The rains have stopped disturbing the city, but reports of dengue cases are still trickling in. In the post-rain season, buzzing armies of mosquitoes breed wherever they can, continuing to carry the sting of dengue and other mosquito-related diseases. What’s the reason behind this situation?

People often complain that the Bruhat Bengaluru Mahanagara Palike (BBMP) is not doing enough, or even anything, to fight the mosquito menace after the rains. Currently, there is some anxiety related to the lack of efforts for “spraying insecticides” in common perception, or “fogging”.

Anant, a resident of HSR Layout, says that BBMP doesn’t seem to be scouring the stagnant lakes and roads. Most living in apartments and gated communities undertake their own attempts for fogging. He asks: “Why isn’t the government doing it?”

Residents say that contracts of fogging contractors have not been renewed. However, Sarfaraz Khan, Joint Commissioner, Health, BBMP, clarifies that old contractors are being paid based on work orders. He says that this year, the BBMP spent Rs 13 crore to fight the mosquito menace. Of these, Rs 10 crore were invested in manpower, while Rs 3 crore went into machinery and medicines in BBMP hospitals, as well as fogging.

This was in response to the shooting up of dengue cases this year. However, what is fogging, and does it really control the dengue-spreading mosquito?

‘Fogging is not of much use’

Mosquito fogging uses a chemicals like pyrethroid or malathion, similar to those found in domestic insect spray cans. As the insecticide is mixed with water droplets and shot through the fogging machine, it clouds the atmosphere around the insects.

However, regular use of fogging would impact humans as well as environmental systems, according to Dr Ravi Kumar, Senior Regional Director, Regional Office for Health and Family Welfare, National Vector Borne Disease Control Programme. Over the years, mosquitoes also tend to develop resistance to these chemicals.

Sarfaraz Khan, Joint Commissioner for Health and Solid Waste Management is emphatic that fogging is irrelevant. The government is not the sole or the main agency that has to fight the deadly insect, Aedes aegypti. It is not fogging that helps, but efforts from house owners and residents, he says.

This surprising information is strengthened by Dr K. Ravi Kumar. “There is absolutely no use fogging,” he says. Fogging is done in open areas and drains. But the dengue carriers do not breed in open grounds, but mostly near and inside houses. The Aedes aegypti mosquito that transmits dengue, breeds primarily in man-made containers like water-storage drums, discarded plastic food containers or any other item that holds water. They are not killed by fogging, which is conducted quite far away from their sites. So who benefits from the practice? Certainly not the government, or the citizens, or the environment!

“Fogging cannot be done near houses or inside it. The chemicals are harmful and would create problems for the residents. Moreover, the chemicals would not kill the mosquitos that give you the disease. Fogging is of no use, and in fact, it is harmful, as it pollutes the air.”

Fogging is useless against malaria as well, he clarifies. At any rate, there isn’t so much malaria in the city. There are about 400 cases of the disease per year in Bengaluru. But fogging doesn’t kill the mosquito that causes either dengue or malaria. Fogging only kills the culex mosquito, which causes elephantiasis, but only in coastal regions, not Bengaluru.

Still, it is surprising that fogging continues to take place. Why does it continue if it is irrelevant? That is mainly because people demand it. So do corporators, MLAs, MPs, gram panchayat members and various others, points out Dr Ravi Kumar. “The authorities need to be seen doing something, and getting more visibility. So they just do it.”

What can be done to control mosquitoes?

What is the role of the BBMP in fighting the disease then? What should it take up?

“Empirical activities,” explains Dr Ravi Kumar. “It needs to conduct a lot more surveys in various houses, to see where stagnant water is getting collected. And it should also spread awareness among people, take vigilant steps to convey that it is upto the people to follow the rules and guidelines. They should see to it that people do not allow stagnant water to collect in any of their rooms and open spaces.”

Residents need to be more vigilant too. Here is what one should follow:

• Do not collect or let water stagnate in open drums, terraces, refrigerator trays, containers, ornamental plant holders, coconut shells or anything that would make water remain still for a long time. These water-storage drums, or plastic containers or anything else that collects water is the breeding ground for dengue viruses.
• The best way to clear up the areas is to discard the water – or the containers.
• Double-check that the garbage has been cleared away, as it might have containers, plastics, or shells that breed the carriers.
• Ensure that people are wearing full-sleeved clothing. It may not look sexy, but you need to starve, not feed, the mosquitos.
• Install nets, barrier creams, aero sprays and repellents.

So the battle is simple. While the BBMP needs to spread awareness on keeping your surroundings clean, you need to do what you can, and stop the municipality from taking action through harmful chemicals.

Improved health data

Dr T Venkatesh, Programme Officer of Public Health Emergency of International Concern, Bruhat Bengaluru Mahanagara Palike, reveals that 1,657 cases of dengue have been reported in the BBMP areas alone from October till date. Bengaluru (East), with 614 cases, has topped the list.

This year shows an exceptional rise in the number of cases too. Dr K. Ravi Kumar, Senior Regional Director, Regional Office for Health and Family Welfare, National Vector Borne Disease Control Programme, says that 6,083 dengue cases were reported in the state last year, but this year the graph line shows an ascent. Information till early November discloses that there are 15,075 dengue cases in Karnataka, of which 6,064 are from the BBMP areas alone.

Why is there such a sudden rise in the cases this year?

“One very simple reason is that earlier, cases were not reported from BBMP areas, while this year, in June, July and August, we reported more cases of dengue here,” explains Dr Ravi Kumar.

But the reporting itself is pretty shoddy. Dr N.S. Prashanth, Assistant Director at the Institute of Public Health, laments the lack of baseline surveillance and weak monthly reporting. “There is no connectivity or accurate data that is available. People going to private hospitals may not even report the cases properly to the BBMP. “  

Citizen Matters had earlier written a report that shows problems in data collection mechanism in healthcare, that leads to problems in the accuracy of data. This year, the reporting mechanism has been better and private hospitals have been able to share their data in the system.