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Adhikari S, Hunter E, Vossenberg JVD, Thomas J. A review of latrine front-end characteristics associated with microbial infection risk; reveals a lack of pathogen density data. Int J Hyg Environ Health 2023; 254:114261. [PMID: 37734133 DOI: 10.1016/j.ijheh.2023.114261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 09/06/2023] [Accepted: 09/09/2023] [Indexed: 09/23/2023]
Abstract
Unsafe sanitation accounts for an estimated 898,000 global deaths annually. The faecal pathogen transmission pathway is complex with several possible routes. Latrine front-end characteristics and usage behaviours are one key transmission pathway for microbial pathogens, however, there has not yet been a synthesis of the available research. This review aims to compare the microbial infection risks with latrine front-end components including any quantified microbial densities within the household latrines. This review was conducted with no restriction on the geographical location of the research. Of 118 studies reviewed, only ten (8%) have quantified the microbial density inside the household latrines compared to 109 (92%) measuring the infection risks. The reported risks were most frequent for specific bacterial (n = 34), and helminths infections (n = 32) compared to diarrhoea (n = 23), combined (n = 15), protozoan (n = 4), and viral (n = 4) infections. The infections risk decreased for using latrines lying at a higher position on the sanitation ladder (for example flush latrines) compared to those lying lower (for example pit latrines). The trend was similar for using floor materials that were easier to clean and less favourable for pathogen survival inside the latrines (for example, concrete as opposed to earth). Faecal coliforms were reported highest on the surface of the squat pan (743 CFU/cm2) of pour-flush latrines and helminths on earth floors of pit latrines (1.5 eggs and larvae per gram of soil). Irrespective of latrine type and its position on the sanitation ladder, a dirty latrine, evidenced by a visible lack of cleanliness, significantly increased the risk for all infections. This study recommends that effective microbial infection risk reduction in latrines can be gained efficiently by ensuring washable surfaces and consistent cleaning practices. Future studies should include more rigorous measurements of microbial densities in various latrine types incorporating the different front-end components and usage behaviours.
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Affiliation(s)
- Sabita Adhikari
- School of Civil Engineering, The University of Sydney, Australia.
| | - Erin Hunter
- Department of Public Health Sciences, College of Behavioural, Social and Health Sciences, Clemson University, United States.
| | - Jack van de Vossenberg
- Water Supply, Sanitation and Environmental Engineering Department, IHE Delft Institute of Water Education, the Netherlands.
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Morphologic Characterization of Strongylida Larvae from Human and Swine Coprocultures in Rural Communities in the State of Piauí, Northeastern Brazil. J Trop Med 2022; 2022:7251922. [PMID: 36051189 PMCID: PMC9427283 DOI: 10.1155/2022/7251922] [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: 04/01/2022] [Accepted: 06/15/2022] [Indexed: 11/17/2022] Open
Abstract
Some helminth species belonging to the order Strongylida are parasites of the digestive tract of vertebrates, including man and domestic animals. In humans, infections with Oesophagostomum spp. and Trichostrongylus spp. may be misdiagnosed as hookworm disease on parasitological stool examination, mainly in regions where these infections are coendemic, since eggs released in hosts’ feces are morphologically similar. This study presents the morphologic characterization of Strongylida larvae recovered from humans and pigs living in close proximity, exploring putative zoonotic cycles. One hundred three humans and 27 pigs were included in low-resource rural communities in the state of Piauí, northeastern Brazil. Strongylida eggs were present in 12 (11.7%) humans and 23 (85.2%) pigs through conventional parasitological examination. Strongylida-positive fecal samples were submitted to coprocultures using the Harada–Mori technique. All 22 larvae obtained from human feces were classified as hookworms (Ancylostomatidae). From a total of 37 larvae obtained from swine, 23 (62.3%) were classified as Oesophagostomum, 6 (16.2%) were Hyostrongylus, and 4 (10.8%) were Trichostrongylus. Four larvae (10.8%) obtained from pigs were classified as Strongyloides. The morphological study of filariform larvae obtained in coprocultures is a useful and inexpensive tool in the screening of intestinal helminthiasis in a One Health approach.
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Higher helminth ova counts and incomplete decomposition in sand-enveloped latrine pits in a coastal sub-district of Bangladesh. PLoS Negl Trop Dis 2022; 16:e0010495. [PMID: 35737672 PMCID: PMC9223371 DOI: 10.1371/journal.pntd.0010495] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Accepted: 05/13/2022] [Indexed: 11/19/2022] Open
Abstract
Pit latrines are the most common latrine technology in rural Bangladesh, and untreated effluent from pits can directly contaminate surrounding aquifers. Sand barriers installed around the latrine pit can help reduce contamination but can also alter the decomposition of the fecal sludge and accelerate pit fill-up, which can counteract their benefits. We aimed to evaluate whether there was a difference in decomposition of fecal sludge and survival of soil-transmitted helminth (STH) ova among latrines where a 50-cm sand barrier was installed surrounding and at the bottom of the pit, compared to latrines without a sand barrier, in coastal Bangladesh. We assessed decomposition in latrine pits by measuring the carbon-nitrogen (C/N) ratio of fecal sludge. We enumerated Ascaris lumbricoides and Trichuris trichiura ova in the pit following 18 and 24 months of latrine use. We compared these outcomes between latrines with and without sand barriers using generalized linear models with robust standard errors to adjust for clustering at the village level. The C/N ratio in latrines with and without a sand barrier was 13.47 vs. 22.64 (mean difference: 9.16, 95% CI: 0.15, 18.18). Pits with sand barriers filled more quickly and were reportedly emptied three times more frequently than pits without; 27/34 latrines with sand barriers vs. 9/34 latrines without barriers were emptied in the previous six months. Most reported disposal methods were unsafe. Compared to latrines without sand barriers, latrines with sand barriers had significantly higher log10 mean counts of non-larvated A. lumbricoides ova (log10 mean difference: 0.35, 95% CI: 0.12, 0.58) and T. trichiura ova (log10 mean difference: 0.47, 95% CI: 0.20, 0.73). Larvated ova counts were similar for the two types of latrines for both A. lumbricoides and T. trichiura. Our findings suggest that sand barriers help contain helminth ova within the pits but pits with barriers fill up more quickly, leading to more frequent emptying of insufficiently decomposed fecal sludge. Further research is required on latrine technologies that can both isolate pathogens from the environment and achieve rapid decomposition. Conventional pit latrines do not fully isolate fecal pathogens and in many settings, pits are emptied manually, and pit contents released into water bodies and fields. Sand barriers installed around the latrine pit can help reduce contamination but can also alter the decomposition of the fecal sludge. We evaluated whether a sand barrier effectively contains STH ova within the pit and whether it alters the decomposition processes of pit contents and/or accelerates pit fill-up. C/N ratio was significantly higher in latrines without a sand barrier and approached the preferable range for optimal decomposition. Pit latrines with sand barriers filled up more rapidly and were emptied more often. No households in either arm used any protective measure when emptying the pits. Larvated STH ova counts were similar in the latrines with vs. without sand barriers while non-larvated ova counts were higher in pits with a sand barrier. The lower C/N ratio and quicker filling up of latrines with sand barriers indicate that pit contents are more likely to be infective at the time of pit emptying, necessitating safe emptying and disposal methods. Latrines with and without sand barrier had similar loading into the pit by infected individuals. Enveloping latrine pits with a sand layer helped contain helminth ova within the pits, allowing time for them to become non-viable and potentially reducing the spread of viable ova into the surrounding environment.
