Leishmaniasis in Thailand: A Review of Causative Agents and Situations

Abstract

Abstract. Before 1999, leishmaniasis was considered an imported disease in Thailand. Since then, autochthonous leishmaniasis was reported in both immmunocompetent and immmunocompromised patients especially in human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS). A new species was identified and named as Leishmania siamensis consisting of two lineages, that is, lineages TR and PG. Analysis of isoenzymes has clarified the more commonly detected L. siamensis lineage PG as Leishmania martiniquensis (MON-229), a species originally reported from the Martinique Island, whereas the L. siamensis lineage TR has been identified as the true novel species, L. siamensis (MON-324). Both cutaneous leishmaniasis (CL) and visceral leishmaniasis (VL) have been found among Thai patients. Disseminated CL and VL could be presented in some reported patients who had HIV/AIDS coinfection. So far, only sporadic cases have been reported; thus, the true prevalence of leishmaniasis should be determined in Thailand among the high-risk populations such as people with HIV/AIDS. A recent survey among animals identified L. martiniquensis DNA in black rats (Rattus rattus) suggesting a potential animal reservoir. In addition, L. martiniquensis DNA was identified in Sergentomyia gemmea and Sergentomyia barraudi, the predominant sandfly species in the affected areas. However, further studies are needed to prove that these sandflies could serve as the vector of leishmaniasis in Thailand.

Infection of the equine population by Leishmania parasites

“…Few autochthonous CL cases, previously attributed to ‘ Leishmania siamensis ’, were reported in Germany (in horses ) and in Texas (in one Morgan horse ). After taxonomic revision of the genus Leishmania subgenus Mundinia , the species Leishmania ( Mundinia ) martiniquensis is considered the aetiological agent; the name of ‘ L. siamensis ’ ( nomen nudum ) being taxonomically invalid .…”

“…After taxonomic revision of the genus Leishmania subgenus Mundinia, the species Leishmania (Mundinia) martiniquensis is considered the aetiological agent; the name of 'L. siamensis' (nomen nudum) being taxonomically invalid [51][52][53].…”

Comparison of Recombinant Proteins of Kinesin 39, Heat Shock Protein 70, Heat Shock Protein 83, and Glycoprotein 63 for Antibody Detection of Leishmania martiniquensis Infection

“…northern, central, and southern Thailand (Leelayoova et al. ). The possibility of asymptomatic infection of this species is high, which has become a serious concerns and urgently requiring attention from national public health policy.…”

“…Leishmania siamensis was a novel species first reported in Thailand, whereas L. martiniquensis was originally reported from Martinique Island, the Caribbean Sea. Infection caused by L. martiniquensis, both among humans and animals, has been reported in different geographical areas including the Caribbean Islands, central Europe, USA (Florida), Thailand and Myanmar (Leelayoova et al 2017). VL, caused by these two species, is currently considered a newly emerging disease that is important to public health policy in Thailand.…”

“…The symptomatic cases of L. martiniquensis infection among humans have continuously increased and are endemic in 11 provinces covering three regions, i.e. northern, central, and southern Thailand (Leelayoova et al 2017). The possibility of asymptomatic infection of this species is high, which has become a serious concerns and urgently requiring attention from national public health policy.…”