Investigation of a New Focus of Cutaneous Leishmaniasis in Ghana

Abstract

Leishmaniasis is a disease of significant public health importance, which burdens a number of countries around the world, particularly in the tropics and subtropics. An outbreak of suspected cutaneous leishmaniasis (CL) has been witnessed in the Ho district of the Volta region in the south-eastern part of Ghana since 1999, where chronic ulcers typical of CL are being diagnosed. In this part of Ghana leishmaniasis has remained endemic to date. To add to the improvement of the level of understanding of the diseases in Ghana; the identity of the parasite, vector incrimination, non-invasive and field friendly diagnosis, and compound susceptibility19 tests were investigated. Patients presenting with cutaneous lesions suggestive of CL were selected where skin aspirates were collected from the sites of active lesion(s). Portions of the aspirates were cultured in M199 medium and DNA extracted from the promastigotes generated, while portions of the aspirates were inoculated onto FTA cards. PCR and PCR-RFLP were directly performed on the isolated DNA and the FTA cards. The pattern of bands produced from the patient samples were a complete deviation from DNAs of all the positive controls of Leishmania species. The sequenced PCR products and the further phylogenetic analysis revealed close relatedness to Leishmania enriettii species. The Leishmania species (GH5) responsible for the CL cases in that part of Ghana were successfully isolated into culture for the first time and proved to be distinct from the known species but closely related to non- pathogenic Leishmania enriettii. The transmission and the scanning electron micrograph evidence of the parasite confirmed their Leishmania identity. A peroxidoxin-based simple field friendly antigen detection test device was found diagnostically sensitive to Ghana species (GH5) and the other species of Leishmania used as controls in the diagnostic investigation. In the compound susceptibility test, the species isolated from Ghana (GH5) was found to be relatively resistant to cryptolepine, at concentrations to which the control species Leishmania mexicana was susceptible.