STAT6 was associated with an increased risk of bearing high burden of S. mansoni both in the additive (p = 0.009) and recessive model (p = 0.01) while the allele C of SNP rs1800871 of IL10 was protective (p = 0.0009) against high burden of S. mansoni. The alleles A of SNP rs2069739 of IL13 and G of SNP rs2243283 of IL4 were associated with an increased risk of having low plasma concentrations of IL-13 (P = 0.04) and IL-10 (P = 0.04), respectively. This study showed that host genetic polymorphisms may influence the outcome (high or low worm burden) of S. mansoni infections and also the plasma concentrations of some cytokines.
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Precision mapping of schistosomiasis and soil-transmitted helminthiasis among school age children at the coastal region, Kenya. PLoS Negl Trop Dis 2023; 17:e0011043. [PMID: 36602986 PMCID: PMC9847902 DOI: 10.1371/journal.pntd.0011043] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 01/18/2023] [Accepted: 12/20/2022] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND Accurate mapping of schistosomiasis (SCH) and soil transmitted helminths (STH) is a prerequisite for effective implementation of the control and elimination interventions. A precision mapping protocol was developed and implemented in the coastal region of Kenya by applying the current World Health Organization (WHO) mapping guide at a much lower administrative level (ward). METHODS A two-stage cluster survey design was undertaken, with 5 villages in each ward selected. From within each village 50 households were randomly selected, and a single child between the ages of 8 and 14 sampled following appropriate assent. The prevalence and intensity of infection of Schistosoma mansoni and STH were determined using the Kato-Katz method (single stool, duplicate slides) and urine filtration for S. haematobium. RESULTS Of the 27,850 school age children sampled, 6.9% were infected with at least one Schistosoma species, with S. haematobium being the most common 6.1% (95% CI: 3.1-11.9), and Tana River County having highest prevalence 19.6% (95% CI: 11.6-31.3). Prevalence of any STH infection was 5.8% (95% CI: 3.7-8.9), with Lamu County having the highest prevalence at 11.9% (95% CI: 10.0-14.1). The most prevalent STH species in the region was Trichuris trichiura at 3.1% (95% CI: 2.0-4.8). According to the WHO threshold for MDA implementation, 31 wards (in 15 sub-Counties) had a prevalence of ≥10% for SCH and thus qualify for annual MDA of all age groups from 2 years old. On the other hand, using the stricter Kenya BTS MDA threshold of ≥2%, 72 wards (in 17 sub-Counties) qualified for MDA and were targeted for treatment in 2021. CONCLUSIONS The precision mapping at the ward level demonstrated the variations of schistosomiasis prevalence and endemicity by ward even within the same sub-counties. The data collected will be utilized by the Kenyan Ministry of Health to improve targeting.
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Kengne Fokam AC, Sumo L, Bagayan M, Nana-Djeunga HC, Kuete T, Nganjou GSO, Tchami Mbagnia MC, Djune-Yemeli L, Wondji CS, Njiokou F. Exposition of Intermediate Hosts of Schistosomes to Niclosamide (Bayluscide WP 70) Revealed Significant Variations in Mortality Rates: Implications for Vector Control. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:12873. [PMID: 36232172 PMCID: PMC9566429 DOI: 10.3390/ijerph191912873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 08/15/2022] [Accepted: 08/23/2022] [Indexed: 06/16/2023]
Abstract
(1) Background: Schistosomiasis remains a public health issue in Cameroon. Snail control using Niclosamide can prevent schistosome transmission. It is safe to determine lethal concentrations for the population. This study aimed at assessing the toxicity of Niclosamide on different developmental stages of snail populations; (2) Methods: Snails were collected, identified, and reared in the laboratory. Egg masses and adult snails were exposed to Niclosamide, at increasing concentrations (0.06, 0.125, 0.25, 0.5, 1 mg/L for egg embryos and 0.06, 0.08, 0.1, 0.12, 0.14, 0.16, 0.18, 0.2 mg/L for adults). After 24 h exposure, egg masses and snails were removed from Niclosamide solutions, washed with source water and observed; (3) Results: Snail susceptibility was species and population dependent. For egg embryos, Biomphalaria pfeifferi was the most susceptible (LC50: 0.1; LC95: 6.3 mg/L) and Bulinus truncatus the least susceptible (LC50: 4.035; LC95: 228.118 mg/L). However, for adults, B. truncatus was the most susceptible (mortality rate: 100%). The LC50 and LC95 for Bi. camerunensis eggs were 0.171 mg/L and 1.102 mg/L, respectively, and were higher than those obtained for adults (0.0357 mg/L and 0.9634 mg/L); (4) Conclusion: These findings will guide the design of vector control strategies targeting these snail species in Cameroon.
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Affiliation(s)
- Alvine Christelle Kengne Fokam
- Department of Animal Biology and Physiology, Faculty of Science, University of Yaoundé 1, Yaoundé P.O. Box 812, Cameroon
- Centre for Research in Infectious Diseases (CRID), Yaoundé P.O. Box 13591, Cameroon
| | - Laurentine Sumo
- Department of Biological Sciences, Faculty of Science, University of Bamenda, Bambili P.O. Box 39, Cameroon
| | - Mohamed Bagayan
- Animal Biology and Ecology Laboratory, University of Joseph Ki-Zerbo, Ouagadougou P.O. Box 7021, Burkina Faso
| | | | - Thomas Kuete
- Department of Biological Sciences, Faculty of Medicine and Pharmaceutical Sciences, University of Douala, Douala P.O. Box 24157, Cameroon
| | - Gabriella S. Ondoua Nganjou
- Department of Animal Biology and Physiology, Faculty of Science, University of Yaoundé 1, Yaoundé P.O. Box 812, Cameroon
- Centre for Research on Filariasis and Other Tropical Diseases (CRFilMT), Yaoundé P.O. Box 5797, Cameroon
| | - Murielle Carole Tchami Mbagnia
- Department of Animal Biology and Physiology, Faculty of Science, University of Yaoundé 1, Yaoundé P.O. Box 812, Cameroon
- Centre for Research in Infectious Diseases (CRID), Yaoundé P.O. Box 13591, Cameroon
| | - Linda Djune-Yemeli
- Centre for Research on Filariasis and Other Tropical Diseases (CRFilMT), Yaoundé P.O. Box 5797, Cameroon
| | - Charles Sinclair Wondji
- Centre for Research in Infectious Diseases (CRID), Yaoundé P.O. Box 13591, Cameroon
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L35QA, UK
| | - Flobert Njiokou
- Department of Animal Biology and Physiology, Faculty of Science, University of Yaoundé 1, Yaoundé P.O. Box 812, Cameroon
- Centre for Research in Infectious Diseases (CRID), Yaoundé P.O. Box 13591, Cameroon
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Macharia PM, Ray N, Gitonga CW, Snow RW, Giorgi E. Combining school-catchment area models with geostatistical models for analysing school survey data from low-resource settings: Inferential benefits and limitations. SPATIAL STATISTICS 2022; 51:100679. [PMID: 35880005 PMCID: PMC7613137 DOI: 10.1016/j.spasta.2022.100679] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
School-based sampling has been used to inform targeted responses for malaria and neglected tropical diseases. Standard geostatistical methods for mapping disease prevalence use the school location to model spatial correlation, which is questionable since exposure to the disease is more likely to occur in the residential location. In this paper, we propose to overcome the limitations of standard geostatistical methods by introducing a modelling framework that accounts for the uncertainty in the location of the residence of the students. By using cost distance and cost allocation models to define spatial accessibility and in absence of any information on the travel mode of students to school, we consider three school catchment area models that assume walking only, walking and bicycling and, walking and motorized transport. We illustrate the use of this approach using two case studies of malaria in Kenya and compare it with the standard approach that uses the school locations to build geostatistical models. We argue that the proposed modelling framework presents several inferential benefits, such as the ability to combine data from multiple surveys some of which may also record the residence location, and to deal with ecological bias when estimating the effects of malaria risk factors. However, our results show that invalid assumptions on the modes of travel to school can worsen the predictive performance of geostatistical models. Future research in this area should focus on collecting information on the modes of transportation to school which can then be used to better parametrize the catchment area models.
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Affiliation(s)
- Peter M. Macharia
- Centre for Health Informatics, Computing, and Statistics, Lancaster Medical School, Lancaster University, Lancaster, LA1 4YW, UK
- Population Health Unit, Kenya Medical Research Institute-Wellcome Trust Research Programme, PO, Box 43640, Nairobi, Kenya
| | - Nicolas Ray
- GeoHealth group, Institute of Global Health, University of Geneva, Geneva, Switzerland
- Institute for Environmental Sciences, University of Geneva, Geneva, Switzerland
| | - Caroline W. Gitonga
- Population Health Unit, Kenya Medical Research Institute-Wellcome Trust Research Programme, PO, Box 43640, Nairobi, Kenya
| | - Robert W. Snow
- Population Health Unit, Kenya Medical Research Institute-Wellcome Trust Research Programme, PO, Box 43640, Nairobi, Kenya
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, OX3 7LG, UK
| | - Emanuele Giorgi
- Centre for Health Informatics, Computing, and Statistics, Lancaster Medical School, Lancaster University, Lancaster, LA1 4YW, UK
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Kamdem CN, Tiofack AAZ, Mewamba EM, Tchounkeu EY, Tatang JRA, Mengoue ELT, Mbagnia CMT, Fogue PS, Womeni HM, Simo G. Fine mapping of Ascaris lumbricoides, Trichuris trichiura and hookworm infections in sub-districts of Makenene in Centre Region of Cameroun. Sci Rep 2022; 12:13935. [PMID: 35978014 PMCID: PMC9385646 DOI: 10.1038/s41598-022-18285-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 08/09/2022] [Indexed: 11/20/2022] Open
Abstract
Preventive chemotherapy (PC) that remains the main control strategy recommended by the World Health Organization to achieve the elimination of soil-transmitted helminth (STH) infections as a public health problem must be strengthened by identifying the remaining transmission hot-spots for the deployment of appropriate control measures. This study was designed to assess the prevalence and infections intensities of soil-transmitted helminths and perform micro scale mapping in order to identify transmission hot-spots for targeted control operations. Stool samples were collected from 1775 children in ten primary schools of eight sub-districts of Makenene in Cameroon. Kato Katz technique was used to process and examine stool samples to detect the eggs of soil-transmitted nematodes. The prevalence of soil-transmitted helminth species as well as the infection intensities was compared. Data visualizations in forms of maps were made using Quantum geographic information system (QGIS) software. The overall prevalence of soil-transmitted helminth infections was 4.8% with a 95% confidence interval (CI) of 3.8–5.9%: 3.0% (95% CI 2.2–3.9) for Ascaris lumbricoides, 1.4% (95% CI 0.9–2.0) for Trichuris trichiura and 0.8% (95% CI 0.5–1.4) for hookworms. The prevalence of soil-transmitted helminth species differ significantly between schools and sub-districts. The intensity of infections was light (2.4%, 1.1% and 0.8%), moderate (0.4%, 0.1% and 0.1%) and heavy (0.2%, 0.2% and 0%) for A. lumbricoides, T. trichiura and hookworm respectively. The mean intensity of infections was 7255 EPG for A. lumbricoides, 2900 EPG for T. trichiura and 298 EPG for hookworm. Between schools, significant difference was recorded in the means of infection intensities of T. Trichiura and hookworms but not for A. lumbricoides. This difference was also significant for T. Trichiura when comparison were between sex. No significant difference were recorded when the comparison were between age. Fine mapping revealed that children harbouring heavy infections were clustered in the same sub-districts; highlighting the presence of high endemicity sub-districts and hot-spots for the transmission of different soil-transmitted helminth species. This study showed a diversity in the prevalence and transmission of different soil-transmitted helminth species. It also hightlighted the need for micro scale mapping to enable the localisation of high endemicity sub-districts and transmission hot-spot sites where targeted control operations must be deployed to achieve STH elimination.
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Affiliation(s)
- Cyrille Nguemnang Kamdem
- Molecular Parasitology and Entomology Unit, Department of Biochemistry, Faculty of Science, University of Dschang, PO Box 67, Dschang, Cameroon
| | - Auvaker Arnol Zebaze Tiofack
- Molecular Parasitology and Entomology Unit, Department of Biochemistry, Faculty of Science, University of Dschang, PO Box 67, Dschang, Cameroon
| | - Estelle Mezajou Mewamba
- Molecular Parasitology and Entomology Unit, Department of Biochemistry, Faculty of Science, University of Dschang, PO Box 67, Dschang, Cameroon
| | - Esthelline Yangea Tchounkeu
- Molecular Parasitology and Entomology Unit, Department of Biochemistry, Faculty of Science, University of Dschang, PO Box 67, Dschang, Cameroon
| | - Joël Rostand Atiokeng Tatang
- Research Unit of Biology and Applied Ecology, Department of Animal Biology, Faculty of Science, University of Dschang, Dschang, Cameroon
| | - Edmond Loic Tekeu Mengoue
- Molecular Parasitology and Entomology Unit, Department of Biochemistry, Faculty of Science, University of Dschang, PO Box 67, Dschang, Cameroon
| | - Carole Mureille Tchami Mbagnia
- Parasitology and Ecology Laboratory, Department of Animal Biology and Physiology, Faculty of Science, University of Yaoundé I, Yaoundé, Cameroon
| | - Pythagore Soubgwi Fogue
- Molecular Parasitology and Entomology Unit, Department of Biochemistry, Faculty of Science, University of Dschang, PO Box 67, Dschang, Cameroon
| | - Hilaire Macaire Womeni
- "Unité de Recherche de Biochimie, des plantes Médicinales, des Sciences Alimentaires et Nutrition", University of Dschang, Dschang, Cameroon
| | - Gustave Simo
- Molecular Parasitology and Entomology Unit, Department of Biochemistry, Faculty of Science, University of Dschang, PO Box 67, Dschang, Cameroon.
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Hybridization increases genetic diversity in Schistosoma haematobium populations infecting humans in Cameroon. Infect Dis Poverty 2022; 11:37. [PMID: 35346375 PMCID: PMC8962594 DOI: 10.1186/s40249-022-00958-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 03/09/2022] [Indexed: 11/10/2022] Open
Abstract
Background Hybrids between Schistosoma haematobium (Sh) and S. bovis (Sb) have been found in several African countries as well as in Europe. Since the consequences of this hybridization are still unknown, this study aims to verify the presence of such hybrids in Cameroonian humans, to describe the structure of S. haematobium populations on a large geographic scale, and to examine the impact of these hybrids on genetic diversity and structure of these populations.
Methods From January to April 2019, urine from infected children was collected in ten geographically distinct populations. Miracidia were collected from eggs in this urine. To detect the presence of hybrids among these miracidia we genotyped both Cox1 (RD-PCR) and ITS2 gene (PCR-RFLP). Population genetic diversity and structure was assessed by genotyping each miracidium with a panel of 14 microsatellite markers. Gene diversity was measured using both heterozygosity and allelic richness indexes, and genetic structure was analyzed using paired Fst, PCA and Bayesian approaches. Results Of the 1327 miracidia studied, 88.7% were identified as pure genotypes of S. haematobium (Sh_Sh/Sh) while the remaining 11.3% were hybrids (7.0% with Sh_Sh/Sb, 3.7% with Sb_Sb/Sh and 0.4% with Sb_Sh/Sb). No miracidium has been identified as a pure genotype of S. bovis. Allelic richness ranged from 5.55 (Loum population) to 7.73 (Matta-Barrage) and differed significantly between populations. Mean heterozygosity ranged from 53.7% (Loum) to 59% (Matta Barrage) with no significant difference. The overall genetic differentiation inferred either by a principal component analysis or by the Bayesian approach shows a partial structure. Southern populations (Loum and Matta Barrage) were clearly separated from other localities but genetic differentiation between northern localities was limited, certainly due to the geographic proximity between these sites. Conclusions Hybrids between S. haematobium and S. bovis were identified in 11.3% of miracidia that hatched from eggs present in the urine of Cameroonian schoolchildren. The percentages of these hybrids are correlated with the genetic diversity of the parasite, indicating that hybridization increases genetic diversity in our sampling sites. Hybridization is therefore a major biological process that shapes the genetic diversity of S. haematobium. Graphical Abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s40249-022-00958-0.
