Dataset Information

Past and current biological factors affecting malaria in the low transmission setting of Botswana: A review.

ABSTRACT: Malaria continues to be one of the top infectious agents contributing to morbidity and mortality in sub-Saharan Africa. Annually, Botswana accounts only for a small proportion of cases (<<1%). Despite significantly reduced incidence rate, the country still experiences sporadic outbreaks that hamper the goal of malaria elimination. This review evaluated previous and current biological factors that impact malaria in Botswana, specifically focussing on the vectors, the parasite and the host. This was accomplished via a literature review evaluating these variables in Botswana. Current literature suggests that Anopheles arabiensis is the main malaria vector in the country. Several other potential vectors have been found widely distributed throughout Botswana in high numbers, yet remain largely unstudied with regards to their contribution to the country's malaria burden. We also report the most up to date list of all Anopheles species that have been found in Botswana. Plasmodium falciparum is responsible for the vast majority of symptomatic malaria in the country and some drug resistance markers have been documented for this species. Plasmodium vivax has been reported in asymptomatic subjects, even though a large proportion of the Botswana population appears to be Duffy antigen negative. Very little is known about the true distribution of P. vivax and no point of care testing infrastructure for this species exists in Botswana, making it difficult to tailor treatment to address possible recrudescence or relapse. Due to a genetically diverse population with a substantial Khoisan contribution into the Bantu genetic background, several phenotypes that potentially impact prevalence and severity of malaria exist within the country. These include sickle cell trait, Glucose-6-Phosphate Dehydrogenase deficiency, and Duffy negativity. This review highlights the information that currently exists on malaria in Botswana. It also postulates that a comprehensive understanding of these aforementioned biological factors may help to explain malaria persistence in Botswana.

SUBMITTER: Bango ZA

PROVIDER: S-EPMC7354381 | biostudies-literature | 2020 Jul

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Past and current biological factors affecting malaria in the low transmission setting of Botswana: A review.

Bango Zackary Austin ZA Tawe Leabaneng L Muthoga Charles Waithaka CW Paganotti Giacomo Maria GM

Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases 20200712

Malaria continues to be one of the top infectious agents contributing to morbidity and mortality in sub-Saharan Africa. Annually, Botswana accounts only for a small proportion of cases (<<1%). Despite significantly reduced incidence rate, the country still experiences sporadic outbreaks that hamper the goal of malaria elimination. This review evaluated previous and current biological factors that impact malaria in Botswana, specifically focussing on the vectors, the parasite and the host. This w ...[more]

PMID: 32668367

Similar Datasets

Project description:BackgroundUnderstanding the behaviour of local malaria vectors is essential as effectiveness of the commonly used vector-targeted malaria control tools heavily relies on behaviour of the major malaria vectors. This study was conducted to determine species composition, biting behaviour, host preference and infectivity of anopheline mosquitoes, and assess utilization of insecticide-treated nets (ITNs) in a low transmission setting in Southwest Ethiopia.MethodsAdult anopheline mosquitoes were collected using human landing catches (HLCs), Centers for Disease Control and Prevention (CDC) light traps (LTs) and Pyrethrum Spray Catches (PSCs) from June 2016 to May 2018 in Kishe, Jimma Zone, Southwest Ethiopia. The anopheline mosquitoes were morphologically identified. Moreover, sub-sample of An. gambiae s.l. was identified to species using polymerase chain reaction (PCR). Circum-sporozoite proteins (CSPs) and blood meal sources of the anopheline mosquitoes were tested using enzyme-linked immunosorbent assay (ELISA). In addition, a cross-sectional survey was conducted to assess ITN utilization by the inhabitants.ResultsA total of 3659 anopheline mosquitoes comprising An. coustani complex (84.4%), An. gambiae s.l. (11.3%), and An. pharoensis and An. squamosus comprising less than 5% were collected. The anopheline mosquitoes showed marked outdoor (67%) and early evening (63%) biting behaviour. An. coustani complex and An. gambiae s.l. were predominantly zoophilic and anthropophilic, respectively. None of the sampled anopheline were CSP-positive. Most of the households (97.8%) owned at least one ITN, with modest usage by the inhabitants (73.4%). ITN usage was significantly higher among under-five children (AOR = 7.9, 95% CI: 4.41-14.03), household heads and spouses (AOR = 4.8, 95% CI: 3.0-7.59), those with sufficient access to ITNs (AOR = 1.8, 95% CI: 1.39-2.35), and who were not utilizing alternative mosquito repellents (AOR = 2.2, 95% CI: 1.58-2.99).ConclusionThe anopheline mosquito species exhibited predominantly outdoor and early evening biting activity. Household ITN coverage was high with slight gap in usage. Vector control interventions should target outdoor and early biting vectors to further suppress the local mosquito population. Moreover, sensitization of the community on consistent use of ITNs is required.

Project description:An increasing number of phylogenomic studies have documented a clear "footprint" of postspeciation introgression among closely related species. Nonetheless, systematic genome-wide studies of factors that determine the likelihood of introgression remain rare. Here, we propose an a priori hypothesis-testing framework that uses introgression statistics-including a new metric of estimated introgression, D p-to evaluate general patterns of introgression prevalence and direction across multiple closely related species. We demonstrate this approach using whole genome sequences from 32 lineages in 11 wild tomato species to assess the effect of three factors on introgression-genetic relatedness, geographical proximity, and mating system differences-based on multiple trios within the "ABBA-BABA" test. Our analyses suggest each factor affects the prevalence of introgression, although our power to detect these is limited by the number of comparisons currently available. We find that of 14 species pairs with geographically "proximate" versus "distant" population comparisons, 13 showed evidence of introgression; in 10 of these cases, this was more prevalent between geographically closer populations. We also find modest evidence that introgression declines with increasing genetic divergence between lineages, is more prevalent between lineages that share the same mating system, and-when it does occur between mating systems-tends to involve gene flow from more inbreeding to more outbreeding lineages. Although our analysis indicates that recent postspeciation introgression is frequent in this group-detected in 15 of 17 tested trios-estimated levels of genetic exchange are modest (0.2-2.5% of the genome), so the relative importance of hybridization in shaping the evolutionary trajectories of these species could be limited. Regardless, similar clade-wide analyses of genomic introgression would be valuable for disentangling the major ecological, reproductive, and historical determinants of postspeciation gene flow, and for assessing the relative contribution of introgression as a source of genetic variation.

Dataset Information

Past and current biological factors affecting malaria in the low transmission setting of Botswana: A review.

Publications

Past and current biological factors affecting malaria in the low transmission setting of Botswana: A review.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets