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Tumusiime J, Valderrama Bhraunxs N, Kagoro-Rugunda G, Namirembe D, Albrecht C, Twongyirwe R, Tolo CU, Jacobs L, Huyse T. Citizens can help to map putative transmission sites for snail-borne diseases. PLoS Negl Trop Dis 2024; 18:e0012062. [PMID: 38574112 PMCID: PMC11020946 DOI: 10.1371/journal.pntd.0012062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 04/16/2024] [Accepted: 03/11/2024] [Indexed: 04/06/2024] Open
Abstract
INTRODUCTION Schistosomiasis and fasciolosis are snail-borne diseases of great medical and veterinary health importance. The World Health Organization recommends complementing drug treatment with snail control and community involvement for disease elimination, but there is a general lack of snail experts and hence snail distribution data. Therefore, we adopted a citizen science approach and involved citizens in the monitoring of medically and veterinary important snail taxa. MATERIALS AND METHODS Snail data was collected weekly by 25 trained citizen scientists (CSs) at 76 sites around southern Lake Albert (Uganda) for 20 months. At each site, snails were searched for 30 minutes, sorted, target snail hosts identified to genus level, counted and data submitted through a smartphone application. The quality of this data was assessed by comparing it to monthly data collected by an 'expert' malacologist using the same sampling protocol. Generalised binomial logistic and linear mixed-effects models were used to analyse the variables for agreement between the CSs and expert. FINDINGS The binary agreement in presence/absence of Biomphalaria, Bulinus and Radix snails reported by the expert and CSs ranged between 70% and 86% (900 reports) with an average of 17% false negatives (sites wrongly defined as snail-free). The agreement for Biomphalaria and Radix increased with snail abundance, and false negatives decreased when the number of snails collected by citizens was aggregated per month. Site type significantly predicted binary agreement, which was lowest at lake sites (55%) and highest at spring sites (99%) with variations across genera. Similar temporal trends in snail abundance were recorded despite the expert reporting higher abundance. However, the relative abundance was consistent across site types. The match between the sites with highest Biomphalaria spp. abundance identified by CSs and expert was consistently high (~84.1%) and increased over time. CONCLUSIONS AND RECOMMENDATIONS Our results demonstrate the potential of citizen science to map putative schistosomiasis transmission sites. We therefore argue that this inclusive, powerful and cost-effective approach can be more sustainable than top-down monitoring and intervention campaigns.
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Affiliation(s)
- Julius Tumusiime
- Department of Biology, Mbarara University of Science and Technology, Mbarara, Uganda
- Institute of Animal Ecology and Systematics, Justus Liebig University Giessen, Giessen, Germany
| | - Noelia Valderrama Bhraunxs
- Department of Biology, Royal Museum for Central Africa, Tervuren, Belgium
- Department of Earth and Environmental Sciences, KU Leuven, Leuven, Belgium
| | - Grace Kagoro-Rugunda
- Department of Biology, Mbarara University of Science and Technology, Mbarara, Uganda
| | - Daisy Namirembe
- Department of Biology, Mbarara University of Science and Technology, Mbarara, Uganda
| | - Christian Albrecht
- Department of Biology, Mbarara University of Science and Technology, Mbarara, Uganda
- Institute of Animal Ecology and Systematics, Justus Liebig University Giessen, Giessen, Germany
| | - Ronald Twongyirwe
- Department of Environment and Livelihoods Support Systems, Mbarara University of Science and Technology, Mbarara, Uganda
| | - Casim Umba Tolo
- Department of Biology, Mbarara University of Science and Technology, Mbarara, Uganda
| | - Liesbet Jacobs
- Department of Earth and Environmental Sciences, KU Leuven, Leuven, Belgium
- Ecosystem and Landscape Dynamics, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands
| | - Tine Huyse
- Department of Biology, Royal Museum for Central Africa, Tervuren, Belgium