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Brown J. Invited Perspective: Sanitation Innovation Holds Promise but Must Consider Risks to Users. ENVIRONMENTAL HEALTH PERSPECTIVES 2022; 130:11301. [PMID: 34985306 PMCID: PMC8729224 DOI: 10.1289/ehp10609] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 12/01/2021] [Accepted: 12/02/2021] [Indexed: 05/10/2023]
Affiliation(s)
- Joe Brown
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
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Spatial distribution and risk factors for human cysticercosis in Colombia. Parasit Vectors 2021; 14:590. [PMID: 34838117 PMCID: PMC8626945 DOI: 10.1186/s13071-021-05092-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 11/08/2021] [Indexed: 11/30/2022] Open
Abstract
Background Cysticercosis is a zoonotic neglected tropical disease (NTD) that affects humans and pigs following the ingestion of Taenia solium eggs. Human cysticercosis poses a substantial public health burden in endemic countries. The World Health Organization (WHO) aims to target high-endemicity settings with enhanced interventions in 17 countries by 2030. Between 2008 and 2010, Colombia undertook a national baseline serosurvey of unprecedented scale, which led to an estimated seroprevalence of T. solium cysticercus antibodies among the general population of 8.6%. Here, we use contemporary geostatistical approaches to analyse this unique dataset with the aim of understanding the spatial distribution and risk factors associated with human cysticercosis in Colombia to inform how best to target intervention strategies. Methods We used a geostatistical model to estimate individual and household risk factors associated with seropositivity to T. solium cysticercus antibodies from 29,253 people from 133 municipalities in Colombia. We used both independent and spatially structured random effects at neighbourhood/village and municipality levels to account for potential clustering of exposure to T. solium. We present estimates of the distribution and residual correlation of seropositivity at the municipality level. Results High seroprevalence was identified in municipalities located in the north and south of Colombia, with spatial correlation in seropositivity estimated up to approximately 140 km. Statistically significant risk factors associated with seropositivity to T. solium cysticercus were related to age, sex, educational level, socioeconomic status, use of rainwater, consumption of partially cooked/raw pork meat and possession of dogs. Conclusions In Colombia, the distribution of human cysticercosis is influenced by socioeconomic considerations, education and environmental factors related to the spread of T. solium eggs. This information can be used to tailor national intervention strategies, such as targeting spatial hotspots and more highly exposed groups, including displaced people and women. Large-scale seroprevalence surveys accompanied by geospatial mapping are an essential step towards reaching the WHO’s 2021‒2030 NTD roadmap targets. Graphical Abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s13071-021-05092-8.
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Boyko RH, Marie Harrison L, Humphries D, Galvani AP, Townsend JP, Otchere J, Wilson MD, Cappello M. Dogs and pigs are transport hosts of Necator americanus: Molecular evidence for a zoonotic mechanism of human hookworm transmission in Ghana. Zoonoses Public Health 2020; 67:474-483. [PMID: 32529782 DOI: 10.1111/zph.12708] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 02/20/2020] [Accepted: 03/22/2020] [Indexed: 01/27/2023]
Abstract
Hookworm infection (Necator americanus and Ancylostoma spp) causes significant morbidity in resource-limited countries. Dog and pig ownership is associated with human infection, although the mechanism through which animals increase risk remains unknown. We first confirmed this association in Kintampo North, Ghana, using a retrospective analysis and serology, followed by a prospective molecular study of animal faeces. As a proxy of exposure to dog faeces, we analysed immunoreactivity of human serum to the zoonotic nematode Toxocara canis. Anti-Toxocara antibodies were present in 62% of samples (n = 89), and reactivity was associated with dog ownership. A subsequent prospective study revealed that 43% of dog and 56% of pig faecal samples contained hookworm eggs by microscopy. PCR analysis confirmed the presence of N. americanus DNA in 47% of samples from dogs and 56% pig samples. Nematode larvae were successfully cultured from samples collected from 36 dogs and seven pigs. These results demonstrate that dogs and pigs have a likely role in the transmission of N. americanus in endemic communities.
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Affiliation(s)
| | | | | | | | | | - Joseph Otchere
- Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
| | - Michael D Wilson
- Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
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Senecal J, Nordin A, Vinnerås B. Fate of Ascaris at various pH, temperature and moisture levels. JOURNAL OF WATER AND HEALTH 2020; 18:375-382. [PMID: 32589622 DOI: 10.2166/wh.2020.264] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Soil-transmitted helminths (STH) are intestinal worms that infect 24% of the world's population. Stopping the spread of STH is difficult, as the eggs are resilient (can withstand high pH) and persistent (can remain viable in soils for several years). To ensure that new sanitation systems can inactivate STH, a better understanding of their resilience is required. This study assessed the inactivation of Ascaris eggs under various conditions, in terms of moisture content (MC) (<20 to >90%), temperature (20-50 °C) and pH (7-12.5). The results highlight that the exposure of Ascaris eggs to elevated pH (10.5-12.5) at temperatures ≤27.5 °C for >70 days had no effect on egg viability. Compounding effects of alkaline pH (≥10.5) or decreasing MC (<20%) was observed at 35 °C, with pH having more of an effect than decreasing MC. To accelerate the inactivation of STH, an increase in the treatment temperature is more effective than pH increase. Alkaline pH alone did not inactivate the eggs but can enhance the effect of ammonia, which is likely to be present in organic wastes.
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Affiliation(s)
- Jenna Senecal
- Department of Energy and Technology, Swedish University of Agricultural Sciences, P.O. Box 7032, 750 07 Uppsala, Sweden E-mail:
| | - Annika Nordin
- Department of Energy and Technology, Swedish University of Agricultural Sciences, P.O. Box 7032, 750 07 Uppsala, Sweden E-mail:
| | - Björn Vinnerås
- Department of Energy and Technology, Swedish University of Agricultural Sciences, P.O. Box 7032, 750 07 Uppsala, Sweden E-mail:
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Sevilimedu V, Pressley KD, Snook KR, Hogges JV, Politis MD, Sexton JK, Duke CH, Smith BA, Swander LC, Baker KK, Gambhir M, Fung ICH. Gender-based differences in water, sanitation and hygiene-related diarrheal disease and helminthic infections: a systematic review and meta-analysis. Trans R Soc Trop Med Hyg 2020; 110:637-648. [PMID: 28115686 DOI: 10.1093/trstmh/trw080] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2016] [Revised: 12/14/2016] [Accepted: 12/30/2016] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Qualitative evidence suggests that inadequate water, sanitation and hygiene (WASH) may affect diarrheal and helminthic infection in women disproportionately. We systematically searched PubMed in June 2014 (updated 2016) and the WHO website, for relevant articles. METHODS Articles dealing with the public health relevance of helminthic and diarrheal diseases, and highlighting the role of gender in WASH were included. Where possible, we carried out a meta-analysis. RESULTS In studies of individuals 5 years or older, cholera showed lower prevalence in males (OR 0.56; 95% CI 0.34-0.94), while Schistosoma mansoni (1.38; 95% CI 1.14-1.67), Schistosoma japonicum (1.52; 95% CI 1.13-2.05), hookworm (1.43; 95% CI 1.07-1.89) and all forms of infectious diarrhea (1.21; 95% CI 1.06-1.38) showed a higher prevalence in males. When studies included all participants, S. mansoni and S. japonicum showed higher prevalence with males (OR 1.40; 95% CI 1.27-1.55 and 1.84; 95% CI 1.27-2.67, respectively). Prevalence of Trichiuris and hookworm infection showed effect modification with continent. CONCLUSIONS Evidence of gender differences in infection may reflect differences in gender norms, suggesting that policy changes at the regional level may help ameliorate gender related disparities in helminthic and diarrheal disease prevalence.
