Schistosomes of small mammals from the Lake Victoria Basin, Kenya: new species, familiar species, and implications for schistosomiasis control

Parasitology ◽  
2010 ◽  
Vol 137 (7) ◽  
pp. 1109-1118 ◽  
Author(s):  
B. HANELT ◽  
I. N. MWANGI ◽  
J. M. KINUTHIA ◽  
G. M. MAINA ◽  
L. E. AGOLA ◽  
...  
Keyword(s):  
Schistosoma Mansoni ◽  
Small Mammals ◽  
Lake Victoria ◽  
Sub Saharan Africa ◽  
Lake Victoria Basin ◽  
Murid Rodent ◽  
Schistosomiasis Control ◽  
Wild Mammals ◽  
Sub Saharan ◽  
Reservoir Hosts

SUMMARYRecent schistosomiasis control efforts in sub-Saharan Africa have focused nearly exclusively on treatment of humans with praziquantel. However, the extent to which wild mammals act as reservoirs forSchistosoma mansoniand therefore as sources of renewed transmission following control efforts is poorly understood. With the objective to study the role of small mammals as reservoir hosts, 480 animals belonging to 9 rodent and 1 insectivore species were examined for infection with schistosomes in Kisumu, in the Lake Victoria Basin, Kenya. Animals were collected from 2 sites: near the lakeshore and from Nyabera Marsh draining into the lake. A total of 6·0% of the animals captured, including 5 murid rodent species and 1 species of shrew (Crocidura olivieri) were infected with schistosomes. Four schistosome species were recovered and identified usingcox1 DNA barcoding:S. mansoni,S. bovis,S. rodhainiandS. kisumuensis, the latter of which was recently described from Nyabera Marsh.Schistosoma mansoniandS. rodhainiwere found infecting the same host individual (Lophuromys flavopunctatus), suggesting that this host species could be responsible for the production of hybrid schistosomes found in the area. Although the prevalence ofS. mansoniinfection in these reservoir populations was low (1·5%), given their potentially vast population size, their impact on transmission needs further study. Reservoir hosts could perpetuate snail infections and favour renewed transmission to humans once control programmes have ceased.

Molecular epidemiology and phylogeography of Schistosoma mansoni around Lake Victoria

Parasitology ◽  
2010 ◽  
Vol 137 (13) ◽  
pp. 1937-1949 ◽  
Author(s):  
C. J. STANDLEY ◽  
N. B. KABATEREINE ◽  
C. N. LANGE ◽  
N. J. S. LWAMBO ◽  
J. R. STOTHARD
Keyword(s):  
Population Genetics ◽  
Schistosoma Mansoni ◽  
Molecular Epidemiology ◽  
Lake Victoria ◽  
Public Health Problem ◽  
Human Migration ◽  
Sub Saharan Africa ◽  
Major Public Health Problem ◽  
Sub Saharan ◽  
Coi Sequences

SUMMARYIntestinal schistosomiasis continues to be a major public health problem in sub-Saharan Africa, and is endemic in communities around Lake Victoria. Interest is growing in the molecular evolution and population genetic structure of Schistosoma mansoni and we describe a detailed analysis of the molecular epidemiology and phylogeography of S. mansoni from Lake Victoria. In total, 388 cytochrome oxidase 1 (COI) sequences were obtained from 25 sites along the Ugandan, Tanzanian and Kenyan shorelines of Lake Victoria, and 122 unique barcodes were identified; 9 corresponded to previously discovered barcodes from Lakes Victoria and Albert. A subset of the data, composed of COI sequences from miracidia from 10 individual children, was used for population genetics analyses; these results were corroborated by microsatellite analysis of 4 isolates of lab-passaged adult worms. Overall, 12 barcodes were found to be shared across all 3 countries, whereas the majority occurred singly and were locally restricted. The population genetics analyses were in agreement in revealing high diversity at the level of the human host and negligible population structuring by location. The lack of correlation between genetic distance and geographical distance in these data may be attributed to the confounding influence of high intra-individual diversity as well as human migration between communities.

scholarly journals UGANDA: A Country Profile

2020 ◽  
Author(s):  
Ahmad Masum
Keyword(s):  
Urban Areas ◽  
Democratic Republic Of Congo ◽  
Lake Victoria ◽  
Sub Saharan Africa ◽  
Positive Development ◽  
Lake Victoria Basin ◽  
The North ◽  
British Colony ◽  
Sub Saharan ◽  
The Government

