Fig 1.
Geographical origin of the studied samples of visceral leishmaniasis.
Map showing the distribution of the 91 registered cases of visceral leishmaniasis in 2009–2016 among the districts of Armenia. These cases were used for ecological niche modeling. Out of these 91 cases, 23 were analyzed by Multilocus Microsatellite Typing (in parentheses). Adjacent foci of visceral leishmaniasis in the neighboring countries are indicated. The map was generated by the use of shapefiles available from https://gadm.org/download_country_v3.html.
Table 1.
Designation, patient characteristics, geographic origin and population assignment by MLMT of the studied Armenian L. infantum samples.
Table 2.
Overview of the 537 strains included in the global MLMT analysis and assignment to the three main populations inferred by STRUCTURE.
Fig 2.
Diversity of genotypes of Leishmania infantum from clinical samples of 23 patients with visceral leishmaniasis.
Samples are from active foci in six districts of Armenia (shown in Fig 1) marked by different colors. The year of occurrence of the infection is indicated in brackets. The neighbor joining tree is based on multilocus microsatellite typing with a standard set of 14 microsatellite markers specific for the Leishmania donovani complex. Populations as inferred by STRUCTURE are indicated by bars next to the tree. According to ΔK the most probable number of populations is two (K = 2, left bar). In addition also the result of the analysis for substructures is shown (right bar). ARM-pop2a and ARM-pop2b are the two subpopulations inferred for population ARM-pop2. ARM-pop1 was not further divided into subpopulations.
Table 3.
Descriptive analysis per locus of the 23 L. infantum samples from Armenia.
Fig 3.
Neighbor joining tree inferred from MLMT profiles of 525 strains of L. infantum and 12 strains of L. donovani obtained with a standard set of 14 microsatellite markers specific for the Leishmania donovani complex.
The tree shows the position of L. infantum from Armenia in comparison to the main endemic regions of visceral leishmaniasis in Europe, Africa and Asia. Strains typed by MLEE as L. donovani are marked by squares. The three populations inferred by STRUCTURE are indicated as pop1-537, pop2-537 and pop3-537 and marked by grey curves. UZ–Uzbekistan, TA–Tajikistan, CN–China, TR—Turkey, CY—Cyprus, AL—Albania, GR—Greece, IL—Israel, PA—Palestine, MA—Malta, DZ—Algeria, IR—Iran, ES—Spain, PT—Portugal, IT—Italy, FR–France.
Fig 4.
Estimated population structure of a subset of 176 L. infantum MON1 strains most closely related to the Armenian strains as inferred by Bayesian analysis of their MLMT profiles.
In the barplots each strain is represented by a single vertical line divided into K colors, where K is the number of populations assumed. Each color represents one population. The length of the colors segment shows the strain’s estimated proportion of membership (Q) in that population. Strains are sorted by membership coefficient (Q). (A) According to ΔK the most probable number of populations is four (K = 4), in addition also K = 3 is shown. (B) Structure of subpopulation 1 (pop1-176) comprising the strains from Armenia, Uzbekistan, Tajikistan and Turkey3. According to ΔK the most probable number of populations is two (K = 2).
Table 4.
FST values and corresponding p-values for the four main populations inferred by STRUCTURE for the dataset of 176 strains.
Fig 5.
Neighbor joining tree inferred from the MLMT profiles of the subset of 176 L. infantum MON1 strains.
The tree shows the position of L. infantum from Armenia in comparison to the most closely related subpopulations of the L. infantum populations of most endemic foci of the Old Word.
Fig 6.
Diversity of sand fly species in Armenia observed during the vector surveys in active foci of visceral leishmaniasis.
The surveys were conducted in six districts of Armenia in 2009–2015. The number of proven and potential vectors of L. infantum (red), L. major (blue), L. tropica (green) and Sauroleishmania (yellow) in the six districts is shown in (A). Eleven distinct sand fly species were collected. The numbers per species are shown in (B). Only two (P. balcanicus and P. kandelakii) are proven vectors of VL in the Southern Caucasus, three are potential vectors of L. infantum (red). P. papatasi, P. caucasicus (and P. mongolensis as morphotype of P. caucasicus) (blue) are proven vectors for zoonotic CL (L. major) in Central Asia, however L. major is absent in the Southern Caucasus. P. sergenti (green) is the potential vector for anthroponotic CL (L. tropica) in the Southern Caucasus. The two species of the subgenus Sergentomyia (yellow) are transmitting only Sauroleishmania.
Table 5.
Overview of sand fly species and the number of respective collected specimens in the surveyed districts.
Fig 7.
Inference of spatiotemporal projection using correlative ecological niche models for risk assessment of leishmaniasis.
Modeled climatic suitability for the vectors transmitting L. infantum—P. balcanicus and P. kandelakii—and risk assessment of visceral leishmaniasis in Armenia (districts are shown). (A) current projection; (B) future projection for 2041–2060. Occurrence of vectors transmitting L. infantum is indicated by green (P. kandelakii) and white (P. balcanicus) triangles, cases of visceral leishmaniasis by black dots. The map was generated by the use of the shapefile of Armenia available from https://gadm.org/download_country_v3.html.