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Affiliation(s)
- Varadan Sevilimedu
- Department of Biostatistics, Jiann-Ping Hsu College of Public Health, Georgia Southern University, GA, USA
| | - Keisha D Pressley
- Department of Epidemiology and Environmental Health Sciences, Jiann-Ping Hsu College of Public Health, Georgia Southern University, GA, USA
| | - Kassandra R Snook
- Department of Epidemiology and Environmental Health Sciences, Jiann-Ping Hsu College of Public Health, Georgia Southern University, GA, USA
| | - Jamesa V Hogges
- Department of Epidemiology and Environmental Health Sciences, Jiann-Ping Hsu College of Public Health, Georgia Southern University, GA, USA
| | - Maria D Politis
- Department of Epidemiology and Environmental Health Sciences, Jiann-Ping Hsu College of Public Health, Georgia Southern University, GA, USA.,Department of Epidemiology, College of Public Health, University of Kentucky, KY, USA
| | - Jessica K Sexton
- Department of Epidemiology and Environmental Health Sciences, Jiann-Ping Hsu College of Public Health, Georgia Southern University, GA, USA
| | - Carmen H Duke
- Department of Epidemiology and Environmental Health Sciences, Jiann-Ping Hsu College of Public Health, Georgia Southern University, GA, USA
| | - Blake A Smith
- Department of Community and Behavioral Health, College of Public Health, University of Iowa, IA, USA
| | - Lena C Swander
- Department of Epidemiology, College of Public Health, University of Iowa, IA, USA
| | - Kelly K Baker
- Department of Occupational and Environmental Health, College of Public Health, University of Iowa, IA, USA
| | - Manoj Gambhir
- Department of Epidemiology and Preventive Medicine, Faculty of Medicine, Nursing and Health Sciences, Monash University, Vic, Australia
| | - Isaac Chun-Hai Fung
- Department of Epidemiology and Environmental Health Sciences, Jiann-Ping Hsu College of Public Health, Georgia Southern University, GA, USA
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Oishi CY, Klisiowicz DDR, Seguí R, Köster PC, Carmena D, Toledo R, Esteban JG, Muñoz-Antoli C. Reduced prevalence of soil-transmitted helminths and high frequency of protozoan infections in the surrounding urban area of Curitiba, Paraná, Brazil. Parasite Epidemiol Control 2019; 7:e00115. [PMID: 31660444 PMCID: PMC6807289 DOI: 10.1016/j.parepi.2019.e00115] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 05/14/2019] [Accepted: 06/17/2019] [Indexed: 12/20/2022] Open
Abstract
Human populations living in the surrounding urban areas of large Brazilian cities have increased vulnerability to intestinal parasites. However, the epidemiological scenario of soil-transmitted helminths (STH) in Curitiba, Paraná's main city, remains largely unknown. To bridge this gap of knowledge, this study aims to determine the prevalence of intestinal parasites and to investigate potential transmission pathways of the most prevalent species detected. We conducted a cross-sectional epidemiological study between July and September 2014 among schoolchildren in urban and peri-urban (deprived) areas of the municipality of Campo do Tenente, Curitiba. A total of 549 stool samples were used for coproparasitological diagnosis. Microscopy-positive samples of the most common species found were re-assessed by PCR and sequencing methods at the small subunit rRNA gene. Prevalence of infection by any given enteroparasite was 24.8%, but soil-transmitted helminths were only detected in 3.5% of the examined samples. Frequency of protozoan infections reached 90% and 97.8% in single and multiple infections, respectively. Blastocystis sp. (38.9%) was the most frequently species found in the surveyed schoolchildren population. A total of 41 Blastocystis-positive samples were unambiguously typed as ST1 (36.4%), ST2 (21.2%), ST3 (39.4%), and ST1 + ST3 mixed infection (3.0%). These results indicate that Blastocystis transmission is primarily anthroponotic in origin. This data highlights the importance of maintaining the anthelminthic control programs currently in place and of improving sanitary disposal of human excreta in poor-resource settings.
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Affiliation(s)
- Camila Yumi Oishi
- Post-Graduate Program in Microbiology and Pathology, Department of Basic Pathology, Biological Sciences Area, Paraná Federal University, Curitiba, Brazil
| | - Débora do Rocio Klisiowicz
- Post-Graduate Program in Microbiology and Pathology, Department of Basic Pathology, Biological Sciences Area, Paraná Federal University, Curitiba, Brazil
| | - Raimundo Seguí
- Departamento Farmacia y Tecnología Farmacéutica y Parasitología, Área Parasitología, Facultat Farmàcia, Universitat València, Spain
| | - Pamela C Köster
- Parasitology Reference and Research Laboratory, National Centre for Microbiology, Majadahonda, Madrid, Spain
| | - David Carmena
- Parasitology Reference and Research Laboratory, National Centre for Microbiology, Majadahonda, Madrid, Spain
| | - Rafael Toledo
- Departamento Farmacia y Tecnología Farmacéutica y Parasitología, Área Parasitología, Facultat Farmàcia, Universitat València, Spain
| | - José Guillermo Esteban
- Departamento Farmacia y Tecnología Farmacéutica y Parasitología, Área Parasitología, Facultat Farmàcia, Universitat València, Spain
| | - Carla Muñoz-Antoli
- Departamento Farmacia y Tecnología Farmacéutica y Parasitología, Área Parasitología, Facultat Farmàcia, Universitat València, Spain
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Gizaw Z, Addisu A, Dagne H. Effects of water, sanitation and hygiene (WASH) education on childhood intestinal parasitic infections in rural Dembiya, northwest Ethiopia: an uncontrolled before-and-after intervention study. Environ Health Prev Med 2019; 24:16. [PMID: 30851729 PMCID: PMC6408793 DOI: 10.1186/s12199-019-0774-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Accepted: 02/27/2019] [Indexed: 01/26/2023] Open
Abstract
BACKGROUND Soil-transmitted helminthes (STH) infections are among the most common infections worldwide and affect the most deprived communities. Adequate water, sanitation, and hygiene (WASH) prevents environmental contamination, thereby preventing transmission of STH. Cognizant of this, WASH education was implemented in rural Dembiya to reduce intestinal parasitic infections. This study was, therefore, conducted to assess the impacts of the intervention on households' WASH conditions and prevalence of intestinal parasitic infections. METHOD An uncontrolled before-and-after intervention study was used. Cross-sectional studies were done before and after the intervention. Two hundred twenty-five and 302 under five children were recruited randomly at the baseline and endline, respectively. Data were collected using a structured questionnaire and observational checklists. Direct stool examination and Kato-Katz methods were used to identify parasites in the stool. We used percent point change and prevalence ratio (PR) to see the effects of the intervention on WASH conditions and prevalence of intestinal parasitic infections respectively. Pearson chi-squared and Fisher's exact tests were used to test for statistically significant percentage point changes of WASH conditions. The effect of the intervention on intestinal parasitic infections was statistically tested on the basis of PR with 95% confidence interval (CI). RESULTS The baseline prevalence of intestinal parasitic infections was 25.8%, and the endline prevalence was 23.8%. The prevalence of intestinal parasitic infections was not significantly decreased at the endline compared with the baseline [PR = 0.92, 95% CI = (0.62, 1.38)]. Ascaris Lumbricoides was the most prevalent parasitic infection both at the baseline and endline. The proportion of children who had good hygienic condition increased from 1.3% at the baseline to 34.4% at the end line (p < 0.05). The percentage of mothers/care givers who washed hands at different pick times was significantly increased from 24.4% at the baseline to 68.2% at the endline (p < 0.001). The proportion of households who practiced home-based water treatment was significantly increased from 7.6% at the baseline to 47% at the endline (p < 0.001). The proportion of households who used sanitary latrine was increased from 32% at the baseline to 49% at the endline (p < 0.05). CONCLUSION This before-and-after intervention study found that households' WASH performance was significantly improved at the endline compared with the baseline. The endline prevalence of intestinal parasitic infections was slightly lower than the baseline prevalence; however, the reduction was not statistically significant. The local health office needs to strengthen the WASH education program, mobilize the community to construct WASH facilities, and support the community to sustain households' WASH performance.
