The current epidemiology of leishmaniasis in Turkey, Azerbaijan and Georgia and implications for disease emergence in European countries

Abstract

Leishmania spp. are sand fly‐borne protozoan parasites causing leishmaniasis in humans and animals. The aim of the study was to analyse the epidemiology of leishmaniasis in Turkey, Azerbaijan and Georgia from 2005 to 2020 and evaluate the associated risk for disease emergence in European countries. It is based on an analysis of WHO and OIE reported cases between 2005 and 2020, a review of scientific articles published in SCOPUS between 2009 and 2020 and a questionnaire survey to public health and veterinary authorities in these countries. Endemic Leishmania spp. include L. infantum in the three countries, L. major in Azerbaijan and Turkey and L. tropica and L. donovani in Turkey. Leishmaniasis is reported in humans, animals and sand flies and incidence is spatially and temporarily variable. In the southern Caucasus and particularly in Georgia, reported incidence of human visceral leishmaniasis by L. infantum remains high. However, whilst Georgia experienced a gradual decrease from >4.0 cases per 100,000 population in 2005–09 to 1.13 cases per 100,000 population in 2020, the period with highest incidence in Azerbaijan, which ranged between 0.40 and 0.61 cases per 100,000 population, was 2016–2019, and no cases have so far been reported for 2020. Visceral leishmaniasis in the Southern Caucasus affects mostly young children from deprived urban areas and its closely associated to canine leishmaniasis. Turkey reported cases of visceral leishmaniasis between 2005 and 2012 and in 2016 only, and incidence ranged between 0.02 and 0.05 per 100,000 population. In contrast, the reported annual incidence of cutaneous leishmaniasis in Turkey was much greater and peaked at 7.02 cases per 100,000 population in 2013, associated to imported cases from cutaneous leishmaniasis endemic Syria. Leishmaniasis by L. infantum in Azerbaijan and Georgia represents a regional public and animal health challenge that requires support to improve diagnosis, treatment and control. The unprecedented rise of cutaneous leishmaniasis and the spread of L. tropica and L. donovani in Turkey is an important risk factor for their emergence in Europe, especially in Mediterranean countries where competent vectors are widespread.

Knock, knock, knocking on Europe’s door: Threat of leishmaniasis in Europe with a focus on Turkey

“…VL caused by L. infantum is the most prevalent form of leishmaniasis in Europe, particularly affecting children and immunocompromised adults ( Barth-Jaeggi and Mäser, 2021 ). The highest incidence rates are reported in the southern Caucasus region, including Georgia and Azerbaijan, as well as the Mediterranean basin countries such as Spain, Italy, Greece, and Portugal ( Özbel et al, 2022 ). The presence of competent sand fly vectors and reservoir hosts, such as dogs, contributes to the transmission of VL in these regions ( Maia et al, 2023 ).…”

“…CL caused by L. major is endemic in parts of Turkey and Azerbaijan, primarily affecting rural populations living in close contact with rodent reservoirs such as gerbils ( Gerbillus dasyurus ) ( Özbel et al, 2022 ). On the other hand, CL caused by L. tropica is endemic in Turkey, primarily affecting urban populations living in poor sanitary conditions ( Özbilgin et al, 2019 ).…”

“…These alterations are influenced by several factors, such as human movement and the presence of various Leishmania spp. The primary species involved in leishmaniasis cases in Turkey are L. infantum , L. major , and L. tropica ( Özbel et al, 2022 ). In Turkey, VL caused by L. infantum is endemic, with higher incidence rates observed in southeastern regions such as Şanlıurfa and Diyarbakır ( Özbel et al, 2022 ).…”

“…The primary species involved in leishmaniasis cases in Turkey are L. infantum , L. major , and L. tropica ( Özbel et al, 2022 ). In Turkey, VL caused by L. infantum is endemic, with higher incidence rates observed in southeastern regions such as Şanlıurfa and Diyarbakır ( Özbel et al, 2022 ). CL caused by L. major is predominantly found in rural areas, particularly in central and eastern regions, where transmission occurs through zoonotic cycles ( Özbilgin et al, 2019 ).…”

Effect of Intralesional Sodium Stibogluconate Alone Versus Combinations with Topical Trichloroacetic Acid 50% or Fractional Carbon Dioxide Laser on Cutaneous Leishmaniasis

“…[ 1 ] Leishmaniasis may present in cutaneous (CL), visceral (kala-azar), or mucocutaneous forms. [ 2 3 4 ] Temperature and humidity are the two most important climatic factors for sandfly survival, development, and activity. Higher temperatures are likely to accelerate the maturation of the parasite, thereby increasing the risk of infection.…”