Identification and characterisation of Mansonella perstans in the Volta Region of Ghana

Abstract

Mansonella spp. have been reported to have a wide global distribution. Despite the distribution and occurrence with other filarial parasites like Wuchereria bancrofti, Onchocerca volvulus and Lao loa, it is given little attention. Hence, there is no surveillance programme for assessing the distribution or mansonellosis, with mild to no symptoms experienced by infected people. However, addressing this infection is critical to the onchocerciasis control program as current rapid diagnostic tools targeting O. volvulus have the tendency to cross react with Mansonella species. In this study we identified and characterised M. perstans from five sites in the Volta region of Ghana and compared them to samples from other regions. Night blood smears and filter blood blots were obtained from individuals as part of a study on lymphatic filariasis. The giemsa stained smears were screened by microscopy for the presence of filarial parasites. Genomic DNA was extracted from blood blots from 39 individuals that were positive for M. perstans and Nested PCR targeting the internal spacer 1 (ITS-1) was conducted. Of these, 30 were sequenced and 24 sequences were kept for further analysis. Phylogenetic analysis of 194 nucleotide positions showed no differences in the samples collected. Samples from Ghana clustered with samples from other reference sequences from Africa and Brazil, possibly supporting the introduction of M. perstans from sub-Saharan Africa, during the trans-Atlantic slave trade. This study draws further attention to a neglected infection and presents the first characterisation of M. perstans in Ghana and calls for more population-based studies across different geographical zones to ascertain species variations and disease distribution.