‘Zero malaria starts with me’, is this year’s World Malaria Day theme. The subtext seems to suggest what a scientist at the National Institute of Malaria Research, New Delhi, told me recently — that we cannot (and should not, for ecological reasons) eliminate an insect. “All you can do is protect yourself,” he said. This year’s campaign that’ll be front and centre on April 25, “aims to keep malaria high on the political agenda, mobilise additional resources, and empower communities to take ownership of malaria prevention and care”. Here’s a quick look at the methods currently available in our markets.
Mosquito repellent. Man using insect repellent spray outdoors.
DEET and DEET-free sprays/creams
Years of experiments and human trials using thousands of compounds have narrowed it down to the most effective chemical DEET (chemical name: N,N-diethyl-meta-toluamide). When sprayed or applied on the skin, it can protect you against mosquitoes, ticks, and even leeches. Commercially available mosquito-repellent creams have DEET or its variants in the range of 10 to 30%. But the problem is DEET is corrosive. Studies have shown that beyond four hours, it starts to corrode clothes, styrofoam. Many European countries have banned DEET from its repellents. DEET-free creams use natural citronella oil as their active ingredient. But how effective is it?
A study published in The New England Journal of Medicine pointed out that while a formulation of about 24% DEET provided complete protection for over 300 minutes, botanical repellents were able to protect for only about 20 minutes. The ones that work are lavender oil, peppermint oil, lemongrass oil, eucalyptus oil, cedar oil, geranium oil. “A person who is highly allergic will be easily irritated by DEET or any insecticide. It is okay only for use for a short span of time. But repeated exposure to any insecticide or pesticide is harmful to the skin,” explains Dr S Murugusundram, founder and medical director, Chennai Skin Foundation and Yesudian Research Institute, Chennai. “There are increased cases of atopy among children, where they are highly susceptible to respiratory and skin problems. Keeping the future generation in mind, our Government should start more studies on this.”
Green spiral insect repellent mosquito coil incense smoking.
Mosquito coils, mats and liquid repellents
A quick stroll through the supermarket aisle will throw up these, with insecticides as their active ingredients. But recent studies on mice have pointed out that repeated exposure to these insecticides was toxic to their vital organs. Also, the World Health Organization (WHO) had stated that “since 2010, a total of 68 countries have reported resistance to at least one class of insecticide”. Yes, mosquitoes are becoming resistant. “Mosquito coils are known to irritate the respiratory tract, and hence, I advise my patients not to use them. If you are sensitive, allergic or have respiratory problems, make sure there is proper ventilation, and fresh air supply when using liquid repellents in the room. When there is a mass spraying near your office or house, try to stay away and not inhale it,” says Dr R Radhakrishnan from RR Chest Clinic, Chennai.
Regular mosquito nets and insecticide-treated ones
The Anopheles mosquito that is known to be the transmitter of malaria is active at night, so a net is advisable. Insecticide-treated nets are available for better protection. Even if there is a hole or a small gap between the bed and net, the mosquito will not enter, claims the WHO’s book on insecticide-treated nets.
Regular nylon nets are treated with insecticides such as deltamethrin, lambda-cyhalothrin, cypermethrin, cyfluthrin, etofenprox, permethrin in prescribed concentrations.
Many governments have started distributing these medicated nets in endemic regions (Odisha and the Northeastern states, for instance), but they are also available online.
“The Government has started distributing these nets freely to poor households. For individual personal protection, you can buy them online, though they are a bit expensive. They are marketed under the name long-lasting insecticide-treated net (LLIN). It is a safe and effective method,” explains Dr P Vadivelan, Additional Director of Public Health and Preventive Medicine, (Malaria and Filaria), Chennai.