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Affiliation(s)
- Zemichael Gizaw
- Department of Environmental and Occupational Health and Safety, Institute of Public Health, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia.
| | - Ayenew Addisu
- Department of Parasitology, School of Biomedical Science, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia
| | - Henok Dagne
- Department of Environmental and Occupational Health and Safety, Institute of Public Health, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia
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Baker JM, Trinies V, Bronzan RN, Dorkenoo AM, Garn JV, Sognikin S, Freeman MC. The associations between water and sanitation and hookworm infection using cross-sectional data from Togo's national deworming program. PLoS Negl Trop Dis 2018; 12:e0006374. [PMID: 29590120 PMCID: PMC5902041 DOI: 10.1371/journal.pntd.0006374] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Revised: 04/16/2018] [Accepted: 03/07/2018] [Indexed: 02/04/2023] Open
Abstract
Background Sustainable control of soil-transmitted helminths requires a combination of chemotherapy treatment and environmental interventions, including access to safe drinking water, sufficient water for hygiene, use of clean sanitation facilities, and handwashing (WASH). We quantified associations between home-, school-, and community-level WASH characteristics and hookworm infection—both prevalence and eggs per gram of stool (intensity)—among Togolese school children in the context of community-based chemotherapy treatments administered in the country from 2010 through 2014. Methodology/Principal findings We analyzed data from two surveys conducted by the Togo Ministry of Health: a school-based survey of students aged 6–9 years across Togo conducted in 2009 and a follow-up survey in 2015, after four to five years of preventive chemotherapy. Data were available for 16,473 students attending 1,129 schools in 2009 and for 16,890 students from 1,126 schools in 2015. Between surveys, children in study schools received 0 to 8 rounds of deworming chemotherapy treatments. Few WASH conditions (only unimproved drinking water) were found to be significantly associated with the presence or absence of hookworms in an individual; however, quantitative eggs per gram of feces was associated with availability of unimproved drinking water, availability of improved drinking water either on or off school grounds, having a handwashing station with water available, and access to a sex-separate non-private or private latrine. The association between school WASH conditions and hookworm infection or burden often depended on the 2009 prevalence of infection, as more WASH characteristics were found to be significant predictors of infection among schools with high underlying endemicity of hookworm. Conclusions/Significance Our findings emphasize the complex and often inconsistent or unpredictable relationship between WASH and hookworm. Specifically, we found that while preventive chemotherapy appeared to dramatically reduce hookworm infection, WASH was associated with infection intensity. Preventive chemotherapy plays a critical role in breaking transmission of soil-transmitted helminths but it is likely that sustainable control of soil-transmitted helminths will require environmental improvements such as access to water for hygiene and hygienic sanitation, access to and use of a clean toilet facility, and handwashing with soap at key times (WASH). Here, we report on school-, home- and community-level WASH and the relationship of these characteristics with the prevalence and intensity of hookworm infection, one of the most prevalent soil-transmitted helminths, observed in the context of preventive chemotherapy among Togolese school children. In this large, country-wide assessment, few WASH conditions were found to be significant predictors of the presence or absence of hookworms in an individual, however, intensity of infection was associated with several WASH characteristics. Our analysis emphasizes the complex and often unpredictable role of WASH characteristics on hookworm, particularly relevant for Togolese and other international policy makers aiming to understand the interaction between WASH, preventive chemotherapy and hookworm. Further research taking into account not only WASH conditions but also use of WASH resources and practices would further strengthen our understanding of the interaction between WASH and deworming treatment as effective hookworm control strategies.
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Affiliation(s)
- Julia M. Baker
- Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, Georgia, United States of America
| | - Victoria Trinies
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta Georgia, United States of America
| | - Rachel N. Bronzan
- Health and Development International, Newburyport, Massachussetts, United States of America
| | | | - Joshua V. Garn
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta Georgia, United States of America
| | - Sêvi Sognikin
- Ministère de la Santé et de la Protection Sociale, Lomé, Togo
| | - Matthew C. Freeman
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta Georgia, United States of America
- * E-mail:
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Muñoz-Antoli C, Gozalbo M, Pavón A, Pérez P, Toledo R, Esteban JG. Enteroparasites in Preschool Children on the Pacific Region of Nicaragua. Am J Trop Med Hyg 2017; 98:570-575. [PMID: 29260648 DOI: 10.4269/ajtmh.17-0551] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The aim of this study was to determine for the first time the prevalence of enteroparasites in preschool children originating from the seven departments of the Pacific region in Nicaragua. One stool sample of each of 1,217 children, from 6 months to 5 years of age, was collected and personal data were recorded on delivery of the container. Samples fixed in 10% formalin were processed by a formol-acetate concentration and a modified Ziehl-Neelsen technique. The overall prevalence of enteroparasite infections was 68.2% with a total of at least 20 species. Blastocystis hominis (45.5%), Giardia intestinalis (31.7%), Trichuris trichiura (8.2%), and Ascaris lumbricoides (5.2%) were the most prevalent protozoa and helminth species in the total study as well as in all departments. Protozoan prevalence presented a statistically significant difference by gender (male: 69.6%; female: 46.7%; P < 0.001), and males presented a higher T. trichiura infection rate than females (male: 9.9%; female 6.4%; P < 0.035). Protozoan prevalence increased with age with a statistically significant difference (P < 0.001). Helminths were always more prevalent in urban areas (P < 0.0002). Protozoan infections result statistically higher than helminth infections so that water-based transmission could be suspected. Based on the differences with respect to species and parasite prevalence between the seven departments in the Pacific region of Nicaragua, the exploration of local factors associated with the transmission of enteroparasites should also be considered to reduce infection.
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Affiliation(s)
- Carla Muñoz-Antoli
- Departamento de Parasitología, Facultad de Farmacia, Universidad de Valencia, Burjassot, Valencia, Spain
| | - Mónica Gozalbo
- Departamento de Parasitología, Facultad de Farmacia, Universidad de Valencia, Burjassot, Valencia, Spain
| | - Aleyda Pavón
- Departamento Bionálisis Clínico, Instituto Politécnico de la Salud (IPS-Polisal), Universidad Nacional Autónoma de Nicaragua, Managua, Nicaragua
| | - Paloma Pérez
- Departamento de Parasitología, Facultad de Farmacia, Universidad de Valencia, Burjassot, Valencia, Spain
| | - Rafael Toledo
- Departamento de Parasitología, Facultad de Farmacia, Universidad de Valencia, Burjassot, Valencia, Spain
| | - Jose-Guillermo Esteban
- Departamento de Parasitología, Facultad de Farmacia, Universidad de Valencia, Burjassot, Valencia, Spain
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Estimating the Health Risk Associated with the Use of Ecological Sanitation Toilets in Malawi. JOURNAL OF ENVIRONMENTAL AND PUBLIC HEALTH 2017; 2017:3931802. [PMID: 29250122 PMCID: PMC5698831 DOI: 10.1155/2017/3931802] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Revised: 08/28/2017] [Accepted: 10/01/2017] [Indexed: 11/17/2022]
Abstract
Use of Ecological Sanitation (EcoSan) sludge is becoming popular due to increasing price of organic fertilizers in Malawi; however, there is little evidence on the associated risks. Quantitative microbiological risk assessment (QMRA) was done to determine health risks associated with use of EcoSan. Pathogens considered included Escherichia coli (E. coli), Salmonella, and soil transmitted helminths (STHs). Exponential and Beta Poisson models were used to estimate the risk from helminthic and bacterial pathogens, respectively. Main exposure pathways were through poor storage of sludge, contamination of foods during drying, walking barefoot on the ground contaminated with sludge, pit emptying without protection, and application of sludge in the fields. Estimated annual risk for Ascaris lumbricoides, Taenia, and hookworms was approximately over 5.6 × 10−1 for both Fossa Alternas (FAs) and Urine Diverting Dry Toilet (UDDTs). Risk from E. coli and Salmonella was 8.9 × 10−2 and above. The risks were higher than WHO acceptable risk for use of faecal sludge in crops of 10−4 infections per year. Promoters and users of EcoSan latrines need to consider advocating for strict guidelines to reduce the risk.