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Chelkeba L, Mekonnen Z, Emana D, Jimma W, Melaku T. Prevalence of soil-transmitted helminths infections among preschool and school-age children in Ethiopia: a systematic review and meta-analysis. Glob Health Res Policy 2022; 7:9. [PMID: 35307028 PMCID: PMC8935818 DOI: 10.1186/s41256-022-00239-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 01/24/2022] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND There is a lack of comprehensive national data on prevalence, geographical distribution of different species, and temporal trends in soil-helminthiasis (STHs). Therefore, this study aimed to provide a summary and location of the available data on STHs infection among preschool and school-age children in Ethiopia. METHODS The search was carried out in Medline via PubMed, Scopus, Science Direct, Web of Science, and Google Scholar on data published between 1997 to February 2020 for studies describing the rate of STHs infection among preschool and school-age in Ethiopian. We followed the Patient, Intervention, Comparison, and Outcome (PICO) approach to identify the studies. Meta-regression was performed to understand the trends and to summarize the prevalence using the "metaprop" command using STATA software version 14.0 RESULTS: A total of 29,311 of the 61,690 children examined during the period under review were infected with one or more species of intestinal parasites yielding an overall prevalence of 48% (95% CI: 43-53%). The overall pooled estimate of STHs was 33% (95% CI: 28-38%). The prevalence was 44% (95% CI: 31-58%) in SNNPR, 34% (95% CI: 28-41%) in Amhara region, 31% (95% CI: 19-43%) in Oromia region and 10% (95% CI: 7-12%) in Tigray region. Soil-transmitted helminths infection rate has been decreasing from 44% (95% CI: 30-57%) pre-Mass Drug Administration (MDA) era (1997-2012) to 30% (95% CI: 25-34%) post-MDA (2013-2020), although statistically not significant (p = 0.45). A lumbricoides was the predominant species with a prevalence of 17%. CONCLUSION Southern Nations Nationalities and Peoples Region, Amhara, and Oromia regions carry the highest-burden and are categorized to Moderate Risk Zones (MRZ) and therefore, requiring MDA once annually with Albendazole or Mebendazole. The prevalence of STHs decreased after MDA compared to before MDA, but the decline was not statistically significant. A. lumbricoides was the predominant species of STHs among preschool and school-age children in Ethiopia. The high prevalence of STHs observed in this review, underscores the need for better control and prevention strategies in Ethiopia.
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Affiliation(s)
- Legese Chelkeba
- Department of Pharmacology and Clinical Pharmacy, School of Pharmacy, College Health Sciences, Black Lion Specialized Hospital, Addis Ababa University, Addis Ababa, Ethiopia
| | - Zeleke Mekonnen
- Department of Parasitology, School of Medical Laboratory Sciences, Institute of Health, Jimma University, Jimma, Ethiopia
| | - Daniel Emana
- Department of Parasitology, School of Medical Laboratory Sciences, Institute of Health, Jimma University, Jimma, Ethiopia
| | - Worku Jimma
- Department of Information Science, College of Natural Sciences, Jimma University, Jimma, Ethiopia
| | - Tsegaye Melaku
- Department of Clinical Pharmacy, School of Pharmacy, Institute of Health, Jimma University, Jimma, Ethiopia.
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Aemiro A, Menkir S, Tegen D, Tola G. Prevalence of Soil-Transmitted Helminthes and Associated Risk Factors Among People of Ethiopia: A Systematic Review and Meta-Analysis. INFECTIOUS DISEASES: RESEARCH AND TREATMENT 2022; 15:11786337211055437. [PMID: 35356097 PMCID: PMC8958720 DOI: 10.1177/11786337211055437] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Accepted: 10/02/2021] [Indexed: 11/15/2022]
Abstract
Background: A Soil-transmitted helminthic infection (STHIs) remains a notable health problem in resource-limited countries. Objective: This systematic review and meta-analysis aimed to determine the overall prevalence of STH infections in Ethiopia. Methods: Articles written in English were searched from online public databases. Searching terms taken separately and jointly were “prevalence,” “soil-transmitted helminths” “nematode,” “Geo-helminths,” “roundworm,” “Necator,” “Ancylostoma,” “Ascaris,” “Trichuris,” “hookworm,” “whipworm,” “ S. strecoralies,” “associated factors,” and “Ethiopia.” We used STATA version 14 for meta-analysis and Cochran’s Q test statistics and the I2 test for heterogeneity. Result: From 297 reviewed articles 41 fulfilled the inclusion criteria. The pooled prevalence of STH infections in Ethiopia was 36.78% Ascaris lumbricoides had the highest pooled prevalence 17.63%, followed by hook worm12.35%. Trichuris trichiura 7.24% when the prevalence of S. strecoralies was 2.16% (95% CI: 0.97-3.35). Age, sex, residence, family education level, lack of shoe wearing habits and open defecation were identified as risk factors for STH infection. Eating unwashed and uncooked fruit and vegetables increased the risk of STH infection by 1.88 times while untrimmed finger nail and lack of hand washing habits increase the risk of STH infection by 1.28 and 3.16 times respectively with 95% CI. Limitation: Lack of published studies from Afar, Gambela, Somali, and Benshangul gumuz regions may affect the true picture. The other limitation is that the search strategy will be restricted articles published only in the English language but there might be articles that published using another language. Conclusion: Ascaris lumbricoides, hookworms and Trichuris trichiura, are the most prevalent soil-transmitted helminthes infections in Ethiopia. Age, sex, residence, family education level, lack of shoe wearing habits Open defecation untrimmed finger nail and lack of hand washing habits significantly associated with STH infection. When eating unwashed, uncooked fruit and vegetables were not significantly associated with STH infection. Strategic use of anti-helminthic, health education, and adequate sanitation, taking into account this epidemiologic information is helpful in the control of STH infections in Ethiopia.
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Affiliation(s)
- Aleka Aemiro
- Department of Biology, Mekdela Amba University College of Natural and Computational Science, Mekdela, Ethiopia
| | - Sisay Menkir
- Department of Biology, College of Science, Bahir Dar University, Bahir Dar, Ethiopia
| | - Dires Tegen
- South Gondar Zone, Dera Woreda Education Office, Ethiopia
| | - Gedam Tola
- Department of Biology, Debark University College of Natural and Computational Science, Debark, Ethiopia
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14
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Landeryou T, Rabone M, Allan F, Maddren R, Rollinson D, Webster BL, Tchuem-Tchuenté LA, Anderson RM, Emery AM. Genome-wide insights into adaptive hybridisation across the Schistosoma haematobium group in West and Central Africa. PLoS Negl Trop Dis 2022; 16:e0010088. [PMID: 35100291 PMCID: PMC8803156 DOI: 10.1371/journal.pntd.0010088] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 12/11/2021] [Indexed: 11/30/2022] Open
Abstract
Schistosomiasis remains a public health concern across sub-Saharan Africa; current control programmes rely on accurate mapping and high mass drug administration (MDA) coverage to attempt disease elimination. Inter-species hybridisation can occur between certain species, changing epidemiological dynamics within endemic regions, which has the potential to confound control interventions. The impact of hybridisation on disease dynamics is well illustrated in areas of Cameroon where urogenital schistosomiasis, primarily due to Schistosoma haematobium and hybrid infections, now predominate over intestinal schistosomiasis caused by Schistosoma guineensis. Genetic markers have shown the ability to identify hybrids, however the underlying genomic architecture of divergence and introgression between these species has yet to be established. In this study, restriction site associated DNA sequencing (RADseq) was used on archived adult worms initially identified as; Schistosoma bovis (n = 4), S. haematobium (n = 9), S. guineensis (n = 3) and S. guineensis x S. haematobium hybrids (n = 4) from Mali, Senegal, Niger, São Tomé and Cameroon. Genome-wide evidence supports the existence of S. guineensis and S. haematobium hybrid populations across Cameroon. The hybridisation of S. guineensis x S. haematobium has not been demonstrated on the island of São Tomé, where all samples showed no introgression with S. haematobium. Additionally, all S. haematobium isolates from Nigeria, Mali and Cameroon indicated signatures of genomic introgression from S. bovis. Adaptive loci across the S. haematobium group showed that voltage-gated calcium ion channels (Cav) could play a key role in the ability to increase the survivability of species, particularly in host systems. Where admixture has occurred between S. guineensis and S. haematobium, the excess introgressive influx of tegumental (outer helminth body) and antigenic genes from S. haematobium has increased the adaptive response in hybrids, leading to increased hybrid population fitness and viability.
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Affiliation(s)
- Toby Landeryou
- Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, Imperial College London, London, United Kingdom
- The Natural History Museum, Department of Life Sciences, London, United Kingdom
- London Centre for Neglected Tropical Disease Research (LCNTDR), Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Muriel Rabone
- The Natural History Museum, Department of Life Sciences, London, United Kingdom
- London Centre for Neglected Tropical Disease Research (LCNTDR), Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Fiona Allan
- The Natural History Museum, Department of Life Sciences, London, United Kingdom
- London Centre for Neglected Tropical Disease Research (LCNTDR), Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Rosie Maddren
- Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, Imperial College London, London, United Kingdom
- London Centre for Neglected Tropical Disease Research (LCNTDR), Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - David Rollinson
- The Natural History Museum, Department of Life Sciences, London, United Kingdom
- London Centre for Neglected Tropical Disease Research (LCNTDR), Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Bonnie L. Webster
- The Natural History Museum, Department of Life Sciences, London, United Kingdom
- London Centre for Neglected Tropical Disease Research (LCNTDR), Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, Imperial College London, London, United Kingdom
| | | | - Roy M. Anderson
- Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, Imperial College London, London, United Kingdom
- London Centre for Neglected Tropical Disease Research (LCNTDR), Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Aidan M. Emery
- The Natural History Museum, Department of Life Sciences, London, United Kingdom
- London Centre for Neglected Tropical Disease Research (LCNTDR), Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, Imperial College London, London, United Kingdom
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Trend of Soil-Transmitted Helminths in Ethiopian Children: A Systematic Review and Meta-Analysis (2000-2018). J Parasitol Res 2021; 2021:5638836. [PMID: 34721896 PMCID: PMC8556119 DOI: 10.1155/2021/5638836] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Accepted: 09/23/2021] [Indexed: 11/23/2022] Open
Abstract
Background Ethiopia is one of the tropical countries with a heavy burden of soil-transmitted helminths. As a result, the nation has been implementing mass drug administration, water, sanitation, and hygiene and health extension programs to control those parasites. Hence, updated data about the prevalence and trend of parasites over time has a pivotal role to assess the success of existing control programs. Methods Studies conducted between 2000 and 2018 were searched from PubMed, Google Scholar, and local journals for systematic reviews and meta-analysis following the PRISMA guideline and checklists. Eligible studies were selected based on preset inclusion and exclusion criteria. The quality of the included studies was assessed using the Newcastle-Ottawa Scale in meta-analysis. Heterogeneity between studies was assessed using the Cochran Q test and I2 test statistics based on the random effect model. Comprehensive meta-analysis (CMA 2.0) was used to calculate the pooled prevalence, and metaregression was run to assess the trend of parasite prevalence over time. Results Thirty-eight studies recruiting 16,266 participants were included in the review. The pooled prevalence of intestinal parasites was 52.0% (95% CI: 44.4-59.5). Amhara region was with the highest prevalence (60.3%; 95% CI: 50.1-69.6). Among soil-transmitted helminths, Ascaris lumbricoides (11.2%; 95% CI: 8.4-14.8) was with the highest pooled prevalence followed by hookworms (10.4%; 95% CI: 7.9-13.7) and Trichuris trichiura (3.6%; 95% CI: 2.4-5.4). Metaregression analysis revealed that all soil-transmitted helminths did not show a significantly decreasing trend over time (p > 0.05). Conclusion Despite various control efforts having been made, soil-transmitted helminths are of high distribution, and their prevalence is not significantly decreasing in Ethiopia. Hence, other control approaches like community-led sanitation should be integrated with mass drug administration to achieve the national goal of soil-transmitted helminth elimination by 2025.
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Doret MPM, Nana-Djeunga HC, Nzune-Toche N, Pion SDS, Chesnais CB, Boussinesq M, Kamgno J, Varlet-Marie E, Locatelli S. Limitations of PCR detection of filarial DNA in human stools from subjects non-infected with soil-transmitted helminths. ACTA ACUST UNITED AC 2021; 28:47. [PMID: 34047694 PMCID: PMC8162058 DOI: 10.1051/parasite/2021046] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 05/11/2021] [Indexed: 11/22/2022]
Abstract
The standard techniques for diagnosis of human filariasis are the microscopic examination of blood smears or skin biopsies, which are relatively invasive and poorly sensitive at low levels of infection. Recently, filarial DNA has been detected in fecal samples from non-human primates in Central Africa. The aim of this study was to demonstrate proof-of-concept of a non-invasive molecular diagnosis technique for human filariasis by targeting fragments of 12S rDNA, Cox1, ITS1 and LL20-15kDa ladder antigen-gene by conventional PCR in DNA extracted from stool samples of 52 people infected with Mansonella perstans and/or Loa loa. Of these, 10 patients were infected with soil-transmitted helminths (Trichuris trichiura and/or Ascaris lumbricoides), and none were positive for Necator americanus. Interestingly, no filarial gene fragments were detected in the stools of any of the 52 patients. Future studies should evaluate whether a co-infection with soil-transmitted helminths causing gastrointestinal bleeding and likely allowing (micro)filaria exit into the digestive tract, may facilitate the molecular detection of filarial DNA fragments in stool samples.
