First Isolation of Leishmania from Northern Thailand
A case report published in the PLoS Neglected Tropical Diseases reports the first isolation of Leishmania from Northern Thailand. From the published abstract:
Since 1996, there have been several case reports of autochthonous visceral leishmaniasis in Thailand. Here we report a case in a 52-year-old Thai male from northern Thailand, who presented with subacute fever, huge splenomegaly and pancytopenia. Bone marrow aspiration revealed numerous amastigotes within macrophages. Isolation of Leishmania LSCM1 into culture and DNA sequence analysis (ribosomal RNA ITS-1 and large subunit of RNA polymerase II) revealed the parasites to be members of the Leishmania enriettii complex, and apparently identical to L. martiniquensis previously reported from the Caribbean island of Martinique. This is the first report of visceral leishmaniasis caused by L. martiniquensis from the region. Moreover, the majority of parasites previously identified as “L. siamensis” also appear to be L. martiniquensis.
|Light micrograph of Leishmania amastigotes in bone marrow aspirate.Two infected macrophages are stained (large arrows), each with a nucleus (N) and numerous amastigotes (examples with small arrows) within the cytoplasm. The specimen was stained using Wright’s stain. The bar represents 20 µm.doi:10.1371/journal.pntd.0003339.g001
Visceral leishmaniasis is a potentially life threatening parasitic disease that is found in many tropical and subtropical regions of the world. We report a case of visceral leishmaniasis in northern Thailand caused by a recently described new species of Leishmania parasite, Leishmania martiniquensis. By comparing DNA sequences from this parasite with those of other isolates, we show that this parasite is more widely spread than previously thought, with several other examples in Thailand, and possibly from Europe and the USA, as well as the original location in the Caribbean island of Martinique. This parasite appears to be an emerging pathogen, which, because it causes a potentially fatal disease, needs to be investigated in detail so that its transmission can be understood and control measures can be developed.
|Giemsa-stained promastigote forms from culture.A–H, examples showing morphological variation of forms observed, all at the same magnification, bar in F represents 5 µm. Procyclic-like promastigotes can be observed in A (arrows);, leptomonad-like promastigotes in B and C (arrows); nectomonad-like promastigotes in D, E and F; and rosettes and aggregates in G and H.doi:10.1371/journal.pntd.0003339.g003
Pothirat T, Tantiworawit A, Chaiwarith R, Jariyapan N, Wannasan A, et al. (2014) First Isolation of Leishmania from Northern Thailand: Case Report, Identification as Leishmania martiniquensis and Phylogenetic Position within the Leishmania enriettii Complex. PLoS Negl Trop Dis 8(12): e3339. doi:10.1371/journal.pntd.0003339 Available from: LINK.