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Babamale OA, Ugbomoiko US, Heukelbach J. High prevalence of Plasmodium falciparum and soil-transmitted helminth co-infections in a periurban community in Kwara State, Nigeria. J Infect Public Health 2017; 11:48-53. [PMID: 28442321 DOI: 10.1016/j.jiph.2017.03.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2016] [Revised: 02/10/2017] [Accepted: 03/25/2017] [Indexed: 10/19/2022] Open
Abstract
Prevalence of malaria and soil-transmitted helminth infections, and the burden of disease are enormous in sub-Saharan Africa. Co-infections aggravate the clinical outcome, but are common due to an overlap of endemic areas. A cross-sectional survey was conducted to assess prevalence, intensity of infection and association between malaria and soil-transmitted helminth infections in a typical periurban community in Kwara State. Fresh blood and faecal samples were examined using thick blood film and Kato-Katz smear techniques. A total of 383/471 study participants (81.3%) were infected with at least one parasite species, with the following prevalences and mean infection intensities: Plasmodium falciparum 63.7% (2313.6 parasites/μl); Ascaris lumbricoides 63.1% (3152.1 epg); Trichuris trichiura 53.3% (1043.5 epg); and hookworms 30.1% (981.7 epg). Sixty-three percent of the study population were co-infected with two or more parasite species. The prevalence of ascariasis was significantly higher in individuals infected with P. falciparum (adjusted OR: 5.87; 95% CI: 3.30-10.42). Heavy A. lumbricoides and T. trichiura infections were associated with high P. falciparum parasitaemia. Co-endemicity of malaria and soil transmitted helminth infections is an important public health problem in the study area. Multi-target integrated approaches focusing on disease intervention are essential to mitigate morbidity caused by multiple infections.
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Affiliation(s)
| | - Uade S Ugbomoiko
- Parasitology Unit, Department of Zoology, University of Ilorin, Ilorin, Nigeria.
| | - Jorg Heukelbach
- College of Public Health, Medical and Veterinary Sciences, Division of Tropical Health and Medicine, James Cook University, Townsville, Queensland, Australia; Department of Community Health, School of Medicine, Federal University of Ceará, Brazil
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Muñoz-Antoli C, Pavón A, Pérez P, Toledo R, Esteban JG. Soil-transmitted Helminth Infections in Schoolchildren of Laguna de Perlas (Nicaragua). J Trop Pediatr 2017; 63:124-134. [PMID: 27616686 DOI: 10.1093/tropej/fmw061] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Soil-transmitted helminth (STH) prevalence, intensity, polyparasitism and co-infections in 425 children from 3 schools of Laguna de Perlas (Nicaragua) were investigated. Single stool samples were analysed by the formalin-ether method and the Kato-Katz. A total of 402 (94.6%) children were infected. Trichuris trichiura 308 (72.4%), Ascaris lumbricoides 115 (27.1%) and Hookworms 54 (12.7%) were the most prevalent STHs. Polyparasitism (322; 75.8%) with two species was most prevalent (109; 25.6%). T. trichiura with A. lumbricoides (19.3%) and T. trichiura with Hookworm (6.8%) were the most common combinations. Positive associations were observed between T. trichiura and A. lumbricoides and T. trichiura and Hookworm (p = 0.0001). Highest Hookworm intensities appeared when three STH co-infections occurred. Moderate- heavy STH intensities appear in up to 42.1% in trichuriasis, 57.5% in ascariasis and 11.1% in Hookworm infections. Integrated control interventions covering children need to be implemented mainly in a rural environment.
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Affiliation(s)
- C Muñoz-Antoli
- Facultad de Farmacia, Departamento de Parasitología, Universidad de Valencia, Av. Vicent Andrés Estellés s/n, Burjassot-Valencia 46100, Spain
| | - A Pavón
- Departamento Bionálisis Clínico, Instituto Politécnico de la Salud (IPS-Polisal), Universidad Nacional Autónoma de Nicaragua, Managua, Nicaragua
| | - P Pérez
- Facultad de Farmacia, Departamento de Parasitología, Universidad de Valencia, Av. Vicent Andrés Estellés s/n, Burjassot-Valencia 46100, Spain
| | - R Toledo
- Facultad de Farmacia, Departamento de Parasitología, Universidad de Valencia, Av. Vicent Andrés Estellés s/n, Burjassot-Valencia 46100, Spain
| | - J G Esteban
- Facultad de Farmacia, Departamento de Parasitología, Universidad de Valencia, Av. Vicent Andrés Estellés s/n, Burjassot-Valencia 46100, Spain
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Pehrsson EC, Tsukayama P, Patel S, Mejía-Bautista M, Sosa-Soto G, Navarrete KM, Calderon M, Cabrera L, Hoyos-Arango W, Bertoli MT, Berg DE, Gilman RH, Dantas G. Interconnected microbiomes and resistomes in low-income human habitats. Nature 2016; 533:212-6. [PMID: 27172044 PMCID: PMC4869995 DOI: 10.1038/nature17672] [Citation(s) in RCA: 352] [Impact Index Per Article: 44.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Accepted: 03/16/2016] [Indexed: 01/27/2023]
Abstract
Antibiotic-resistant infections annually claim hundreds of thousands of lives worldwide. This problem is exacerbated by resistance gene exchange between pathogens and benign microbes from diverse habitats. Mapping resistance gene dissemination between humans and their environment is a public health priority. We characterized the bacterial community structure and resistance exchange networks of hundreds of interconnected human fecal and environmental samples from two low-income Latin American communities. We found that resistomes across habitats are generally structured by bacterial phylogeny along ecological gradients, but identified key resistance genes that cross habitat boundaries and determined their association with mobile genetic elements. We also assessed the effectiveness of widely-used excreta management strategies in reducing fecal bacteria and resistance genes in these settings representative of low- and middle-income countries. Our results lay the foundation for quantitative risk assessment and surveillance of resistance dissemination across interconnected habitats in settings representing over two-thirds of the world’s population.