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Affiliation(s)
- Maxime P M Doret
- Institut de Recherche pour le Développement (IRD), UMI 233-INSERM U1175-University of Montpellier, 34394 Montpellier Cedex 5, France
| | - Hugues C Nana-Djeunga
- Centre for Research on Filariasis and Other Tropical Diseases (CRFilMT), PO Box 5797 Yaoundé, Cameroon
| | - Narcisse Nzune-Toche
- Centre for Research on Filariasis and Other Tropical Diseases (CRFilMT), PO Box 5797 Yaoundé, Cameroon
| | - Sébastien D S Pion
- Institut de Recherche pour le Développement (IRD), UMI 233-INSERM U1175-University of Montpellier, 34394 Montpellier Cedex 5, France
| | - Cédric B Chesnais
- Institut de Recherche pour le Développement (IRD), UMI 233-INSERM U1175-University of Montpellier, 34394 Montpellier Cedex 5, France
| | - Michel Boussinesq
- Institut de Recherche pour le Développement (IRD), UMI 233-INSERM U1175-University of Montpellier, 34394 Montpellier Cedex 5, France
| | - Joseph Kamgno
- Centre for Research on Filariasis and Other Tropical Diseases (CRFilMT), PO Box 5797 Yaoundé, Cameroon - Department of Public Health, Faculty of Medicine and Biomedical Sciences (FMBS), PO Box 1364 Yaoundé, Cameroon
| | - Emmanuelle Varlet-Marie
- Department of Parasitology-Mycology, Centre Hospitalier Universitaire (CHU) of Montpellier, University of Montpellier, 34295 Montpellier Cedex 5, France
| | - Sabrina Locatelli
- Institut de Recherche pour le Développement (IRD), UMI 233-INSERM U1175-University of Montpellier, 34394 Montpellier Cedex 5, France
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Green AE, Anchang-Kimbi JK, Wepnje GB, Ndassi VD, Kimbi HK. Distribution and factors associated with urogenital schistosomiasis in the Tiko Health District, a semi-urban setting, South West Region, Cameroon. Infect Dis Poverty 2021; 10:49. [PMID: 33845904 PMCID: PMC8042887 DOI: 10.1186/s40249-021-00827-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 03/16/2021] [Indexed: 12/11/2022] Open
Abstract
Background Increased risk of schistosomiasis in peri-urban and urban towns is not uncommon. An epidemiological survey was carried out in the Tiko Health District (THD), an unmapped transmission focus for urogenital schistosomiasis (UGS), to assess the distribution, intensity, and risk factors associated with the occurrence of UGS. Methods In this cross-sectional survey, 12 communities were purposively selected from four health areas (HAs) (Likomba, Holforth, Holforth-Likomba, and Mutengene) in South West Region of Cameroon between June and August 2018. Consenting individuals were enrolled using a convenient sampling technique and administered a semi-structured questionnaire to document information on socio-demographic and water contact behaviour. Urine samples were examined for Schistosomahaematobium infection using test strip, filtration, and microscopy methods. Bivariate and binary logistic regression analyses were used to identify predictors of infection. Results The overall prevalence of UGS in Likomba, Holforth-Likomba and Holforth was 31.5% [95% confidence interval (CI): 28.3–34.8] with geometric mean (GM) egg count of 28.7 (range: 2–450) eggs per 10 ml of urine. S.haematobium infection was not found in Mutengene HA. Infection was unevenly distributed among the HAs, Holforth-Likomba and Holforth being the most and least affected, respectively. The prevalence of infection varied (P < 0.001) among the affected communities, ranging from 12.0 to 56.9%. Infection status of the community related positively (P < 0.001) with proximity to stream (< 100 m), the degree of contact with water and number of improved water sources. Younger age group (5–14 years) [adjusted odds ratio (aOR): 3.7, 95% CI: 1.1–12.2] and intense water contact (degree II) (aOR: 5.2, 95% CI: 3.4–8.1) were associated with increased risk of infection. Similarly, significantly higher egg load was observed among younger aged groups (P = 0.02) and those who carried out intense water contact activities (P < 0.001). Conclusions Generally, THD is a moderate risk endemic focus for UGS but prevalence higher than 50.0% was observed in some communities. These findings warrant immediate mass chemotherapy with praziquantel to reduce morbidity. Provision of portable water and health education are proposed measures to reduce and eventually eliminate transmission in the area. Graphic abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s40249-021-00827-2.
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Affiliation(s)
- Adeline Enjema Green
- Department of Zoology and Animal Physiology, Faculty of Science, University of Buea, P.O. Box 63, Buea, Cameroon.
| | - Judith Kuoh Anchang-Kimbi
- Department of Zoology and Animal Physiology, Faculty of Science, University of Buea, P.O. Box 63, Buea, Cameroon
| | - Godlove Bunda Wepnje
- Department of Zoology and Animal Physiology, Faculty of Science, University of Buea, P.O. Box 63, Buea, Cameroon
| | - Vicky Daonyle Ndassi
- Department of Zoology and Animal Physiology, Faculty of Science, University of Buea, P.O. Box 63, Buea, Cameroon
| | - Helen Kuokuo Kimbi
- Department of Zoology and Animal Physiology, Faculty of Science, University of Buea, P.O. Box 63, Buea, Cameroon.,Department of Medical Laboratory Sciences, Faculty of Health Sciences, The University of Bamenda, P.O. Box 39, Bambili, Cameroon
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Sumbele IUN, Otia OV, Bopda OSM, Ebai CB, Kimbi HK, Nkuo-Akenji T. Polyparasitism with Schistosoma haematobium, Plasmodium and soil-transmitted helminths in school-aged children in Muyuka-Cameroon following implementation of control measures: a cross sectional study. Infect Dis Poverty 2021; 10:14. [PMID: 33597042 PMCID: PMC7890808 DOI: 10.1186/s40249-021-00802-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 01/29/2021] [Indexed: 01/04/2023] Open
Abstract
Background Despite the ubiquity of polyparasitism, its health impacts have been inadequately studied. The aim of this study was to determine the prevalence and determinants of polyparasitism with Schistosoma haematobium, Plasmodium and soil-transmitted helminths (STH) following sustained control measures, as well as evaluate the outcomes and clinical correlates of infection in school-aged children (SAC) living in the schistosomiasis endemic focus of Muyuka-Cameroon. Methods In a cross-sectional study, urine, blood and stool samples were each collected from SAC (4–14 years) selected at random between March and June 2015. Microhaematuria in urine was detected using reagent strip and S. haematobium ova by filtration/microscopy methods. Plasmodium was detected using Giemsa-stained blood films and complete blood count was obtained using an auto-haematology analyser. STH in stool was detected by the Kato-Katz method. Categorical and continuous variables were compared as required, Kappa value estimated and the adjusted odds ratio (aOR) in the multivariate analysis was used to evaluate association of the risk factors with infection. Results Out of the 638 SAC examined, single infection was prevalent in 33.4% while polyparasitism was 19.9%. Prevalence of S. haematobium + Plasmodium was 7.8%; S. haematobium + STH was 0.8%; Plasmodium + STH was 0.8%; while S. haematobium + Plasmodium + STH was 0.9%. Higher preponderance of S. haematobium + Plasmodium infection occurred in females, those from Likoko, did not use potable water, practiced bathing in stream and carried out open defecation than their equivalents. However, being female (aOR = 2.38, P = 0.009) was the only significant risk factor identified. Anaemia was a common morbidity (74.3%) with a slight agreement with microscopy in predicting S. haematobium and Plasmodium infections. The sensitivity and specificity of haematuria (13.0%) in predicting S. haematobium infection was 46.5% and 100% with a moderate agreement with microscopy. Co-infection with S. haematobium and malaria parasite was significantly associated with threefold odds of history of fever in the last three days. Conclusions Polyparasitism is a public health problem in Muyuka with females most at risk. Anaemia prevalence is exacerbated in co- and triple-infections and together with a history of fever are of value in predicting polyparasitism.![]()
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Affiliation(s)
- Irene Ule Ngole Sumbele
- Department of Zoology and Animal Physiology, University of Buea, Buea, Cameroon. .,Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA.
| | - Ofon Vitalis Otia
- Department of Zoology and Animal Physiology, University of Buea, Buea, Cameroon
| | - Orelien Sylvain Mtopi Bopda
- Department of Zoology and Animal Physiology, University of Buea, Buea, Cameroon.,Department of Medical Laboratory Sciences, University of Buea, Buea, Cameroon
| | - Calvin Bisong Ebai
- Department of Zoology and Animal Physiology, University of Buea, Buea, Cameroon.,Department of Medical Laboratory Science, University of Bamenda, Bambili, Cameroon
| | - Helen KuoKuo Kimbi
- Department of Zoology and Animal Physiology, University of Buea, Buea, Cameroon.,Department of Medical Laboratory Science, University of Bamenda, Bambili, Cameroon
| | - Theresa Nkuo-Akenji
- Department of Microbiology and Parasitology, University of Buea, Buea, Cameroon
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Effects of Soil-Transmitted Helminths and Intestinal Protozoan Infections on Haemoglobin Levels among School-Aged Children in Belo and Bui, North West Cameroon: A Cross-Sectional Study. J Parasitol Res 2021. [DOI: 10.1155/2021/8873555] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Introduction. Soil-transmitted helminths (STH) remain a public health problem worldwide especially in low-income countries. Soil-transmitted helminths are known to affect both growth and haemoglobin levels. In this study, we determine the prevalence of intestinal parasites and explored its association with anaemia in school-aged children (SAC). Methodology. A cross-sectional study was carried out amongst pupils selected from 18 primary schools in four communities of the North West Region. Stool samples were examined using direct wet mount and formol-ether concentration techniques, while finger prick was performed for the measurement of haemoglobin with a haemoglobinometer. Results. The results showed significant variation of STHs, intestinal protozoan prevalence, and anaemia between age, sex, and communities. The prevalence of Ascaris lumbricoides, Trichuris trichiura, and hookworms was 15.1%, 0.8%, and 2%, respectively, with an overall STH prevalence of 18.3% across the four communities. Soil-transmitted helminths were more prevalent in Mbessa (30.2%) in comparison to Nkor (26.7%), Djottin (17.5%), and Kumbo (9.6%) communities. The prevalence of Entamoeba histolytica/dispar was 25.4% and Giardia duodenalis (6.9%), with an overall intestinal protozoa prevalence of 31% across the four communities. The prevalence of anaemia in the study population was 23.1%. Conclusion. Soil-transmitted helminths, intestinal protozoan infections, and anaemia are prevalent in the study area. Anaemia was observed to be associated with STH, intestinal protozoa, and the communities under study. This study recommends continuous deworming and health education on personal sanitation and environmental sanitation.
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20
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Masong MC, Wepnje GB, Marlene NT, Gamba V, Mengue MT, Kouokam E, Stothard JR, Ekobo ALS. Female Genital Schistosomiasis (FGS) in Cameroon: A formative epidemiological and socioeconomic investigation in eleven rural fishing communities. PLOS GLOBAL PUBLIC HEALTH 2021; 1:e0000007. [PMID: 36962084 PMCID: PMC10022362 DOI: 10.1371/journal.pgph.0000007] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 09/15/2021] [Indexed: 02/01/2023]
Abstract
BACKGROUND Female Genital Schistosomiasis (FGS) is most often caused by presence of Schistosoma haematobium eggs lodged in the female reproductive tract which results in chronic fibrosis and scarring. In Cameroon, despite high community prevalences of urine-patent S. haematobium infections, FGS has yet to be studied in depth. To shed light on the clinical prevalence and socioeconomic effects of FGS, we undertook a formative community-based epidemiological and qualitative survey. METHOD A cross sectional multidisciplinary study of 304 girls and women from 11 remote rural fishing communities in Cameroon was undertaken using parasitological sampling, clinical colposcopy, and interviews. The lived experiences of those with FGS were documented using a process of ethnography with participant observation and in-depth interviews. RESULT Amongst 304 women and girls aged >5 years (Median age: 18; Interquartile range: 9.6-28), 198 females were eligible for FGS testing and 58 adult women were examined by clinical colposcopy. Of these, 34 were positive for FGS (proportion: 58.6%; 95% CI: 45.8-70.4), younger girls showing a higher FGS prevalence, and older women not shedding eggs showing a pattern for cervical lesions from earlier infection. In a subset of women with FGS selected purposively (12/58), in-depth interviews with participant observation revealed out-of-pocket expenditures of up to 500USD related health spending for repeated diagnosis and treatment of gynecological illnesses, and 9 hours daily lost reproductive labour. Psychosocial unrest, loss in social capital, and despair were linked with sub-fertility and persistent vaginal itch. CONCLUSION With our first formative evidence on prevalence, socioeconomic effects and experiences of FGS amongst women and girls in Cameroon, we have clarified to a new level of detail the deficit in provision of and access to peripheral health services in remote areas of Cameroon. Using this information, there is now strong evidence for national programs and services on women's health and schistosomiasis to update and revise policies targeted on prevention and management of FGS. We therefore stress the need for regular provision of Praziquantel treatment to adolescent girls and women in S. haematobium endemic areas, alongside better access to tailored diagnostic services that can detect FGS and appropriately triage care at primary health level.
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Affiliation(s)
- Makia Christine Masong
- Department of Social Sciences and Management, Catholic University of Central Africa, Yaoundé, Cameroon
| | | | - Ntsinda Tchoffo Marlene
- Department of Social Sciences and Management, Catholic University of Central Africa, Yaoundé, Cameroon
| | - Victoria Gamba
- Department of Obstetrics and Gynecology, University of Nairobi, Nairobi, Kenya
| | - Marie-Therese Mengue
- Department of Social Sciences and Management, Catholic University of Central Africa, Yaoundé, Cameroon
| | - Estelle Kouokam
- Department of Social Sciences and Management, Catholic University of Central Africa, Yaoundé, Cameroon
| | - J Russell Stothard
- Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
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21
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Djune-Yemeli L, Nana-Djeunga HC, Lenou-Nanga CG, Donfo-Azafack C, Domche A, Fossuo-Thotchum F, Niamsi-Emalio Y, Ntoumi F, Kamgno J. Serious limitations of the current strategy to control Soil-Transmitted Helminths and added value of Ivermectin/Albendazole mass administration: A population-based observational study in Cameroon. PLoS Negl Trop Dis 2020; 14:e0008794. [PMID: 33141853 PMCID: PMC7665818 DOI: 10.1371/journal.pntd.0008794] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 11/13/2020] [Accepted: 09/13/2020] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Soil-transmitted helminth (STH) infections remain a public health concern in sub-Saharan Africa. School-based mass drug administration (MDA) using the anthelminthic drug Mebendazole/Albendazole have succeeded in controlling morbidity associated to these diseases but failed to interrupt their transmission. In areas were filarial diseases are co-endemic, another anthelminthic drug (Ivermectin) is distributed to almost the entire population, following the community-directed treatment with ivermectin (CDTI) strategy. Since Ivermectin is a broad spectrum anthelmintic known to be effective against STH, we conducted cross-sectional surveys in two health districts with very contrasting histories of Ivermectin/Albendazole-based PC in order to investigate whether CDTI might have contributed in STH transmission interruption. METHODOLOGY Cross-sectional surveys were conducted in two health districts with similar socio-environmental patterns but with very contrasting CDTI histories (Akonolinga health district where CDTI was yet to be implemented vs. Yabassi health district where CDTI has been ongoing for two decades). Stool samples were collected from all volunteers aged >2 years old and analyzed using the Kato-Katz technique. Infections by different STH species were compared between Akonolinga and Yabassi health districts to decipher the impact of Ivermectin/Albendazole-based MDA on STH transmission. PRINCIPAL FINDINGS A total of 610 and 584 participants aged 2-90 years old were enrolled in Akonolinga and Yabassi health districts, respectively. Two STH species (Ascaris lumbricoides and Trichuris trichiura) were found, with prevalence significantly higher in Akonolinga health district (43.3%; 95% CI: 38.1-46.6) compared to Yabassi health district (2.5%; 95% CI: 1.1-5.1) (chi-square: 90.8; df: 1; p < 0.001). CONCLUSION/SIGNIFICANCE These findings (i) suggest that Mebendazole- or Albendazole-based MDA alone distributed only to at-risk populations might not be enough to eliminate STH, (ii) support the collateral impact of Ivermectin/Albendazole MDA on A. lumbricoides and T. trichiura infections, and (iii) suggest that Ivermectin/Albendazole-based PC could accelerate STH transmission interruption.
