In a research finding that could help in bringing down fatal cases of Japanese encephalitis (JE), a team of IICT researchers has observed that mosquitoes transmitting Japanese Encephalitis follow a weather pattern, with the minimum infection rate differing with change in the climate

By Syed Akbar
Hyderabad: In a research finding that could help in bringing
down fatal cases of Japanese encephalitis (JE), a team of city
researchers has observed that mosquitoes transmitting JE follow a
weather pattern, with the minimum infection rate differing with
change in the climate.

In a sample research study in Kurnool district, scientists from the
bioinformatics group in the biology division of the Indian Institute
of Chemical Technology (IICT) have established a correlation with
various climatic factors. The virus infection in mosquitoes differed
during different seasons.

Infected mosquitoes transmit diseases to human beings and animals.
Their bite, however, does not cause any harm if they are not infected
with virus in case of Japanese encephalitis or protozoan in case of
malaria. Knowing the time when the mosquitoes are infected with the
disease-causing organisms helps in taking preventive measures, and
thus stops spread of fatal diseases like Japanese encephalitis.

The IICT team collected mosquitoes of the genus Culex and screened
them for Japanese encephalitis virus. The Culex species with infection
were Cx. tritaeniorhynchus and Cx. gelidus during winter when JE cases
are in high numbers. Mosquitoes collected during summer and rainy
seasons showed relatively less viral infection.

The study revealed that the minimum infection rate of JE transmitting
mosquitoes is modulated by various meteorological parametres. The
mosquito vector abundance increases during winter and decreases
significantly during summer. The minimum infection rate was also
higher during winter and lower during rainy and summer seasons, it
pointed out.

The JE virus thrives in a little over dozen mosquito species, though
Culex is the main host in the country. The other mosquito genera are
Aedes and anopheles. The main host is pig which serves as the
reservoir. The mosquito carries the disease-causing virus from pig to
man. Andhra Pradesh is one of the States with significant number of JE
cases.