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Affiliation(s)
- Erica C Pehrsson
- Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St Louis, Missouri 63110, USA
| | - Pablo Tsukayama
- Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St Louis, Missouri 63110, USA
| | - Sanket Patel
- Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St Louis, Missouri 63110, USA.,Department of Pathology and Immunology, Washington University School of Medicine, St Louis, Missouri 63110, USA
| | - Melissa Mejía-Bautista
- Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St Louis, Missouri 63110, USA.,Facultad de Ciencias de la Salud "Dr. Luis Edmundo Vásquez", Universidad Dr. José Matías Delgado, El Salvador
| | - Giordano Sosa-Soto
- Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St Louis, Missouri 63110, USA.,Facultad de Ciencias de la Salud "Dr. Luis Edmundo Vásquez", Universidad Dr. José Matías Delgado, El Salvador
| | - Karla M Navarrete
- Facultad de Ciencias de la Salud "Dr. Luis Edmundo Vásquez", Universidad Dr. José Matías Delgado, El Salvador
| | - Maritza Calderon
- Laboratorios de Investigación y Desarrollo, Universidad Peruana Cayetano Heredia, San Martin de Porres, Lima 31, Peru
| | - Lilia Cabrera
- Asociacion Benéfica PRISMA, San Miguel, Lima 32, Peru
| | - William Hoyos-Arango
- Facultad de Ciencias de la Salud "Dr. Luis Edmundo Vásquez", Universidad Dr. José Matías Delgado, El Salvador
| | - M Teresita Bertoli
- Facultad de Ciencias de la Salud "Dr. Luis Edmundo Vásquez", Universidad Dr. José Matías Delgado, El Salvador
| | - Douglas E Berg
- Department of Molecular Microbiology, Washington University School of Medicine, St Louis, Missouri 63110, USA.,Department of Medicine, University of California San Diego, La Jolla, California 92093, USA
| | - Robert H Gilman
- Laboratorios de Investigación y Desarrollo, Universidad Peruana Cayetano Heredia, San Martin de Porres, Lima 31, Peru.,Asociacion Benéfica PRISMA, San Miguel, Lima 32, Peru.,Department of International Health, Johns Hopkins School of Public Health, Baltimore, Maryland 21205, USA
| | - Gautam Dantas
- Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St Louis, Missouri 63110, USA.,Department of Pathology and Immunology, Washington University School of Medicine, St Louis, Missouri 63110, USA.,Department of Molecular Microbiology, Washington University School of Medicine, St Louis, Missouri 63110, USA.,Department of Biomedical Engineering, Washington University, St Louis, Missouri 63105, USA
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Berendes D, Levy K, Knee J, Handzel T, Hill VR. Ascaris and Escherichia coli Inactivation in an Ecological Sanitation System in Port-au-Prince, Haiti. PLoS One 2015; 10:e0125336. [PMID: 25932948 PMCID: PMC4416818 DOI: 10.1371/journal.pone.0125336] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 03/13/2015] [Indexed: 11/19/2022] Open
Abstract
The goal of this study was to evaluate the microbial die-off in a latrine waste composting system in Port-au-Prince, Haiti. Temperature data and samples were collected from compost aged 0-12+ months. Samples collected from compost bin centers and corners at two depths were assessed for moisture content, E. coli concentration, and Ascaris spp. viability. Center temperatures in compost bins were all above 58 °C, while corner temperatures were 10 - 20 °C lower. Moisture content was 67 ± 10% in all except the oldest compost. A 4-log reduction in E. coli was observed over the first sixteen weeks of composting at both locations and depths, after which E. coli was undetectable (LOD: 142 MPN g(-1) dry weight). In new compost, 10.4% and 8.3% of Ascaris eggs were viable and fully embryonated, respectively. Percent viability dropped to zero in samples older than six weeks. These findings indicate that the Haitian EcoSan composting process was effective in inactivating E. coli and Ascaris spp. in latrine waste within sixteen weeks. This study is one of the first to document efficacy of an ecological sanitation system under field conditions and provides insight into composting methods and monitoring for other international settings.
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Affiliation(s)
- David Berendes
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, United States of America
- Emergency Response and Recovery Branch, Division of Global Health Protection, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Karen Levy
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, United States of America
| | - Jackie Knee
- Environmental Microbiology Laboratory, Waterborne Disease Prevention Branch, Division of Food, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Thomas Handzel
- Emergency Response and Recovery Branch, Division of Global Health Protection, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Vincent R. Hill
- Environmental Microbiology Laboratory, Waterborne Disease Prevention Branch, Division of Food, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
- * E-mail:
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Gabrie JA, Rueda MM, Canales M, Gyorkos TW, Sanchez AL. School hygiene and deworming are key protective factors for reduced transmission of soil-transmitted helminths among schoolchildren in Honduras. Parasit Vectors 2014; 7:354. [PMID: 25091035 PMCID: PMC4132920 DOI: 10.1186/1756-3305-7-354] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2014] [Accepted: 07/29/2014] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND Among many neglected tropical diseases endemic in Honduras, soil-transmitted helminth (STH) infections are of particular importance. However, knowledge gaps remain in terms of risk factors involved in infection transmission. The aim of this study was to investigate risk factors associated with STH infections in schoolchildren living in rural Honduras. METHODS A cross-sectional study was conducted among Honduran rural schoolchildren in 2011. Demographic, socio-economic, and epidemiological data were obtained through a standardized questionnaire and STH infections were determined by the Kato-Katz method. Logistic regression models accounting for school clustering were used to assess putative risk factors for infection. RESULTS A total of 320 children completed the study. Prevalences for any STH and for Ascaris lumbricoides, Trichuris trichiura and hookworms were: 72.5%, 30.3%, 66.9% and 15.9%, respectively. A number of risk factors were identified at the individual, household, and school level. Boys were at increased odds of infection with hookworms (OR 2.33, 95% CI = 1.23-4.42). Higher socio-economic status in the family had a protective effect against infections by A. lumbricoides (OR 0.80, 95% CI = 0.65-0.99) and T. trichiura (OR 0.77, 95% CI = 0.63-0.94).Low school hygiene conditions significantly increased the odds for ascariasis (OR 14.85, 95% CI = 7.29-30.24), trichuriasis (OR 7.32, 95% CI = 3.71-14.45), mixed infections (OR 9.02, 95% CI = 4.66-17.46), and ascariasis intensity of infection (OR 3.32, 95% CI = 1.05 -10.52).Children attending schools not providing deworming treatment or that had provided it only once a year were at increased odds of ascariasis (OR 10.40, 95% CI = 4.39-24.65), hookworm (OR 2.92, 95% CI = 1.09-7.85) and mixed infections (OR 10.57, 95% CI = 4.53-24.66). CONCLUSIONS Poverty-reduction strategies will ultimately lead to sustainable control of STH infections in Honduras, but as shorter-term measures, uninterrupted bi-annual deworming treatment paired with improvements in school sanitary conditions may result in significant reductions of STH prevalence among Honduran schoolchildren.
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Affiliation(s)
| | | | | | | | - Ana Lourdes Sanchez
- Department of Health Sciences, Brock University, St, Catharines, Ontario, Canada.