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Affiliation(s)
- Linda Djune-Yemeli
- Centre for Research on Filariasis and other Tropical Diseases (CRFilMT), Yaoundé, Cameroon.,Molecular Diagnosis Research Group, Biotechnology Centre-University of Yaoundé I (BTC-UY-I), Yaoundé, Cameroon
| | - Hugues C Nana-Djeunga
- Centre for Research on Filariasis and other Tropical Diseases (CRFilMT), Yaoundé, Cameroon.,Parasitology and Ecology Laboratory, Department of Animal Biology and Physiology, Faculty of Sciences, University of Yaoundé I, Yaoundé, Cameroon
| | - Cédric G Lenou-Nanga
- Centre for Research on Filariasis and other Tropical Diseases (CRFilMT), Yaoundé, Cameroon
| | - Cyrille Donfo-Azafack
- Centre for Research on Filariasis and other Tropical Diseases (CRFilMT), Yaoundé, Cameroon
| | - André Domche
- Centre for Research on Filariasis and other Tropical Diseases (CRFilMT), Yaoundé, Cameroon.,Parasitology and Ecology Laboratory, Department of Animal Biology and Physiology, Faculty of Sciences, University of Yaoundé I, Yaoundé, Cameroon
| | | | - Yannick Niamsi-Emalio
- Centre for Research on Filariasis and other Tropical Diseases (CRFilMT), Yaoundé, Cameroon
| | - Francine Ntoumi
- Fondation Congolaise pour la Recherche Médicale, Brazzaville, Republic of the Congo.,Marien Ngouabi University, Brazzaville, Republic of the Congo
| | - Joseph Kamgno
- Centre for Research on Filariasis and other Tropical Diseases (CRFilMT), Yaoundé, Cameroon.,Department of Public Health, Faculty of Medicine and Biomedical Sciences, University of Yaoundé I, Yaoundé, Cameroon
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22
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Ruberanziza E, Wittmann U, Mbituyumuremyi A, Mutabazi A, Campbell CH, Colley DG, Fleming FM, Ortu G, van Dam GJ, Umulisa I, Tallant J, Kabera M, Semakula M, Corstjens PLAM, Munyaneza T, Lancaster W, Mbonigaba JB, Clements MN. Nationwide Remapping of Schistosoma mansoni Infection in Rwanda Using Circulating Cathodic Antigen Rapid Test: Taking Steps toward Elimination. Am J Trop Med Hyg 2020; 103:315-324. [PMID: 32431276 PMCID: PMC7356434 DOI: 10.4269/ajtmh.19-0866] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The field standard for the detection of Schistosoma mansoni infection is Kato–Katz (KK), although it misses many active infections, especially light infections. In 2014, a reassessment of S. mansoni prevalence was conducted in Rwanda using the more sensitive point-of-care circulating cathodic antigen (POC-CCA) rapid assay. A total of 19,371 children from 399 schools were selected for testing for single urine CCA. Of these, 8,697 children from 175 schools were also tested with single stool double-slide KK. Samples from eight of these 175 schools were tested again with CCA and additionally with the highly specific and sensitive up-converting phosphor-lateral flow circulating anodic antigen (UCP-LF CAA) assay. Latent class analysis was applied to all four test results to assess sensitivity and specificity of POC-CCA and estimate the proportion of trace results from Rwanda likely to be true infections. The overall prevalence of S. mansoni infection in Rwanda when CCA trace results were considered negative was 7.4% (school interquartile range [IQR] 0–8%) and 36.1% (school IQR 20–47%) when trace was considered positive. Prevalence by KK was 2.0% with a mean intensity of infection of 1.66 eggs per gram. The proportion of active infections among children diagnosed with CCA trace was estimated by statistical analysis at 61% (Bayesian credibility interval: 50–72%). These results indicate that S. mansoni infection is still widespread in Rwanda and prevalence is much underestimated by KK testing. Circulating cathodic antigen is an affordable alternative to KK and more suitable for measuring S. mansoni prevalence in low-intensity regions.
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Affiliation(s)
- Eugene Ruberanziza
- Malaria and Other Parasitic Diseases Division, Rwanda Biomedical Center, Ministry of Health, Kigali, Rwanda.,Neglected Tropical Diseases and Other Parasitic Diseases Unit, Rwanda Biomedical Center, Ministry of Health, Kigali, Rwanda
| | - Udo Wittmann
- Consult A.G. Statistical Servicesc, Zurich, Switzerland.,SCI Foundation, London, United Kingdom
| | - Aimable Mbituyumuremyi
- Malaria and Other Parasitic Diseases Division, Rwanda Biomedical Center, Ministry of Health, Kigali, Rwanda
| | - Alphonse Mutabazi
- Vector Control Unit, Rwanda Biomedical Center, Ministry of Health, Kigali, Rwanda.,Malaria and Other Parasitic Diseases Division, Rwanda Biomedical Center, Ministry of Health, Kigali, Rwanda
| | - Carl H Campbell
- Schistosomiasis Consortium for Operational Research and Evaluation, Center for Tropical and Global Emerging Diseases, University of Georgia, Athens, Georgia
| | - Daniel G Colley
- Department of Microbiology, University of Georgia, Athens, Georgia.,Schistosomiasis Consortium for Operational Research and Evaluation, Center for Tropical and Global Emerging Diseases, University of Georgia, Athens, Georgia
| | | | | | | | - Irenee Umulisa
- African Leaders Malaria Alliance (ALMA), National Institute of Medical Research Complex, Dar-es-Salam, Tanzania
| | | | - Michee Kabera
- Epidemiology Unit, Rwanda Biomedical Center, Ministry of Health, Kigali, Rwanda.,Malaria and Other Parasitic Diseases Division, Rwanda Biomedical Center, Ministry of Health, Kigali, Rwanda
| | - Muhammed Semakula
- HIV/AIDS and STIs Division, Rwanda Biomedical Center, Ministry of Health, Kigali, Rwanda
| | | | - Tharcisse Munyaneza
- Microbiology Unit, National Reference Laboratory (NRL) Division, Rwanda Biomedical Center, Ministry of Health, Kigali, Rwanda
| | | | - Jean Bosco Mbonigaba
- Neglected Tropical Diseases and Other Parasitic Diseases Unit, Rwanda Biomedical Center, Ministry of Health, Kigali, Rwanda.,Malaria and Other Parasitic Diseases Division, Rwanda Biomedical Center, Ministry of Health, Kigali, Rwanda
| | - Michelle N Clements
- MRC Clinical Trials Unit, University College London, London, United Kingdom.,SCI Foundation, London, United Kingdom
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Tchami Mbagnia MC, Melachio Tanekou TT, Kengne Fokam AC, Nguiffo Nguete D, Wondji CS, Njiokou F. PCR-based molecular identification of two intermediate snail hosts of Schistosoma mansoni in Cameroon. Parasit Vectors 2020; 13:158. [PMID: 32228678 PMCID: PMC7106826 DOI: 10.1186/s13071-020-04033-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Accepted: 03/25/2020] [Indexed: 11/24/2022] Open
Abstract
Background Snails of the genus Biomphalaria are intermediate hosts of Schistosoma mansoni, the causative agent of the human intestinal schistosomiasis. Two Biomphalaria species (Biomphalaria pfeifferi and Biomphalaria camerunensis) are involved in the transmission in Cameroon, where the disease is present nationwide. However, difficulty in the identification of both vectors impedes proper assessment of the epidemiological burden caused by each species. To overcome this issue, we designed a PCR-based molecular diagnostic tool to improve the identification of these species. Methods We analyzed the internal transcribed spacer 2 (ITS2) region of Biomphalaria ribosomal DNA (rDNA) using polymerase chain reaction amplification (PCR) and restriction fragment length polymorphism (RFLP). Results The amplification of the ITS2 region of Biomphalaria snails resulted in a 490 bp fragment and produced two profiles for each species after digestion with the restriction enzyme Hpa II. The profile 1 (Bc-HpaII-1: 212-bp and 139-bp bands) for B. camerunensis, was common in all the sampling points; the profile 2 (Bc-HpaII-2: 212-bp and 189-bp bands), was only observed in the Lake Monoun Njindoun sampling site. Biomphalaria pfeifferi profile 1 (Bpf-HpaII-1: 211-bp and 128-bp bands) was common in most of B. pfeifferi sampling points; the profile 2 (Bpf-HpaII-2: 289-bp and 128-bp bands) was only observed in Mokolo (Far North Cameroon).The second restriction enzyme TaqαI, revealed three band profiles, Bc-TaqαI-1 (243-bp, 136-bp and 118-bp bands) and Bc-TaqαI-2 (244-bp, 136-bp and 99-bp) for B. camerunensis and Bpf-TaqαI-1 (242-bp, 135-bp and 107-bp bands) for B. pfeifferi. Sequencing analysis revealed the occurrence of six haplotypes for B. camerunensis and three haplotypes for B. pfeifferi. The level of gene flow was low and the Biomphalaria populations were not in demographic expansion according to neutrality tests (Tajima’s D and Fu’s Fs). Conclusions The PCR-RFLP technique revealed genetic diversity in Biomphalaria snails, and the combination with the morphological method could improve the identification of B. pfeifferi and B. camerunensis in Cameroon. This could help focus on the infection to evaluate the transmission risk with respect of the different species and to develop efficient and cost-effective control measures.![]()
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Affiliation(s)
- Mureille Carole Tchami Mbagnia
- Parasitology and Ecology Laboratory, Department of Animal Biology and Physiology, Faculty of Science, University of Yaoundé I, Yaoundé, Cameroon
| | - Tito Trésor Melachio Tanekou
- Centre for Research in Infectious Diseases, Yaoundé, Cameroon.,Department of Biological Sciences, Faculty of Science, University of Bamenda, Bamenda, Cameroon
| | - Alvine Christelle Kengne Fokam
- Parasitology and Ecology Laboratory, Department of Animal Biology and Physiology, Faculty of Science, University of Yaoundé I, Yaoundé, Cameroon
| | - Daniel Nguiffo Nguete
- Centre for Research in Infectious Diseases, Yaoundé, Cameroon.,Research Unit of Applied Biology and Ecology, University of Dschang, Dschang, Cameroon
| | - Charles Sinclair Wondji
- Centre for Research in Infectious Diseases, Yaoundé, Cameroon.,Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Flobert Njiokou
- Parasitology and Ecology Laboratory, Department of Animal Biology and Physiology, Faculty of Science, University of Yaoundé I, Yaoundé, Cameroon. .,Centre for Research in Infectious Diseases, Yaoundé, Cameroon.
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Epidemiology of intestinal parasitic infections in preschool and school-aged Ethiopian children: a systematic review and meta-analysis. BMC Public Health 2020; 20:117. [PMID: 31992252 PMCID: PMC6988312 DOI: 10.1186/s12889-020-8222-y] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2019] [Accepted: 01/15/2020] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Numerous studies have been carried out on assessing the prevalence of intestinal parasites infections (IPIs) amongpreschool and school-age children in Ethiopia, but there is lack of study systematically gathered and analyzedinformation for policymakers. Therefore, the aim of this systematic review and meta-analysis was to provide a summary on prevalence, geographical distribution and trends of IPIs among preschool and school-age childrenin Ethiopia. METHODS The search were carried out in Medline via PubMed, Scopus, Science Direct, Web of Science, and Google Scholar from 1996to July2019 for studies describing prevalence of IPIs among preschooland school-age children. We conducted meta-regression to understand the trends and the source of heterogeneity and pooled the prevalence using 'metaprop' command using STATA software version 14. RESULTS Eighty-three(83) studies examining 56,786 fecal specimens were included. The prevalence of IPIs was 48%(95%CI: 42 to 53%) and showedsignificantly decreasing trends 17% (95% CI: 2.5 to 32%) for each consecutive 6 years) and was similar in males and females. The pooled prevalence in years 1997-2002, 2003-2008, 2009-2014 and > 2014 was 71% (95% CI: 57 to 86%), 42% (95% CI: 27 to 56%), 48% (95% CI: 40 to 56%) and 42% (95% CI: 34 to 49%), respectively. Poly-parasitism was observed in 16% (95% CI: 13 to 19%,) of the cases. CONCLUSION Intestinal parasite infections are highly prevalent among preschool and school-age children and well distributed across the regional states of Ethiopia. Southern and Amhara regional states carry the highest burden. We observed significant decreasing trends in prevalence of IPIs among preschool and school-ageEthiopian children over the last two decades. Therefore, this study is important to locate the geographical distribution and identified high risk areas that should be prioritized further interventions, which complement global efforts towards elimination of IPIs infections by 2020.
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Oloume ME, Mouliom A, Melingui BF, Belinga S, Nana JS, Tejiokem M, Sack FN, Manga J, Epote AR. Haematological values in a healthy adult population in Yaoundé, Cameroon. Afr J Lab Med 2019; 8:852. [PMID: 31745457 PMCID: PMC6852616 DOI: 10.4102/ajlm.v8i1.852] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Accepted: 01/21/2019] [Indexed: 11/17/2022] Open
Abstract
Background Haematological values derived from local populations are useful in laboratories to improve diagnoses for local patients. In Cameroon, these data are not yet available. Moreover, there is great variation in baseline parameters pertaining to full blood cell count among medical laboratories. Objectives This study aimed to determine values for the complete blood cell count of a healthy adult Cameroonian population for use in locally derived ranges in our medical laboratories. Methods A cross-sectional study was conducted among blood donors attending three blood banks in Yaoundé from November 2015 to September 2016. We expected to obtain at least 120 venous blood samples from both men and women. Tests were performed for (1) HIV, (2) complete blood cell count, (3) hepatitis B virus, (4) malaria, (5) syphilis, (6) C-reactive protein and (7) hepatitis C virus. Results We enrolled 294 healthy participants (161 men, 133 women) aged 18 to 55 years. The median haemoglobin concentration was 135 g/L in men and 114 g/L in women (p < 0.001). The median reticulocyte count was 60 × 109/L in men and 40 × 109/L in women (p < 0.001). Significant variation by sex was observed for the platelet count. The median white blood cell count was 4.1 × 109/L in men and 4.6 × 109/L in women (p = 0.008). Conclusion This study provides locally derived ranges for complete blood cell and reticulocyte counts for a healthy adult population in Yaoundé, Cameroon. These results can be used pending larger studies.
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Affiliation(s)
| | - Abas Mouliom
- Haematology Laboratory, Centre Pasteur, Yaoundé, Cameroon
| | | | - Suzanne Belinga
- Medical Analysis Department, Centre Pasteur, Yaoundé, Cameroon
| | - Julie S Nana
- Haematology and Immunology Department, Catholic University of Central Africa, Yaoundé, Cameroon
| | | | - Francoise N Sack
- Haematology Department and Blood Bank, Central Hospital, Yaoundé, Cameroon
| | - Jeanne Manga
- Quality Management, Centre Pasteur, Yaoundé, Cameroon
| | - Annie R Epote
- Haematology Laboratory, Centre Pasteur, Yaoundé, Cameroon
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Nkengni SMM, Zoumabo ATC, Soppa NPS, Sizono ABN, Vignoles P, Tchuenté LAT, Teukeng FFD. Current decline in schistosome and soil-transmitted helminth infections among school children at Loum, Littoral region, Cameroon. Pan Afr Med J 2019; 33:94. [PMID: 31489072 PMCID: PMC6713490 DOI: 10.11604/pamj.2019.33.94.18265] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2019] [Accepted: 05/09/2019] [Indexed: 11/24/2022] Open
Abstract
Introduction Soil-transmitted helminth infections (STHs) and schistosomiasis have serious consequences for the health, education and nutrition of children in developing countries. As Loum is known as a highly endemic commune for these infections, several deworming campaigns have been carried out in the past. The purpose of this study was to determine any changes that have occurred since then in the characteristics of these infections among schoolchildren in this site. Methods A cross-sectional study was conducted in October 2016 on 289 schoolchildren. Stool and urine samples were collected and examined to determine the prevalence and intensity of helminth infections. Results The highest prevalence was noted for Schistosoma haematobium (34.2%), followed by Ascaris lumbricoides (8.6%), S. mansoni (4.9%) and Trichuris trichiura (4.9%) in decreasing order. A prevalence of less than 2% was noted for each of the other two helminths. The highest mean intensity was found for S. haematobium (39.6 eggs/10 ml of urine), followed by A. lumbricoides (24.2 eggs per gram of faeces: epg), Strongyloides stercoralis (16.6 epg) and Schistosoma mansoni (12.3 epg). The prevalence of T. trichiura was significantly higher in boys and that of S. haematobium in children aged 10 years or older, while the differences between other values of prevalence or between egg burdens were not significant. Conclusion Compared with values reported in 2003, the prevalence and intensity of schistosomiases and STH infections in Loum has sharply decreased in 2016. Confirmation of this decrease in the years to come allowed to space deworming campaigns among schoolchildren.
