A narrative review of visceral leishmaniasis in Armenia, Azerbaijan, Georgia, Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, Uzbekistan, the Crimean Peninsula and Southern Russia

Abstract

There is an extensive body of medical and scientific research literature on visceral leishmaniasis (VL) in the Caucasus, Central Asia, the Crimean Peninsula and the southern part of The Russian Federation that is written in Russian, making it inaccessible to the majority of people who are interested in the leishmaniases in general and VL in particular. This review and summary in English of VL in what was Imperial Russia, which then became the Soviet Union and later a number of different independent states intends to give access to that majority. There are numerous publications in Russian on VL and, mostly, those published in books and the main scientific journals have been included here. The vast geographical area encompassed has been subdivided into four main parts: the southern Caucasus, covering Armenia, Azerbaijan and Georgia; Central Asia, covering Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan and Uzbekistan; the Crimean Peninsula and the northern Caucasus, which is part of The Russian Federation. Only rare cases of VL have been recorded in the northern Caucasus and Crimean Peninsula. In the other countries mentioned, human VL has been more intense but epidemics like those associated with L. donovani in India and East Africa have not occurred. For most of the countries, there are sections on the distribution, clinical aspects, the causative agent, the reservoirs and the vectors. Serological surveys and research into therapy are also covered. Recent studies on VL in Uzbekistan covered the application of serological, biochemical and molecular biological methods to diagnose human and canine VL, to identify the leishmanial parasites causing them in Uzbekistan and neighbouring Tajikistan and the epidemiology of VL in the Namangan Region of the Pap District, Eastern Uzbekistan. More recently, two studies were carried out in Georgia investigating the prevalence of human and canine VL, and the species composition of phlebotomine sand flies and their rates of infection with what was probably L. infantum in Tbilisi, eastern Georgia and Kutaisi, a new focus, in western Georgia. Though published in English, summaries of this information have been included where relevant to update the parts on VL in Uzbekistan and Georgia.

Identification of Visceral Leishmaniasis‐Susceptible Areas using Spatial Modelling in Southern Caucasus

“…The fuzzy logic model was applied to southern Caucasus using the same data categories that were used in the comparative analysis section (see Section ‎ ). The results were validated by investigating the relationship between known VL‐endemic areas in Iran, Armenia and Azerbaijan described in sporadic studies conducted in different parts of the study area (Salahi‐Moghaddam et al., ; Oshaghi et al., ; Alvar et al., ; Strelkova et al., ) and their calculated incidence probabilities. The calculated susceptibility and membership values obtained using the fuzzy operators showed highly similar trends to those identified in the training area in southern Caucasus (Fig.…”

“…Moreover, Siunikskaya, the area in which VL is most endemic in Armenia (Alvar et al., ), was predicted to be a highly susceptible area using the fuzzy logic output map. An endemic area in southern Azerbaijan, Jalilabad (Alvar et al., ; Strelkova et al., ), was also investigated using the fuzzy logic map and showed reasonable susceptibility values. From a regional viewpoint, the Jalilabad area was assigned medium and lower susceptibilities, and because VL is a fatal infectious disease, even small threats should be considered to be serious.…”

“…Visceral leishmaniasis infections have been identified in different areas in southern Caucasus during the past decade (Alvar et al., ; Strelkova et al., ). The social and physical environment of southern Caucasus has been predominantly characterized by the presence of several factors that have been identified as strongly associated with VL, including nomadic lifestyles, suitable climatic conditions and large rural populations (Mirsamadi et al., ; Salahi‐Moghaddam Abdoreza et al., ; Edrissian et al., ; Rajabi et al., ; Alvar et al., ; Rajabi et al., ; De Oliveira Lara‐Silva et al., ).…”

“…The majority of VL infections in Caucasus occur in an area at the conjunction of Iran, Armenia and Azerbaijan. The high number of VL infections in areas in Armenia and Azerbaijan neighbouring endemic sites in Iran (Alvar et al., ; Strelkova et al., ) constituted the main motivation for this study. This area is part of Caucasus and was considered as the study area within this paper (Fig.…”

“…Over 76% of VL cases in Iran during the past decade were identified in the north‐western area of the country, where the protozoan Leishmania infantum is the responsible agent of the disease (Salahi‐Moghaddam Abdoreza et al., ). The most important VL‐endemic areas in Azerbaijan and Armenia are their southern provinces, for example Jalilabad (Alvar et al., ; Strelkova et al., ), Agdam (Strelkova et al., ; Pigott et al., ), Ordubad (Strelkova et al., ) and Siunikskaya (Alvar et al., ; Pigott et al., ), which, surprisingly, are adjacent to Iran's most endemic areas, for example Ardabil, Meshkin‐Shahr (Salahi‐Moghaddam et al., ; Oshaghi et al., ), Kalaybar and Ahar (Rajabi et al., , ). Recently, several novel sites in this area have experienced the emergence of VL; this emergence has convinced healthcare authorities to implement further preventive measures.…”