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Strunz EC, Addiss DG, Stocks ME, Ogden S, Utzinger J, Freeman MC. Water, sanitation, hygiene, and soil-transmitted helminth infection: a systematic review and meta-analysis. PLoS Med 2014; 11:e1001620. [PMID: 24667810 PMCID: PMC3965411 DOI: 10.1371/journal.pmed.1001620] [Citation(s) in RCA: 427] [Impact Index Per Article: 42.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Accepted: 02/13/2014] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Preventive chemotherapy represents a powerful but short-term control strategy for soil-transmitted helminthiasis. Since humans are often re-infected rapidly, long-term solutions require improvements in water, sanitation, and hygiene (WASH). The purpose of this study was to quantitatively summarize the relationship between WASH access or practices and soil-transmitted helminth (STH) infection. METHODS AND FINDINGS We conducted a systematic review and meta-analysis to examine the associations of improved WASH on infection with STH (Ascaris lumbricoides, Trichuris trichiura, hookworm [Ancylostoma duodenale and Necator americanus], and Strongyloides stercoralis). PubMed, Embase, Web of Science, and LILACS were searched from inception to October 28, 2013 with no language restrictions. Studies were eligible for inclusion if they provided an estimate for the effect of WASH access or practices on STH infection. We assessed the quality of published studies with the Grades of Recommendation, Assessment, Development and Evaluation (GRADE) approach. A total of 94 studies met our eligibility criteria; five were randomized controlled trials, whilst most others were cross-sectional studies. We used random-effects meta-analyses and analyzed only adjusted estimates to help account for heterogeneity and potential confounding respectively. Use of treated water was associated with lower odds of STH infection (odds ratio [OR] 0.46, 95% CI 0.36-0.60). Piped water access was associated with lower odds of A. lumbricoides (OR 0.40, 95% CI 0.39-0.41) and T. trichiura infection (OR 0.57, 95% CI 0.45-0.72), but not any STH infection (OR 0.93, 95% CI 0.28-3.11). Access to sanitation was associated with decreased likelihood of infection with any STH (OR 0.66, 95% CI 0.57-0.76), T. trichiura (OR 0.61, 95% CI 0.50-0.74), and A. lumbricoides (OR 0.62, 95% CI 0.44-0.88), but not with hookworm infection (OR 0.80, 95% CI 0.61-1.06). Wearing shoes was associated with reduced odds of hookworm infection (OR 0.29, 95% CI 0.18-0.47) and infection with any STH (OR 0.30, 95% CI 0.11-0.83). Handwashing, both before eating (OR 0.38, 95% CI 0.26-0.55) and after defecating (OR 0.45, 95% CI 0.35-0.58), was associated with lower odds of A. lumbricoides infection. Soap use or availability was significantly associated with lower infection with any STH (OR 0.53, 95% CI 0.29-0.98), as was handwashing after defecation (OR 0.47, 95% CI 0.24-0.90). Observational evidence constituted the majority of included literature, which limits any attempt to make causal inferences. Due to underlying heterogeneity across observational studies, the meta-analysis results reflect an average of many potentially distinct effects, not an average of one specific exposure-outcome relationship. CONCLUSIONS WASH access and practices are generally associated with reduced odds of STH infection. Pooled estimates from all meta-analyses, except for two, indicated at least a 33% reduction in odds of infection associated with individual WASH practices or access. Although most WASH interventions for STH have focused on sanitation, access to water and hygiene also appear to significantly reduce odds of infection. Overall quality of evidence was low due to the preponderance of observational studies, though recent randomized controlled trials have further underscored the benefit of handwashing interventions. Limited use of the Joint Monitoring Program's standardized water and sanitation definitions in the literature restricted efforts to generalize across studies. While further research is warranted to determine the magnitude of benefit from WASH interventions for STH control, these results call for multi-sectoral, integrated intervention packages that are tailored to social-ecological contexts.
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Affiliation(s)
- Eric C. Strunz
- Children Without Worms, The Task Force for Global Health, Decatur, Georgia, United States of America
| | - David G. Addiss
- Children Without Worms, The Task Force for Global Health, Decatur, Georgia, United States of America
| | - Meredith E. Stocks
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, United States of America
| | - Stephanie Ogden
- Children Without Worms, The Task Force for Global Health, Decatur, Georgia, United States of America
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, United States of America
- International Trachoma Initiative, The Task Force for Global Health, Decatur, Georgia, United States of America
| | - Jürg Utzinger
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Matthew C. Freeman
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, United States of America
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Boubacar Maïnassara H, Tohon Z. Assessing the Health Impact of the following Measures in Schools in Maradi (Niger): Construction of Latrines, Clean Water Supply, Establishment of Hand Washing Stations, and Health Education. J Parasitol Res 2014; 2014:190451. [PMID: 24563779 PMCID: PMC3915855 DOI: 10.1155/2014/190451] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Revised: 10/03/2013] [Accepted: 10/14/2013] [Indexed: 11/17/2022] Open
Abstract
Objective. To assess the effect on health of the following measures in schools in Maradi (Niger): clean water supply, construction of latrines, establishment of hand washing stations, and health education. Methodology. It was a "before and after" intervention study on a sample of school children aged 7 to 12 years in the Maradi region. The interventions included building of latrines, supplying clean water, setting up hand washing stations, and teaching health education lessons. An individual questionnaire, analysis of stool samples, and a group questionnaire were administered to children and teachers, respectively. The threshold for significance was set at P < 0.05. Results. A statistically significant reduction in cases of diarrhoea and abdominal pains was noted after the project. Overall, carriage of at least one parasite increased from 7.5% before the project to 10.2% after it (P = 0.04). In the programme group schools, there was a statistically significant increase in the prevalence of Hymenolepis nana, from 0 to 1.9 (P = 0.02). Pinworm prevalence remained stable in this group but increased significantly in the control group. Conclusions. Putting health infrastructure in place in schools obviously had an impact on hygiene-related habits in the beneficiary schools and communities.
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Affiliation(s)
- Halima Boubacar Maïnassara
- Centre de Recherche Médicale et Sanitaire (CERMES), 634 Boulevard de la Nation YN034, P.O. Box 10887, Niamey, Niger
| | - Zilahatou Tohon
- College of Public Health, University of Kentucky, 111 Washington Avenue, Lexington, KY 40536-0003, USA
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Fidjeland J, Magri ME, Jönsson H, Albihn A, Vinnerås B. The potential for self-sanitisation of faecal sludge by intrinsic ammonia. WATER RESEARCH 2013; 47:6014-6023. [PMID: 23941983 DOI: 10.1016/j.watres.2013.07.024] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Revised: 06/28/2013] [Accepted: 07/16/2013] [Indexed: 06/02/2023]
Abstract
Faecal sludge has the potential to be used as a sustainable fertiliser in agriculture, but the sludge must be sanitised due to its content of pathogenic microorganisms. The intrinsic ammonia from the urine may be sufficient for sanitisation of the sludge if it is not too diluted by flush water or lost by ventilation. To evaluate the potential for this sanitisation method, inactivation of Enterococcus faecalis, Salmonella typhimurium and Ascaris suum eggs during treatment were assessed. The inactivation was studied at different storage temperatures (10-28 °C) and in several sludge mixes with different contents of urine, faeces and flush water, and with ammonia concentrations from 40 to 400 mM. All pathogens were inactivated by the ammonia, and ascaris eggs were the most persistent. Lower flush water volume and higher urine content favoured inactivation, mainly due to increased uncharged ammonia (NH3) concentration. The lag phase in ascaris inactivation was shortened by increasing temperature and NH3 concentration, while post-lag phase inactivation was not influenced by NH3 concentration. Faecal sludge can be sanitised by airtight storage without the use of additives when flush water volumes are sufficiently low. For temperatures of 23-28 °C, a 3 log reduction of ascaris egg viability can be achieved within 1-6 months depending on ammonia concentration and temperature.
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Affiliation(s)
- Jørgen Fidjeland
- Swedish University of Agricultural Sciences, Department of Energy & Technology, Box 7032, SE-750 07 Uppsala, Sweden; National Veterinary Institute, Department of Chemistry, Environment and Food Security, SE-751 89 Uppsala, Sweden.