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Affiliation(s)
| | | | - Naomi Paloma Sangue Soppa
- Faculty of Health Sciences, Campus of Banekane, Université des Montagnes, P.O. Box 208, Bangangté, Cameroon
| | - Adèle Besch Ngwem Sizono
- Faculty of Health Sciences, Campus of Banekane, Université des Montagnes, P.O. Box 208, Bangangté, Cameroon
| | - Philippe Vignoles
- INSERM U 1094, Institute of Neuroepidemiology and Tropical Neurology, 2, rue du Docteur Raymond Marcland, 87025 Limoges, France
| | - Louis-Albert Tchuem Tchuenté
- Centre for Schistosomiasis and Parasitology, Texaco Omnisport and Laboratory of Parasitology and Ecology, Faculty of Sciences, University of Yaoundé I, Yaoundé, Cameroon
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Bekolo CE, Williams TD. Adding proactive and reactive case detection into the integrated community case management system to optimise diagnosis and treatment of malaria in a high transmission setting of Cameroon: an observational quality improvement study. BMJ Open 2019; 9:e026678. [PMID: 31182444 PMCID: PMC6561439 DOI: 10.1136/bmjopen-2018-026678] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
OBJECTIVE Integrated community case management (iCCM) of childhood illness is a powerful intervention to reduce mortality. Yet, only 29% and 59% of children with fever in sub-Saharan Africa had access to malaria testing and treatment between 2015 and 2017. We report how iCCM+ based on incorporating active case detection of malaria into iCCM could help improve testing and treatment. DESIGN A community-led observational quality improvement study. SETTING The rural community of Bare-Bakem in Cameroon. PARTICIPANTS Children and adults with fever between April and June 2018. INTERVENTION A modified iCCM programme (iCCM+) comprising a proactive screening of febrile children <5 years old for malaria using rapid diagnostic testing to identify index cases and a reactive screening triggered by these index cases to detect secondary cases in the community. PRIMARY AND SECONDARY OUTCOME MEASURES The proportion of additional malaria cases detected by iCCM+ over iCCM. RESULTS We screened 501 febrile patients of whom Plasmodium infection was confirmed in 425 (84.8%) cases. Of these cases, 102 (24.0%) were index cases identified in the community during routine iCCM activity and 36 (8.5%) cases detected passively in health facilities; 38 (8.9%) were index cases identified proactively in schools and 249 (58.6%) were additional cases detected by reactive case detection-computing to a total of 287 (67.5%) additional cases found by iCCM+ over iCCM. The likelihood of finding additional cases increased with increasing family size (adjusted odd ratio (aOR)=1.2, 95% CI: 1.1 to 1.3) and with increasing age (aOR=1.7, 95% CI: 1.5 to 1.9). CONCLUSION Most symptomatic cases of malaria remain undetected in the community despite the introduction of CCM of malaria. iCCM+ can be adopted to diagnose and treat more of these undiagnosed cases especially when targeted to schools, older children and larger households.
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Affiliation(s)
- Cavin Epie Bekolo
- Centre Medical d'Arrondissement de Bare, Nkongsamba, Cameroon
- Department of Public Health, University of Dschang, Faculty of Medicine and Pharmaceutical Sciences, Dschang, West Region, Cameroon
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Djuikwo-Teukeng FF, Kouam Simo A, Allienne JF, Rey O, Njayou Ngapagna A, Tchuem-Tchuente LA, Boissier J. Population genetic structure of Schistosoma bovis in Cameroon. Parasit Vectors 2019; 12:56. [PMID: 30678712 PMCID: PMC6346511 DOI: 10.1186/s13071-019-3307-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Accepted: 01/08/2019] [Indexed: 11/24/2022] Open
Abstract
Background Schistosomiasis is neglected tropical parasitic disease affecting both humans and animals. Due to the human health impact, population genetic studies have focused on the three main human-infecting schistosome species: Schistosoma mansoni, S. haematobium and S. japonicum. Here we present novel data on the population genetic structure of Schistosoma bovis, a highly widespread and prevalent schistosome infecting ruminants, and therefore of veterinary importance. Methods Adult S. bovis were sampled in the two main abattoirs of Cameroon (Yaoundé and Douala). Twenty-two cows originating from four distinct localities were sampled and a total of 218 parasites were recovered. All parasites were genotyped using a panel of 14 microsatellite markers and a sub-sample of 91 parasites were sequenced and characterized with the mitochondrial (cox1) and nuclear (ITS) genetic markers. Results No significant difference in allelic richness, heterozygosity, nucleotide diversity and haplotype diversity was observed between the populations. Additionally, no strong genetic structure was observed at the country scale. Our data also show that S. bovis is more polymorphic than its sister species, S. haematobium, and that the haplotype diversity is similar to that of S. mansoni while the nucleotide diversity does not significantly differ from that of S. haematobium. The resulting negative Tajima’s D* and Fu and Li’s D* indices could be a signature of population demographic expansion. No S. haematobium/S. bovis hybrids were observed in our populations, thus all samples were considered as pure S. bovis. Conclusions This study provides novel insights into genetic diversity and population genetic structure of S. bovis. No strong genetic structure was observed at the country scale but some genetic indices could be associated as a signature of population demographic expansion. Electronic supplementary material The online version of this article (10.1186/s13071-019-3307-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | - Alain Kouam Simo
- Université des Montagnes, Faculty of Heath Science, PO Box: 208, Bangangté, Cameroon
| | - Jean-François Allienne
- Université de Perpignan Via Domitia, IHPE UMR 5244, CNRS, IFREMER, Université de Montpellier, F-66860, Perpignan, France
| | - Olivier Rey
- Université de Perpignan Via Domitia, IHPE UMR 5244, CNRS, IFREMER, Université de Montpellier, F-66860, Perpignan, France
| | | | - Louis Albert Tchuem-Tchuente
- Centre for Schistosomiasis and Parasitology, Yaoundé, Cameroon.,Laboratory of Parasitology and Ecology, Faculty of Sciences, University of Yaoundé I, Yaoundé, Cameroon
| | - Jérôme Boissier
- Université de Perpignan Via Domitia, IHPE UMR 5244, CNRS, IFREMER, Université de Montpellier, F-66860, Perpignan, France.
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Mintsa Nguema R, Mavoungou JF, Mengue Me Ngou-Milama K, Mabicka Mamfoumbi M, Koumba AA, Sani Lamine M, Diarra A, Nkone Asseko G, Mourou JR, Bouyou Akotet MK, Moné H, Mouahid G, Atsame J. Baseline Mapping of Schistosomiasis and Soil Transmitted Helminthiasis in the Northern and Eastern Health Regions of Gabon, Central Africa: Recommendations for Preventive Chemotherapy. Trop Med Infect Dis 2018; 3:tropicalmed3040119. [PMID: 30423901 PMCID: PMC6306699 DOI: 10.3390/tropicalmed3040119] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Revised: 11/06/2018] [Accepted: 11/07/2018] [Indexed: 12/22/2022] Open
Abstract
In order to follow the Preventive Chemotherapy (PC) for the transmission control as recommended by WHO, Gabon initiated in 2014 the mapping of Schistosomiasis and Soil Transmitted Helminthiasis (STH). Here, we report the results of the Northern and Eastern health regions, representing a third of the land area and 12% of its total population. All nine departments of the two regions were surveyed and from each, five schools were examined with 50 schoolchildren per school. The parasitological examinations were realized using the filtration method for urine and the Kato-Katz technique for stool samples. Overall 2245 schoolchildren (1116 girls and 1129 boys), mean aged 11.28 ± 0.04 years, were examined. Combined schistosomiasis and STH affected 1270 (56.6%) with variation between regions, departments, and schools. For schistosomiasis, prevalence were 1.7% across the two regions, with no significant difference (p > 0.05) between the Northern (1.5%) and the Eastern (1.9%). Schistosomiasis is mainly caused by Schistosoma haematobium with the exception of one respective case of S. mansoni and S. guineensis. STH are more common than schistosomiasis, with an overall prevalence of 56.1% significantly different between the Northern (58.1%) and Eastern (53.6%) regions (p = 0.034). Trichuris trichiura is the most abundant infection with a prevalence of 43.7% followed by Ascaris lumbricoides 35.6% and hookworms 1.4%. According to these results, an appropriate PC strategy is given. In particular, because of the low efficacy of a single recommended drug on T. trichiura and hookworms, it is important to include two drugs for the treatment of STH in Gabon, due to the high prevalence and intensities of Trichuris infections.
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Affiliation(s)
- Rodrigue Mintsa Nguema
- Research Institute in Tropical Ecology, National Center for Scientific and Technological Research, Libreville BP 13354, Gabon.
- Department of Parasitology-Mycology, Faculty of Medicine, University of Health Sciences of Libreville, Libreville BP 4009, Gabon.
- Control Program of Parasitic Diseases, Libreville BP 2434, Gabon.
| | - Jacques F Mavoungou
- Research Institute in Tropical Ecology, National Center for Scientific and Technological Research, Libreville BP 13354, Gabon.
| | - Krystina Mengue Me Ngou-Milama
- Control Program of Parasitic Diseases, Libreville BP 2434, Gabon.
- National Laboratory of Public Health, Libreville BP 10736, Gabon.
| | - Modeste Mabicka Mamfoumbi
- Department of Parasitology-Mycology, Faculty of Medicine, University of Health Sciences of Libreville, Libreville BP 4009, Gabon.
| | - Aubin A Koumba
- Research Institute in Tropical Ecology, National Center for Scientific and Technological Research, Libreville BP 13354, Gabon.
| | | | - Abdoulaye Diarra
- Word Health Organization Country Office Gabon, Libreville BP 820, Gabon.
| | | | - Jean R Mourou
- Department of Parasitology-Mycology, Faculty of Medicine, University of Health Sciences of Libreville, Libreville BP 4009, Gabon.
| | - Marielle K Bouyou Akotet
- Department of Parasitology-Mycology, Faculty of Medicine, University of Health Sciences of Libreville, Libreville BP 4009, Gabon.
| | - Hélène Moné
- IHPE, Univ Montpellier, CNRS, UM, IFREMER, Univ Perpignan Via Domitia, Perpignan F-66860, France.
| | - Gabriel Mouahid
- IHPE, Univ Montpellier, CNRS, UM, IFREMER, Univ Perpignan Via Domitia, Perpignan F-66860, France.
| | - Julienne Atsame
- Control Program of Parasitic Diseases, Libreville BP 2434, Gabon.
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30
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Nono JK, Kamdem SD, Netongo PM, Dabee S, Schomaker M, Oumarou A, Brombacher F, Moyou-Somo R. Schistosomiasis Burden and Its Association With Lower Measles Vaccine Responses in School Children From Rural Cameroon. Front Immunol 2018; 9:2295. [PMID: 30356757 PMCID: PMC6189399 DOI: 10.3389/fimmu.2018.02295] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2018] [Accepted: 09/17/2018] [Indexed: 12/19/2022] Open
Abstract
Background and Methods: Schistosomiasis is debilitating and reported to impair immune responsiveness of infected hosts. In Cameroon, mass drug administration (MDA) is used in schoolchildren to reduce transmission of S. haematobium and S. mansoni. The effects of MDA and the impact of schistosomiasis on the titers of antibodies in vaccinated children have been poorly studied. We therefore assessed the prevalence of schistosomiasis in schoolchildren, eight months after MDA, in two locations: Barombi Koto (BK), endemic for S. haematobium (N = 169) and Yoro (Y), endemic for S. mansoni (N = 356). Age, gender, residence time and frequency of contact with river water were assessed as risk factors for infection and morbidity in both localities. In 70 schoolchildren from BK and 83 from Y, ultrasound was used to assess morbidity according to the WHO guidelines. Evaluation of measles antibodies was performed in previously vaccinated schoolchildren (14 with S. haematobium and 12 egg-negative controls from BK and 47 with S. mansoni and12 egg-negative controls from Y). Principal Findings and conclusions: The prevalence of S. haematobium was 25. 4% in BK (43/169) and 34.8% for S. mansoni in Y (124/356), indicating the persistent transmission of schistosomiasis despite MDA. Older age (AOR 1.31; 95%CI 1.12–1.54) and higher frequencies of exposure to river water (AOR 1.99; 95%CI 1.03–3.86) were identified as risks for infection in BK whereas only older age (OR 1.15; 95%CI 1.04–1.27) was a risk for infection in Y. Bladder pathology (score 2 to 5) was observed in 29.2% (7/24) of egg-positive children in BK and liver pathology (pattern C) in 31.1% (19/61) of egg-positive children in Y. There was a positive correlation between S. haematobium egg burden and bladder pathology (AOR 1.01; 95% CI 0.99–1.02) and positive correlation between S. mansoni-driven liver pathology and female gender (AOR 3.01; 95% CI 0.88–10.26). Anti-measles antibodies in vaccinated children were significantly lower in S. mansoni-infected when compared to egg-negative controls (p = 0.001), which was not observed in the S. haematobium-infected group from BK. Our results demonstrate a questionable efficacy of MDA alone in halting schistosomiasis transmission and confirm a possible immunomodulatory effect of S. mansoni on response to vaccines.
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Affiliation(s)
- Justin Komguep Nono
- The Medical Research Centre, Institute of Medical Research and Medicinal Plant Studies, Ministry of Scientific Research and Innovation, Yaoundé, Cameroon.,Division of Immunology, Health Science Faculty, University of Cape Town, Cape Town, South Africa.,Cytokines and Diseases Group, International Centre for Genetic Engineering and Biotechnology, Cape Town, South Africa.,Immunology of Infectious Disease Research Unit, South African Medical Research Council, Cape Town, South Africa
| | - Severin Donald Kamdem
- Division of Immunology, Health Science Faculty, University of Cape Town, Cape Town, South Africa.,Cytokines and Diseases Group, International Centre for Genetic Engineering and Biotechnology, Cape Town, South Africa.,Immunology of Infectious Disease Research Unit, South African Medical Research Council, Cape Town, South Africa
| | | | - Smritee Dabee
- Division of Medical Virology, Department of Pathology, University of Cape Town, Cape Town, South Africa
| | - Michael Schomaker
- Centre for Infectious Disease Epidemiology & Research, University of Cape Town, Cape Town, South Africa
| | | | - Frank Brombacher
- Division of Immunology, Health Science Faculty, University of Cape Town, Cape Town, South Africa.,Cytokines and Diseases Group, International Centre for Genetic Engineering and Biotechnology, Cape Town, South Africa.,Immunology of Infectious Disease Research Unit, South African Medical Research Council, Cape Town, South Africa.,Wellcome Centre for Infectious Diseases Research in Africa, Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Roger Moyou-Somo
- The Medical Research Centre, Institute of Medical Research and Medicinal Plant Studies, Ministry of Scientific Research and Innovation, Yaoundé, Cameroon
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Tchuem Tchuenté LA, Stothard JR, Rollinson D, Reinhard-Rupp J. Precision mapping: An innovative tool and way forward to shrink the map, better target interventions, and accelerate toward the elimination of schistosomiasis. PLoS Negl Trop Dis 2018; 12:e0006563. [PMID: 30071014 PMCID: PMC6071947 DOI: 10.1371/journal.pntd.0006563] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Affiliation(s)
- Louis-Albert Tchuem Tchuenté
- University of Yaoundé I, Yaoundé, Cameroon
- Centre for Schistosomiasis and Parasitology, Yaoundé, Cameroon
- * E-mail:
| | - J. Russell Stothard
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - David Rollinson
- Global Schistosomiasis Alliance, Department of Life Sciences, Natural History Museum, London, United Kingdom
| | - Jutta Reinhard-Rupp
- Merck Global Health Institute, Ares Trading SA, Switzerland, Subsidiary of Merck KGaA, Darmstadt, Germany
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Karshima SN. Prevalence and distribution of soil-transmitted helminth infections in Nigerian children: a systematic review and meta-analysis. Infect Dis Poverty 2018; 7:69. [PMID: 29983115 PMCID: PMC6036687 DOI: 10.1186/s40249-018-0451-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Accepted: 06/14/2018] [Indexed: 01/20/2023] Open
Abstract
Background Soil transmitted helminth (STH) infections still remain a notable health problem in resource-limited countries due to difficulties in the implementation of control measures. In Nigeria for instance, despite several community-based and provincial reports, national data on prevalence, burdens and risk zones (RZs) for STH infections are lacking. Methods The present study employed the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) to determine the prevalence, distribution and RZs for STH infections among Nigerian children through a meta-analysis of data published between 1980 and 2015. Pooled prevalence estimate (PPE) was determined by the random-effects model while heterogeneity was evaluated using the Cochran’s Q-test. Results A total of 18 901 of the 34 518 Nigerian children aged 0–17 years examined across 19 Nigerian states during the period under review were infected with one or more species of STHs. The overall PPE for STH infections was 54.8% (95% CI: 54.2–55.3). PPEs for sub-groups ranged between 13.2% (95% CI: 11.5–15.1) and 80.9% (95% CI: 80.0–81.7). Highest PPEs for STH infections were observed among children within community settings (59.0%, 95% CI: 57.7–60.4) and school-aged children (54.9%, 95% CI: 54.3–55.5). Ascaris lumbricoides was the most prevalent species (44.6%, 95% CI: 44.0–45.2). Over 36% (15/41) of the studies were published from south-western Nigeria. South-western region was the only high risk zone (HRZ) for STH infections while the rest of the regions were low risk zones (LRZs). Conclusions STH infections involving Ascaris lumbricoides, Strongyloides stercoralis, Trichuris trichiura and hookworms are highly prevalent across Nigeria. Strategic use of anthelmintics, health education and adequate sanitation, taking into account this epidemiologic information will help in the control of these infections in Nigeria. Electronic supplementary material The online version of this article (10.1186/s40249-018-0451-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Solomon Ngutor Karshima
- Department of Veterinary Public Health and Preventive Medicine, University of Jos, PMB 2084, Jos, Nigeria.
