Leishmania (Leishmania) mexicana causes cutaneous leishmaniasis, an endemic zoonosis affecting a growing number of patients in the southeastern states of Mexico. Some foci are found in shade-grown cocoa and coffee plantations, or near perennial forests that provide rich breeding grounds for the sand fly vectors, but also harbor a variety of bat species that live off the abundant fruits provided by these shade-giving trees. The close proximity between sand flies and bats makes their interaction feasible, yet bats infected with Leishmania (L.) mexicana have not been reported. Here we analyzed 420 bats from six states of Mexico that had reported patients with leishmaniasis. Tissues of bats, including skin, heart, liver and/or spleen were screened by PCR for Leishmania (L.) mexicana DNA. We found that 41 bats (9.77%), belonging to 13 species, showed positive PCR results in various tissues. The infected tissues showed no evidence of macroscopic lesions. Of the infected bats, 12 species were frugivorous, insectivorous or nectarivorous, and only one species was sanguivorous (Desmodus rotundus), and most of them belonged to the family Phyllostomidae. The eco-region where most of the infected bats were caught is the Gulf Coastal Plain of Chiapas and Tabasco. Through experimental infections of two Tadarida brasiliensis bats in captivity, we show that this species can harbor viable, infective Leishmania (L.) mexicana parasites that are capable of infecting BALB/c mice. We conclude that various species of bats belonging to the family Phyllostomidae are possible reservoir hosts for Leishmania (L.) mexicana, if it can be shown that such bats are infective for the sand fly vector. Further studies are needed to determine how these bats become infected, how long the parasite remains viable inside these potential hosts and whether they are infective to sand flies to fully evaluate their impact on disease epidemiology. Leishmaniasis is endemic in southeastern Mexico, where Leishmania (L.) mexicana is the principle parasite species causing disease in humans. Previous studies using methodology for inferring potential biotic interactions between species had shown a high prevalence of bat species as potential hosts for Leishmania, yet bats have not been identified as hosts in Mexico. Motivated by these predictions, we currently analyze whether bats are infected with Leishmania (L.) mexicana and to what extent they serve as hosts for this parasite. We analyzed 420 bats from six states, and through PCR analysis of skin, heart, liver and/or spleen we found that 41 bats (9.77%) of 13 different bat species were infected. Most of the infected bats were netted in an eco-region characterized by plantations grown beneath shade-providing fruit trees that favors breeding conditions for the sand fly vectors and brings them in close proximity with frugivorous, insectivorous or nectarivorous bats. None of the infected bat tissues showed macroscopic lesions. Through artificial infections, we were also able to show that Leishmania (L.) mexicana remains viable and infective after passage through one species of bat. We conclude that various species of bats belonging to the family Phyllostomidae are possible reservoir hosts of Leishmania (L.) mexicana.

Dengue is the most important mosquito-borne viral disease to humans. Bats are potential reservoirs for flaviviruses, including dengue virus (DENV). In this work, Artibeus jamaicensis bats were inoculated with two serotypes of DENV using different routes. For experimental inoculations (EI) 1 and 2, bats were inoculated subcutaneously or intraperitoneally with DENV-4; for EI-3 bats were inoculated intraperitoneally with DENV-1. Mock inoculated bats were kept as controls. In EI-4, bats were bitten by Aedes aegypti mosquitoes infected with DENV-1 or 4. Reverse transcription-polymerase chain reaction assays in plasma and spleen tissue collected from Day 1 to Days 9–17 after inoculation failed to reveal the presence of viral RNA in any of the samples. No evidence of circulating NS1 or specific anti-DENV IgG was detected in the plasma of the inoculated bats. These results indicate that A. jamaicensis bats are incapable of sustaining dengue virus replication and are unlikely to act as reservoirs for this virus.

Species distribution models were constructed for tenIxodesspecies andAmblyomma cajennensefor a region including Mexico and Texas. The model was based on a maximum entropy algorithm that used environmental layers to predict the relative probability of presence for each taxon. For Mexico, species geographic ranges were predicted by restricting the models to cells which have a higher probability than the lowest probability of the cells in which a presence record was located. There was spatial nonconcordance between the distributions ofAmblyomma cajennenseand theIxodesgroup with the former restricted to lowlands and mainly the eastern coast of Mexico and the latter to montane regions with lower temperature. The risk of Lyme disease is, therefore, mainly present in the highlands where someIxodesspecies are known vectors; ifAmblyomma cajennenseturns out to be a competent vector, the area of risk also extends to the lowlands and the east coast.