Exposure to Phlebotomus argentipes (Diptera, Psychodidae, Phlebotominae) Sand Flies in Rural Areas of Bihar, India: The Role of Housing Conditions

Abstract

BackgroundVisceral Leishmaniasis (VL) is a vector-borne infectious disease, caused by the protozoan Leishmania donovani, which is transmitted by phlebotomine sand flies. In an earlier study in Bihar, India, we found an association between incidence of VL and housing conditions. In the current study we investigated the influence of housing structure and conditions in and around the house on the indoor abundance of Phlebotomus argentipes, the vector of VL in this area.MethodsIn each of 50 study villages in Muzaffarpur district, we randomly selected 10 houses. Light traps were installed in each house for one night during three annual peaks of sand fly density over two successive years. Sand flies captured were morphologically identified and segregated by species, sex and feeding status. Data on housing conditions and socio-economic status were also collected. We fitted a linear mixed-effects regression model with log-transformed P. argentipes counts as outcome variable and village as random effect.Results P. argentipes was found in all but four of the 500 households. There was considerable variability between the years and the seasons. On bivariate analysis, housing structure, dampness of the floor, keeping animals inside, presence of animal dung around the house, and socio-economic status were all significantly associated with sand fly density. Highest sand fly densities were observed in thatched houses. In the multivariate model only the housing structure and socio-economic status remained significant.ConclusionsBetter housing conditions are associated with lower sand fly densities, independent of other socio-economic conditions. However, in this area in Bihar even in the better-built houses sand flies are present.

DDT-based indoor residual spraying suboptimal for visceral leishmaniasis elimination in India

“…Aside from the 0.0 abundance seen in all sentinel sites during the pre-IRS surveys, the lowest abundance was seen in IRS sentinel sites in Patna, 3 mo post-IRS (1). This pattern of abundance concurs with previously observed seasonal sand fly distributions in Bihar, India, where the numbers of sandflies is naturally low during the winter months, followed by a peak in June through August, before naturally declining again toward the winter months (28).…”

Risk factors for anthroponotic cutaneous leishmaniasis in unresponsive and responsive patients in a major focus, southeast of Iran

“…The results of the present study showed that creation of unresponsive forms in patients with unsuitable interior housing condition was significantly higher than those with suitable interior housing condition ( P <0.05). The rate of sand flies in the cracks and crevices of walls and ceilings in unsuitable houses is higher than suitable ones [ 24 , 25 ]. This study showed that there was a positive association between the rate of unresponsiveness in ACL and poor interior housing conditions.…”

Housing Characteristics and Leishmaniasis: A Systematic Review

“…22,23 Several studies have shown the relationship of vector-borne diseases such as malaria, dengue, and Chagas disease with traditional architectural practices and features of rural housing, including mud walls, thatched roofs, open eaves, and unscreened windows. [24][25][26][27][28] In the case of leishmaniasis, information available about house-related risk factors is scarce.…”