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Tabi ESB, Eyong EM, Akum EA, Löve J, Cumber SN. Soil-transmitted Helminth infection in the Tiko Health District, South West Region of Cameroon: a post-intervention survey on prevalence and intensity of infection among primary school children. Pan Afr Med J 2018; 30:74. [PMID: 30344858 PMCID: PMC6191252 DOI: 10.11604/pamj.2018.30.74.15676] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 05/11/2018] [Indexed: 11/30/2022] Open
Abstract
Introduction Soil-transmitted helminths (STH) infection remains a public health problem in sub-Saharan Africa with children being most vulnerable. STH infection may result in impairment, permanent disability or death. Annual mass deworming has been implemented in the Tiko Health District (THD), however, no study has assessed the current prevalence of STH infection. This study aimed to determine the prevalence, intensity of STH infections and associated risk factors among school children. Methods Two months after the school deworming exercise, 400 children were sampled from 10 schools in THD. Stool samples were collected and analyzed using the Kato-katz technique. Data on socio-demographic and behavioral factors were collected using questionnaires. Data were analyzed using SPSS and intensity of infection categorized following WHO recommendations. Descriptive data were calculated with frequencies (n) and proportions (%), prevalence and 95% confidence interval calculated for gender and age respectively. Differences in prevalence for socio-demographic characteristics and behavioral variables were calculated with Chi square (χ2). Independent sample t-test was used to compare the means in the number of eggs in feces between male and female school children. Results The prevalence of STH was 1% (95% CI: 0.02-1.98). Ascaris lumbricoides was the only STH species detected and all cases were of low intensities. The arithmetic mean egg intensity was 3.1egg per gram of faeces. Rates of infection were similar between gender and age. Site of defecation showed an association with STH infection (χ2 = 13.63, p=0.03). Conclusion These findings suggested a low prevalence of STH infection which could be explained by the prior deworming of children, modification in environmental and behavioral factors. Questions on effectiveness of annual mass deworming in achieving STH elimination targets need to be investigated further.
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Affiliation(s)
- Egbe Sarah Balle Tabi
- Department of Microbiology and Parasitology, Faculty of Science, University of Buea, Buea, Cameroon.,Cameroon Society of Epidemiology (CaSE) P.O BOX, 1411, Yaoundé, Cameroon.,Health Education and Research Organization (HERO) Cameroon
| | - Esum Mathias Eyong
- Department of Microbiology and Parasitology, Faculty of Science, University of Buea, Buea, Cameroon
| | - Eric Achidi Akum
- Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, Buea, Cameroon
| | - Jesper Löve
- Section for Epidemiology and Social Medicine, Department of Public Health, Institute of Medicine (EPSO), the Sahlgrenska Academy at University of Gothenburg, P.O Box 414, SE, 405 Gothenburg, Sweden
| | - Samuel Nambile Cumber
- Section for Epidemiology and Social Medicine, Department of Public Health, Institute of Medicine (EPSO), the Sahlgrenska Academy at University of Gothenburg, P.O Box 414, SE, 405 Gothenburg, Sweden
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34
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Folefac LN, Nde-Fon P, Verla VS, Tangye MN, Njunda AL, Luma HN. Knowledge, attitudes and practices regarding urinary schistosomiasis among adults in the Ekombe Bonji Health Area, Cameroon. Pan Afr Med J 2018; 29:161. [PMID: 30050625 PMCID: PMC6057561 DOI: 10.11604/pamj.2018.29.161.14980] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Accepted: 02/24/2018] [Indexed: 11/11/2022] Open
Abstract
Introduction Urinary schistosomiasis (US) is endemic in Cameroon. Knowledge, attitudes and practices (KAP) are important aspects for control of the disease. However, data on these remain scanty. We aimed at evaluating knowledge, attitudes and practices regarding urinary schistosomiasis among adults in households in the Ekombe Bonji health area. Methods A community-based, cross-sectional study was carried out at Ekombe Bonji health area from February to March, 2017, involving all 12 communities. A pre-tested questionnaire was used to assess knowledge, attitudes and practices regarding urinary schistosomiasis among 198 adults and to record their socio-demographic, environmental and clinical variables. Data were stored in Excel version 2013 and analysed using Stata version 14.2. Results Of the 198 adults interviewed, only 35.4% had prior knowledge about urinary schistosomiasis. Among these, 94.3%, 74.3%, 57.7% knew the signs and symptoms, modes of transmission and preventive measures respectively. Only 14.3% knew the cause and treatment. 81.2% considered urinary schistosomiasis a serious disease and 77.1% believed it could be prevented, albeit, their practices to prevent infection were inadequate. Conclusion Knowledge, attitudes and practices regarding urinary schistosomiasis among adults are inadequate, since most of them are not aware of the disease. Therefore, there is need for community-based interventions especially health education to effectively reduce the disease burden.
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Affiliation(s)
- Laura Ngolere Folefac
- Department of Medicine, Faculty of Health Sciences, University of Buea, South West Region, Cameroon
| | - Peter Nde-Fon
- Department of Public Health and Hygiene, Faculty of Health Sciences, University of Buea, South West Region, Cameroon
| | - Vincent Siysi Verla
- Department of Medicine, Faculty of Health Sciences, University of Buea, South West Region, Cameroon
| | - Michael Nkemanjong Tangye
- Department of Zoology and Animal Physiology, Faculty of Science, University of Buea, South West Region, Cameroon
| | - Anna Longdoh Njunda
- Department of Medical Laboratory Sciences, Faculty of Health Sciences, University of Buea, South West Region, Cameroon
| | - Henry Namme Luma
- Department of Microbiology, Infectious Diseases, Faculty of Medicine and Biomedical Sciences, University of Yaoundé, Central Region, Cameroon
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Kengne-Fokam AC, Nana-Djeunga HC, Bagayan M, Njiokou F. Biomphalaria camerunensis as a viable alternative intermediate host for Schistosoma mansoni in southern Cameroon. Parasit Vectors 2018. [PMID: 29534740 PMCID: PMC5848459 DOI: 10.1186/s13071-018-2763-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Background Intestinal schistosomiasis due to Schistosoma mansoni was mapped in Cameroon in the 1990s and preventive chemotherapy launched since 2005. A situation analysis conducted in 2011 revealed an increase in schistosomiasis transmission, especially in the equatorial part of the country, despite the fact that Biomphalaria pfeifferi, the main intermediate host of this parasite, is now scarce in many foci. Biomphalaria camerunensis, restricted to the equatorial part of the country, is considered as a less suitable host for S. mansoni due to it resistance to the parasite, although exhibiting a better survival than B. pfeifferi. In a context where human migration is quite frequent as a consequence of terrorism, war in neighboring countries, as well as development of hydraulic projects, it seems appropriate to evaluate the current epidemiological role of B. camerunensis to estimate the risk of extension of S. mansoni distribution in Cameroon. To do this, the susceptibility of three B. pfeifferi and five B. camerunensis populations to a strain of S. mansoni was assessed. Juvenile snails (G1) of each population were infected with S. mansoni miracidia, and prepatent period, infection and survival rates of infected snails, as well as cercarial production were recorded and compared between snail species and populations. Results Compatibility tests were performed on a total of 827 snails: 344 B. pfeifferi and 483 B. camerunensis. Infection rates were quite heterogeneous, higher in B. pfeifferi (61.5%) as compared to B. camerunensis (7.8%) (Chi-square test: χ2 = 258.88, df = 1, P < 0.0001). All the three B. pfeifferi-infected populations were susceptible to S. mansoni. However, among the five B. camerunensis populations tested, four were susceptible to S. mansoni, with 21.9% as the highest infection rate. The prepatent period was, on average, shorter in B. pfeifferi than in B. camerunensis (P < 0.0001), but the cercarial production was significantly higher in B. camerunensis as compared to B. pfeifferi (P < 0.001). Conclusion These findings indicate that B. camerunensis populations might substantially contribute to S. mansoni transmission and dissemination in Cameroon, their low susceptibility being compensated by their high cercariae production. More attention and surveillance towards this species are required to achieve intestinal schistosomiasis elimination in Cameroon. Electronic supplementary material The online version of this article (10.1186/s13071-018-2763-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Alvine C Kengne-Fokam
- Parasitology and Ecology Laboratory, Faculty of Science, University of Yaoundé 1, PO Box 812, Yaoundé, Cameroon
| | - Hugues C Nana-Djeunga
- Parasitology and Ecology Laboratory, Faculty of Science, University of Yaoundé 1, PO Box 812, Yaoundé, Cameroon.,Center for Research on Filariasis and other Tropical Diseases (CRFilMT), PO Box 5797, Yaoundé, Cameroon
| | - Mohamed Bagayan
- Parasitology and Ecology Laboratory, Faculty of Science, University of Yaoundé 1, PO Box 812, Yaoundé, Cameroon.,Laboratory of Animal Biology and Ecology, University of Ouaga I Pr Joseph Ki-Zerbo, Ouagadougou, Burkina Faso.,Health Science Research Institute (IRSS), Ouagadougou, Burkina Faso
| | - Flobert Njiokou
- Parasitology and Ecology Laboratory, Faculty of Science, University of Yaoundé 1, PO Box 812, Yaoundé, Cameroon.
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Loy DE, Rubel MA, Avitto AN, Liu W, Li Y, Learn GH, Ranciaro A, Mbunwe E, Fokunang C, Njamnshi AK, Sharp PM, Tishkoff SA, Hahn BH. Investigating zoonotic infection barriers to ape Plasmodium parasites using faecal DNA analysis. Int J Parasitol 2018; 48:531-542. [PMID: 29476866 DOI: 10.1016/j.ijpara.2017.12.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Revised: 11/09/2017] [Accepted: 12/15/2017] [Indexed: 01/17/2023]
Abstract
African apes are endemically infected with numerous Plasmodium spp. including close relatives of human Plasmodium falciparum, Plasmodium vivax, Plasmodium ovale, and Plasmodium malariae. Although these ape parasites are not believed to pose a zoonotic threat, their ability to colonise humans has not been fully explored. In particular, it remains unknown whether ape parasites are able to initiate exo-erythrocytic replication in human hepatocytes following the bite of an infective mosquito. Since animal studies have shown that liver stage infection can result in the excretion of parasite nucleic acids into the bile, we screened faecal samples from 504 rural Cameroonians for Plasmodium DNA. Using pan-Laverania as well as P. malariae- and P. vivax-specific primer sets, we amplified human P. falciparum (n = 14), P. malariae (n = 1), and P. ovale wallikeri (n = 1) mitochondrial sequences from faecal DNA of 15 individuals. However, despite using an intensified PCR screening approach we failed to detect ape Laverania, ape P. vivax or ape P. malariae parasites in these same subjects. One faecal sample from a hunter-gatherer contained a sequence closely related to the porcupine parasite Plasmodium atheruri. Since this same faecal sample also contained porcupine mitochondrial DNA, but a matching blood sample was Plasmodium-negative, it is likely that this hunter-gatherer consumed Plasmodium-infected bushmeat. Faecal Plasmodium detection was not secondary to intestinal bleeding and/or infection with gastrointestinal parasites, but indicative of blood parasitaemia. Quantitative PCR identified 26-fold more parasite DNA in the blood of faecal Plasmodium-positive than faecal Plasmodium-negative individuals (P = 0.01). However, among blood-positive individuals only 10% - 20% had detectable Plasmodium sequences in their stool. Thus, faecal screening of rural Cameroonians failed to uncover abortive ape Plasmodium infections, but detected infection with human parasites, albeit with reduced sensitivity compared with blood analysis.
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Affiliation(s)
- Dorothy E Loy
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Meagan A Rubel
- Department of Anthropology, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Genetics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Alexa N Avitto
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Weimin Liu
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Yingying Li
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Gerald H Learn
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Alessia Ranciaro
- Department of Genetics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Eric Mbunwe
- Department of Genetics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Charles Fokunang
- Department of Pharmacotoxicology and Pharmacokinetics, Faculty of Medicine and Biomedical Sciences, University of Yaoundé I, Yaoundé, Cameroon
| | - Alfred K Njamnshi
- Department of Neurology, Faculty of Medicine and Biomedical Sciences, Central Hospital Yaoundé, University of Yaoundé I, Yaoundé, Cameroon
| | - Paul M Sharp
- Institute of Evolutionary Biology and Centre for Immunity, Infection and Evolution, University of Edinburgh, Edinburgh EH9 3FL, United Kingdom
| | - Sarah A Tishkoff
- Department of Genetics, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Beatrice H Hahn
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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Sokolow SH, Wood CL, Jones IJ, Lafferty KD, Kuris AM, Hsieh MH, De Leo GA. To Reduce the Global Burden of Human Schistosomiasis, Use 'Old Fashioned' Snail Control. Trends Parasitol 2018; 34:23-40. [PMID: 29126819 PMCID: PMC5819334 DOI: 10.1016/j.pt.2017.10.002] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Revised: 09/30/2017] [Accepted: 10/16/2017] [Indexed: 12/27/2022]
Abstract
Control strategies to reduce human schistosomiasis have evolved from 'snail picking' campaigns, a century ago, to modern wide-scale human treatment campaigns, or preventive chemotherapy. Unfortunately, despite the rise in preventive chemotherapy campaigns, just as many people suffer from schistosomiasis today as they did 50 years ago. Snail control can complement preventive chemotherapy by reducing the risk of transmission from snails to humans. Here, we present ideas for modernizing and scaling up snail control, including spatiotemporal targeting, environmental diagnostics, better molluscicides, new technologies (e.g., gene drive), and 'outside the box' strategies such as natural enemies, traps, and repellants. We conclude that, to achieve the World Health Assembly's stated goal to eliminate schistosomiasis, it is time to give snail control another look.
