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Alo C, Okedo-Alex IN, Akamike IC, Agu AP, Okeke IM, Amuzie CI, Alo NC. Utilising community volunteers can increase the detection and referral of Buruli ulcer cases in endemic communities in Southeast, Nigeria. Trop Dis Travel Med Vaccines 2022; 8:24. [PMID: 36316742 PMCID: PMC9623928 DOI: 10.1186/s40794-022-00181-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 09/12/2022] [Indexed: 01/24/2023] Open
Abstract
BACKGROUND Buruli ulcer (BU) is a debilitating neglected tropical disease which causes disability and mostly affects inhabitants in impoverished settings where access to medical care is challenging. This study aims to determine the effect of training community members as volunteers for or in the detection and referral of people who have Buruli ulcer to the hospital. METHODS The following study is a before and after study in the BU-endemic Local Government Areas (LGA) of Ebonyi State. A cluster random sampling technique was used to select 90 volunteers from three LGAs (30 from each LGA). In each LGA, the volunteers underwent a one-day training and six months field work to identify all those who have any form of ulcer on any part of their bodies. A short questionnaire was used to capture socio-demographic characteristics of the patient, site of the ulcer, duration of the ulcer, initial appearance of the ulcer, referral to hospital, result of laboratory investigation, and treatment received. The data was analysed using the Statistical Package for Social Sciences (SPSS) for Microsoft Windows version 20 software. The Z test statistic was used to compare the number of referred BU patients before and after the intervention by LGA. The Chi square test was used to examine the association between the dependent and independent variables. RESULTS The mean age of volunteers was 39 ± 9.5 while mean age of the patients was 42.3 ± 17.1. Most of the ulcers were on the legs (79.4%) and lasted 1-5 years (65.6%). There was a significant increase in the proportion of BU suspects identified by the community volunteers in all 3 LGAs (Afikpo north (p = < 0.001), Abakaliki (p = 0.02), Ikwo (p = 0.001). The duration of the ulcer was associated with the detection and referral of the patients with higher levels of detection and referral among those whose ulcer had lasted 1-5 years in two of the LGAs (P < 0.001). CONCLUSION We recommend that program managers and stakeholders integrate and scale up the services of trained community health volunteers for the rapid detection of Buruli ulcer cases in rural endemic communities. Awareness and sensitization campaigns on BU preventive measures should be intensified.
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Kushwaha V, Capalash N. Aminoacyl-tRNA synthetase (AARS) as an attractive drug target in neglected tropical trypanosomatid diseases-Leishmaniasis, Human African Trypanosomiasis and Chagas disease. Mol Biochem Parasitol 2022; 251:111510. [PMID: 35988745 DOI: 10.1016/j.molbiopara.2022.111510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 08/09/2022] [Accepted: 08/16/2022] [Indexed: 10/15/2022]
Abstract
TriTryp diseases (Leishmaniasis, Human African Trypanosomiasis (HAT), and Chagas disease) are devastating parasitic neglected tropical diseases (NTDs) that affect billions of people in developing countries, cause high mortality in humans, and impose a large socio-economic burden. The current treatment options against tritryp diseases are suboptimal and challenging due to the emergence of resistance against available tritryp drugs. Hence, designing and developing effective anti-tritryp drugs with novel targets are required. Aminoacyl-tRNA synthetases (AARSs) involved in specific aminoacylation of transfer RNAs (tRNAs), interrupt protein synthesis through inhibitors, and retard the parasite growth. AaRSs have long been studied as therapeutic targets in bacteria, and three aaRS inhibitors, mupirocin (against IleRS), tavaborole AN2690 (against LeuRS), and halofuginone (against ProRS), are already in clinical practice. The structural differences between tritryp and human aaRSs and the presence of unique sequences (N-terminal domain/C-terminal domain/catalytic domain) make them potential target for developing selective inhibitors. Drugs based on a single aaRS target developed by high-throughput screening (HTS) are less effective due to the emergence of resistance. However, designing multi-targeted drugs may be a better strategy for resistance development. In this perspective, we discuss the characteristics of tritryp aaRSs, sequence conservation in their orthologs and their peculiarities, recent advancements towards the single-target and multi-target aaRS inhibitors developed through rational design.
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de Oca-Aguilar ACM, Rebollar-Téllez EA, Sosa-Bibiano EI, López-Avila KB, Torres-Castro JR, Loría-Cervera EN. Effect of land use change on the phlebotomine sand fly assemblages in an emergent focus of cutaneous leishmaniasis in Yucatan, Mexico. Acta Trop 2022; 235:106628. [PMID: 35952923 DOI: 10.1016/j.actatropica.2022.106628] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 07/14/2022] [Accepted: 07/28/2022] [Indexed: 11/01/2022]
Abstract
As land use intensifies in tropical forests, it is expected that species assemblages will be modified and that key functions of these ecosystems will be affected. The latter scenario is important from a public health perspective, because the land use change has been linked the outbreaks of vector-borne diseases. In this study, we evaluated the response of Phlebotominae (Diptera: Psychodidae) assemblages and their pattern of co-occurrence in four sites with different land use in an emerging cutaneous leishmaniasis focus in Yucatan, Mexico. Our hypothesis is that the conservation status (as forest cover) will positively influence the structure and composition of sand flies' assemblages. Using three different traps over a period of five months, a sampling effort of 1, 440 night-traps was performed. A total of 7, 897 sand fly specimens belonging to six genera and 10 species were collected. Our hypothesis was partially achieved since sand fly diversity increased as forest cover increased and vice versa, however random patterns of co-occurrence in assemblages were detected among sites. Even though the high abundance of sand flies in the forest fragment suggests an amplification effect, our results show that different vector species directly dominate in each site. We discuss the potential implications of the nestedness of species dominance. We suggest that in this emerging focus and under the land use gradient, Lutzomyia cruciata and Psathyromyia cratifer could play a pivotal role in maintaining the transmission cycles of Leishmania. The apparent generalist or colonialist profile of Lu. cruciata in disturbed areas deserves attention, due to the potential risk of leishmaniasis "domiciliation". This information is essential to understand the eco-epidemiology of leishmaniasis and the factors associated with its emergence in Yucatan, Mexico.
