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A major challenge in defining the vector status of phlebotomine sand flies is selecting the appropriate criteria. Vectors can be graded by importance, with successful transmission as the highest grade. Potential vectors are often identified based on high frequency in transmission foci, anthropophily, and more recently by identification of DNA in field samples. However, a species' ability to transmit a pathogen depends not only on its intrinsic biology of sand fly-Leishmania interactions but also on ecological parameters, which are rarely evaluated. This study aimed to analyze the literature data describing characteristics of Colombian sand flies related to their role as vectors of Leishmaniinae parasites. Based on information contained in scientific publications using combinations of five criteria, sand fly species were graded into five levels, and 26 species were considered as potential or proven leishmaniasis vectors in Colombia. Levels one to four refer to potential or suspected status, while level five denotes proven vectors. Studying vectors in a regional context is crucial because species' behaviors vary with environmental and ecological conditions, meaning a species may be a key vector in one area but not in another. A better understanding of vector-parasite interactions will aid in developing innovative control strategies and formulating significant epidemiological perspectives., Competing Interests: Declaration of competing interest The authors declare that they have no competing interests., (Copyright © 2024. Published by Elsevier B.V.)

An increase in cutaneous and visceral leishmaniasis cases has been reported in recent years in the state of Mato Grosso do Sul, Brazil, and little is known to date about their etiological agents. An investigation into natural Leishmania infection of sand flies captured in this state between December 2003 and August 2004 was carried out. Mini-exon sequences were used as targets to identify Leishmania, and an RFLP technique was employed for those identified as belonging to the Viannia subgenus. Calculation of the minimal infection rate (MR) revealed that 1.6% of sand flies captured in the forest, peridomicile and intradomicile were positive. Six species were found to be infected by Leishmania (V.) braziliensis. Interestingly, two of the six species, Lutzomyia longipalpis and Nyssomyia whitmani, were captured in anthropic environments. The findings of this study constitute a useful tool for planning control measures against this disease in the State of Mato Grosso do Sul., (2010 Elsevier B.V. All rights reserved.)

To identify natural infections by Leishmania spp. in insect vectors of cutaneous and visceral leishmaniasis, we performed field studies in natural and anthropic environments in the Guaicurus Settlement (Bodoquena Range) of the Bonito municipality, Mato Grosso do Sul state, Brazil. From October 2002 to October 2003, a total of 1395 sandfly females were captured with Shannon and light traps and dissected in search of flagellates. The sample is composed of a total of 13 species, with Lutzomyia almerioi (59.9%) and Lutzomyia longipalpis (31.4%) predominant. Infections by flagellates were directly observed in three of the dissected of Lu. almerioi females (0.36%). To increase the sensitivity of detection, DNA extracted from pools of the 1220 dissected females (Lu. almerioi 808, Lu. longipalpis 399 and Nyssomyia whitmani 13) was subjected to small subunit rRNA-based polymerase chain reactions (SSU-PCR). DNA from Leishmania (L.) infantum chagasi was detected in at least 0.37% of Lu. almerioi females and in 0.25% of Lu. longipalpis females. The DNA of the Leishmania (Viannia) sp. was detected in 0.12% of Lu. almerioi and in 0.70% of Lu. longipalpis. Leishmania (L.) amazonensis was found in 1.25% of Lu. longipalpis. Mixed infections of L. (Leishmania) sp. and L. (Viannia) sp. were found in 0.50% of Lu. longipalpis. When considering that each positive pool contained at least a single infected specimen, we found a 1.23% rate of Leishmania spp. infection among the total population of dissected female sand flies as determined by PCR. This is the first report of natural infection by L. (L.) infantum chagasi and L. (Viannia) sp. in Lu. almerioi. It is also the first report of infection by L. (Viannia) sp. in Lu. longipalpis. The observation that Lu. longipalpis and Lu. almerioi are naturally infected by agents of both cutaneous and visceral leishmaniases suggests that these two species play a role in the transmission of these diseases within the study area. Furthermore, the finding that Lu. longipalpis has been naturally infected by L. (L.) amazonensis and L. (Viannia) sp., and Lu. almerioi by L. (L.) infantum chagasi and L. (Viannia), suggests their participation as permissive vectors.

Sand flies were captured weekly with CDC light traps from December 2003 to November 2005 in three areas of Campo Grande, in the Brazilian state of Mato Grosso do Sul. These areas incorporated two patches of remnant forest and five houses. The blood meals of engorged female sand flies were identified using the avidin-biotin system of immunoenzymatic ELISA capture. Most (327/355) of the females analysed were Lutzomyia longipalpis, of which 66.4% reacted with human blood, 64.8% with that of birds and 8.9% with that of dogs. Females that had taken human blood predominated in the residential areas and two forest patches. The following combinations of blood were also detected for L. longipalpis in some of the samples analysed: bird+human (43.4%), bird+human+dog (6.1%). The combination bird+human+dog+pig was also found for Nyssomyia whitmani. Dogs and pigs appear to have little attractiveness for L. longipalpis. The results obtained demonstrate the eclecticism and high anthropophily of L. longipalpis and raise new questions with regard to the importance of dogs in VL epidemiology and the possible role of man as a source of infection for sand flies.