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Affiliation(s)
- Susanne H Sokolow
- Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950, USA; Marine Science Institute, University of California, Santa Barbara, CA 93106, USA.
| | - Chelsea L Wood
- School of Aquatic and Fishery Sciences, University of Washington, Box 355020, Seattle, WA 98195-5020, USA
| | - Isabel J Jones
- Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950, USA
| | - Kevin D Lafferty
- U.S. Geological Survey, Western Ecological Research Center, c/o Marine Science Institute, University of California, Santa Barbara, CA 93106, USA
| | - Armand M Kuris
- Marine Science Institute, University of California, Santa Barbara, CA 93106, USA
| | - Michael H Hsieh
- Children's National Health System, Washington DC, 20010, USA; The George Washington University, Washington DC, 20037, USA; Biomedical Research Institute, Rockville, MD 20850, USA
| | - Giulio A De Leo
- Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950, USA
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Domngang Noche C, Fotsing Kwetche PR, Tumameu T, Tambo E, Moyou R, Bella AL. Relationship between tropical endemic limbo-conjunctivitis and intestinal helminths in a population of Cameroonian children. COGENT MEDICINE 2017. [DOI: 10.1080/2331205x.2017.1345587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
Affiliation(s)
| | | | - Thierry Tumameu
- Faculty of Health Sciences, Université des Montagnes, Bangangte, Cameroon
| | - Ernest Tambo
- Faculty of Health Sciences, Université des Montagnes, Bangangte, Cameroon
| | - Roger Moyou
- Faculty of Medicine and Biomedical Sciences, Université de Yaounde, Yaounde, Cameroon
- Institut de Recherche Médicale et d’Etudes des Plantes Médicinales de Yaounde, Université de Yaounde, Yaounde, Cameroon
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Njunda AL, Ndzi EN, Assob JCN, Kamga HLF, Kwenti ET. Prevalence and factors associated with urogenital schistosomiasis among primary school children in barrage, Magba sub-division of Cameroon. BMC Public Health 2017; 17:618. [PMID: 28673343 PMCID: PMC5496429 DOI: 10.1186/s12889-017-4539-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Accepted: 06/23/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The purpose of this study was to determine the prevalence and intensity as well as the factors associated with urogenital schistosomiasis (US) in Barrage, a rural community around the Mape΄ dam, in the West region of Cameroon not previously documented for transmission. METHODS In this cross sectional parasitological survey, 382 children were enrolled from three primary schools in the study area between March and May 2016. A semi-structured questionnaire was used to collect information on demographics, clinical and predisposing factors. The syringe filtration technique was used to analyse urine samples. Samples with visible or gross haematuria were recorded prior to filtration. The Pearson chi-square, the student T-test and logistic regression were all performed as part of the statistical analyses. RESULTS The overall prevalence of US was 41.1% (95% CI: 36.1-46.2). Infection was more common in children below 10 years (p = 0.009), in males (p = 0.029), and in children who frequently come into contact with water from the dam (p < 0.001). Furthermore, US was more common in children attending Ecole Public (EP) Manbonko Bord (81.1%, p < 0.001) which is very close to the dam and in children from a fishing background (80.9%, p < 0.001). On the contrary, knowledge about schistosomiasis was not observed to be associated with prevalence. In this study, the intensity of infection was observed to be higher in children below 10 years (p < 0.001), in males (p = 0.001), and in children attending EP Manbonko Bord (p < 0.001). The intensity of infection was also highest in children presenting with haematuria (p < 0.001). Frequent contact with water from the dam and having parents whose occupation was fishing were identified as the associated factors for US. CONCLUSION A high prevalence of US was observed in school-aged children in the study area especially in those attending EP Manbonko Bord. Limiting contact with water from the dam, control of the snail intermediate host, provision of portable water and mass treatment of the entire population are proposed as some of the measures to reduce and eventually eliminate transmission in the area.
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Affiliation(s)
- Anna Longdoh Njunda
- Department of Medical Laboratory Sciences, University of Buea, P.B, 63 Buea, Cameroon
| | - Emmanuel Ngala Ndzi
- Department of Medical Laboratory Sciences, University of Buea, P.B, 63 Buea, Cameroon
| | | | | | - Emmanuel Tebit Kwenti
- Department of Medical Laboratory Sciences, University of Buea, P.B, 63 Buea, Cameroon
- Department of Microbiology and Parasitology, University of Buea, P.B, 63 Buea, Cameroon
- Department of Public Health and Hygiene, University of Buea, P.B, 63 Buea, Cameroon
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Campbell SJ, Stothard JR, O'Halloran F, Sankey D, Durant T, Ombede DE, Chuinteu GD, Webster BL, Cunningham L, LaCourse EJ, Tchuem-Tchuenté LA. Urogenital schistosomiasis and soil-transmitted helminthiasis (STH) in Cameroon: An epidemiological update at Barombi Mbo and Barombi Kotto crater lakes assessing prospects for intensified control interventions. Infect Dis Poverty 2017; 6:49. [PMID: 28238285 PMCID: PMC5327519 DOI: 10.1186/s40249-017-0264-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Accepted: 02/17/2017] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND The crater lakes of Barombi Mbo and Barombi Kotto are well-known transmission foci of schistosomiasis and soil-transmitted helminthiasis having had several important control initiatives previously. To collect contemporary epidemiological information, a cross-sectional survey was undertaken inclusive of: signs and symptoms of disease, individual treatment histories, local water, sanitation and hygiene (WASH)-related factors and malacological surveillance, with molecular characterisation of specimens. METHODS At each lake, a community cross-sectional survey was undertaken using a combination of stool and urine parasitological sampling, and interview with pro-forma questionnaires. A total of 338 children and adults participated. Material from snail and parasite species were characterised by DNA methods. RESULTS Egg-patent prevalence of urogenital schistosomiasis was 8.7% at Barombi Mbo (all light-intensity infections) and 40.1% at Barombi Kotto (21.2% heavy-intensity infections). Intestinal schistosomiasis was absent. At Barombi Kotto, significantly more women reported signs and symptoms associated with female genital schistosomiasis. While there had been extensive recent improvement in WASH-related infrastructure at Barombi Mbo, water contact risk scores were higher among schistosomiasis-infected participants (P < 0.001) and at Barombi Kotto in general (P < 0.001). Across both lakes, mean prevalence of STH was very low (6.3%) evidencing an impressive decrease of 79.0% over the last decade; neither Strongyloides stercoralis nor Ascaris lumbricoides were found. A total of 29 freshwater sampling sites were inspected for snails, 13 in Barombi Mbo and 16 in Barombi Kotto; water chemistry differed significantly (P < 0.0001) between lakes for both mean pH (7.9 v. 9.6) and mean conductivity (64.3 μS v. 202.1 μS) respectively. Only two Bulinus camerunensis found on the central island of Barombi Kotto were observed to shed schistosome cercariae, but schistosome DNA was later detected in Bulinus sampled from both lakes as well as in Indoplanorbis exustus, an invasive species from Asia. CONCLUSIONS STH is currently at very low levels while urogenital schistosomiasis is of greatest concern at Barombi Kotto. This assessment highlights a unique opportunity for further study of the epidemiological dynamics at these crater lakes, to evaluate future intensified interventions both in terms of gaining and sustaining control at Barombi Kotto or in moving towards local interruption of transmission of both diseases at Barombi Mbo.
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Affiliation(s)
- Suzy J Campbell
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - J Russell Stothard
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK.
| | - Faye O'Halloran
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Deborah Sankey
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Timothy Durant
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | | | | | - Bonnie L Webster
- Department of Life Sciences, Parasites and Vectors Division, Natural History Museum, London, SW7 5BD, UK
- London Centre for Neglected Tropical Disease Research, London, UK
| | - Lucas Cunningham
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - E James LaCourse
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Louis-Albert Tchuem-Tchuenté
- Centre for Schistosomiasis and Parasitology, Yaoundé, Cameroon
- Laboratory of Parasitology and Ecology, Faculty of Sciences, University of Yaoundé I, Yaoundé, Cameroon
- National Programme for the Control of Schistosomiasis and Intestinal Helminthiasis, Ministry of Public Health, Yaoundé, Cameroon
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Lagatie O, Van Dorst B, Stuyver LJ. Identification of three immunodominant motifs with atypical isotype profile scattered over the Onchocerca volvulus proteome. PLoS Negl Trop Dis 2017; 11:e0005330. [PMID: 28125577 PMCID: PMC5295699 DOI: 10.1371/journal.pntd.0005330] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Revised: 02/07/2017] [Accepted: 01/14/2017] [Indexed: 01/30/2023] Open
Abstract
Understanding the immune response upon infection with the filarial nematode Onchocerca volvulus and the mechanisms that evolved in this parasite to evade immune mediated elimination is essential to expand the toolbox available for diagnostics, therapeutics and vaccines development. Using high-density peptide microarrays we scanned the proteome-wide linear epitope repertoire in Cameroonian onchocerciasis patients and healthy controls from Southern Africa which led to the identification of 249 immunodominant antigenic peptides. Motif analysis learned that 3 immunodominant motifs, encompassing 3 linear epitopes, are present in 70, 43, and 31 of these peptides, respectively and appear to be scattered over the entire proteome in seemingly non-related proteins. These linear epitopes are shown to have an atypical isotype profile dominated by IgG1, IgG3, IgE and IgM, in contrast to the commonly observed IgG4 response in chronic active helminth infections. The identification of these linear epitope motifs may lead to novel diagnostic development but further evaluation of cross-reactivity against common co-infecting human nematode infections will be needed. Infection with the filarial parasite Onchocerca volvulus is the cause of river blindness. We analyzed the immune response against this parasite in infected individuals in order to identify linear epitopes. Using high-density peptide microarrays we discovered three immunodominant motifs in the Onchocerca volvulus proteome that induce a broad IgG response, but the typical IgG4 immune response against parasites was absent. Our study led to the identification of novel potential epitope sequences that can potentially be used for detection of infection with Onchocerca volvulus.
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Affiliation(s)
- Ole Lagatie
- Janssen Diagnostics, Janssen Pharmaceutica NV, Beerse, Belgium
- * E-mail:
| | - Bieke Van Dorst
- Janssen Diagnostics, Janssen Pharmaceutica NV, Beerse, Belgium
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Coinfection with Schistosoma haematobium and Plasmodium falciparum and Anaemia Severity among Pregnant Women in Munyenge, Mount Cameroon Area: A Cross-Sectional Study. J Parasitol Res 2017; 2017:6173465. [PMID: 28168042 PMCID: PMC5266839 DOI: 10.1155/2017/6173465] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Revised: 10/24/2016] [Accepted: 11/30/2016] [Indexed: 01/06/2023] Open
Abstract
Background. Malaria and urogenital schistosomiasis are coendemic in Mount Cameroon Area. This study investigated the prevalence of S. haematobium, P. falciparum, and coinfections and their effect on anaemia in pregnancy. Methods. Pregnant women reporting for antenatal care (ANC) clinic visit in Munyenge were enrolled. S. haematobium and P. falciparum infections were determined by urine filtration and microscopy, respectively. Haemoglobin (Hb) levels were measured using haemoglobinometer. Of 250 women, 46.8%, 39.2%, and 15.2% had S. haematobium, P. falciparum, and coinfections, respectively. Schistosomes infection was higher in younger women (≤25 years) and those who bathe in and had domestic contact with stream compared with older age (>25 years) women and those who had only domestic contact with stream. Lower infection rate was associated with less water contact (≤2 times/day) compared with more water contact (>2 times/day). Compared with no sulphadoxine-pyrimethamine (SP) usage, malaria parasitaemia was less among women who used SP. Stream usage increased risk of coinfection while less water contact and SP usage decreased its risk. All coinfected cases were anaemic and coinfection accounted for 93.8% of severe anaemia. Conclusion. Coinfection contributes to anaemia severity. Less water contact and SP usage will reduce coinfection in pregnancy in Munyenge.
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Bladder outlet obstruction; a rare complication of the neglected schistosome, Schistosoma haematobium: two case reports and public health challenges. BMC Res Notes 2016; 9:493. [PMID: 27876076 PMCID: PMC5120452 DOI: 10.1186/s13104-016-2303-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Accepted: 11/16/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Schistosomiasis is a severe parasitic infestation with debilitating complications and is the third most devastating tropical disease in the world. It is one of the neglected tropical diseases (NTDs) with a high disease-burden. We present two rare cases of bladder outlet obstruction: one which led to a chronic kidney disease and ultimately death and a second which recovered after treatment with praziquantel. CASE PRESENTATIONS A 72 year old male presented with lower urinary tract symptoms which culminated in an episode of acute urinary retention. The patient had never received preventive chemotherapy with praziquantel. After suprapubic aspiration, the cause of the obstructive uropathy was found to be several mature live worms of Schistosoma haematobium. Despite treatment with praziquantel and haemodialysis; we lost the patient due to sepsis from a urinary tract infection. In the second case, a 15 year old male presented with LUTS for a 1 year duration and was diagnosed to have schistosomiasis after eggs of Schistosoma haematobium were found in his urine. He was treated with praziquantel. CONCLUSION There are several gaps in the public health policies in place to control this NTD in Cameroon as annual distribution of preventive chemotherapy is inadequate due to inaccessibility of some high-endemic zones and is based on data obtained two decades ago. Population education is insufficient leading to poor health-seeking behaviour. These gaps in public health policies need to be addressed to aid in the overall achievement of the sustainable development goals.
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The Effect of Intestinal Parasitic Infection on the Clinical Outcome of Malaria in Coinfected Children in Cameroon. PLoS Negl Trop Dis 2016; 10:e0004673. [PMID: 27128975 PMCID: PMC4851403 DOI: 10.1371/journal.pntd.0004673] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 04/07/2016] [Indexed: 12/03/2022] Open
Abstract
Background The interaction between intestinal parasites and malaria is still not clear. Data in published literature are conflicting. We studied the effect of intestinal parasitic infection (IPI) on the clinical outcome of malaria in coinfected children. Methods In a cross sectional study performed between October 2014 and September 2015, children infected with malaria, as demonstrated by the presence of asexual parasites in Giemsa stained blood films, were enrolled. Stool samples were obtained from participants and subjected to the formol-ether concentration technique for the detection of intestinal parasites. The Complete blood count was performed using an automated haematology analyser (Mindray, BC-2800). The risk ratio, Pearson’s chi-square and the student T test were all performed as part of the statistical analyses. Statistical significance was set at p < 0.05. Results In all, 405 children successfully took part in the study. The children were between 1 week and 120 months of age (mean ± SD = 41.5 ± 33.5). Coinfection with intestinal parasites was observed in 11.6%. The rate of severe malaria (SM) attack in this study was 10.9%. SM was not observed to be associated with age (p = 0.377) or gender (p = 0.387), meanwhile coinfection with intestinal parasites was associated with age (p = 0.003). Among SM cases, IPI prevalence was higher in children with mild (WHO group 3) severe malaria (p = 0.027). Overall, IPI was not observed to be associated with SM (p = 0.656) or malaria parasite density (p = 0.185) or haemoglobin concentration (p = 0.205). The main clinical features of SM observed were hyperpyrexia (68.2%), severe malarial anaemia (61.4%), and multiple convulsion (52.3%). Conclusion IPI was not observed to be associated with the severity of malaria, the malaria parasite density, and the haemoglobin concentration in coinfected children in Cameroon. The clinical outcome of malaria in children coinfected with intestinal parasites may depend on the geographical setting after all. Coinfection with malaria and intestinal parasites are common in Sub-Saharan Africa, particularly in impoverished and poor sanitary settings. The interaction between intestinal parasites and malaria in coinfected children is still not clear. Some published papers suggest intestinal parasites, especially Ascaris lumbricoides, may attenuate the severity of malaria in the presence of coinfection. In this cross-sectional study, we evaluated the effect of intestinal parasitic infection on the severity of malaria, malaria parasite density and the haemoglobin concentration in children coinfected with malaria and intestinal parasites in Cameroon. We did not observe any significant association between intestinal parasitic infection and severe malaria or malaria parasite density or haemoglobin concentration. Stratification of severe malaria according to the degree of severity revealed a significant association with intestinal parasitic infection, in which prevalence of intestinal parasites was higher in children with mild severe malaria. Analyzing the different species of intestinal parasite did not yield any significant association either. These findings are contrary to many research publication on the subject. Several factors could have contributed to our observation, including the regular deworming campaign organized by the Cameroon Ministry of Public health, accounting for the lower prevalence of intestinal parasitic infection, and also the geographical setting.