Uganda lies in the heart of Sub-Saharan Africa. It is situated in East Africa and occupies an area of 241,038 sq km (roughly twice the size of the state of Pennsylvania) and its population is about 35,873,253 (CIA World Factbook, 2012). Uganda is bordered by Tanzania and Rwanda to the south, Democratic Republic of Congo to the west, South Sudan to the north, and Kenya to the east. Uganda is a landlocked country and occupies most of the Lake Victoria Basin, which was formed by the geological shifts that created the Rift Valley during the Pleistocene era. Uganda was a British colony and became an independent- sovereign nation in 1962 without a bloody struggle. Several ethnic groups reside in the country i.e. Baganda, Banyankole, Bahima, Bakiga, Bunyoro, Batoro, Basoga, Bagisu, Langi, Acholi, Lugbara, Karamojong and others. English is the official language by virtue of Article 6(1) of the 1995 Constitution and Swahili is also widely spoken especially in the urban areas. Uganda has no State religion. As a country, Uganda has witnessed some positive development in the area of security. The government managed to plant the seeds of peace in the north by defeating the Lord Resistance Army (LRA) led by Joseph Kony.    

scholarly journals Characterizing the genomic variation and population dynamics of Plasmodium falciparum malaria parasites in and around Lake Victoria, Kenya

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ashley Osborne ◽  
Emilia Manko ◽  
Mika Takeda ◽  
Akira Kaneko ◽  
Wataru Kagaya ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Population Dynamics ◽  
Malaria Elimination ◽  
Lake Victoria ◽  
Genomic Variation ◽  
Genomic Diversity ◽  
Sub Saharan Africa ◽  
Lake Victoria Basin ◽  
East African ◽  
Lake Region

AbstractCharacterising the genomic variation and population dynamics of Plasmodium falciparum parasites in high transmission regions of Sub-Saharan Africa is crucial to the long-term efficacy of regional malaria elimination campaigns and eradication. Whole-genome sequencing (WGS) technologies can contribute towards understanding the epidemiology and structural variation landscape of P. falciparum populations, including those within the Lake Victoria basin, a region of intense transmission. Here we provide a baseline assessment of the genomic diversity of P. falciparum isolates in the Lake region of Kenya, which has sparse genetic data. Lake region isolates are placed within the context of African-wide populations using Illumina WGS data and population genomic analyses. Our analysis revealed that P. falciparum isolates from Lake Victoria form a cluster within the East African parasite population. These isolates also appear to have distinct ancestral origins, containing genome-wide signatures from both Central and East African lineages. Known drug resistance biomarkers were observed at similar frequencies to those of East African parasite populations, including the S160N/T mutation in the pfap2mu gene, which has been associated with delayed clearance by artemisinin-based combination therapy. Overall, our work provides a first assessment of P. falciparum genetic diversity within the Lake Victoria basin, a region targeting malaria elimination.

scholarly journals Effect of Phenotypic Screening of Extracts and Fractions of Erythrophleum ivorense Leaf and Stem Bark on Immature and Adult Stages of Schistosoma mansoni

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Gertrude Kyere-Davies ◽  
Christian Agyare ◽  
Yaw Duah Boakye ◽  
Brian M. Suzuki ◽  
Conor R. Caffrey
Keyword(s):  
Schistosoma Mansoni ◽  
Petroleum Ether ◽  
Developmental Stages ◽  
Stem Bark ◽  
Current Treatment ◽  
Sub Saharan Africa ◽  
Bark Extract ◽  
Phenotypic Screening ◽  
Sub Saharan ◽  
New Treatments

Schistosomiasis is a disease caused by a flatworm parasite that infects people in tropical and subtropical regions of Sub-Saharan Africa, South America, China, and Southeast Asia. The reliance on just one drug for current treatment emphasizes the need for new chemotherapeutic strategies. The aim of this study was to determine the phenotypic effects of extracts and fractions of leaf and stem bark of Erythrophleum ivorense (family Euphorbiaceae), a tree that grows in tropical parts of Africa, on two developmental stages of Schistosoma mansoni, namely, postinfective larvae (schistosomula or somules) and adults. Methanol leaf and stem bark extracts of E. ivorense were successively fractionated with acetone, petroleum ether, ethyl acetate, and methanol. These fractions were then incubated with somules at 0.3125 to 100 μg/mL and with adults at 1.25 μg/mL. The acetone fractions of both the methanol leaf and bark of E. ivorense were most active against the somules whereas the petroleum ether fractions showed least activity. For adult parasites, the acetone fraction of methanol bark extract also elicited phenotypic changes. The data arising provide the first step in the discovery of new treatments for an endemic infectious disease using locally sourced African medicinal plants.

scholarly journals When Should the Emphasis on Schistosomiasis Control Move to Elimination?

