Effectiveness of dog collars impregnated with 4% deltamethrin in controlling visceral leishmaniasis in Lutzomyia longipalpis (Diptera: Psychodidade: Phlebotominae) populations

BACKGROUND There is little information on the effect of using deltamethrin-impregnated dog collars for the control of canine visceral leishmaniasis. OBJECTIVES The objective of this study was to evaluate the effectiveness of the use of 4% deltamethrin-impregnated collars (Scalibor®) in controlling visceral leishmaniasis in Lutzomyia longipalpis by comparing populations in intervention and non-intervention areas. METHODS Phlebotomine flies were captured over 30 months in four neighbourhoods with intense visceral leishmaniasis transmission in Fortaleza and Montes Claros. We calculated the rates of domicile infestation, relative abundance of Lu. longipalpis, and Lu. longipalpis distribution in each site, capture location (intra- and peridomestic locations) and area (intervention and non-intervention areas). FINDINGS In the control area in Fortaleza, the relative abundance of Lu. longipalpis was 415 specimens at each capture site, whereas in the intervention area it was 159.25; in Montes Claros, the relative abundance was 5,660 specimens per capture site in the control area, whereas in the intervention area it was 2,499.4. The use of dog collars was associated with a reduction in captured insects of 15% (p = 0.004) and 60% (p < 0.001) in Montes Claros and Fortaleza, respectively. MAIN CONCLUSIONS We observed a lower vector abundance in the intervention areas, suggesting an effect of the insecticide-impregnated collars.

Effect of untreated bed nets on blood-fed Phlebotomus argentipes in kala-azar endemic foci in Nepal and India

Observational studies in the Indian subcontinent have shown that untreated nets may be protective against visceral leishmaniasis (VL). In this study, we evaluated the effect of untreated nets on the blood feeding rates of Phlebotomus argentipes as well as the human blood index (HBI) in VL endemic villages in India and Nepal. The study had a "before and after intervention" design in 58 households in six clusters. The use of untreated nets reduced the blood feeding rate by 85 percent (95 percent CI 76.5-91.1 percent) and the HBI by 42.2 percent (95 percent CI 11.1-62.5 percent). These results provide circumstantial evidence that untreated nets may provide some degree of personal protection against sand fly bites.

Are light traps baited with kairomones effective in the capture of Lutzomyia longipalpis and Lutzomyia intermedia? An evaluation of synthetic human odor as an attractant for phlebotomine sand flies (Diptera: Psychodidae: Phlebotominae)

Phlebotomine sand flies are often captured with human bait and/or light traps, either with or without an animal bait. More recently, synthetic attractants have been used as bait in traps to improve the capture of phlebotomine sand flies as well as other insects of medical and veterinary importance. The aim of the present study was to evaluate the effects of the kairomone 1-octen-3-ol (octenol) and the synthetic human odor BG-Mesh LureTM (BGML - lactic acid, caproic acid and ammonia) baited in modified CDC light traps on the capture of phlebotomine sand flies. The experiments followed the 5x5 Latin square design. Among the species caught, Lutzomyia intermedia apparently presented a dose-dependent response to octenol. The response obtained with the BGML, alone or in combination with octenol (5 mg/h), indicated some degree of attractiveness of these baits to different phlebotomine sand fly species. Octenol seems to be more attractive to L. intermedia than to Lutzomyia longipalpis, while the BGML presented a higher success in capturing L. longipalpis. When the components of the BGML were used separately, there was no increase in catching the female of L. intermedia. Apparently, there was no synergistic effect between the octenol and the BGML. In conclusion, the octenol and the BGML were demonstrated to be possible baits to attract some phlebotomine sand fly species.

Modification of Disney trap for capture of sand flies (Diptera: Psychodidae: Phlebotominae)

This paper describes the modifications made to the original model of the Disney trap, with a view to easier handling of the same, greater practicability in the collection of sand flies, protection of the animal bait and durability of the trap in the field.

Impacto del Plan de Atención Básica en la Prevención de Leishmaniasis Cutánea en Zonas Rurales de Santander, Colombia / The Basic Health PlanÆs impact on preventing cutaneous leishmaniasis in rural areas of Santander, Colombia

Objetivo: Evaluar el impacto de los programas del Plan de Atención Básica en la prevención de leishmaniasis cutánea en tres municipios santandereanos. Materiales y Métodos: Estudio ecológico con unidad de análisis vivienda. Se seleccionaron aleatoriamente niños menores de diez años de las escuelas rurales, se aplicaron encuestas estructuradas por vivienda y se examinó la presencia de cicatriz/lesión. Se hizo un análisis de regresión binomial ajustando por conglomerados. Resultados: Se muestrearon un total de 18 veredas con 284 viviendas y 609 niños menores de diez años. La prevalencia general de niños con cicatriz/lesión fue de 19,1 por ciento distribuida en forma diferencial en los tres municipios. El 42,8 por ciento de las viviendas reportaron haber recibido algún tipo de información y el 39,9 por ciento algún tipo de intervención de leishmaniasis del Plan de Atención Básica. Las intervenciones del Plan de Atención Básica mostraron un efecto protector en el análisis bivariado, pero luego de ajustar por variables socioeconómicas y ambientales, su efecto no fue significativo (PR=1,39 IC95 por ciento 0,76-2,56) Conclusión: Las intervenciones del Plan de Atención Básica en leishmaniasis no tienen asociación significativa con la presencia de cicatriz/lesión en los niños menores de diez años, probablemente porque su efecto es superado por las condiciones socioeconómicas y ambientales de la zona, así como por las condiciones administrativas relacionadas con la baja cobertura de los programas.

A device for monitoring and control of mosquitoes by behaviour manipulation.

A trap was designed and fabricated for capturing mosquito larvae based on their behavioural responses to food and light. The larvae upon entering the trap died ultimately due to asphyxiation. Maximum success was achieved with Aedes aegypti larvae in lesser water volumes. The usefulness of the device for studying the response of mosquito larvae and aquatic organisms to chemicals, baits, light, various stimuli and possible pest/vector monitoring and management in aquatic eco-system is discussed.

Field trial with redtop flycatcher baited with ready made protein meal for the control of houseflies in Gazipur dairy farm, Delhi.

A field trial with Redtop Flycatcher having bait formulated as ready made protein meal a.i 977 gms/kg was carried out for the control of adult housefly Musca domestica domestica L. in Gazipur dairy farm situated at eastern corner of Delhi and observation compared with another field trial with commonly available Baygon bait using scattering method. The observation recorded during the field trial revealed that the new flycatcher was capable of retaining the trapped flies and the protein bait remained active for a period of 35 to 42 days (with peak attractability around the ninth day) without requiring refilling the flycatcher with bait during this period. The flycatcher installed in indoor situation was found to be more effective than that kept outside. Parallel tests with Baygon bait containing 2 per cent Propoxur scattered @ 40 gms a.i/100 m2 were found to kill more flies than the new protein baited flycatcher but required daily replenishment of the insecticide. Fly attractancy of the protein sample was also compared with that of other food sources for the flies available in the study area over a period of five days, independently using the same flycatcher. Wheat flour dough was observed to be the most efficient fly attractant compared to other food sources including protein bait.