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Bopda J, Nana-Djeunga H, Tenaguem J, Kamtchum-Tatuene J, Gounoue-Kamkumo R, Assob-Nguedia C, Kamgno J. Prevalence and intensity of human soil transmitted helminth infections in the Akonolinga health district (Centre Region, Cameroon): Are adult hosts contributing in the persistence of the transmission? Parasite Epidemiol Control 2016; 1:199-204. [PMID: 29988185 PMCID: PMC5991827 DOI: 10.1016/j.parepi.2016.03.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2015] [Revised: 03/01/2016] [Accepted: 03/02/2016] [Indexed: 12/24/2022] Open
Abstract
Background Soil-transmitted helminthiases (STHs) are among the most prevalent afflictions of the developing world, with approximately 2 billion people infected worldwide. Heavily infected individuals suffer from severe morbidity that can result in death. These parasitic diseases also impair physical and mental growth in childhood, thwart educational advancement, and hinder economic development. Periodic deworming with Albendazole or Mebendazole of high-risk groups (school-age children, preschool children, and pregnant women) can significantly lower the levels of infections below the threshold associated with morbidity. However, an important proportion of the population (adults) is excluded from this high-risk group treatment based-strategy, and might lead to the persistence of these diseases in endemic areas despite the repeated treatments. The main objective of this study was to evaluate the contribution of this neglected at-risk group in the spread and persistence of STH in Cameroon. Methods A cross sectional survey was conducted in the Akonolinga health district (Centre Region, Cameroon) to assess the prevalence and intensity of these helminth infections. Stool samples were collected from males and females, aged 18 years and over, and analyzed using the Kato-Katz technique. Results A total of 334 patients, among which 181 (54.2%) females and 153 (45.8%) males, were examined. The STH of major concern was found in this group of individuals, with overall prevalence equal to 18.0% (95% CI: 14.2–22.4) for Ascaris lumbricoides, 43.7% (95% CI: 38.5–49.1) for Trichuris trichiura, and 7.5% (95% CI: 5.1–10.8) for Necator americanus. Conclusion This study reveals that STH infections are prevalent in adults in the Akonolinga health district, with moderate to high risk and light intensity of infection. These infected adults might constitute a potential parasite reservoir and a source of dissemination and persistence of these infections, highlighting the need to really take into account this neglected group of individuals in the mass treatment policy.
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Affiliation(s)
- Jean Bopda
- Centre for Research on Filariasis and other Tropical Diseases (CRFilMT), P.O. Box 5797, Yaounde, Cameroon
| | - Hugues Nana-Djeunga
- Centre for Research on Filariasis and other Tropical Diseases (CRFilMT), P.O. Box 5797, Yaounde, Cameroon.,Parasitology and Ecology Laboratory, Department of Animal Biology and Physiology, Faculty of Science, P.O. Box 812, University of Yaounde 1, Yaounde, Cameroon
| | - Jean Tenaguem
- Centre for Research on Filariasis and other Tropical Diseases (CRFilMT), P.O. Box 5797, Yaounde, Cameroon
| | - Joseph Kamtchum-Tatuene
- Centre for Research on Filariasis and other Tropical Diseases (CRFilMT), P.O. Box 5797, Yaounde, Cameroon
| | - Raceline Gounoue-Kamkumo
- Centre for Research on Filariasis and other Tropical Diseases (CRFilMT), P.O. Box 5797, Yaounde, Cameroon.,Laboratory of Animal Physiology, Department of Animal Biology and Physiology, Faculty of Science, P.O. Box 812, University of Yaounde 1, Yaounde, Cameroon
| | - Clément Assob-Nguedia
- INSAM, Department of Medicine and Biomedical Sciences, University of Buea, P.O. Box 63, Buea, Cameroon
| | - Joseph Kamgno
- Centre for Research on Filariasis and other Tropical Diseases (CRFilMT), P.O. Box 5797, Yaounde, Cameroon.,Department of Public Health, Faculty of Medicine and Biomedical Sciences, P.O. Box 1364, University of Yaounde 1, Yaounde, Cameroon
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Xu J, Yu Q, Tchuenté LAT, Bergquist R, Sacko M, Utzinger J, Lin DD, Yang K, Zhang LJ, Wang Q, Li SZ, Guo JG, Zhou XN. Enhancing collaboration between China and African countries for schistosomiasis control. THE LANCET. INFECTIOUS DISEASES 2016; 16:376-83. [PMID: 26851829 DOI: 10.1016/s1473-3099(15)00360-6] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Revised: 09/19/2015] [Accepted: 09/30/2015] [Indexed: 11/25/2022]
Abstract
Schistosomiasis remains an important public health issue, with a large number of cases reported across sub-Saharan Africa, and parts of Asia and Latin America. China was once highly endemic, but has made substantial progress and is moving towards elimination of schistosomiasis. Meanwhile, despite long-term, repeated, school-based chemotherapy in many African countries, more than 90% of all schistosomiasis cases are concentrated in Africa, and hence, this continent constitutes the key challenge for schistosomiasis control. Opportunities and issues for international collaboration in the fight against schistosomiasis are outlined with a focus on China's experiences, including the role of public health authorities and intersectoral collaboration, use of new and effective snail control approaches and diagnostic tools adapted to the specific stage of control, as well as the strengthening of risk mapping and surveillance-response mechanisms. Training courses targeting African governmental officials and professionals, coupled with field visits of African scientists and control programme managers to China, and vice versa, are considered important for improved schistosomiasis control and elimination. The crucial question remains whether the Chinese experience can be translated and applied in African countries to improve the effectiveness of health interventions and scale-up.
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Affiliation(s)
- Jing Xu
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, WHO Collaborating Center for Tropical Diseases, Shanghai, China
| | - Qing Yu
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, WHO Collaborating Center for Tropical Diseases, Shanghai, China
| | | | | | - Moussa Sacko
- National Institute for Research in Public Health, Ministry of Health, Bamako, Mali
| | - Jürg Utzinger
- Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland
| | - Dan-Dan Lin
- Jiangxi Provincial Institute of Parasitic Disease, Nanchang, China
| | - Kun Yang
- Jiangsu Provincial Institute of Schistosomiasis Control, Wuxi, China
| | - Li-Juan Zhang
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, WHO Collaborating Center for Tropical Diseases, Shanghai, China
| | - Qiang Wang
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, WHO Collaborating Center for Tropical Diseases, Shanghai, China
| | - Shi-Zhu Li
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, WHO Collaborating Center for Tropical Diseases, Shanghai, China
| | - Jia-Gang Guo
- Department of Control of Neglected Tropical Diseases, WHO, Geneva, Switzerland
| | - Xiao-Nong Zhou
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, WHO Collaborating Center for Tropical Diseases, Shanghai, China.
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Engle-Stone R, Nankap M, Ndjebayi AO, Vosti SA, Brown KH. Estimating the Effective Coverage of Programs to Control Vitamin A Deficiency and Its Consequences Among Women and Young Children in Cameroon. Food Nutr Bull 2015; 36:S149-71. [PMID: 26385984 DOI: 10.1177/0379572115595888] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND To compare the cost-effectiveness of nutrition programs, the anticipated nutritional benefits of each intervention must be expressed using a common metric. OBJECTIVE We present the methodology for estimating the benefits of vitamin A (VA)-related interventions among women and children in Cameroon. METHODS We estimated "reach" (proportion of the population that receives a program), "coverage" (proportion that is deficient and receives a program), and "effective coverage" (proportion that "converts" from inadequate to adequate VA intake following an intervention) using dietary data collected during a national survey in 3 macro-regions of Cameroon (North, South, and Yaoundé/Douala). Effective coverage of programs such as (bio)fortification and micronutrient powders was estimated by adding the dietary VA contributed by the intervention to baseline VA intakes, including the contribution of increased maternal VA intake to infant VA intake through increases in breast milk VA. For interventions that provide VA-related benefits through other pathways (eg, periodic high-dose VA supplements and deworming), we developed alternative methods of estimating "daily VA intake equivalents. " RESULTS Baseline VA intakes and intervention reach varied by geographic macro-region. On average, estimates of program reach were greater than the effective coverage estimates by ∼50%. Effective coverage varied by intervention package and macro-region, ranging from <20 000 (deworming, Yaoundé/Douala) to >400 000 (micronutrient powder or VA supplement, North) children effectively covered per year. CONCLUSION These estimates of effective coverage, along with macro-region-specific information on the costs of each intervention package, serve as inputs into an economic optimization model to identify the most cost-effective package of VA interventions for each macro-region of Cameroon.
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Affiliation(s)
- Reina Engle-Stone
- Department of Nutrition, University of California-Davis, Davis, CA, USA
| | | | | | - Stephen A Vosti
- Department of Agricultural and Resource Economics, University of California-Davis, Davis, CA, USA
| | - Kenneth H Brown
- Department of Nutrition, University of California-Davis, Davis, CA, USA Bill & Melinda Gates Foundation, Seattle, WA, USA
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Okeke OC, Ubachukwu PO. Performance of three rapid screening methods in the detection of Schistosoma haematobium infection in school-age children in Southeastern Nigeria. Pathog Glob Health 2014; 108:111-7. [PMID: 24593687 DOI: 10.1179/2047773214y.0000000128] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
BACKGROUND A cross-sectional study of primary school children was conducted to evaluate and compare the performance of some rapid screening methods in the detection of Schistosoma haematobium infection in Nigeria Cement Factory (NigerCem) and Nike Lake areas of Southeastern Nigeria. METHODS Urine samples of school children were examined for macro-haematuria and tested for micro-haematuria and proteinuria using reagent strips followed by egg microscopy. Self-reported haematuria was assessed using simple questionnaire. The performances of these rapid diagnoses singly and in combination were calculated using egg microscopy as gold standard. RESULTS The prevalence of the infection was 26·6% in NigerCem and 5·1% in Nike Lake area, classifying these areas as moderate- and low-prevalence areas (MPA and LPA); while in the subsample used for self-reported haematuria, the prevalence was 27·2 and 4·2% in MPA and LPA, respectively. The positive predictive value (PPV) of micro-haematuria was comparable in MPA (55·26%) and LPA (57·89%). Overall PPV of macro-haematuria was 87·50% in MPA and 66·70% in LPA while in the detection of heavy infection; PPV was higher in LPA (75%) than in MPA (66·67%). In LPA and MPA, combination of micro-haematuria and proteinuria, and concomitant presence of macro-haematuria, micro-haematuria, and proteinuria had PPV of 83·33 and 63·16%, and 100 versus 66·67%, respectively. Generally, the rapid screening tests had lower negative predictive values (NPVs) in MPA than in LPA. The use of simple questionnaire increased the PPV of heavy infection in MPA (77·78%). This was further increased to 80% when self-reported haematuria was combined with micro-haematuria. CONCLUSION The result suggests that in MPA with chronic infections, combination of self-reported haematuria and micro-haematuria may reduce the chance of missing those who should be treated.
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Tchuem Tchuenté LA, Dongmo Noumedem C, Ngassam P, Kenfack CM, Gipwe NF, Dankoni E, Tarini A, Zhang Y. Mapping of schistosomiasis and soil-transmitted helminthiasis in the regions of Littoral, North-West, South and South-West Cameroon and recommendations for treatment. BMC Infect Dis 2013; 13:602. [PMID: 24365046 PMCID: PMC3878270 DOI: 10.1186/1471-2334-13-602] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Accepted: 12/17/2013] [Indexed: 11/19/2022] Open
Abstract
Background The previous nationwide mapping of schistosomiasis and soil-transmitted helminthiasis (STH) in Cameroon was conducted 25 years ago. Based on its results, mass drug administration (MDA) of praziquantel was limited to the three northern regions and few health districts in the southern part of Cameroon. In 2010, we started the process of updating the disease distribution in order to improve the control strategies. Three of the ten regions of Cameroon were mapped in 2010 and the data were published. In 2011, surveys were conducted in four additional regions, i.e. Littoral, North-West, South and South-West. Methods Parasitological surveys were conducted in March 2011 in selected schools in all 65 health districts of the four targeted regions, using appropriate research methodologies, i.e. Kato-Katz and urine filtration. Results The results showed significant variation of schistosomiasis and STH prevalence between schools, villages, districts and regions. Schistosoma haematobium was the most prevalent schistosome species, with an overall prevalence of 3.2%, followed by S. mansoni (3%) and S. guineensis (1.2%). The overall prevalence of schistosomiasis across the four regions was 7.4% (95% CI: 6.7-8.3%). The prevalence for Ascaris lumbricoides was 19.5% (95% CI: 18.3-20.7%), Trichuris trichiura 18.9% (95% CI: 17.7-20.1%) and hookworms 7.6% (95% CI: 6.8-8.4%), with an overall STH prevalence of 32.5% (95% CI: 31.1-34.0%) across the four regions. STH was more prevalent in the South region (52.8%; 95% CI: 48.0-57.3%), followed by the South-West (46.2%; 95% CI: 43.2-49.3%), the North-West (35.9%; 95% CI: 33.1-38.7%) and the Littoral (13.0%; 95% CI: 11.3-14.9%) regions. Conclusions In comparison to previous data in 1985–87, the results showed an increase of schistosomiasis transmission in several health districts, whereas there was a significant decline of STH infections. Based on the prevalence data, the continuation of annual or bi-annual MDA for STH is recommended, as well as an extension of praziquantel in identified moderate and high risk communities for schistosomiasis.
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Affiliation(s)
- Louis-Albert Tchuem Tchuenté
- National Programme for the Control of Schistosomiasis and Intestinal Helminthiasis, Ministry of Public Health, Yaoundé, Cameroon.
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Rollinson D, Knopp S, Levitz S, Stothard JR, Tchuem Tchuenté LA, Garba A, Mohammed KA, Schur N, Person B, Colley DG, Utzinger J. Time to set the agenda for schistosomiasis elimination. Acta Trop 2013; 128:423-40. [PMID: 22580511 DOI: 10.1016/j.actatropica.2012.04.013] [Citation(s) in RCA: 376] [Impact Index Per Article: 34.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2011] [Revised: 04/25/2012] [Accepted: 04/27/2012] [Indexed: 12/19/2022]
Abstract
It is time to raise global awareness to the possibility of schistosomiasis elimination and to support endemic countries in their quest to determine the most appropriate approaches to eliminate this persistent and debilitating disease. The main interventions for schistosomiasis control are reviewed, including preventive chemotherapy using praziquantel, snail control, sanitation, safe water supplies, and behaviour change strategies supported by information, education and communication (IEC) materials. Differences in the biology and transmission of the three main Schistosoma species (i.e. Schistosoma haematobium, S. mansoni and S. japonicum), which impact on control interventions, are considered. Sensitive diagnostic procedures to ensure adequate surveillance in areas attaining low endemicity are required. The importance of capacity building is highlighted. To achieve elimination, an intersectoral approach is necessary, with advocacy and action from local communities and the health community to foster cooperative ventures with engineers, the private sector, governments and non-governmental organizations specialized in water supply and sanitation. Examples of successful schistosomiasis control programmes are reviewed to highlight what has been learnt in terms of strategy for control and elimination. These include St. Lucia and other Caribbean islands, Brazil and Venezuela for S. mansoni; Saudi Arabia and Egypt for both S. mansoni and S. haematobium; Morocco, Tunisia, Algeria, Mauritius and the Islamic Republic of Iran for S. haematobium; Japan and the People's Republic of China for S. japonicum. Additional targets for elimination or even eradication could be the two minor human schistosome species S. guineenisis and S. intercalatum, which have a restricted distribution in West and Central Africa. The examples show that elimination of schistosomiasis is an achievable and desirable goal requiring full integration of preventive chemotherapy with the tools of transmission control. An agenda for the elimination of schistosomiasis would aim to identify the gaps in knowledge, and define the tools, strategies and guidelines that will help national control programmes move towards elimination, including an internationally accepted mechanism that allows verification/confirmation of elimination.
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Affiliation(s)
- David Rollinson
- Wolfson Wellcome Biomedical Laboratories, Department of Zoology, Natural History Museum, Cromwell Road, London SW7 5BD, UK.
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