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Tumusiime J, Kagoro-Rugunda G, Tolo CU, Namirembe D, Schols R, Hammoud C, Albrecht C, Huyse T. An accident waiting to happen? Exposing the potential of urogenital schistosomiasis transmission in the Lake Albert region, Uganda. Parasit Vectors 2023; 16:398. [PMID: 37919743 PMCID: PMC10623741 DOI: 10.1186/s13071-023-06017-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 10/16/2023] [Indexed: 11/04/2023] Open
Abstract
BACKGROUND Urogenital schistosomiasis caused by the parasitic blood fluke Schistosoma haematobium is the most common form of that constitutes a majority of over 240 million schistosomiasis cases. The enigmatic absence of urogenital schistosomiasis in Uganda has, until now, been attributed to the absence of substantial populations of suitable snail intermediate hosts. METHODS Malacological surveys were carried out in 73 sites southeast of Lake Albert, Uganda in October and November 2020. Collected snails were transported to the laboratory for identification. The snails were identified using partial mitochondrial cytochrome c oxidase subunit one and nuclear internal transcribed spacer barcoding. Schistosome infections in snails were also assessed using cercarial shedding and rapid diagnostic PCR techniques. RESULTS We found Bulinus globosus and Bulinus nasutus productus, the main intermediate species in the transmission of S. haematobium in mainland East Africa. In this survey, B. globosus was more common than B. nasutus productus, with the former reported at four sites (total count = 188) and the latter reported at one site (total count = 79). Molecular testing revealed a high prevalence of Schistosoma bovis in B. nasutus productus (16%), but no S. haematobium infections were found. CONCLUSIONS Given the abundance of snail hosts and the risky human water contact behaviours observed, we highlight the potential for urogenital schistosomiasis transmission in the region.
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Affiliation(s)
- Julius Tumusiime
- Department of Biology, Mbarara University of Science and Technology, Mbarara, Uganda.
- Institute of Animal Ecology and Systematics, Justus Liebig University Giessen, Giessen, Germany.
| | - Grace Kagoro-Rugunda
- Department of Biology, Mbarara University of Science and Technology, Mbarara, Uganda
| | - Casim Umba Tolo
- Department of Biology, Mbarara University of Science and Technology, Mbarara, Uganda
| | - Daisy Namirembe
- Department of Biology, Mbarara University of Science and Technology, Mbarara, Uganda
| | - Ruben Schols
- Department of Biology, Royal Museum for Central Africa, Tervuren, Belgium
- Laboratory of Aquatic Biology, KU Leuven, Campus Kortrijk, Kortrijk, Belgium
| | - Cyril Hammoud
- Department of Biology, Royal Museum for Central Africa, Tervuren, Belgium
- Department of Biology, Ghent University, Ghent, Belgium
| | - Christian Albrecht
- Department of Biology, Mbarara University of Science and Technology, Mbarara, Uganda
- Institute of Animal Ecology and Systematics, Justus Liebig University Giessen, Giessen, Germany
| | - Tine Huyse
- Department of Biology, Royal Museum for Central Africa, Tervuren, Belgium
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Hammoud C, Kayenbergh A, Tumusiime J, Verschuren D, Albrecht C, Huyse T, Van Bocxlaer B. Trematode infection affects shell shape and size in Bulinus tropicus. Int J Parasitol Parasites Wildl 2022; 18:300-311. [PMID: 35957748 PMCID: PMC9357703 DOI: 10.1016/j.ijppaw.2022.07.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 07/07/2022] [Accepted: 07/09/2022] [Indexed: 12/02/2022]
Abstract
Trematodes can increase intraspecific variation in the phenotype of their intermediate snail host. However, the extent of such phenotypic changes remains unclear. We investigated the influence of trematode infection on the shell morphology of Bulinus tropicus, a common host of medically important trematodes. We focused on a snail population from crater lake Kasenda (Uganda). We sampled a single homogeneous littoral habitat to minimize the influence of environmental variation on shell phenotype, and barcoded snails to document snail genotypic variation. Among the 257 adult snails analysed, 99 tested positive for trematode infection using rapid-diagnostic PCRs. Subsequently we used high-throughput amplicon sequencing to identify the trematode (co-)infections. For 86 out of the 99 positive samples trematode species delineation could discriminate among combinations of (co-)infection by 11 trematode species. To avoid confounding effects, we