BackgroundCurrent 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.ResultsAddition 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.ConclusionsWe 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.

Current control methodologies have not prevented the spread of visceral leishmaniasis (VL) across Brazil. Here, we describe the development of a new tool for controlling the sand fly vector of the disease: a long-lasting lure, which releases a synthetic male sex pheromone, attractive to both sexes of Lutzomyia longipalpis. This device could be used to improve the effectiveness of residual insecticide spraying as a means of sand fly control, attracting L. longipalpis to insecticide-treated animal houses, where they could be killed in potentially large numbers over a number of weeks. Different lure designs releasing the synthetic pheromone (±)-9-methylgermacrene-B (CAS 183158-38-5) were field-tested in Araçatuba, São Paulo (SP). Experiments compared numbers of sand flies caught overnight in experimental chicken sheds with pheromone lures, to numbers caught in control sheds without pheromone. Prototype lures, designed to last one night, were first used to confirm the attractiveness of the pheromone in SP, and shown to attract significantly more flies to test sheds than controls. Longer-lasting lures were tested when new, and at fortnightly intervals. Lures loaded with 1 mg of pheromone did not attract sand flies for more than two weeks. However, lures loaded with 10 mg of pheromone, with a releasing surface of 15 cm2 or 7.5 cm2, attracted female L. longipalpis for up to ten weeks, and males for up to twelve weeks. Approximately five times more sand flies were caught with 7.5 cm2 10 mg lures when first used than occurred naturally in non-experimental chicken resting sites. These results demonstrate that these lures are suitably long-lasting and attractive for use in sand fly control programmes in SP. To our knowledge, this is the first sex pheromone-based technology targeting an insect vector of a neglected human disease. Further studies should explore the general applicability of this approach for combating other insect-borne diseases.

ObjectiveTo evaluate the efficacy of a synthetic sex-aggregation pheromone of the sand fly vector Lu. longipalpis, co-located with residual insecticide, to reduce the infection incidence of Leishmania infantum in the canine reservoir.MethodsA stratified cluster randomised trial was designed to detect a 50% reduction in canine incident infection after 24 months in 42 recruited clusters, randomly assigned to one of three intervention arms (14 cluster each): synthetic pheromone + insecticide, insecticide-impregnated dog collars, or placebo control. Infection incidence was measured by seroconversion to anti-Leishmania serum antibody, Leishmania parasite detection and canine tissue parasite loads. Changes in relative Lu. longipalpis abundance within households were measured by setting three CDC light traps per household.ResultsA total 1,454 seronegative dogs were followed-up for a median 15.2 (95% C.I.s: 14.6, 16.2) months per cluster. The pheromone + insecticide intervention provided 13% (95% C.I. 0%, 44.0%) protection against anti-Leishmania antibody seroconversion, 52% (95% C.I. 6.2%, 74·9%) against parasite infection, reduced tissue parasite loads by 53% (95% C.I. 5.4%, 76.7%), and reduced household female sand fly abundance by 49% (95% C.I. 8.2%, 71.3%). Variation in the efficacy against seroconversion varied between trial strata. Equivalent protection attributed to the impregnated-collars were 36% (95% C.I. 14.4%, 51.8%), 23% (95% C.I. 0%, 57·5%), 48% (95% C.I. 0%, 73.4%) and 43% (95% C.I. 0%, 67.9%), respectively. Comparison of the two interventions showed no statistically consistent differences in their efficacies; however, the errors were broad for all outcomes. Reductions in sand fly numbers were predominant where insecticide was located (chicken and dog sleeping sites), with no evidence of insecticide-induced repellence onto humans or dogs.ConclusionThe synthetic pheromone co-located with insecticide provides protection particularly against canine L. infantum parasite transmission and sand fly vector abundance. The effect estimates are not dissimilar to those of the insecticide-impregnated collars, which are documented to reduce canine infection incidence, human infection and clinical VL disease incidence, in different global regions. The trialled novel lure-and-kill approach is a low-cost potential vector control tool against ZVL in the Americas.

