Spatiotemporal changes in exposition risk to leishmaniases vector in residences within a fishing tourism area of Pantanal wetland

Miranda Municipality of Mato Grosso do Sul, borders the Pantanal wetland, a famous fishing destination visited by tourists from all over the world, and is a location where visceral leishmaniasis has been reported. To assess the risk of Leishmania infantum transmission, we studied the sandfly community, focusing on known vector and parasite presence. We conducted light trap collections twice per month at nine sites within the city (including two forested areas) for one year. We collected a total of 12,727 sand flies, 10,891 males and 1,836 females belonging to 11 species: Brumptomyia avellari, Evandromyia aldafalcaoae, Ev. evandroi, Ev. lenti, Ev. sallesi, Ev. walkeri, Lu. longipalpis, Nyssomyia whitmani, Psathyromyia bigeniculata, Pa. hermanlenti and Pa. punctigeniculata. Lutzomyia longipalpis, the proven vector of Leishmania infantum, was captured each month, and was the most abundant species observed, accounting for more than 99% of sand flies captured in most sites, especially where chicken coops were present. Evidence of Leishmania infantum infection was detected in 0.40% of Lu. longipalpis tested. We developed a generalized mixed multilevel model for Lu. longipalpis, that includes within-year seasonality, location of capture (indoors vs. outdoors), vector abundance, and sex ratio. The VL vector was abundant both inside and outside houses. Large numbers of Lu. longipalpis were observed in outdoor sites where domestic animals were present but were absent from forest sites. Our findings suggest high vector populations and Le. infantum presence in a city where tourists could be exposed to visceral leishmaniasis, with significant implications for more surveillance and control activities. Several localities in Mato Grosso do Sul have already recorded human visceral leishmaniasis cases, including the city of Miranda, which is a famous fishing and tourism destination. Due to the high number of visitors, we decided to evaluate the risk of Leishmania infantum transmission in the area. Thus, we conducted vector collections over one year, detecting both the presence of the main vector (Lutzomyia longipalpis) and the Le. infantum parasite. We used nonlinear multilevel mixed models, under the Bayesian framework, to investigate the seasonal changes on transmission risk (i.e.; overall vector abundance and the proportion of females), taking into account the residence space. We found that the overall vector abundance outdoors was higher than in the indoors. Outdoors abundance was more consistent with two-peaks during the year, whereas indoors abundance was more seasonal with a single peak. Although, indoor abundance was lower than observed outdoors, the proportion of females captured was up to twice that observed outdoors. These findings highlighted the spatiotemporal component of leishmaniasis transmission risk, which can guide entomological surveillance and control measures.