The seasonal distribution of Lutzomyia longipalpis was studied in two forested and five domiciliary areas of the urban area of Campo Grande; MS, from December 2003 to November 2005. Weekly captures were carried out with CDC light traps positioned on ground and in the canopy inside a residual forest and on the edge (ground) of a woodland and in at least one of the following ecotopes in peridomiciles-a cultivated area, a chicken coop, a pigsty, a kennel, a goat and sheep shelter and an intradomicile. A total of 9519 sand flies were collected, 2666 during the first year and 6853 during the second. L. longipalpis was found throughout the 2-year period, presenting smaller peaks at intervals of 2-3 months and two greater peaks, the first in February and the second in April 2005, soon after periods of heavy rain. Only In one of the woodlands was a significant negative correlation (p<0.05) between the number of insects and temperature during the first year and the climatic factors (temperature, RHA and rain) was observed. In the domiciliary areas in four domiciles some positive correlations (p< or =0.05) occurred in relation to one or more climatic factors; however, the species shows a clear tendency to greater frequency (72%) in the rainy season than in the dry (28%). Thus, we recommend an intensification of the VL control measures applied in Campo Grande, MS, during the rainy season with a view to reducing the risk of the transmission of the disease.

We describe a seroepidemiological survey of malaria prevalence in two areas of low endemicity: Intervales State Park and Alto Ribeira State Tourist Park (PETAR). Both are located in the Vale do Ribeira in the state of São Paulo, Brazil. In this study, 318 subjects from both areas had their blood analyzed for the presence of malaria parasites by thin and thick blood smears. One hundred and sixty-three (51.2%) of the subjects were from Intervales State Park and 155 (48.7%) were from PETAR. We analyzed all the samples by indirect immunofluorescent assay (IFA) to detect antibodies against asexual forms of Plasmodium vivax and Plasmodium malariae and enzyme immunosorbent assay (ELISA) to detect the presence of antibodies against circumsporozoite proteins (CSP) from P. vivax VK210, human P. vivax-like/Plasmodium simiovale, P. vivax VK247 and Plasmodium brasilianum/P. malariae. The presence of Plasmodium species was detected by polymerase chain reaction (PCR). Eighteen of the subjects analyzed had positive IFA results for IgM against P. malariae antigens, and three others were positive for P. vivax antigens. Positivity of IgG antibodies against P. vivax detected by IFA was high in samples from both Intervales State Park and PETAR (32.0% and 49.0%, respectively), while positivity for P. malariae was lower (16.0% and 19.3% in Intervales State Park and PETAR, respectively). ELISA tests showed a higher prevalence of antibodies against P. vivax VK210 (35.0%) in samples from Intervales State Park and against human P. vivax-like (29.7%) in samples from PETAR. PCR reactions revealed the presence of parasites in several of the samples analyzed. In Intervales State Park, one subject was infected by P. malariae and two by Plasmodium falciparum, while in PETAR, one subject was positive for P. falciparum and three for both P. falciparum and P. vivax parasites. The areas where these parks are located belong to the Atlantic Forest habitat, and inhabitants frequently, see monkeys. Our data suggest that monkeys may constitute a natural reservoir for malaria in both areas.

Leishmaniasis is one of the most diverse and complex of all vector-borne diseases. Because it involves several overlapping species and sandfly vectors, the disease has a complex ecology and epidemiology. Adequate therapy and follow-up depend on parasitological diagnosis, but classical methods present several constraints when identifying species. We describe a polymerase chain reaction (PCR) which uses primers designed from mini-exon repetitive sequences that are specific for subgenus LeishmaniaViannia (PV), as well as sequences with specificity for genus (PG) that can distinguish between Leishmania species from other insect flagellates with minor differences in PCR products. For standardization, these PCR were tested in experimentally infected sandflies, and Leishmania infection in these insects was successfully confirmed. This methodology identified a 3.9% infection rate in field-captured phlebotomine sandflies from an endemic region in Brazil. Natural infection by Leishmania species was identified in three samples of Lutzomyia longipalpis, of which two were Leishmania (L.) chagasi and one Leishmania (L.) amazonensis. Irrespective of specific epidemiological conclusions, the method used in this study was able to identify Leishmania infections both in experimentally infected and field-captured phlebotomine sandflies, and could be a useful tool in epidemiological studies and strategic planning for the control of human leishmaniasis.