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Gwayi-Chore MC, Aruldas K, Avokpaho E, Chirambo CM, Kaliappan SP, Houngbégnon P, Togbevi CI, Chabi F, Nindi P, Simwanza J, Johnson J, Miech EJ, Kalua K, Ibikounlé M, Ajjampur SSR, Weiner BJ, Walson JL, Means AR. Defining optimal implementation packages for delivering community-wide mass drug administration for soil-transmitted helminths with high coverage. BMC Health Serv Res 2022; 22:792. [PMID: 35717193 PMCID: PMC9206125 DOI: 10.1186/s12913-022-08080-5] [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: 02/10/2022] [Accepted: 05/13/2022] [Indexed: 11/21/2022] Open
Abstract
Background Recent evidence suggests that community-wide mass drug administration (MDA) may interrupt the transmission of soil-transmitted helminths (STH), a group of intestinal worms that infect 1.5 billion individuals globally. Although current operational guidelines provide best practices for effective MDA delivery, they do not describe which activities are most essential for achieving high coverage or how they work together to produce effective intervention delivery. We aimed to identify the various packages of influential intervention delivery activities that result in high coverage of community-wide MDA for STH in Benin, India, and Malawi. Methods We applied coincidence analysis (CNA), a novel cross-case analytical method, to process mapping data as part of the implementation science research of the DeWorm3 Project, a Hybrid Type 1 cluster randomized controlled trial assessing the feasibility of interrupting the transmission of STH using bi-annual community-wide MDA in Benin, India, and Malawi. Our analysis aimed to identify any necessary and/or sufficient combinations of intervention delivery activities (i.e., implementation pathways) that resulted in high MDA coverage. Activities were related to drug supply chain, implementer training, community sensitization strategy, intervention duration, and implementation context. We used pooled implementation data from three sites and six intervention rounds, with study clusters serving as analytical cases (N = 360). Secondary analyses assessed differences in pathways across sites and over intervention rounds. Results Across all three sites and six intervention rounds, efficient duration of MDA delivery (within ten days) singularly emerged as a common and fundamental component for achieving high MDA coverage when combined with other particular activities, including a conducive implementation context, early arrival of albendazole before the planned start of MDA, or a flexible community sensitization strategy. No individual activity proved sufficient by itself for producing high MDA coverage. We observed four possible overall models that could explain effective MDA delivery strategies, all which included efficient duration of MDA delivery as an integral component. Conclusion Efficient duration of MDA delivery uniquely stood out as a highly influential implementation activity for producing high coverage of community-wide MDA for STH. Effective MDA delivery can be achieved with flexible implementation strategies that include various combinations of influential intervention components. Supplementary Information The online version contains supplementary material available at 10.1186/s12913-022-08080-5.
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On characterizing the Red-headed Krait (Bungarus flaviceps) venom: Decomplexation proteomics, immunoreactivity and toxicity cross-neutralization by hetero-specific antivenoms. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. PART D, GENOMICS & PROTEOMICS 2022; 43:101006. [PMID: 35717758 DOI: 10.1016/j.cbd.2022.101006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2022] [Revised: 05/31/2022] [Accepted: 06/03/2022] [Indexed: 12/26/2022]
Abstract
The Red-headed Krait (Bungarus flaviceps) is a medically important venomous snake species in Southeast Asia, while there is no specific antivenom available for its envenoming. This study investigated the venom composition through a decomplexation proteomic approach, and examined the immunoreactivity as well as cross-neutralization efficacy of two hetero-specific krait antivenoms, Bungarus candidus Monovalent Antivenom (BcMAV) and Bungarus fasciatus Monovalent Antivenom (BfMAV), against the venom of B. flaviceps from Peninsular Malaysia. A total of 43 non-redundant proteoforms belonging to 10 toxin families were identified in the venom proteome, which is dominated by phospholipases A2 including beta-bungarotoxin lethal subunit (56.20 % of total venom proteins), Kunitz-type serine protease inhibitors (19.40 %), metalloproteinases (12.85 %) and three-finger toxins (7.73 %). The proteome varied in quantitative aspect from the earlier reported Indonesian (Sumatran) sample, suggesting geographical venom variation. BcMAV and BfMAV were immunoreactive toward the B. flaviceps venom, with BcMAV being more efficacious in immunological binding. Both antivenoms cross-neutralized the venom lethality with varying efficacy, where BcMAV was more potent than BfMAV by ~13 times (normalized potency: 38.04 mg/g vs. 2.73 mg/g, defined as the venom amount completely neutralized by one-gram antivenom protein), supporting the potential utility of BcMAV for para-specific neutralization against B. flaviceps venom.
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Tantengco OAG, Rojo RD. Bibliometric analysis of schistosomiasis research in Southeast Asia (1908-2020). Acta Trop 2022; 228:106322. [PMID: 35065014 DOI: 10.1016/j.actatropica.2022.106322] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 01/15/2022] [Accepted: 01/18/2022] [Indexed: 12/17/2022]
Abstract
OBJECTIVES This study determined the characteristics and trends of published articles regarding schistosomiasis in Southeast Asian countries through a bibliometric analysis. METHODS Using the Scopus database, we identified all original research articles on schistosomiasis from 1908 to 2020 from SEA countries: Brunei, Cambodia, Indonesia, Laos, Malaysia, Myanmar, Philippines, Singapore, Thailand, and Vietnam. Bibliographic and citation information was obtained, and visualization of collaboration networks of countries and keywords related to schistosomiasis was conducted using VOSviewer software. RESULTS We obtained 528 schistosomiasis articles published between 1908 and 2020 from SEA countries. The number of publications continued to increase and peaked from 2000 until 2020. The Philippines had the highest number of publications (n = 231), followed by Thailand (n = 153), and Malaysia (n = 64). The leading journals with the highest number of publications in this field include the Southeast Asian Journal of Tropical Medicine and Public Health (n = 96), Acta Tropica (n = 27), and Plos Neglected Tropical Diseases (n = 24). The most common keywords related to schistosomiasis research in SEA were "schistosomiasis", "Schistosoma japonicum", "Schistosoma mekongi", "Schistosoma mansoni", and "praziquantel". International collaboration was significantly correlated with scientific productivity for schistosomiasis research. CONCLUSION Our study showed the research landscape, trends and development, and collaboration among researchers in schistosomiasis in SEA. Our results also revealed the limited schistosomiasis research in several SEA countries. There is a need for more research to improve our understanding of the epidemiology of schistosomiasis in SEA, which can help in improving the control and prevention of this disease.
