Natural Wolbachia infections in malaria vectors in Kayin state, Myanmar

<ns4:p><ns4:bold>Background</ns4:bold><ns4:bold>:</ns4:bold> Natural <ns4:italic>Wolbachia </ns4:italic>infections in malaria mosquitoes were recently reported in Africa, and negatively correlated with the development of <ns4:italic>Plasmodium falciparum</ns4:italic> in the vectors. The occurrence and effects of <ns4:italic>Wolbachia </ns4:italic>infections outside Africa have not been described and may have been underestimated.</ns4:p><ns4:p> <ns4:bold>Methods</ns4:bold><ns4:bold>:</ns4:bold> Mosquitoes were collected by human-landing catch during May and June 2017 in ten villages in Kayin state, Myanmar. Closely related species of malaria vectors were identified with molecular assays. <ns4:italic>Wolbachia</ns4:italic> infection rates were assessed by quantitative real-time PCR.</ns4:p><ns4:p> <ns4:bold>Results:</ns4:bold> Malaria vectors were identified in the Funestus, Maculatus and Leucosphyrus Groups<ns4:italic>. Wolbachia </ns4:italic>were detected in 6/6 <ns4:italic>Anopheles</ns4:italic> species and in 5/10 villages. Mean prevalence of <ns4:italic>Wolbachia </ns4:italic>infection was 2.7% (95%CI= [1.3; 4.9]). The median <ns4:italic>Wolbachia </ns4:italic>load was seven orders of magnitude less in naturally infected malaria vectors than in artificially infected laboratory-reared <ns4:italic>Aedes aegypti</ns4:italic>. Phylogenetic analysis based on 16S rRNA sequences revealed a high diversity of <ns4:italic>Wolbachia </ns4:italic>strains and identified lineages different from those described in Africa.</ns4:p><ns4:p> <ns4:bold>Conclusion:</ns4:bold> Natural <ns4:italic>Wolbachia </ns4:italic>infections are common and widespread in malaria vectors in Kayin state, Myanmar. Their effects on <ns4:italic>Anopheles </ns4:italic>mosquitoes and malaria transmission is yet to be determined.</ns4:p>