Absence of Phlebotomus argentipes Ann & Brun. (Diptera: Psychodidae) the vector of Indian kala-azar from Kamrup district, Assam.

ABSTRACT

In the past Assam was devastated by epidemics of Kala-azar. However, inspite of resurgence of this disease in Bihar and neighbouring areas Assam has remained untouched by this disease since the mid 1950s so far. The study undertaken in Kamrup district, sought to provide an entomological explanation for Assam's present freedom from Kala-azar. Sandfly collections were made in 15 villages. Three different methods were used; namely hand collections by aspirator and torch, sticky traps and examination of soft parts of cattle in the villages for mating swarms. 1049 sandflies were collected which did not include any specimens of P. argentipes. The vector of Indian Kala-azar has either been eliminated by continuous insecticide spraying in this high P. falciparum, and chloroquine resistance area or reduced to such low levels of prevalence that routine sampling methods are unable to reveal its presence. The implications of this finding are discussed in relation to Kala-azar control in India, in general.