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Wampande LN, Nyabuga LM, Fowler K, Okengwu GC, Bayisenge U, Schurer JM. Podoconiosis instruction at nursing schools in Kenya, Rwanda, and Uganda. Trop Med Health 2022; 50:14. [PMID: 35148785 PMCID: PMC8831868 DOI: 10.1186/s41182-022-00405-8] [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: 09/24/2021] [Accepted: 01/27/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Podoconiosis is a preventable, progressive, and non-infectious form of elephantiasis that can contribute to significant disability and economic burden when not treated early. Nurses play a critical role in early detection and response in rural Africa, but it is unclear if they receive adequate training on podoconiosis. We aimed to characterize podoconiosis instruction at all government accredited, post-secondary nursing institutions in three African countries. METHODS Data for this cross-sectional study was collected through a quantitative survey with several open-answer questions. Through a rigorous online search, we identified all post-secondary institutions in Kenya, Rwanda and Uganda accredited to teach human nursing. A total of 289 accredited programs, including 85 certificate, 56 degree and 148 diploma programs were invited to participate. Respondents completed surveys online or by telephone. Measures focused on podoconiosis knowledge, perceptions of quality/quantity of podoconiosis instruction, and barriers to sufficient podoconiosis education. RESULTS We obtained information about 212 curricula across 149 nursing institutions in the three countries (participation rate: 73.4%). Podoconiosis coverage was limited across programs (certificate-24.1%; diploma-55.6%; degree-30.3%). Most respondents felt that the quality and quantity of instruction were insufficient (60.6%, 62.9%), respectively. Exclusion from government curricula, low priority and faculty lack of knowledge were commonly reported barriers to podoconiosis inclusion. CONCLUSIONS This study demonstrated clear gaps in podoconiosis training for nurses across the three countries and highlights a serious challenge in eliminating podoconiosis as a public health problem. Interventions to improve nurses' knowledge could include the development and free distribution of podoconiosis teaching materials, designed for integration into pre-existing courses.
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Akinokun RT, Ilesanmi EB, Adebisi YA, Akingbade O. The status of neglected tropical diseases amidst COVID-19 in Africa: Current evidence and recommendations. Health Promot Perspect 2022; 11:430-433. [PMID: 35079586 PMCID: PMC8767084 DOI: 10.34172/hpp.2021.53] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Accepted: 09/20/2021] [Indexed: 12/29/2022] Open
Abstract
Health care services and programs directed towards combating the neglected tropical diseases (NTDs) have been disrupted because of the impact of the coronavirus disease 2019 (COVID-19). The African continent because of its staggering health care system and poor economy disproportionately bears the burden of these diseases. While successes have been recorded in controlling and eliminating the NTDs, policymakers in Africa should consider the potential of the COVID-19 to dwindle these successes an issue of high priority. This commentary seeks to discuss the current status of NTDs in Africa and proffer recommendations to help combat these diseases at this period. It is worthy to say that similar dedication directed towards fighting the COVID-19 should also be deployed into eliminating other diseases like the NTDs which often, are neglected.
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Erber AC, Sandler PJ, de Avelar DM, Swoboda I, Cota G, Walochnik J. Diagnosis of visceral and cutaneous leishmaniasis using loop-mediated isothermal amplification (LAMP) protocols: a systematic review and meta-analysis. Parasit Vectors 2022; 15:34. [PMID: 35073980 PMCID: PMC8785018 DOI: 10.1186/s13071-021-05133-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 12/16/2021] [Indexed: 12/13/2022] Open
Abstract
Sensitive, reliable and fast diagnostic tools that are applicable in low-resource settings, at the point of care (PoC), are seen as crucial in the fight against visceral leishmaniasis (VL) and cutaneous leishmaniasis (CL). Addressing the need for a PoC test, several diagnostic tests, including serological and molecular methods, have been developed and evaluated in the past. One promising molecular method, already implemented for diagnosis of a range of diseases, is the loop-mediated isothermal amplification (LAMP) protocol. In this systematic review and meta-analysis, using a comprehensive search strategy, we focus on studies evaluating the performance of LAMP for the diagnosis of leishmaniasis in humans and other mammals such as dogs, compared with microscopy and/or any other molecular diagnostic method. A meta-analysis, pooling sensitivity and specificity rates and calculating areas under the curve (AUCs) in summary receiver operating characteristic (SROC) plots, was conducted on datasets extracted from studies, grouped by clinical condition and sample type. We found high sensitivity and specificity for LAMP when compared with microscopy and PCR using blood samples, with pooled estimate values of > 90% for all subgroups, corresponding to calculated AUC values > 0.96, except for LAMP compared to microscopy for diagnosis of CL. However, only a limited number of studies were truly comparable. Most of the observed heterogeneity is likely based on true differences between the studies rather than sampling error only. Due to simple readout methods and low laboratory equipment requirements for sample preparation compared to other molecular methods, LAMP is a promising candidate for a molecular (near-)PoC diagnostic method for VL and CL.
