Sir Ronald Ross discovers the link between mosquitoes and malaria
On 20 August 1897, Dr Ronald Ross, a British doctor working in India, made a discovery that changed the course of medical history: he proved that mosquitoes are the carriers of malaria. Examining the stomach tissue of a mosquito that had fed on a malaria patient, Ross found the malaria parasite – solving one of the greatest medical mysteries of the time.
For this groundbreaking achievement, Ross was awarded the Nobel Prize in Physiology or Medicine in 1902, becoming the first Briton to receive the honour. He was later knighted, becoming Sir Ronald Ross, and dedicated much of his career to malaria research, control, and prevention.
Who was Ronald Ross?
Ronald Ross was born on 13 May 1857 in Almora, India, where his father served in the British Army. He studied medicine in London, later joining the Indian Medical Service in 1881. While working in India, he focused his research on tropical diseases. Inspired by earlier work by French physician Charles Louis Alphonse Laveran (who first identified the malaria parasite), Ross investigated how malaria spread.
His 1897 discovery laid the foundation for modern tropical medicine. Ross continued to work on malaria prevention across the world, from Africa to the Mediterranean, advocating for mosquito control and public health measures.
What is malaria?
Malaria is a life-threatening disease caused by Plasmodium parasites, transmitted to humans through the bites of infected female Anopheles mosquitoes.
Symptoms include:
- High fever and chills
- Sweats, headaches, nausea
- Muscle pain and fatigue
- In severe cases: organ failure, coma, and death
Malaria has plagued humanity for thousands of years, once common across Europe, Asia, and the Americas. It remains one of the world’s deadliest infectious diseases.
Global burden of malaria
According to the World Health Organization (WHO), there were around 263 million malaria cases and approximately 597,000 worldwide in 2022.
The most affected regions are:
- Sub-Saharan Africa – over 90% of global cases
- Parts of South Asia and Southeast Asia
- Areas of Latin America and Oceania
Children under 5 and pregnant women are the most vulnerable.
Treatment and prevention
Historically, malaria was treated with quinine (from cinchona bark) and later chloroquine, but resistance developed. Today, the frontline treatment is artemisinin-based combination therapy (ACTs).
Prevention includes:
- Insecticide-treated bed nets (ITNs)
- Indoor spraying with insecticides
- Rapid testing and treatment in endemic areas
- Preventive medication for travellers and pregnant women
Vaccines against malaria
For decades, a malaria vaccine seemed impossible – but progress has been made.
- In 2021, the WHO approved the world’s first malaria vaccine, RTS,S (Mosquirix), for children in Africa.
- In October 2023, the WHO also recommended R21/Matrix-M, a new, highly effective vaccine.
Countries rolling out malaria vaccines:
- Ghana, Kenya, and Malawi were among the first to pilot RTS,S.
- More African nations are now adopting both vaccines, aiming to protect millions of children most at risk.
World Mosquito Day
In recognition of Ross’s discovery, 20 August is observed annually as World Mosquito Day.
The day serves two purposes:
- To honour Ronald Ross and his pioneering contribution.
- To raise global awareness about mosquitoes as carriers of deadly diseases such as malaria, dengue, Zika, chikungunya, and yellow fever.
Health organisations, research institutes, and charities use the day to promote prevention, research, and eradication efforts.
Legacy
Ronald Ross’s 1897 discovery remains one of the greatest triumphs in medical science. It not only unravelled the mystery of malaria transmission but also paved the way for global campaigns to control and eventually eliminate the disease. Though malaria is still a deadly threat today, vaccines, better treatments, and international cooperation bring hope that one day malaria may finally be eradicated.
Also read: ON THIS DAY: Linus Pauling died (1994)
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