Jpn. J. Infect. Dis., 53, 107-110, 2000
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Original Article
The Impact of Housing Structures on Filarial Infection
Kalpana Baruah* and Raj Narayan Rai1
Medical Entomology and Vector Control Division, National Institute of Communicable Diseases, 22-Shamnath Marg, Delhi 110054 and 1Regional Filaria Training and Research Centre, National Institute of Communicable Diseases, Varanasi Branch, B-20/44, Bhelupura, Varanasi 221001, Uttar Pradesh, India
(Received December 13, 1999. Accepted May 12, 2000)
SUMMARY: A study was undertaken to correlate the impact
of housing and patterns of house construction on the vector density
and transmission of filaria among the inhabitants of these houses.
Three different types of houses in ecologically similar hamlets
of Hariharpur village in Varanasi were selected for determining
the density of Culex quinquefasciatus, the vector of Wuchereria
bancrofti and its infectivity. The maximum per man hour density
of the vector was recorded during March (31.66, 40.33 and 41.33)
while minimum was recorded during June (1.3, 2.6 and 0.33) in
all the three types of houses. Infection rate in the vectors collected
from poorly constructed houses was observed during April, May,
October and January of the following year, whereas in moderately
constructed houses, infection was observed only in September and
in the well constructed houses dissection results did not reveal
any infection during the months of the study. Infectivity rate
was observed to be 10.0% in moderately
constructed houses (group B) during the month of September and
14.2% in poorly constructed houses (group C) during the month
of October. Parasitological observations of the population showed
a 12.2% microfilaria (mf) rate and 6.7% disease rate among the
residents of poorly constructed houses, 5.8% mf rate and 2.9%
disease rate among residents of moderately constructed houses.
Among residents of well built houses
(Group A), none were found to be positive with mf, but disease
rate was observed to be 2.7%. Throughout the year the relative
humidity was observed to be higher in the poorly constructed houses
and ambient temperatures were found to be lower during the summer
but higher during the winter than to those of the better constructed
houses. The study made evident that the construction of houses
plays an important role in the
vector's resting preference, leading to a higher density in poorly
constructed houses, thereby increasing the possibility of infection
within them, and thus maintaining a higher potential for filarial
transmission among its inhabitants.
*Corresponding author: Tel/Fax: +91-11-3912963
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