RESUMEN
Leishmaniasis involves the participation of several species of both wild and domestic mammal hosts and sandfly vectors, which demonstrates the eco-epidemiological complexity observed in this disease. Bats are among the most abundant types of mammals and the scarcity of research on Leishmania infection in these animals gives evidence of the importance of new studies that aim to clarify this relationship. This study aimed to detect the Leishmania spp. in bats. 146 bats, representing 16 different species belonging to the Molossidae, Vespertilionidae, and Phyllostomidae families, were received and processed for collection of tissues. Skin samples were collected from 100% of the bats, and liver samples were collected from 87% (n = 127). After evaluating the quality of the DNA extracted by means of PCR directed to the IRBP gene, the samples considered suitable for the Leishmania detection test were submitted for PCR directed to Leishmania kDNA, and to confirm positivity, were tested to the SSUrRNA gene-directed Nested-PCR. The Leishmania presence in the species Molossus pretiosus, Nyctinomops macrotis, and Lasiurus cinereus are the first reports this encounter in these species of bats in Brazil. Furthermore, new species of bats as possible hosts for L. infantum are reported, such as Molossus pretiosus, Myotis nigricans, Nyctinomops laticaudatus, Nyctinomops macrotis, and, for L. braziliensis, Lasiurus cinereus and Cynomops planirostris. These findings in bats in an area endemic for leishmaniasis indicate that these animals may be involved in sustaining the disease cycle in this location.
RESUMEN
BACKGROUND: Current strategies for controlling American visceral leishmaniasis (AVL) have been unable to prevent the spread of the disease across Brazil. With no effective vaccine and culling of infected dogs an unpopular and unsuccessful alternative, new tools are urgently needed to manage populations of the sand fly vector, Lutzomyia longipalpis Lutz and Neiva (Diptera: Psychodidae). Here, we test two potential strategies for improving L. longipalpis control using the synthetic sand fly pheromone (+/-)-9-methylgermacrene-B: the first in conjunction with spraying of animal houses with insecticide, the second using coloured sticky traps. RESULTS: Addition of synthetic pheromone resulted in greater numbers of male and female sand flies being caught and killed at experimental chicken sheds sprayed with insecticide, compared to pheromone-less controls. Furthermore, a ten-fold increase in the amount of sex pheromone released from test sheds increased the number of females attracted and subsequently killed. Treating sheds with insecticide alone resulted in a significant decrease in numbers of males attracted to sheds (compared to pre-spraying levels), and a near significant decrease in numbers of females. However, this effect was reversed through addition of synthetic pheromone at the time of insecticide spraying, leading to an increase in number of flies attracted post-treatment.In field trials of commercially available different coloured sticky traps, yellow traps caught more males than blue traps when placed in chicken sheds. In addition, yellow traps fitted with 10 pheromone lures caught significantly more males than pheromone-less controls. However, while female sand flies showed a preference for both blue and yellow pheromone traps sticky traps over white traps in the laboratory, neither colour caught significant numbers of females in chicken sheds, either with or without pheromone. CONCLUSIONS: We conclude that synthetic pheromone could currently be most effectively deployed for sand fly control through combination with existing insecticide spraying regimes. Development of a standalone pheromone trap remains a possibility, but such devices may require an additional attractive host odour component to be fully effective.