2018 ◽  
Vol 3 (3) ◽  
pp. 85 ◽  
Author(s):  
W. Secor ◽  
Daniel Colley
Keyword(s):  
South America ◽  
Operational Research ◽  
Sub Saharan Africa ◽  
World Health ◽  
Evidence Based ◽  
Clean Water ◽  
Schistosomiasis Control ◽  
The World ◽  
The Caribbean ◽  
Sub Saharan

The stated goal of the World Health Organization’s program on schistosomiasis is paraphrased as follows: to control morbidity and eliminate transmission where feasible. Switching from a goal of controlling morbidity to interrupting transmission may well be currently feasible in some countries in the Caribbean, some areas in South America, northern Africa, and selected endemic areas in sub-Saharan Africa where there have been improvements in sanitation and access to clean water. However, in most of sub-Saharan Africa, where programmatic interventions still consist solely of annual mass drug administration, such a switch in strategies remains premature. There is a continued need for operational research on how best to reduce transmission to a point where interruption of transmission may be achievable. The level of infection at which it is feasible to transition from control to elimination must also be defined. In parallel, there is also a need to develop and evaluate approaches for achieving and validating elimination. There are currently neither evidence-based methods nor tools for breaking transmission or verifying that it has been accomplished. The basis for these statements stems from numerous studies that will be reviewed and summarized in this article; many, but not all of which were undertaken as part of SCORE, the Schistosomiasis Consortium for Operational Research and Evaluation.

scholarly journals Dilemma of nitrogen management for future food security in sub-Saharan Africa – a review

Soil Research ◽  
2017 ◽  
Vol 55 (6) ◽  
pp. 425 ◽  
Author(s):  
Cargele Masso ◽  
Fredrick Baijukya ◽  
Peter Ebanyat ◽  
Sifi Bouaziz ◽  
John Wendt ◽  
...  
Keyword(s):  
Food Security ◽  
Food Production ◽  
Smallholder Farmers ◽  
Lake Victoria ◽  
Research Capacity ◽  
Sub Saharan Africa ◽  
N Recovery ◽  
Sub Saharan ◽  
Other World ◽  
N Use

Food security entails having sufficient, safe, and nutritious food to meet dietary needs. The need to optimise nitrogen (N) use for nutrition security while minimising environmental risks in sub-Saharan Africa (SSA) is overdue. Challenges related to managing N use in SSA can be associated with both insufficient use and excessive loss, and thus the continent must address the ‘too little’ and ‘too much’ paradox. Too little N is used in food production (80% of countries have N deficiencies), which has led to chronic food insecurity and malnutrition. Conversely, too much N load in water bodies due mainly to soil erosion, leaching, limited N recovery from wastewater, and atmospheric deposition contributes to eutrophication (152 Gg N year–1 in Lake Victoria, East Africa). Limited research has been conducted to improve N use for food production and adoption remains low, mainly because farming is generally practiced by resource-poor smallholder farmers. In addition, little has been done to effectively address the ‘too much’ issues, as a consequence of limited research capacity. This research gap must be addressed, and supportive policies operationalised, to maximise N benefits, while also minimising pollution. Innovation platforms involving key stakeholders are required to address N use efficiency along the food supply chain in SSA, as well as other world regions with similar challenges.

scholarly journals Modelling potential range expansion of an underutilised food security crop in Sub-Saharan Africa

2021 ◽  
Author(s):  
Olef Koch ◽  
Wendawek Abebe Mengesha ◽  
Samuel Pironon ◽  
Pagella Tim ◽  
Ian Ondo ◽  
...  
Keyword(s):  
Food Security ◽  
Range Expansion ◽  
Lake Victoria ◽  
Sub Saharan Africa ◽  
Eastern Africa ◽  
Small Scale ◽  
Potential Range ◽  
Niche Modelling ◽  
Ethical Implications ◽  
Sub Saharan