focused on four prevalent trematode species. We performed landmark-based geometric morphometrics to characterize shell phenotype and used regressions to examine whether shell size and shape were affected by trematode infection and the developmental stage of infection (as inferred from read counts). Snails infected by Petasiger sp. 5, Echinoparyphium sp. or Austrodiplostomum sp. 2 had larger shells than uninfected snails or than those infected by Plagiorchiida sp. Moreover, the shell shape of snails infected solely by Petasiger sp. 5 differed significantly from that of uninfected snails and snails infected with other trematodes, except from Austrodiplostomum sp. 2. Shape changes included a more protuberant apex, an inward-folded outer apertural lip and a more adapically positioned umbilicus. Size differences were more pronounced in snails with ‘late’ infections (>25 days) compared to earlier-stage infections. No phenotypic differences were found between snails infected by a single trematode species and those harbouring co-infections. Further work is required to assess the complex causal links between trematode infections and shell morphological alterations of snail hosts. Trematode infections are linked to Bulinus tropicus shell shape and size variations. Variations in shell phenotype are trematode species-dependant. Trematode infections were analysed using diagnostic PCRs and amplicon sequencing. Snail shell morphology was analysed using landmark-based geometric morphometrics.
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Anyolitho MK, Poels K, Huyse T, Tumusiime J, Mugabi F, Tolo CU, Masquillier C, Nyakato VN. Knowledge, attitudes, and practices regarding schistosomiasis infection and prevention: A mixed-methods study among endemic communities of western Uganda. PLoS Negl Trop Dis 2022; 16:e0010190. [PMID: 35196328 PMCID: PMC8865686 DOI: 10.1371/journal.pntd.0010190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Accepted: 01/21/2022] [Indexed: 11/18/2022] Open
Abstract
INTRODUCTION In Uganda, schistosomiasis (re)infections have continued to remain high despite the implementation of mass drug administration and sensitization campaigns aimed at controlling the disease. This could imply that there are some barriers to the implemented preventive measures. We conducted a mixed-methods study in Kagadi and Ntoroko districts around Lake Albert to assess knowledge, attitudes, and practices regarding schistosomiasis and to explore and understand perspectives regarding the disease. MATERIALS AND METHODS Semi-structured survey questionnaires were administered to 337 household adults selected through systematic random sampling. We also interviewed 12 participants and held 28 focus-group discussion sessions with 251 individuals respectively. Quantitative data was analysed using frequencies, percentages, and chi-square tests for associations, while themes and sub-themes were used to analyse qualitative data respectively. FINDINGS A total of 98.5%, 81.3%, and 78.5% had heard about schistosomiasis, and knew the main transmission modes and symptoms, respectively. The majority (75.8%) said avoiding contact with water was a preventative way, while 67.5% said observing signs and symptoms was a form of diagnosis. Furthermore, 98.4% and 73.4% said it was important to defecate in latrines and to avoid contact with contaminated water respectively. However, it is difficult to avoid contact with lake water because it is the only source of livelihood, especially for fisher communities. Open defecation is commonly practiced along the lake due to insufficient space and difficulties in the construction of latrines. Myths and misconceptions reported include; lake water is safe, gassing in water causes transmission, fetching water early in the morning and from deep water is safe, and feces in the lake water act as a bait for catching fish. CONCLUSIONS AND RECOMMENDATIONS Despite adequate knowledge of schistosomiasis and a positive attitude towards its prevention, existing myths and misconceptions, coupled with persistent risky water, sanitation, and hygiene practices still pose a challenge. A more robust community-based awareness intervention using bottom-up participatory approaches, accompanied by the provision of clean and safe water sources and increasing latrine coverage, could provide lasting solutions to these barriers.