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Clemens B, Douglas TJ. To What Degree Can Potable Water Foster International Economic Development and Sustainability? What Role Does Health Play? ORGANIZATION MANAGEMENT JOURNAL 2012. [DOI: 10.1080/15416518.2012.687988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Ziegelbauer K, Speich B, Mäusezahl D, Bos R, Keiser J, Utzinger J. Effect of sanitation on soil-transmitted helminth infection: systematic review and meta-analysis. PLoS Med 2012; 9:e1001162. [PMID: 22291577 PMCID: PMC3265535 DOI: 10.1371/journal.pmed.1001162] [Citation(s) in RCA: 325] [Impact Index Per Article: 27.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2010] [Accepted: 12/09/2011] [Indexed: 12/04/2022] Open
Abstract
BACKGROUND In countries of high endemicity of the soil-transmitted helminth parasites Ascaris lumbricoides, Trichuris trichiura, and hookworm, preventive chemotherapy (i.e., repeated administration of anthelmintic drugs to at-risk populations) is the main strategy to control morbidity. However, rapid reinfection of humans occurs after successful deworming, and therefore effective preventive measures are required to achieve public health goals with optimal efficiency and sustainability. METHODS AND FINDINGS We conducted a systematic review and meta-analysis to assess the effect of sanitation (i.e., access and use of facilities for the safe disposal of human urine and feces) on infection with soil-transmitted helminths. PubMed, Embase, ISI Web of Science, and the World Health Organization Library Database were searched without language restrictions and year of publication (search performed until December 31, 2010). Bibliographies of identified articles were hand-searched. All types of studies reporting data on sanitation availability (i.e., having access at own household or living in close proximity to sanitation facility), or usage, and soil-transmitted helminth infections at the individual level were considered. Reported odds ratios (ORs) of the protective effect of sanitation on soil-transmitted helminth infections were extracted from the papers or calculated from reported numbers. The quality of published studies was assessed with a panel of criteria developed by the authors. Random effects meta-analyses were used to account for observed heterogeneity. Thirty-six publications, consisting of 39 datasets, met our inclusion criteria. Availability of sanitation facilities was associated with significant protection against infection with soil-transmitted helminths (OR = 0.46 to 0.58). Regarding the use of sanitation, ORs of 0.54 (95% confidence interval [CI] 0.28-1.02), 0.63 (95% CI 0.37-1.05), and 0.78 (95% CI 0.60-1.00) were determined for T. trichiura, hookworm, and A. lumbricoides, respectively. The overall ORs, combining sanitation availability and use, were 0.51 (95% CI 0.44-0.61) for the three soil-transmitted helminths combined, 0.54 (95% CI 0.43-0.69) for A. lumbricoides, 0.58 (95% CI 0.45-0.75) for T. trichiura, and 0.60 (95% CI 0.48-0.75) for hookworm. CONCLUSIONS Despite a number of limitations (e.g., most studies used a cross-sectional design and were of low quality, with potential biases and considerable heterogeneity), our results reveal that sanitation is associated with a reduced risk of transmission of helminthiases to humans. Access to improved sanitation should be prioritized alongside preventive chemotherapy and health education to achieve a durable reduction of the burden of helminthiases.
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Affiliation(s)
- Kathrin Ziegelbauer
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Benjamin Speich
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Daniel Mäusezahl
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Robert Bos
- Department of Public Health and Environment, World Health Organization, Geneva, Switzerland
| | - Jennifer Keiser
- University of Basel, Basel, Switzerland
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel Switzerland
| | - Jürg Utzinger
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
- * E-mail:
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Enander RT, Ramirez Amaya A, Enander RA, Gute DM. Neurocysticercosis: risk and primary prevention strategies update. INTERNATIONAL JOURNAL OF ENVIRONMENTAL HEALTH RESEARCH 2010; 20:329-365. [PMID: 20853197 DOI: 10.1080/09603123.2010.482152] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Neurocysticercosis results from the infestation of the central nervous system with invading tapeworm larvae. Though uncommon in the US prior to 1965, new cases are currently being diagnosed at an unprecedented rate. Drawing on environmental health, intervention and risk data retrieved from standard/alternative databases and in-country sources, we present an update and summary of modifiable risk factors and field-tested primary prevention measures. While points of intervention, subpopulations at risk and overall magnitude of the problem are addressed, particular attention is paid to defining risk reduction measures that can be adopted by individuals and high risk groups in the near-term to interrupt or eliminate pathways of exposure leading to disease transmission. Though global eradication is not attainable in the near future, effective preventative measures exist and should be taken now by international travellers and workers, US/foreign government agencies, and individuals living in endemic regions to reduce human suffering.
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Affiliation(s)
- Richard T Enander
- Rhode Island Department of Environmental Management, Providence, Rhode Island, USA.
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High latrine coverage is not reducing the prevalence of soil-transmitted helminthiasis in Hoa Binh province, Vietnam. Trans R Soc Trop Med Hyg 2008; 103:237-41. [PMID: 18814894 DOI: 10.1016/j.trstmh.2008.08.012] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2008] [Revised: 08/11/2008] [Accepted: 08/12/2008] [Indexed: 11/24/2022] Open
Abstract
A baseline epidemiological survey for parasite infections was conducted between December 2007 and January 2008 in 155 villagers in a rural commune in Hoa Binh province, Vietnam. The prevalence of Ascaris lumbricoides, Trichuris trichiura and hookworm infection was 13.5%, 45.2% and 58.1%, respectively. At least one of the parasites was detected in 72.3% of the samples. We found no association between infection with A. lumbricoides or T. trichiura and engagement in agriculture, while hookworm infection was more prevalent in populations having frequent contact with soil. Agricultural use of human faeces was not correlated with any of the infections. We suggest that the consumption of vegetables that are commonly fertilized with human faeces in the community has led to the high infection rates with A. lumbricoides and T. trichiura, rather than the manipulation of faeces in farming activity. This also explains the high infection prevalence, despite high latrine coverage (98.1%) in the study population. The presence of latrines alone is not sufficient to reduce the prevalence of helminthiasis in a rural agricultural community if fresh faeces are used as fertilizer.
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Alaofè H, Zee J, Dossa R, O'Brien HT. Intestinal parasitic infections in adolescent girls from two boarding schools in southern Benin. Trans R Soc Trop Med Hyg 2008; 102:653-61. [PMID: 18395236 DOI: 10.1016/j.trstmh.2008.02.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2007] [Revised: 02/18/2008] [Accepted: 02/18/2008] [Indexed: 11/19/2022] Open
Abstract
Intestinal parasitic infections (IPI), especially helminths, represent a major public health problem that increase iron deficiency anaemia in developing countries. This study investigated the prevalence, risk factors and nutritional consequences of IPIs in 180 adolescent girls aged 12-17 years living in two boarding schools in southern Benin. Data were collected using a structured questionnaire and laboratory analysis of blood and faecal samples. The relationships between socioeconomic indicators, IPIs and iron status were analysed using logistic regression analysis. Fifty percent of the subjects were infected with at least one IPI: 2% with helminths, 41% with protozoa and 7% with two or more intestinal parasites. Adolescent girls from a large family and those whose mothers were manual workers showed a higher risk of intestinal parasitism (odds ratio (OR)=3.5, 95% CI 2.5-5.2 (P=0.02) and OR=2.4, 95% CI 2.0-3.0 (P=0.03), respectively). Likewise, drinking untreated water was also a high risk factor for infection (OR=2.3, 95% CI 1.5-2.4; P=0.03). No significant association was observed between IPIs and iron deficiency or iron deficiency anaemia, which can be explained by the low wormload observed. These findings reinforce the need to involve mothers in health initiatives to control intestinal parasitism in Benin.
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Affiliation(s)
- Halimatou Alaofè
- Département des Sciences des Aliments et de Nutrition, Faculté des Sciences de l'Agriculture et de l'Alimentation, Pavillon Paul-Comtois, Université Laval, Québec, Canada
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Scott ME. Ascaris lumbricoides: A Review of Its Epidemiology and Relationship to Other Infections. ACTA ACUST UNITED AC 2008. [DOI: 10.1159/000113305] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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