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Background: To improve vector control of tsetse transmitted trypanosomiases through a better understanging of the vectorial competence of tsetse flies, investigations have been undertaken on the bacterial fauna of different tsetse species. It is in this light that Wolbachia and Sodalis glossinidius were detected in wild populations of Glossina morsistans submorsistans caught in the area of lake Iro in the south of Chad with the aim of generating data that may help to understand the influence of these symbiotic microorganisms on the vectorial competence of G. m. submorsistans. Methods: Tsetse flies were captured using biconical traps. DNA was extracted from tsetse body using the resin chelex. Sodalis glossinidius and Wolbachia were investigated by PCR using specific primers for pSG 2 and wsp genes. Comparisons between S. glossinidius and Wolbachia infections were performed according to sex and sampling periods and association studies between trypanosome infections and S. glossinidius or Wolbachia were performed. Results: From 345 G. m. submorsitans analyzed, 9.0% and 14.5% were respectively infected with S. glossinidius and Wolbachia. Only 2.31% of all tsetse flies hosted the 2 bacteria. Of all trypanosome-infected flies, 7.1% and 9.8% hosted respectively S. glossinidius and Wolbachia. No association was observed between Wolbachia and trypanosomes while significant association (r = 4.992; P = 0.025) was found between S. glossinidius and trypanosome infections. Although significant association (r = 3.147; P = 0.043) was observed between S. glossinidius and T. simiae, none was found with T. congolense or T. godfreyi. Conclusion: This study revealed S. glossinidius and Wolbachia in wild population of G. m. submorsitans of lake Iro. It showed that few tsetse flies are co-infected by Wolbachia and S. glossinidius. The presence of S. glossinidius seems to favor trypanosome infections while Wolbachia has probably no effect. Decrypting the tripartite association requires to investigate the relationship between haplotypes or genotypes of Wolbachia and/or S. glossiniduis and trypanosome infections.

Background: A better understanding of parasite population genetic processes in specific biogeography is needed to support onchocerciasis elimination goals. The genetic diversity of Onchocerca microfilariae was explored by amplifying a fragment of the 16S rRNA gene in the endemic area in Taraba State, Nigeria, Methods: Eight (8) communities were selected including six onchocerciasis endemic communities with records of ivermectin treatment having been annually distributed for 10 to 16 years, and two non-onchocerciasis endemic areas. The participants were 211 from endemic and 110 from non-endemic areas as control. Skin snips were taken from consenting participants by convenience sampling methods using a sterile sclera punch, from males and females residing within the communities for ten years and above or since birth, microfilaria and residual skin snips were preserved in RNALater® in a 1.5 ml micro-centrifuge tube. DNA was extracted from microfilariae recovered and from those in residual skin snip specimens. Polymerase Chain Reaction (PCR) amplification using specific primers for 16S genes was done to detect the identity of Onchocerca species. The amplified products were sequenced and analyzed for species identity. Results: Multiple sequence alignment and phylogenetic analysis results showed distinct diversity of two sample sequences (G49_O.v. Gashaka and Y02_O.v. Yorro) from other samples from the study area and other regions, indicating emergence of a new polymorphic strain of O. volvulus. Report of a preliminary case of emerging zoonosis of O. ochengi infection in human (skin snips) sample (O. ochengi G44) in this study. Conclusions: It is clear there is genetic diversity of Onchocerca species and emerging zoonosis in the study site. We suggest further investigation on the extent and potentials of emerging zoonotic onchocerciasis by O. ochengi, in the light of cattle, Simulium vectors, environmental and humans overlap in the study area.