Mosquitoes are breeding freely in city

Published: 10/11/2010

A family of insect having a lifespan of about two weeks have virtually swarmed the industrial city. From malaria to dengue and chikangunya, the increasing population of female mosquitoes has wrecked havoc on the immune system of the masses.

The denizens have been rendered even more vulnerable by the various potential mosquito breeding grounds in almost all parts of the city. As per the information provided by the urban malaria department, different species of malaria and dengue are found in dense areas of the city.

With more than 50 patients confirmed dengue positive in the past three weeks, an alarm has been sounded. The concerning body has identified areas from where a majority of the cases are being reported. "There are three different species of 'Aedes' mosquito that is causing dengue. They are aegyptis, vittatus and albopictus. The laboratory reports have revealed that agypti and albopictus are the main vectors of dengue," said urban malaria officer AK Singh.

The two species have been found in abundance in areas like Gwaltoli, Harbansh Mohal, Shyam Nagar, Civil Lines, Netaji Nagar, Govind Nagar, Awas Vikas Kalyanpur, Naubasta and Panki. These areas are dengue sensitive as the number of houses inspected for Aedes larvae was greater than five per cent. Also, areas with human population density greater than two man per house are considered to be high risk areas, he said.

The mosquito menace is being felt equally in posh areas as in slum areas. The characteristics of Aedes, as pointed out by Singh, are: "The Aedes mosquitoes can be easily distinguished by the white strips on a black body. Therefore they are called Tiger mosquitoes. A. aegyptis occupies the congested localities of urban areas while A. albopictus are found on the outskirts of the city and especially in areas with maximum green cover."

Male mosquito never bite. They survive on plant juice while females are haemotophagus. They require blood meal once in two to three days to nurture the eggs. Females are the fearless biters and they bite mostly during the day time. The biting activity increases two hours after the sunrise and several hours before sunset.

It needs to be mentioned that the life cycle of Aedes varies from eight to 34 days. Over 100-250 eggs are laid at a time on the surface of the water. The cigar-shaped eggs turn into larva within one to two days and into pupa in five to seven days. The pupa finally turns into an adult mosquito within two to seven days and is ready to transfer the virus to human beings.

On a similar note, Anopheles, vector of malaria has been traced to areas like Gwaltoli, Juhi, Krishna Nagar and Geeta Nagar. The locals suffering from malaria have been found infected with different species of Anopheles. It included A.stephensi, A. culicifecies, A. annolaries and A. subpictus.

The malaria officer informed that female anopheles contain minute organism 'Sporozite' in their salivary ducts. "When mosquito pierces our skin for blood meal, it puts small drops of saliva. As saliva reaches the blood, thousands of sporozites are inoculated in the blood. It causes itching and burning sensation. These micro-organisms reach the liver cells and further divide. Many of them are destroyed but a significant number attack the red blood corpuscles," he informed.

Once again the mosquito feed on an infected person where these parasites attain maturity and become infective to man. Therefore, health experts say indoor breeding of mosquitoes should be prevented by emptying the earthen jars for water storage, water storage tanks should be closed, the stagnant water in saucer for ornamental plants should be removed and any other container which can accumulate water for several days should be checked.

Meanwhile, the outdoor breeding sites like tree holes, discarded tires, coconut shell and husks and water accumulated in pot holes should be treated with insecticides.

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Mosquitoes are breeding freely in city