Geographical Distribution of Biomphalaria pfeifferi snails in East Africa

There is limited information on the distribution of B. pfeifferi, an important snail intermediate host of schistosomiasis, in East Africa. This study assessed the incidence and geographical distribution of B. pfeifferi snails in Kenya, Uganda and Tanzania. Maximum Entropy modeling was used to predict the potential distribution of B. pfeifferi snails, in line with habitat suitability. Malacological surveys were then conducted guided by MaxEnt predictions and information obtained from previous research papers. The surveys were conducted at a total of 156 sites including streams, rivers, lake shores, dams and irrigation canals over a 3 year period (2018 to 2020). Geographical coordinates, ecological and physicochemical information was recorded for the sites visited. Snails were identified morphologically, based on shell characters using established identification keys. B. pfeifferi snails were found at 23.07% (36/156) of the sites sampled. Streams proved to be the habitats most preferred by B. pfeifferi snails (50% of all of the sites where the snails were found were streams), followed by rivers (20.6%), irrigation canals (8.8%), lake shores (8.8%), springs (5.9%), and dams (5.9%) with snail abundance increasing with increase in temperature and decrease in water depth. B. pfeifferi was found in the Lake Victoria basin, Mwea Irrigation Scheme and Eastern Province of Kenya, the Lake Albert region, Lango region, Soroti district, Lower Moshi irrigation scheme, Babati district, Iringa region, Tabora region and Kigoma region. Information on the distribution of B. pfeifferi in East Africa will aid in developing prevention and control strategies for schistosomiasis.

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

Characterising 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.

Molecular Diversity of Arbuscular Mycorrhizal Fungi (AMF) Associated with Carissa edulis, an Endangered Plant Species along Lake Victoria Basin of Kenya

Carissa edulis is a tropical plant belonging to the family Apocynaceae. The species is widely used in the preparation of various herbal medicines. Earlier works in Kenya show that an aqueous extract from the roots of C. edulis has remarkable anti-herpes simplex virus. Due to its medicinal value, the species has been overexploited in its natural range and requires conservation interventions. Studies show that the species has beneficial relationships with arbuscular mycorrhizal fungi (AMF) that can enhance restoration of its population; however, no study has been undertaken to document the diversity of these AMF species. This study evaluated the genetic diversity of AMF associated with the roots of C. edulis within Lake Victoria basin ecosystem of Kenya. A cross-sectional, laboratory-based prospective study was carried out from roots of C. edulis collected from six sites within the ecosystem. Root samples were collected from 6 points (replicates) per site. AMF was assessed through morphological characterization and sequencing of small subunit of ribosomal DNA. Morphological identification identified four genera of AMF (Gigaspora, Acaulospora, Scutellospora, and Glomus) with no significant difference among the sites. Molecular analysis also revealed presence of four genera, but only two (Glomus and Acaulospora) were common for both the analyses with Glomus as the most predominant genera. In all the sites, there were large numbers of spores both in soil and in the roots confirming the association between C. edulis and AMF.