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Eslahi AV, Hashemipour S, Olfatifar M, Houshmand E, Hajialilo E, Mahmoudi R, Badri M, Ketzis JK. Global prevalence and epidemiology of Strongyloides stercoralis in dogs: a systematic review and meta-analysis. Parasit Vectors 2022; 15:21. [PMID: 35012614 PMCID: PMC8750836 DOI: 10.1186/s13071-021-05135-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Accepted: 12/16/2021] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Strongyloides stercoralis, a soil-transmitted helminth, occurs in humans, non-human primates, dogs, cats and wild canids. The zoonotic potential between these hosts is not well understood with data available on prevalence primarily focused on humans. To increase knowledge on prevalence, this review and meta-analysis was performed to estimate the global status of S. stercoralis infections in dogs. METHODS Following the PRISMA guidelines, online literature published prior to November 2020 was obtained from multiple databases (Science Direct, Web of Science, PubMed, Scopus and Google Scholar). Prevalence was calculated on a global and country level, by country income and climate, and in stray/animal shelter dogs versus owned dogs. Statistical analyses were conducted using R-software (version 3.6.1). RESULTS From 9428 articles, 61 met the inclusion criteria. The estimated pooled global prevalence of S. stercoralis in dogs was 6% (95% CI 3-9%). Infection was found to be the most prevalent in low-income countries with pooled prevalence of 22% (95% CI 10-36%). The highest pooled prevalence of S. stercoralis in dogs was related to regions with average temperature of 10-20 °C (6%; 95% CI 3-11%), an annual rainfall of 1001-1500 mm (9%; 95% CI 4-15%) and humidity of 40-75% (8%; 95% CI 4-13%). Prevalence was higher in stray and shelter dogs (11%; 95% CI 1-26%) than in owned dogs (3%; 95% CI 1-7%). CONCLUSIONS As with S. stercoralis in humans, higher prevalence in dogs is found in subtropical and tropical regions and lower-income countries, locations which also can have high dog populations. While this study presents the first estimated global prevalence of S. stercoralis in dogs, it is potentially an underestimation with 15 of 61 studies relying on diagnostic methods of lower sensitivity and a paucity of data from most locations. Standardized protocols (e.g. quantity of feces and number of samples for a Baermann) in future studies could improve reliability of results. More prevalence studies and raising veterinary awareness of S. stercoralis are needed for a One Health approach to protect humans and dogs from the impact of the infection.
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Badri M, Olfatifar M, Wandra T, Budke CM, Mahmoudi R, Abdoli A, Hajialilo E, Pestehchian N, Ghaffarifar F, Foroutan M, Hashemipour S, Sotoodeh S, Samimi R, Eslahi AV. The prevalence of human trichuriasis in Asia: a systematic review and meta-analysis. Parasitol Res 2022; 121:1-10. [PMID: 34993634 DOI: 10.1007/s00436-021-07365-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 10/27/2021] [Indexed: 11/30/2022]
Abstract
Trichuriasis is one of the most common soil-transmitted helminth (STH) infections, affecting populations globally. The condition is particularly prevalent in tropical and subtropical areas with low levels of sanitation and poor living conditions. The objective of this systematic review and meta-analysis was to evaluate the prevalence of Trichuris trichiura infection in Asia at the country and region level. Multiple databases/academic search engines (Web of Science, PubMed, ProQuest, Scopus, and Google Scholar) were searched for literature on T. trichiura prevalence in Asia published through January 2021. Pooled prevalence was determined using the meta-package in R (version 3.6.1). Out of 13,836 articles, 226 studies (5,439,500 individuals) from 26 countries met the inclusion criteria. Of the 226 studies, 151 were community-based studies that included individuals across the age spectrum, while 75 studies focused on school children (typically in the 5-16 years age range). The overall T. trichiura pooled prevalence was 15.3% (95% CI: 12.4-19.1%), with a pooled prevalence of 13.3% (95% CI: 10.0-17.1%) for the community studies and 20.9% (95% CI: 14.7-27.9%) for the studies only including school children. For studies including all age groups, individuals in the 1-15 years age group had the highest pooled prevalence at 23.4% (95% CI: 1.7-49.4%). There was a significant difference found in overall pooled prevalence by sex (p < 0.001) and community type (rural versus urban) (p < 0.001). Although prevalence appears to be decreasing, study findings suggest that T. trichiura infection continues to be a public health problem in Asia. Therefore, control programs focused on at-risk individuals in endemic areas are needed.
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Gomes ECDS, Silva IEPD, Nascimento WRCD, Loyo RM, Domingues ALC, Barbosa CS. Urban schistosomiasis: An ecological study describing a new challenge to the control of this neglected tropical disease. LANCET REGIONAL HEALTH. AMERICAS 2021; 8:100144. [PMID: 36778731 PMCID: PMC9904042 DOI: 10.1016/j.lana.2021.100144] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Background Social and environmental vulnerabilities contribute to the persistence and increase of Schistosomiasis, which has been a public health problem in Brazil and worldwide. In this study, we aimed to monitor the entry, installation, and maintenance of schistosomiasis transmission in an urban area on the Brazilian coast over two decades (2000-2010/2010-2020). Methods This population-based cross-sectional study was conducted in Porto de Galinhas, state of Pernambuco, Brazil, to investigate the dynamics of schistosomiasis transmission in the urban area. Through 3 malacological and parasitological surveys and using geoprocessing technologies, schistosomiasis transmission foci (STF), as well as cases of the disease were identified and quantified. Statistical and geoprocessing tools were used to analyse the data. Findings Overall, the number of STF decreased from 15 (2000) to 11 (2010) and then to 9 (2020). Although the infection ratio of snails in 2000 has decreased from 16·1% to 5·8% in 2010, we observed an increase to 7·2% in 2020. Additionally, 6,499 individuals were analysed (2012 in 2000; 2459 in 2010, and 2028 in 2020) and the prevalence of human infection has decreased over years, from 32·5% (2000), 16·6% (2010) to 8·8% (2020). The disorderly urbanization process was directly related to the spatial distribution of STF and schistosomiasis cases, causing a new scenario where people became infected by walking on unpaved and flooded streets. Interpretation Although we observed a decreasing in schistosomiasis cases and STF, this NTD became a health problem related to urbanization in the study area. The challenge to overcome this new sort of transmission will require a greater understanding of the disorderly migration, spatial occupation, and degradation of the environment. Funding National Council for Scientific and Technological Development (CNPq), Ministry of Science, Technology, Innovations and Communications, Brazil.
