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.
