ASSESSMENT OF SAND FLIES (DIPTERA PSYCHODIDAE) DIVERSITY, SEASONAL ABUNDANCE AND LEISHAMNIASIS RISK FACTORS IN DISTRICTS DIR, KHYBER PAKHTUNKHWA, PAKISTAN
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Date
2012
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Publisher
Department Of Zoology
Abstract
The aim of the current study was to determined sand flies species composition,
diversity, seasonal variations, spatial distribution and leishmaniasis associated risk
factors in Dir districts. The fieldwork was carried out in 40 villages from January to
December, 2014 in Timergara, Balambat, Khall and Warae. A total of 7292 sand flies
comprising 20 species of two genera; Phlebotomus and Sergentomyia were recorded
through sticky traps, insecticide spray and mouth aspiration. Phlebotomus was
presented by nine species while Sergentomyia was shown by eleven species. Peak
number (6229) of flies were collected through sticky traps followed by insecticide
spray (978) and mouth aspirator (85). Overall, male to female ratio was 3:1.
A total of 15 species were recorded in Tehsil Timergara; 13(Balambat); 10 (Khall);
and 7 (Warae). Diversity of sand flies was high in Timergara followed by Balambat,
Khall and Warae. P. salengensis was the most abundant species and was collected
from three Tehsils (Timergara, Balambat and Khall) followed by P. sergenti.
Similarity of species was high between Khall and Timergara as well as in Balambat
and Warae. P. sergenti, S. babu, S. baghdadis, S. dentata and S. hospittii were
reported from four tehsils. The remaining fifteen (15) species showed restricted
distribution to one, two or three tehsils. P. salengensis, P. hindustanicus, P. andrejevi,
P. kazeroni, P. bergeroti, P. ansari, S. turkistanica and S. grekovi were reported for
the first time from Khyber Pakhtunkhwa. Among them P. ansari was recorded for this
first time from Pakistan. A total of 88 specimens were not identified up to species
level.
Regarding seasonal variation in the studied area, sand flies showed their appearance
in May and presented peak aggregation in August and were disappeared from
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November to April. Density of sand flies was positively associated with climatic
factors (temperature and relative humidity). Flies presented greater abundance in
domestic habitats (6535) as compared to peridomestic sites (621). Males to female
ratio inside houses were 3:1 and outside houses 6:1. In domestic sites sand flies were
collected from different designed houses; mud made, concreted and stone made
houses. High flies abundance were found in mud made houses followed by concreted
and stone made houses.
During the survey, immature males of three species (P. salengensis, P. sergenti and P.
andrejevi) were collected from cattle sheds most particularly from combined
dwellings and cattle corrals. Which were the probable breeding sites of these sand fly
species. Similarly, a total of seven species were recorded from twelve plant species
and greater number was recorded from plants belonging to Cucurbitaceae family.
Moreover, eleven caves were visited and flies were sampled in which S. bailyi was the
most abundant species.
Species specific spatial distribution of sand flies in relation to related physical factor
(elevation) probably attributed to a variable land escape.
In univariate analysis, factors such as villages, number of rooms, family size, level of
education, eaves, cooling equipment used, family members residing outside country,
mosquito bed nets and vegetation were positively associated with the Leishmaniasis
in the study area. In bivariate analysis, villages, low level of education, eaves and
family members residing outside country were found to increase the risk of the
disease in the region.