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Application of a POCCCA rapid diagnostic test and serology for detection of schistosomiasis in HIV-positive individuals in urban Malawi. Acta Trop 2021; 224:106142. [PMID: 34562420 DOI: 10.1016/j.actatropica.2021.106142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 08/07/2021] [Accepted: 09/12/2021] [Indexed: 11/20/2022]
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Venom proteomic analysis of medically important Nigerian viper Echis ocellatus and Bitis arietans snake species. Biochem Biophys Rep 2021; 28:101164. [PMID: 34765747 PMCID: PMC8571701 DOI: 10.1016/j.bbrep.2021.101164] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 10/13/2021] [Accepted: 10/25/2021] [Indexed: 11/29/2022] Open
Abstract
Snakebite envenoming remains a neglected tropical disease which poses severe health hazard, especially for the rural inhabitants in Africa. In Nigeria, vipers are responsible for the highest number of deaths. Hydrophilic interaction liquid chromatography coupled with LC-MS/MS was used to analyze the crude venoms of Echis ocellatus (Carpet viper) and Bitis arietans (Puff adder) in order to understand their venom proteomic identities. Results obtained revealed that gel-free proteomic analysis of the crude venoms led to the identification of 85 and 79 proteins, respectively. Seventy-eight (78) proteins were common between the two snake species with a 91.8% similarity score. The identified proteins belong to 18 protein families in E. ocellatus and 14 protein families in B. arietans. Serine proteases (22.31%) and metalloproteinases (21.06%) were the dominant proteins in the venom of B. arietans; while metalloproteinases (34.84%), phospholipase A2s (21.19%) and serine proteases (15.50%) represent the major toxins in the E. ocellatus venom. Other protein families such as three-finger toxins and cysteine-rich venom proteins were detected in low proportions. This study provides an insight into the venom proteomic analysis of the two Nigerian viper species, which could be useful in identifying the toxin families to be neutralized in case of envenomation. Venom proteomic of Nigeria's most medically important snakes is presented. SVMP, SVSP and PLA2 were the major toxin families in E. ocellatus and B. arietans. The venom proteomes of these vipers displayed 91.8% similarity in composition.
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Drug discovery in leishmaniasis using protein lipidation as a target. Biophys Rev 2021; 13:1139-1146. [PMID: 35035594 PMCID: PMC8724199 DOI: 10.1007/s12551-021-00855-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Accepted: 10/14/2021] [Indexed: 01/03/2023] Open
Abstract
The leishmaniases are infectious diseases caused by a number of species of obligate intracellular protozoa of the genus Leishmania with disease manifesting as cutaneous, mucocutaneous and visceral forms. Despite being endemic in more than 80 countries and its being the cause of high morbidity and mortality, leishmaniasis remains a neglected tropical disease. Chemotherapy is the frontline treatment, but drugs in current use suffer from toxic side effects, difficulties in administration and extended treatment times - moreover, resistance is emerging. New anti-leishmanial drugs are a recognised international priority. Here, we review investigations into N-myristoyltransferase (NMT) as a potential drug target. NMT catalyses the co-translational transfer of a C14 fatty acid from myristoyl-CoA onto the N-terminal glycine residue of a significant subset of proteins in eukaryotic cells. This covalent modification influences the stability and interactions of substrate proteins with lipids and partner proteins. Structure-guided development of new lead compounds emerging from high-throughput screening campaigns targeting Leishmania donovani NMT has led to the discovery of potent inhibitors which have been used to gain insights into the role of protein myristoylation in these parasites and to validate NMT as a drug target.
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Souza LS, Lins-Silva DH, Dorea-Bandeira I, Barouh JL, Tolentino A, Bandeira ID, Quarantini LC. Prevalence and factors associated with depression and anxiety in people living with HTLV-1: A systematic review with meta-analysis and meta-regression. Gen Hosp Psychiatry 2021; 73:54-63. [PMID: 34600354 DOI: 10.1016/j.genhosppsych.2021.08.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 08/11/2021] [Accepted: 08/27/2021] [Indexed: 11/29/2022]
Abstract
OBJECTIVE Human T-cell lymphotropic virus type-1 (HTLV-1) infection is a neglected tropical disease associated with many clinical manifestations, such as erythematous-scaling skin lesions, cutaneous lymphomas, and spastic paraparesis, which could be a potential cause of mental health concerns. This study investigates the prevalence of symptoms and diagnoses of depression and anxiety and its associated factors in people living with HTLV-1 (PLWH). METHOD A systematic review was performed in the Pubmed/MEDLINE, Embase, LILACS, and PsycINFO databases for original studies investigating symptoms of depression and anxiety and diagnoses of major depressive disorder and anxiety disorders in PLWH, and a random-effects meta-analysis with meta-regression was performed to obtain a summary frequency of symptoms and diagnoses of depression and anxiety. RESULTS Considering both symptoms and diagnoses, the pooled prevalence for depression was 35% (95% CI: 27 to 43) and for anxiety was 33% (95% CI: 23 to 45). Clinically significant symptoms were more prevalent than diagnosed disorders for depression (47% vs. 21%) and anxiety (44% vs. 11%). PLWH were more likely than seronegative controls to present symptoms and diagnoses of depression (pooled OR: 4.25; 95% CI: 2.7 to 6.68) and anxiety (pooled OR: 3.79; 95% CI: 2.6 to 5.52). Spastic paraparesis was significantly associated with symptoms and diagnoses of depression (pooled OR: 1.81; 95% CI: 1.11 to 2.95) and anxiety (pooled OR: 2.75; 95% CI 1.26 to 5.96). CONCLUSIONS PLWH present a much higher prevalence of symptoms and diagnoses of depression and anxiety than seronegative controls, which could be explained by social vulnerability or neurological impairment associated with spastic paraparesis. More studies comparing asymptomatic PLWH and seronegative controls are needed.
