Why is there a need to worry?

• Culex mosquitoes are known carriers of some serious diseases. They can fly up to a distance of 1-1.5 km. Here are some diseases caused by mosquito bites
• Japanese Encephalitis is a disease that can spread by Culex mosquitoes. Maximum cases of the disease are reported in Asia. The symptoms of the disease include fever and headache. One in 250 people develop severe symptoms like convulsions, disorientation and paralysis. Getting vaccinated is the only effective protection against Japenese encephalitis.
• The Aedes albopictus can transmit the Zika virus. The symptoms include red eyes, fatigue and muscle ache. Most people who get infected by the virus, recover without any serious complication. In pregnant women, the virus can be transmitted from the mother to the fetus.
• To prevent the disease, it is best to wear full sleeves clothes and sleep under a mosquito net or use a mosquito repellent.
• Aedes aegypti mosquito can cause dengue fever by biting. People who get infected by the virus mostly show symptoms in three to 14 days. Symptoms of dengue fever are like that of flu and disappear after a few days. The only way to prevent yourself from getting dengue is by wearing full sleeves clothes and use a mosquito repellent.
• Apart from dengue fever, Aedes aegypti mosquito can also cause yellow fever. Symptoms of yellow fever are fever, headache, jaundice and muscle ache. The symptoms get better after four to six days of getting infected. Some people might get severe symptoms like bleeding from the nose, mouth or stomach. It's best to get vaccinated before you plan to travel in areas where yellow fever has been reported.
• The disease is common in the tropical regions of Africa and America.
• Aedes aegypti mosquito is known to transfer another disease called Chikungunya. The symptoms of chikungunya appear between two to 14 days after getting bitten by the mosquito.
• Common symptoms include fever, body ache, headache, skin rashes and nausea. The joint pain can last for several weeks to months and even years. Wearing full sleeves clothes and using mosquito repellent can help keep the mosquitoes away.
• The female Anopheles mosquitoes are known to transmit malaria. They catch this dangerous disease-causing parasite by drinking infected blood. The symptoms of malaria include fever, chills and headache. The disease, if not treated on time, can be fatal.

When mercury level start soaring in Delhi ?

The mercury level started soaring in Delhi from mid-March, Culex or house mosquitoes swarmed back in large numbers causing much inconvenience to Delhiites. Resident welfare associations have expressed their concern to the municipal corporation coercing them to call for or a high-level meeting to dig deep into the matter and find out measures to control their growth. From using mosquito larvicidal oil to house-inspections, the Delhi Municipality Corporations are picking on all kinds of necessary means to curb their menace. Even with MCD officials are continuously inspecting households with open defecation and providing favourable weather conditions, the number of mosquitoes has seen a sharp rise in the past few weeks. The workers are monitoring houses, doing tax survey and encouraging people in unauthorised colonies to register their houses. However, sources said 1,000 works have been diverted from their inspection duties and house visits gave declined from 44 lakh in 2018 to 21 lakh this year till March second week. The numbers dipped massively in 2020 due to the pandemic as workers were utilized to perform Covid-related duties.
On a usual day, near to 3,500 workers visit 60 to 70 Delhi homes to inspect coolers, tanks surrounding to find they have stagnant water or other favourable breeding ground in their surroundings.

Where mosquitoes are most active in daytime?
Most types of mosquitoes are active around dusk and dawn, so avoiding the outdoors at those times will reduce the likelihood of getting a bite. If you're outside, wear long sleeves, long pants and insect repellent to protect skin from mosquitoes. A small fan at outdoor gatherings may also reduce mosquitoes, as they are not strong flyers. It is especially important to wear effective insect repellents and protective clothing if traveling outside.

Who gave evidence that mosquito cannot spread corona virus?

Scientists from Kansas State University have provided evidence that mosquitoes indeed cannot. The researchers have demonstrated in lab experiments that SARS-CoV-2 cannot infect mosquitoes. It is the first such confirmation. “We did everything possible to get the mosquitoes infected even though the conditions that we used would not be found in nature. The mosquitoes did not get infected even in these extreme conditions. The experiments were conducted on three common and widely distributed species of mosquitoes. Aedes aegypti, Aedes albopictus and Culex quinquefasciatus. The first two species are the vectors for dengue fever, chikungunya, Zika fever, and yellow fever. Culex quinquefasciatus spreads viruses that cause lymphatic filariasis and certain kinds of encephalitis.
All three species are present in India. The coronavirus was unable to replicate in any of them.

How are they harmful?

• Culex mosquitoes are known carriers of Japanese encephalitis, a potentially life-threatening but rare viral disease that causes “acute inflammation” of the brain. They breed in dirty, stagnant water.
• The water recedes in the summers, there are depressions in the flood plains where water still remains and doesn’t dry even in hot weather as the water table is high. Such areas are ideal breeding grounds for culex.  Temperature for mosquito breeding is ideal at present: “The ideal condition for mosquitoes to breed is when the temperature is between 10 degrees Celsius and 40 degrees Celsius. This is the time to intensify the anti-mosquito drive.