Health Original explainer
Two mosquito diseases, two very different mosquitoes. How dengue and malaria spread, and what actually prevents them.
Every monsoon, India sees the same two headlines: dengue cases rising in the cities, and malaria persisting in forests and tribal districts. Both are spread by mosquitoes, both cause fever, and both are preventable. Yet they are very different diseases, spread by different mosquitoes, at different times of day, and controlled in different ways. Knowing the difference is the first step to protecting your family.
Dengue is now India's most rapidly expanding mosquito-borne disease. Reported cases rose more than tenfold, from about 28,000 in 2010 to a peak of about 289,000 in 2023, before falling to about 233,500 in 2024 and about 121,800 in 2025. Malaria has moved the other way. Official surveillance recorded about 227,500 cases and 83 deaths in 2023, part of a long decline, with the country aiming to eliminate the disease by 2030.
Dengue is spread by the Aedes aegypti mosquito, and to a lesser extent by Aedes albopictus. Unlike the malaria mosquito, Aedes bites during the day, especially in the early morning and late afternoon, and it lives in and around homes. It breeds in clean, still water: rooftop tanks, coolers, flower pots, discarded tyres, and even a bottle cap of rainwater.
That is why dengue is a city disease. Rapid urban growth, construction sites, erratic water supply and stored water create endless breeding spots. Cases peak during and just after the monsoon, from July to November, when stagnant water and humidity are at their worst. There are four types of the dengue virus, and a person can catch dengue more than once. A second infection with a different type carries a higher risk of severe illness, which is why repeat infections worry doctors.
Most dengue infections cause high fever with headache, pain behind the eyes, muscle and joint pain, and a rash. Severe dengue is less common but dangerous: it can cause bleeding, a sharp drop in blood pressure and organ damage. There is no specific medicine that kills the virus. Treatment is supportive: rest, fluids, fever control, and hospital care when warning signs appear.
Malaria is far older in India, and for decades it was the bigger killer. It is caused by a parasite carried by the female Anopheles mosquito, which bites mainly at night. The parasite enters the blood, multiplies in the liver and then in red blood cells, and causes cycles of fever, chills and sweating. Severe malaria can damage the brain, kidneys and lungs, and it can kill, especially in children and pregnant women.
India's fight against malaria has been one of public health's quiet successes. Cases have fallen by about 79 per cent since 2015, and deaths by even more. The National Strategic Plan for Malaria Elimination aims to end the disease in phases by 2027 to 2030. The tools are proven: rapid diagnostic tests, artemisinin-based treatment, insecticide-treated bed nets, and indoor spraying in high-risk areas. But malaria persists in forested, tribal and hard-to-reach districts of Odisha, Chhattisgarh, Jharkhand, Madhya Pradesh and the northeast, where mosquitoes breed freely and health services are thin.
Neither disease spreads from person to person. You cannot catch dengue or malaria by sharing food, water or a room with a patient. Only the mosquito carries them.
For dengue, the most effective step is also the simplest: do not let water stand. Once a week, empty, scrub and dry coolers, tanks, pots and trays. Cover water storage containers. Clear roof gutters. Turn over unused buckets and tyres. Health departments call this the weekly dry day, and it works because the Aedes mosquito completes its breeding cycle in about a week. Community clean-up drives matter more than any single household, because mosquitoes do not respect fences.
For malaria, the bed net is the hero. Sleeping under an insecticide-treated net, especially in high-risk areas, is the most reliable protection at night. Long sleeves and trousers in the evening, mosquito repellents, and indoor spraying add further protection. When travelling to a malaria-prone district, ask a doctor whether preventive medicine is needed.
Both diseases are tracked by the National Centre for Vector Borne Diseases Control, which runs the national programme against six mosquito- and vector-borne diseases, including dengue, malaria, chikungunya and kala-azar. The programme was created in 2003-04 by merging older disease control programmes, and it works through state health departments.
Any fever during or after the monsoon deserves attention, and a blood test is the only way to tell dengue from malaria or other fevers. See a doctor promptly if fever lasts more than two days, if there is severe headache, pain behind the eyes, vomiting, rash, bleeding from the gums or nose, severe abdominal pain, or unusual drowsiness. Do not self-medicate with painkillers beyond basic fever relief without medical advice, and do not ignore a fever that keeps returning. Early testing and early treatment save lives, for both diseases.
This article is general information, not medical advice. If you have a fever or symptoms described here, please consult a doctor promptly.
This explainer was written by The Daily Short's desk from the sources listed above. It is general information, not professional advice. Spot an error? See our Corrections Policy or tell us via the Contact page and we will correct it. Follow our official Instagram @thedaily.short.