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Amoako YA, Ackam N, Omuojine JP, Oppong MN, Owusu-Ansah AG, Boateng H, Abass MK, Amofa G, Ofori E, Okyere PB, Frimpong M, Bailey F, Molyneux DH, Phillips RO. Mental health and quality of life burden in Buruli ulcer disease patients in Ghana. Infect Dis Poverty 2021; 10:109. [PMID: 34404483 PMCID: PMC8367773 DOI: 10.1186/s40249-021-00891-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 08/02/2021] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND Buruli ulcer disease (BUD) is a necrotic skin neglected tropical disease (NTD) that has both a mental and physical health impact on affected individuals. Although there is increasing evidence suggesting a strong association between neglected tropical diseases (NTDs) and mental illness, there is a relative lack of information on BUD's impact on the mental health and quality of life (QoL) of affected individuals in Ghana. This study is to assess the impact of BUD on mental health and quality of life of patients with active and past BUD infection, and their caregivers. METHODS We conducted a case control study in 3 BUD endemic districts in Ghana between August and November 2019. Face-to-face structured questionnaire-based interviews were conducted on BUD patients with active and past infection, as well as caregivers of BUD patients using WHO Quality of Life scale, WHO Disability Assessment Schedule, Self-Reporting Questionnaire, Buruli Ulcer Functional Limitation Score and Hospital Anxiety and Depression Scale data tools. Descriptive statistics were used to summarize the characteristics of the study participants. Participant groups were compared using student t test and chi-square (χ2) or Fisher's exact tests. Mean quality of life scores are reported with their respective 95% confidence intervals. Data was analysed using STATA statistical software. RESULTS Our results show that BUD patients with active and past infection, along with their caregivers, face significant levels of distress and mental health sequelae compared to controls. Depression (P = 0.003) was more common in participants with active (27%) and past BU infection (17%), compared to controls (0%). Anxiety was found in 42% (11/26) and 20% (6/29) of participants with active and past BUD infection compared to 14% (5/36) of controls. Quality of life was also significantly diminished in active BUD infection, compared to controls. In the physical health domain, mean QoL scores were 54 ± 11.1 and 56 ± 11.0 (95% CI: 49.5‒58.5 and 52.2‒59.7) respectively for participants with active infection and controls. Similarly in the psychological domain, scores were lower for active infection than controls [57.1 ± 15.2 (95% CI: 50.9‒63.2) vs 64.7 ± 11.6 (95% CI: 60.8‒68.6)]. Participants with past infection had high QoL scores in both physical [61.3 ± 13.5 (95% CI: 56.1‒66.5)] and psychological health domains [68.4 ± 14.6 (95% CI: 62.7‒74.0)]. CONCLUSIONS BUD is associated with significant mental health distress and reduced quality of life in affected persons and their caregivers in Ghana. There is a need for integration of psychosocial interventions in the management of the disease.
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Means AR, Orlan E, Gwayi-Chore MC, Titus A, Kaliappan SP, Togbevi CI, Chabi F, Halliday KE, Nindi P, Avokpaho E, Kalua K, Ibikounlé M, Ajjampur SSR, Weiner BJ, Walson JL, Aruldas K. Structural readiness to implement community-wide mass drug administration programs for soil-transmitted helminth elimination: results from a three-country hybrid study. Implement Sci Commun 2021; 2:80. [PMID: 34281614 PMCID: PMC8287777 DOI: 10.1186/s43058-021-00164-3] [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: 10/16/2020] [Accepted: 05/28/2021] [Indexed: 11/29/2022] Open
Abstract
Background Current soil-transmitted helminth (STH) control programs target pre-school and school-age children with mass drug administration (MDA) of deworming medications, reducing morbidity without interrupting ongoing transmission. However, evidence suggests that STH elimination may be possible if MDA is delivered to all community members. Such a change to the STH standard-of-care would require substantial systems redesign. We measured baseline structural readiness to launch community-wide MDA for STH in Benin, India, and Malawi. Methods After field piloting and adaptation, the structural readiness survey included two constructs: Organizational Readiness for Implementing Change and Organizational Capacity for Change. Sub-constructs of organizational readiness include change commitment and change efficacy. Sub-constructs of organizational capacity include flexibility, organizational structure, and demonstrated capacity. Survey items were also separately organized into seven implementation domains. Surveys were administered to policymakers, mid-level managers, and implementers in each country using a five-point Likert scale. Item, sub-construct, construct, and domain-level medians and interquartile ranges were calculated for each stakeholder level within each country. Results Median organizational readiness for change scores were highest in Malawi (5.0 for all stakeholder groups). In India, scores were 5.0, 4.0, and 5.0 while in Benin, scores were 4.0, 3.0, and 4.0 for policymakers, mid-level managers, and implementers, respectively. Median change commitment was equal to or higher than median change efficacy across all countries and stakeholder groups. Median organizational capacity for change was highest in India, with a median of 4.5 for policymakers and mid-level managers and 5.0 for implementers. In Malawi, the median capacity was 4.0 for policymakers and implementers, and 3.5 for mid-level managers. In Benin, the median capacity was 4.0 for policymakers and 3.0 for mid-level managers and implementers. Median sub-construct scores varied by stakeholder and country. Across countries, items reflective of the implementation domain ‘policy environment’ were highest while items reflective of the ‘human resource’ domain were consistently lower. Conclusion Across all countries, stakeholders valued community-wide MDA for STH but had less confidence in their collective ability to effectively implement it. Perceived capacity varied by stakeholder group, highlighting the importance of accounting for multi-level stakeholder perspectives when determining organizational preparedness to launch new public health initiatives. Trial registration NCT03014167