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Affiliation(s)
- Maxson Kenneth Anyolitho
- Department of Public Health, Lira University, Lira, Uganda
- Department of Human Development and Relational Sciences, Mbarara University of Science and Technology, Mbarara, Uganda
| | - Karolien Poels
- Department of Communication Studies, University of Antwerp, Antwerp, Belgium
| | - Tine Huyse
- Department of Biology, Royal Museum for Central Africa, Tervuren, Belgium
| | - Julius Tumusiime
- Department of Biology, Mbarara University of Science and Technology, Mbarara, Uganda
| | - Faith Mugabi
- Department of Human Development and Relational Sciences, Mbarara University of Science and Technology, Mbarara, Uganda
| | - Casim Umba Tolo
- Department of Biology, Mbarara University of Science and Technology, Mbarara, Uganda
| | | | - Viola Nilah Nyakato
- Department of Human Development and Relational Sciences, Mbarara University of Science and Technology, Mbarara, Uganda
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Tumwebaze I, Clewing C, Dusabe MC, Tumusiime J, Kagoro-Rugunda G, Hammoud C, Albrecht C. Molecular identification of Bulinus spp. intermediate host snails of Schistosoma spp. in crater lakes of western Uganda with implications for the transmission of the Schistosoma haematobium group parasites. Parasit Vectors 2019; 12:565. [PMID: 31775865 PMCID: PMC6882369 DOI: 10.1186/s13071-019-3811-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Accepted: 11/15/2019] [Indexed: 12/05/2022] Open
Abstract
Background Human schistosomiasis is the second most important tropical disease and occurs in two forms in Africa (intestinal and urogenital) caused by the digenetic trematodes Schistosoma mansoni and Schistosoma haematobium, respectively. A proposed recent shift of schistosomiasis above a previously established altitudinal threshold of 1400 m above sea level in western Ugandan crater lakes has triggered more research interest there. Methods Based on extensive field sampling in western Uganda and beyond and employing an approach using sequences of the mitochondrial barcoding gene cytochrome c oxidase subunit 1 (cox1) this study aims were: (i) identification and establishment of the phylogenetic affinities of Bulinus species as potential hosts for Schistosoma spp.; (ii) determining diversity, frequency and distribution patterns of Bulinus spp.; and (iii) establishing genetic variability and phylogeographical patterns using Bayesian inference and parsimony network analyses. Results Out of the 58 crater lakes surveyed, three species of Bulinus snails were found in 34 crater lakes. Bulinus tropicus was dominating, Bulinus forskalii was found in two lakes and Bulinus truncatus in one. The latter two species are unconfirmed potential hosts for S. haematobium in this region. However, Bulinus tropicus is an important species for schistosomiasis transmission in ruminants. Bulinus tropicus comprised 31 haplotypes while both B. forskalii and B. truncatus exhibited only a single haplotype in the crater lakes. All species clustered with most of the haplotypes from surrounding lake systems forming source regions for the colonization of the crater lakes. Conclusions This first detailed malacological study of the crater lakes systems in western Uganda revealed presence of Bulinus species that are either not known or not regionally known to be hosts for S. haematobium, the causing agent of human urogenital schistosomiasis. Though this disease risk is almost negligible, the observed dominance of B. tropicus in the crater lakes shows that there is a likelihood of a high risk of infections with Schistosoma bovis. Thus, extra attention should be accorded to safeguard wild and domestic ruminants in this region as the population benefits from these animals.
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Affiliation(s)
- Immaculate Tumwebaze
- Department of Animal Ecology and Systematics, Justus Liebig University Giessen, Giessen, Germany.
| | - Catharina Clewing
- Department of Animal Ecology and Systematics, Justus Liebig University Giessen, Giessen, Germany
| | | | - Julius Tumusiime
- Department of Biology, Mbarara University of Science and Technology, Mbarara, Uganda
| | - Grace Kagoro-Rugunda
- Department of Biology, Mbarara University of Science and Technology, Mbarara, Uganda
| | - Cyril Hammoud
- Department of Biology, Royal Museum for Central Africa, Leuvensesteenweg 13, 3080, Tervuren, Belgium.,Limnology Research Unit, Ghent University, K. L. Ledeganckstraat 35, 9000, Ghent, Belgium
| | - Christian Albrecht
- Department of Animal Ecology and Systematics, Justus Liebig University Giessen, Giessen, Germany.,Department of Biology, Mbarara University of Science and Technology, Mbarara, Uganda
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