Spatio-Temporal distribution of a vector of cutaneous leishmaniasis: Pintomyia longiflocosa, in a population from the Colombian Andean Mountains.

BACKGROUND: Leishmaniasis, a neglected disease and public health concern, is associated with various factors such as biological, social, economical conditions and climate, increasing the risk of human infection. Understanding the population dynamics of the vectors, like Pintomyia longiflocosa, and its relationship with ecological variables is crucial for developing effective strategies to control sand fly populations and combat cutaneous leishmaniasis in a tropical country like Colombia. METHODOLOGY: Adult sand flies were collected in three different sample locations: outdoor, indoor, and peri-domestic areas in three houses located in the rural settlement of Campoalegre (Huila) between February 2020 and February 2021, using the CDC light traps. The sand fly density was quantified and associated with the sample locations and the sampling months using Analysis of Variance and Pearson correlations. PRINCIPAL FINDINGS: In the period of the sample, 98.86% of sand fly collected was identified as Pi. longiflocosa. The density of this species was significantly different between males and females, the latter contributing more to density in all sample locations (P<0.0001). The outdoor was the sample location with the highest and most significative density in this study (70%, P = 0.04). The density of these sand flies is related to the seasonality of Campoalegre, revealing a density peak from February and June to October (P < 0.05). Finally, precipitation is the environmental variable prominently linked to the density pattern, showing a negative correlation with it. Months with the highest precipitations show the lowest values of Pi. longiflocosa abundance. CONCLUSIONS/SIGNICANCE: Our investigation reveals a inverse correlation between precipitation levels and the abundance of Pi. longiflocosa in Campoalegre (Huila), particularly in outdoor areas. This suggests that vector control strategies to periods of reduced precipitation in outdoor settings could offer an effective approach to minimizing cases of cutaneous leishmaniasis in the region.

High Levels of Diversity in Anopheles Subgenus Kerteszia Revealed by Species Delimitation Analyses.

The Anopheles subgenus Kerteszia is a poorly understood group of mosquitoes that includes several species of medical importance. Although there are currently twelve recognized species in the subgenus, previous studies have shown that this is likely to be an underestimate of species diversity. Here, we undertake a baseline study of species delimitation using the barcode region of the mtDNA COI gene to explore species diversity among a geographically and taxonomically diverse range of Kerteszia specimens. Beginning with 10 of 12 morphologically identified Kerteszia species spanning eight countries, species delimitation analyses indicated a high degree of cryptic diversity. Overall, our analyses found support for at least 28 species clusters within the subgenus Kerteszia. The most diverse taxon was Anopheles neivai, a known malaria vector, with eight species clusters. Five other species taxa showed strong signatures of species complex structure, among them Anopheles bellator, which is also considered a malaria vector. There was some evidence for species structure within An. homunculus, although the results were equivocal across delimitation analyses. The current study, therefore, suggests that species diversity within the subgenus Kerteszia has been grossly underestimated. Further work will be required to build on this molecular characterization of species diversity and will rely on genomic level approaches and additional morphological data to test these species hypotheses.

Colonization of Ochlerotatus taeniorhynchus from Riohacha, Colombia.

The main objective of the present work was to establish and maintain a colony of Ochlerotatus taeniorhynchus, Riohacha strain, under laboratory conditions and to study its life cycle. The colony's insectary was established from adult male and female mosquitoes collected from peripheral neighborhoods of Riohacha, Colombia. Environmental conditions established in the insectary were 26.5 degrees C average temperature, 80% average relative humidity, and 12 h photoperiodicity. Eight continuous generations were taken into account for maintaining the mosquitoes and analyzing their life cycle. The male mosquito's average life cycle was 26.8 days. The female's cycle was 30.8 days. Analysis of each of the biological stages of development (mean days) produced the following results: egg incubation 4.55 +/- 0.291, larvae 8.28 +/- 0.499, pupae 1.32 +/- 0.215, adult male 12.65 +/- 5.920. and adult female 16.73 +/- 6.034. The Riohacha colony has been maintained for 32 generations in 31 months. Comparison of the Riohacha colony with the previously established Cartagena and Barranquilla colonies showed few differences in the duration of stages of the life cycle between strains.

Prevalencia de leishmaniasis visceral canina en municipios de Huila - Colombia / Prevalence of canine visceral leishmaniasis in municipalities of Huila, Colombia

Con el propósito de establecer la prevalencia de leishmaniasis canina se efectuó un estudio descriptivo en 307 caninos, ubicados en 17 veredas de los municipios de Neiva, Tello y Algeciras, a los cuales se les practicó examen clínico, punción y aspiración del ganglio linfático poplíteo para extendido y coloración en lámina; toma de sangre completa por venopunción para análisis mediante la técnica de inmunofluorescencia indirecta. La población canina estuvo conformada por perros mestizos con edad promedio de tres años: el 30,6/100 fueron hembras y el 69,4/100 machos. En el examen físico de los caninos se observó enflaquecimiento, 31/100; onicogrifosis, 29.3/100; linfadenitis de ganglio popliteo 3,2/100; areas alopécicas 21,8/100; lesiones eritematosas 11,5/100 y úlceras cutáneas 3,3/100. El 1,4/100 de los caninos analizados presentaron amastigotes en el aspirado y el 17,2/100 fueron seropositivos. La prevalencia de anticuerpos contra L.chagasi es alta comparada con otros estudios realizados en colombia y otros paises, corroborando la endemicidad de la enfermedad en el área. Por consiguiente, es necesario fortalecer las estrategias de vigilancia epidemiológica y la búsqueda activa de casos humanos.