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Lana JT, Mallipudi A, Ortiz EJ, Arevalo JH, Llanos-Cuentas A, Pan WK. Risk factors for cutaneous leishmaniasis in a high-altitude forest region of Peru. Trop Med Health 2021; 49:40. [PMID: 34001266 PMCID: PMC8130303 DOI: 10.1186/s41182-021-00332-0] [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: 02/09/2021] [Accepted: 05/06/2021] [Indexed: 11/21/2022] Open
Abstract
BACKGROUND American cutaneous leishmaniasis (CL) is a neglected tropical disease typically associated with men working in remote, sylvatic environments. We sought to identify CL risk factors in a highly deforested region where anecdotal reports suggested an atypical proportion of women and children were infected with CL raising concern among authorities that transmission was shifting towards domestic spaces and population centers. METHODS We describe the characteristics of CL patients from four participating clinics after digitizing up to 10 years of patient data from each clinic's CL registries. We assessed risk factors of CL associated with intradomestic, peridomestic, or non-domestic transmission through a matched case-control study with 63 patients who had visited these same clinics for CL (cases) or other medical reasons (controls) between January 2014 and August 2016. The study consisted of an in-home interview of participants by a trained field worker using a standard questionnaire. Risk factors were identified using bivariable and multivariable conditional logistic regression. RESULTS Between 2007 and 2016, a total of 529 confirmed CL positives were recorded in the available CL registries. Children and working aged women made up 58.6% of the cases. Our final model suggests that the odds of sleeping in or very near an agricultural field were five times greater in cases than controls (p = 0.025). Survey data indicate that women, children, and men have similar propensities to both visit and sleep in or near agricultural fields. CONCLUSIONS Women and children may be underappreciated as CL risk groups in agriculturally dependent regions. Despite the age-sex breakdown of clinical CL patients and high rates of deforestation occurring in the study area, transmission is mostly occurring outside of the largest population centers. Curbing transmission in non-domestic spaces may be limited to decreasing exposure to sandflies during the evening, nighttime, and early morning hours. Our paper serves as a cautionary tale for those relying solely on the demographic information obtained from clinic-based data to understand basic epidemiological trends of vector-borne infections.
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Wang YC, Grundy-Warr C, Namsanor J, Kenney-Lazar M, Tang CJY, Goh LYW, Chong YC, Sithithaworn P, Ngonkum S, Khuntikeo N. Masculinity and misinformation: Social dynamics of liver fluke infection risk in Thailand. Parasitol Int 2021; 84:102382. [PMID: 33984515 DOI: 10.1016/j.parint.2021.102382] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 04/17/2021] [Accepted: 05/09/2021] [Indexed: 10/21/2022]
Abstract
Liver fluke infection through the consumption of raw or undercooked freshwater fish is a major public health problem in the Mekong Region. Despite the extensive efforts of liver fluke health campaigns, Northeast Thailand still reports high human infection prevalence as consumption of raw fish dishes has diminished but not ceased. This study examines the roles of social-cultural factors, particularly the influences of masculinity and misinformation, on liver fluke infection risk. Participant observation, questionnaire surveys and semi-structured interviews were conducted in four villages in Kalasin Province, Thailand, to scrutinize reasons for raw fish consumption, gender differences in raw fish culture, processes of liver fluke information dissemination, and the extent of information mismatch. Our results show that one of the key reasons (76.9%) underlying continued raw fish consumption are deeply embedded cultural practices associated with ways of rural life. About 30% of the participants indicated that they would not avoid eating raw fish, regardless of knowing the health consequences. Gender difference is evident, with 75.6% of males consuming raw fish salad (koi pla), compared to 42.7% of females. Some male participants associate raw meat consumption with virility and strength. Such beliefs underscore the cultural linkage of koi pla consumption with masculinity. Misconceptions of liver fluke life cycle and risk of infection remain, as only 15.3% of the participants correctly selected raw fish as the food source for liver fluke infection while 84.2% misunderstood that other raw foods could lead to infection. The multi-layered and hierarchical structure of public health information dissemination from medical professionals to health officers and village health volunteers to villagers has contributed to information mismatch between different layers. Our study builds on others which call for multi-pronged scientific and social strategies, as well as culturally attuned approaches to public health messaging. The study raises masculinity and misinformation as relevant considerations in disease prevention. Incorporating grounded research and gendered perspectives are part of appreciating the cultural roots of raw fish consumption. Realizing the significant role of village health volunteers in information dissemination and in supplying coherent public health messages is vital for effective health campaigns.
