Fighting mosquito menace with repellents, vaccines

Fighting mosquito menace with repellents, vaccines

Subject: Science and Tech

Sec: Health

Context:

Since 2007, WHO has called April 15 World Malaria Day to highlight the need for continued investment and sustained political commitment to malaria prevention and control.

More on News:

• In 1902, Sir Ronald Ross received the Nobel Prize in Physiology/Medicine for having shown how malaria was transmitted by the bite of Anopheles mosquitoes infecting a human patient in Hyderabad suffering from malaria.
• The National Centre for Vector-borne Diseases, of the Indian Health Ministry, points out that mosquito bites lead to malaria, dengue, filaria, Japanese encephalitis and chikungunya.

Malaria?

• Malaria is a life-threatening mosquito borne blood disease caused by plasmodium parasites.
  • There are 5 Plasmodium parasite species that cause malaria in humans and 2 of these species – falciparum and P. vivax– pose the greatest threat.
• Malaria is predominantly found in the tropical and subtropical areas of Africa, South America as well as Asia.
• Malaria is spread by the bite of an infected female Anopheles mosquito.
  • The mosquito becomes infected after biting an infected person. The malaria parasites then enter the bloodstream of the next person the mosquito bites. The parasites travel to the liver, mature, and then infect red blood cells.
• Symptoms of malaria include fever and flu-like illness, including shaking chills, headache, muscle aches, and tiredness.
• Malaria is both preventable and curable.

Prevalence:

• Across India, mosquitoes are most prevalent in highly water-borne areas such as Odisha, West Bengal and the Northeastern states.
• However, even Pune, Delhi, Chennai and Kolkata have shown a large increase in mosquito population due to heavy rains and inefficient water handling.

Breed:

• Mosquitoes breed in stagnant waters such as agricultural farms, plant pots, gutters, bird baths, tires of bicycles, autos and other vehicles, and trash containers.
• Periodic cleaning of these will help in reducing mosquito growth.

Repellents:

• While some of these are usable in cities and towns, people in rural areas (where rice/wheat breeding occurs and has a lot of stagnant water) can use camphor and the leaves of ‘tulsi’ plants, both of which are used in their homes for prayers.
• The plant citronella offers an oil that is an effective mosquito-repellent, out of which the mosquito repellent Odomos is produced, which is available in the market for affordable prices.
• The widely used insect-repellent DEET was developed to protect soldiers during the Second World War.
• A simple change in the chemical structure of DEET improved the efficiency of this molecule.

Vaccines against malaria

• In 2021, WHO recommended the malaria vaccine called ‘Mosquirix’, produced by Glaxo-Smith-Kline and PATH, in four doses for infants, and allowed it for large-scale use in some parts of
• Two biotech firms in India have initiated programmes for the manufacture and supply of malaria vaccines.
• Bharat Biotech, which has already been working on some malaria-related vaccines, has tied up with GSK-PATH for technology transfer for long-term supply of ‘Mosquirix’, and hopes to manufacture and supply it to people in India by 2026.
• In 2021, the WHO also recommended the R21/Matrix vaccine.
• Serum Institute (in collaboration with Oxford University) has produced R21/Matrix vaccine; in mid-July this year the vaccine was rolled out in Cote d’Ivoire in West Africa, the first country to begin administering R21/Matrix-M.