Introduction: Leishmaniasis is expanding across Brazil, including the State of Mato Grosso (MT). The aim of this study was to characterize the phlebotomine sandfly fauna at three rural settlements located in the municipality of Cáceres, MT, from August 2010 to July 2011. Methods: Sandfly captures were conducted at the forest border and in intra and peridomicile areas with automatic light traps, biweekly, from 5pm to 6am. Results: Of the 630 sandflies collected, 348 were female, and 282 were male. Captured specimens were distributed across 11 genera -Brumptomyia, Evandromyia, Expapillata, Lutzomyia, Martinsmyia, Micropygomyia, Nyssomyia, Pintomyia, Psathyromyia, Psychodopygus, species. Among these, six species had not been marked yet in MT (Brumptomyia avellari, Br. mangabeirai, Evandromyia aldafalcaoae, Micropygomyia echinatopharynx, Micropygomyia peresi, and Pa. campograndensis). Nyssomyia whitmani was the most abundant species across ecotopes at all settlements. Interestingly, Lutzomyia longipalpis and Lutzomyia cruzi were found in sympatry. Conclusions: The disorganized occupation of the environment that is happening at the rural settlements of Mata Comprida, Laranjeira I and II could provide opportunities for the domiciliation of wild populations of phlebotomine, including vectors of leishmaniasis. Therefore, more studies are needed to understand the epidemiology of the disease in these areas and its impact on the human population. Keywords: Mato Grosso. Phlebotomine fauna. Nyssomyia whitmani. Rural settlement. RESUMO Introdução:As leishmanioses encontram-se em expansão no Brasil, inclusive no Estado de Mato Grosso (MT). A presente pesquisa teve como objetivo estudar a fauna flebotomínica em três assentamentos rurais localizados no município de Cáceres, MT, entre agosto de 2010 e julho de 2011. Métodos: As coletas foram realizadas na margem da mata, no intra e peridomicílio com armadilhas automáticas luminosas, quinzenalmente, das 17h às 6h. Resultados: Foram coletados 630 exemplares, sendo 348 fêmeas e 282 machos. Os espécimes foram distribuídos em 11 gêneros: Brumptomyia, Evandromyia, Expapillata, Lutzomyia, Martinsmyia, Micropygomyia, Nyssomyia, Pintomyia, Psathyromyia, Psychodopygus e Sciopemyia e 28 espécies, sendo que dentre estas, seis não haviam sido assinaladas em MT (Brumptomyia avellari, Br. mangabeirai, Evandromyia aldafalcaoae, Micropygomyia echinatopharynx, Micropygomyia peresi e Pa. campograndensis). Ressalta-se o encontro de Nyssomyia whitmani, espécie mais abundante nos diferentes ecótopos em todos os assentamentos. Destaca-se também a presença das espécies Lutzomyia longipalpis e Lutzomyia cruzi em simpatria. Conclusões: A ocupação desordenada do ambiente, como vem ocorrendo nos assentamentos Mata Comprida, Laranjeira I e II, pode proporcionar a domiciliação de populações selváticas de flebotomíneos, dentre estes os vetores das leishmanioses, tornando-se necessários maiores estudos para entender a dinâmica de transmissão dessas morbidades nestes locais. Palavras-chaves: Mato Gr...

Because canine intestinal parasites are considered cosmopolitan, they carry significant zoonotic potential to public health. These etiological agents are routinely diagnosed using microscopic examination commonly used because of its low cost, simple execution, and direct evidence. However, there are reports in the literature on the poor performance of this test due to low to moderate sensitivity resulting from frequent errors, procedures and interpretation. Therefore, to improve the diagnostic efficiency of microscopic examination in veterinary medicine, we developed and evaluated a unique new protocol. This system was tested in a study involving four genera of highly prevalent canine intestinal parasites in an endemic region in São Paulo state, Brazil. Fecal samples from 104 animals were collected for this research. The new protocol had a significantly higher (p < 0.0001) number of positive cases on image data, including parasites and impurities, and was elaborate to test them with the TF-GII/Dog technique, with a moderate agreement and Kappa index of 0.7636. We concluded that the new Prototic Coproparasitological Test for Dogs (PC-Test Dog) allowed a better visualization of the parasitic structures and showed a favorable result for the diagnosis of intestinal parasites in dogs.

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In this study, we evaluated the performance of a new enzyme‐linked immunosorbent assay (ELISA) variant known as indirect “plasmonic ELISA” (pELISA) for the detection of Leishmania spp. infection. Serum samples from 170 dogs from an area where canine leishmaniosis (CanL) is endemic and from 26 healthy dogs from a nonendemic area were tested by indirect pELISA, and the results were compared to those of an indirect ELISA (both with recombinant antigen rK28) and those of an immunochromatographic test (dual‐path platform, TR‐DPP®) using real‐time PCR on blood samples or conjunctival swabs as the gold standard. The pELISA, indirect rK28 ELISA and the TR‐DPP® immunochromatographic test presented sensitivities of 94.7%, 89.5% and 79.0% and specificities of 100%, 92.7% and 91.5%, respectively. The analysis of the results revealed that the specificity of the indirect pELISA was greater than that of the method recommended by the Ministry of Health in Brazil and may increase the feasibility of diagnosis in resource‐constrained countries because it does not require sophisticated instruments to read. Thus, this method can be used as an additional tool for the detection of Leishmania spp. infection in these areas.