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Tiruneh A, Zemene E, Mekonnen Z. Strongyloidiasis: the most neglected tropical disease in Ethiopia. Infect Dis Poverty 2021; 10:65. [PMID: 33962697 PMCID: PMC8106120 DOI: 10.1186/s40249-021-00851-2] [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: 02/19/2021] [Accepted: 04/22/2021] [Indexed: 11/10/2022] Open
Abstract
Background Strongyloidiasis is the most neglected of the neglected tropical diseases (NTDs). The aim of this commentary is to describe the possible reasons why strongyloidiasis is so overlooked in Ethiopia, and shed light on better ways of control and elimination of the disease. Main body This commentary highlights three points why strongyloidiasis is the most neglected of the NTDs in Ethiopia. Firstly, lack of clear category within the NTDs resulted in omission of the disease from reports, intervention programs, and preventive chemotherapy guidelines. Secondly, magnitude of the disease is underestimated due to paucity of studies and low sensitivity of diagnostic methods coupled with asymptomatic nature of most of the infections. Finally, ivermectin (the drug of choice for treatment of strongyloidiasis) is not in use for control of the other soil-transmitted helminthiasis, nor is there ivermectin mass drug administration for control of strongyloidiasis. This might have created gap in control and elimination of the disease in Ethiopia and possibly elsewhere. Conclusion Strongyloidiasis appears to be the most neglected of the NTDs mainly due to nature of the infection, low sensitivity of the routine diagnostic tools and it’s exclusion from strategic plans and intervention programs. Moreover, studies on strongyloidiasis should use sensitive diagnostic tools. Strongyloidiasis control and elimination programs should be based on reliable evidence of epidemiology of the disease in Ethiopia. Graphic Abstract ![]()
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Guirou N, Resnikoff S, Yakoura AKH, Gouda M, Bakayoko S, Napo A, Elien RR, Rocca RD, Sylla F, Traoré L. Orbital migration of schistosome eggs: a case report. BMC Ophthalmol 2021; 21:189. [PMID: 33906611 PMCID: PMC8077795 DOI: 10.1186/s12886-021-01956-w] [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: 01/20/2021] [Accepted: 04/21/2021] [Indexed: 11/10/2022] Open
Abstract
Background Ocular damage, including damage to the conjunctiva, lacrimal gland, eyelids, and orbit, caused by Schistosoma haematobium is sporadic. We report a clinical case of orbital migration of schistosome eggs. Case presentation A 14-year-old boy of Malian nationality presented with a painless swelling of the upper right eyelid, which had been gradually increasing for approximately 3 months. Visual acuity was logMAR 0.10 and 0.00 in the right and left eye, respectively. External examination revealed a right palpebral mass, pushing the globe slightly downward and inward. Computed tomography revealed a mass of the right lacrimal gland. Total excision of the mass was performed by transpalpebral orbitotomy. Pathological examination revealed an inflammatory granulomatous infiltrate of the lacrimal gland consisting of lymphocytes, eosinophils, giant cells, epithelioid cell, histiocytes and calcified Schistosoma eggs with terminal spine. Urine examination revealed eggs of S. haematobium. Praziquantel 40 mg/kg was administered to the patient. The hematuria stopped after 1 week. After 3 years of follow-up, no recurrence was noted. Conclusions The bilharzian granuloma of the lacrimal gland is an ectopic site of the parasite. In this case, the granuloma was cured by surgical excision followed by a course of Praziquantel.
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Clinical implications and treatment options of tungiasis in domestic animals. Parasitol Res 2021; 120:4113-4123. [PMID: 33818640 DOI: 10.1007/s00436-021-07121-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 03/09/2021] [Indexed: 10/21/2022]
Abstract
Tunga penetrans, Tunga trimamillata and Tunga hexalobulata are the three species of sand fleas which cause tungiasis in domestic animals. Tunga penetrans and T. trimamillata are zoonotic in the tropical and sub-tropical endemic communities of Latin America and Africa. Tungiasis in animals frequently occurs alongside human tungiasis. Currently, most of the attention given to tungiasis is focusing on the human disease, and animal tungiasis is extremely neglected despite its public health and animal health significance. This review highlights recent findings concerning the clinical implications and treatment options but also summarises the occurrence, major features, public health and economic significance of tungiasis in domestic animals. Pigs, dogs, cats and domestic ruminants have been reported to harbour high intensities of sand fleas in endemic communities. High infection intensities cause significant animal morbidity which is often exacerbated by excoriations and secondary bacterial infections which are potentially fatal. In addition to the potential economic losses accruing from tungiasis-related morbidity, infected domestic animals contribute to transmission and persistence of sand fleas and eventually also to severe human disease. Although control of animal tungiasis is possible by adoption of proper husbandry practices, affected communities may not afford the resources required to implement them. Also, there are no widely acceptable and affordable insecticides for treatment of tungiasis in animals. Extension services aiming at increasing awareness on tungiasis and its control should be intensified. Also, available commercial insecticides should be evaluated for therapeutic and prophylactic properties against animal tungiasis.
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Rollins RL, Cowie RH, Echaluse MV, Medeiros MCI. Host snail species exhibit differential Angiostrongylus cantonensis prevalence and infection intensity across an environmental gradient. Acta Trop 2021; 216:105824. [PMID: 33422544 DOI: 10.1016/j.actatropica.2021.105824] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 12/30/2020] [Accepted: 12/31/2020] [Indexed: 01/27/2023]
Abstract
Diverse snail species serve as intermediate hosts of the parasitic nematode Angiostrongylus cantonensis, the etiological agent of human neuroangiostrongyliasis. However, levels of A. cantonensis infection prevalence and intensity vary dramatically among these host species. Factors contributing to this variation are largely unknown. Environmental factors, such as precipitation and temperature, have been correlated with overall A. cantonensis infection levels in a locale, but the influence of environment on infection in individual snail species has not been addressed. We identified levels of A. cantonensis prevalence and intensity in 16 species of snails collected from 29 sites along an environmental gradient on the island of Oahu, Hawaii. The relationship between infection levels of individual species and their environment was evaluated using AIC model selection of Generalized Linear Mixed Models incorporating precipitation, temperature, and vegetation cover at each collection site. Our results indicate that different mechanisms drive parasite prevalence and intensity in the intermediate hosts. Overall, snails from rainy, cool, green sites had higher infection levels than snails from dry, hot sites with less green vegetation. Intensity increased at the same rate along the environmental gradient in all species, though at different levels, while the relation between prevalence and environmental variables depended on species. These results have implications for zoonotic transmission, as human infection is a function of infection in the intermediate hosts, ingestion of which is the main pathway of transmission. The probability of human infection is greater in locations with higher rainfall, lower temperature and more vegetation cover because of higher infection prevalence in the gastropod hosts, but this depends on the host species. Moreover, severity of neuroangiostrongyliasis symptoms is likely to be greater in locations with higher rainfall, lower temperature, and more vegetation because of the higher numbers of infectious larvae (infection intensity) in all infected snail species. This study highlights the variation of infection prevalence and intensity in individual gastropod species, the individualistic nature of interactions between host species and their environment, and the implications for human neuroangiostrongyliasis in different environments.
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Middleton K, Bowen AC. Addressing normalization using culturally relevant approaches: An important adjunct to reducing the burden of impetigo and scabies. THE LANCET REGIONAL HEALTH. WESTERN PACIFIC 2021; 7:100102. [PMID: 34327421 PMCID: PMC8315659 DOI: 10.1016/j.lanwpc.2021.100102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 01/20/2021] [Indexed: 11/23/2022]
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