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Chloroquine/hydroxychloroquine have been proposed as potential treatments for COVID-19. These drugs have warning labels for use in individuals with glucose-6-phosphate dehydrogenase (G6PD) deficiency. Analysis of whole genome sequence data of 458 individuals from sub-Saharan Africa showed significant G6PDvariation across the continent. We identified nine variants, of which four are potentially deleterious to G6PD function, and one (rs1050828) that is known to cause G6PD deficiency. We supplemented data for the rs1050828 variant with genotype array data from over 11,000 Africans. Although this variant is common in Africans overall, large allele frequency differences exist between sub-populations. African sub-populations in the same country can show significant differences in allele frequency (e.g. 16.0% in Tsonga vs 0.8% in Xhosa, both in South Africa, p= 2.4 × 10−3). The high prevalence of variants in the G6PDgene found in this analysis suggests that it may be a significant interaction factor in clinical trials of chloroquine and hydroxychloroquine for treatment of COVID-19 in Africans.

The cattle tick Rhipicephalus microplusis the most important arthropod vector of livestock diseases globally. Since its introduction in West Africa a decade ago, it has been reported in Ivory Coast, Benin, Togo, Mali, Burkina Faso and Nigeria with potentially far-reaching adverse impacts on the livestock sector in the region. Cameroon is located on a major route for transboundary cattle trade between Central and West Africa and it is therefore at risk from R. microplusinvasion. This study investigated the occurrence of R. microplusin Cameroon, the genetic polymorphism of the tick and population structure of isolates from different regions of the country to provide data that underpin the design of future vector control programs.

Human African trypanosomiasis (HAT) has been targeted for zero transmission to humans by 2030. Animal reservoirs of gambiense-HAT could jeopardize these elimination goals. This study was undertaken to identify potential host reservoirs for Trypanosoma brucei gambienseby detecting its natural infections in domestic animals of Chadian HAT foci. Blood samples were collected from 267 goats, 181 sheep, 154 dogs, and 67 pigs. Rapid diagnostic test (RDT) and capillary tube centrifugation (CTC) were performed to search for trypanosomes. DNA was extracted from the buffy coat, and trypanosomes of the subgenus Trypanozoonas well as T. b. gambiensewere identified by PCR. Of 669 blood samples, 19.4% were positive by RDT and 9.0% by CTC. PCR revealed 150 animals (22.4%) with trypanosomes belonging to Trypanozoon, including 18 (12%) T. b. gambiense. This trypanosome was found in all investigated animal species and all HAT foci. Between animal species or villages, no significant differences were observed in the number of animals harboring T. b. gambienseDNA. Pigs, dogs, sheep and goats appeared to be potential reservoir hosts for T. b. gambiensein Chad. The identification of T. b. gambiensein all animal species of all HAT foci suggests that these animals should be considered when designing new control strategies for sustainable elimination of HAT. Investigations aiming to decrypt their specific role in each epidemiological setting are important to achieve zero transmission of HAT.

Tsetse flies are the cyclical vector of human and animal African trypanosomiasis. To improve vector control in order to achieve the elimination of human African trypanosomiasis (HAT) and boost the control of animal diseases, investigations have been undertaken on the tripartite association between tsetse, trypanosome, and symbionts. It is in this light that Sodalis glossinidiusand different trypanosomes were identified in Glossina palpalis palpaliscaught in Fontem in southern Cameroon. For this study, DNA was extracted from whole flies, and S. glossinidiusand different trypanosome species were identified by polymerase chain reaction (PCR). Statistical analyses were performed to compare the trypanosome and S. glossinidiusinfection rates and to look for an association between these microorganisms. Of the 274 G. p. palpaliscaught, 3.3% (9/274) were teneral. About 35% (96/274) of these flies harbored S. glossinidius.Of the 265 non-teneral flies, 37.7% were infected by trypanosomes. The infection rates of Trypanosoma congolense “forest type” and Trypanosoma vivaxwere 26.04% and 18.11%, respectively. About 6.41% of tsetse harbored mixed infections of T. congolenseand T. vivax. Of the 69 tsetse with T. congolenseinfections, 33.33% (23/69) harbored S. glossinidiuswhile 71.86% (69/96) of flies harboring S. glossinidiuswere not infected by trypanosomes. No association was observed between S. glossinidiusand trypanosome infections. Some wild tsetse harbor S. glossinidiusand trypanosomes, while others have no infection or are infected by only one of these microorganisms. We conclude that the presence of S. glossinidiusdoes not favor trypanosome infections in G. p. palpalisof the Fontem focus.

Despite the economic impact of trypanosome infections, few investigations have been undertaken on the population genetics and transmission dynamics of animal trypanosomes. In this study, microsatellite markers were used to investigate the population genetics of Trypanosoma congolense“forest type”, with the ultimate goal of understanding its transmission dynamics between tsetse flies and domestic animals. Blood samples were collected from pigs, sheep, goats and dogs in five villages in Fontem, South-West region of Cameroon. In these villages, tsetse were captured, dissected and their mid-guts collected. DNA was extracted from blood and tsetse mid-guts and specific primers were used to identify T. congolense“forest type”. All positive samples were genetically characterized with seven microsatellite markers. Genetic analyses were performed on samples showing single infections of T. congolense“forest type”. Of the 299 blood samples, 137 (46%) were infected by T. congolense“forest type”. About 3% (54/1596) of tsetse fly mid-guts were infected by T. congolense“forest type”. Of 182 samples with T. congolense“forest type”, 52 were excluded from the genetic analysis. The genetic analysis on the 130 remaining samples revealed polymorphism within and between subpopulations of the target trypanosome. The dendrogram of genetic similarities was subdivided into two clusters and three sub-clusters, indicating one major and several minor genotypes of T. congolense“forest type” in tsetse and domestic animals. The low FSTvalues suggest low genetic differentiation and no sub-structuration within subpopulations. The same T. congolensegenotypes appear to circulate in tsetse and domestic animals.