Abstract Despite substantial growth in global agricultural production, food and nutritional insecurity is rising in Sub-Saharan Africa. Identification of underutilised indigenous crops with useful food security traits may provide part of the solution. Enset (Ensete ventricosum) is a perennial banana relative with cultivation restricted to southwestern Ethiopia, where high productivity and harvest flexibility enables it to provide a starch staple for ~20 million people. An extensive wild distribution suggests that a much larger region may be climatically suitable for cultivation. Here we use ensemble ecological niche modelling to predict the potential range for enset cultivation within southern and eastern Africa. We find contemporary bioclimatic suitability for a 12-fold range expansion, equating to 21.9% of crop land and 28.4% of the population in the region. Integration of crop wild relative diversity, which has broader climate tolerance, could enable a 19-fold expansion, particularly to dryer and warmer regions. Whilst climate change may cause a 37% – 52% reduction in potential range by 2070, large centres of suitability remain in the Ethiopian Highlands, Lake Victoria region and the Drakensberg Range. We combine our bioclimatic assessment with socioeconomic data to identify priority areas with high population density, seasonal food deficits and predominantly small-scale subsistence agriculture, where integrating enset may be particularly feasible and deliver climate resilience. When incorporating the genetic potential of wild populations, enset cultivation might prove feasible for an additional 87.2 - 111.5 million people, 27.7 – 33 million of which are in Ethiopia outside of enset’s current cultivation range. Finally, we consider explanations why enset cultivation has not expanded historically, and ethical implications of expanding previously underutilised species.

scholarly journals Mini-FLOTAC as an alternative, non-invasive diagnostic tool for Schistosoma mansoni and other trematode infections in wildlife reservoirs

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Stefano Catalano ◽  
Amelia Symeou ◽  
Kirsty J. Marsh ◽  
Anna Borlase ◽  
Elsa Léger ◽  
...  
Keyword(s):  
Schistosoma Mansoni ◽  
Sub Saharan Africa ◽  
Health Concern ◽  
Post Mortem ◽  
Post Mortem Examination ◽  
Non Invasive ◽  
Flotac Technique ◽  
Endemic Areas ◽  
Sub Saharan ◽  
Trematode Infections

Abstract Background Schistosomiasis and food-borne trematodiases are not only of major public health concern, but can also have profound implications for livestock production and wildlife conservation. The zoonotic, multi-host nature of many digenean trematodes is a significant challenge for disease control programmes in endemic areas. However, our understanding of the epidemiological role that animal reservoirs, particularly wild hosts, may play in the transmission of zoonotic trematodiases suffers a dearth of information, with few, if any, standardised, reliable diagnostic tests available. We combined qualitative and quantitative data derived from post-mortem examinations, coprological analyses using the Mini-FLOTAC technique, and molecular tools to assess parasite community composition and the validity of non-invasive methods to detect trematode infections in 89 wild Hubert’s multimammate mice (Mastomys huberti) from northern Senegal. Results Parasites isolated at post-mortem examination were identified as Plagiorchis sp., Anchitrema sp., Echinostoma caproni, Schistosoma mansoni, and a hybrid between Schistosoma haematobium and Schistosoma bovis. The reports of E. caproni and Anchitrema sp. represent the first molecularly confirmed identifications for these trematodes in definitive hosts of sub-Saharan Africa. Comparison of prevalence estimates derived from parasitological analysis at post-mortem examination and Mini-FLOTAC analysis showed non-significant differences indicating comparable results between the two techniques (P = 1.00 for S. mansoni; P = 0.85 for E. caproni; P = 0.83 for Plagiorchis sp.). A Bayesian model, applied to estimate the sensitivities of the two tests for the diagnosis of Schistosoma infections, indicated similar median posterior probabilities of 83.1% for Mini-FLOTAC technique and 82.9% for post-mortem examination (95% Bayesian credible intervals of 64.0–94.6% and 63.7–94.7%, respectively). Conclusions Our results showed that the Mini-FLOTAC could be applied as an alternative diagnostic technique for the detection of the zoonotic S. mansoni and other trematodes in rodent reservoirs. The implementation of non-invasive diagnostics in wildlife would offer numerous advantages over lethal sampling methodologies, with potential impact on control strategies of zoonotic helminthiases in endemic areas of sub-Saharan Africa and on fostering a framework of animal use reduction in scientific practice.

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