Malaria

Female Anopheles mosquitoes contract malaria by feeding on the blood of a human already infected with the disease-causing parasite. The parasite then develops in the mosquito's gut for one to two weeks before it migrates to the mosquito's salivary glands. Next, when the mosquito bites another person the parasite is delivered into the bloodstream of another human. This graphic further details what happens inside the human body during infection.

In Kenya, as one malaria-sufferer explains, the disease is common enough that anytime a child has a fever or any sort of sickness families and the community will wonder if it's malaria. Sleeping under a mosquito net is recommended. Unfortunately, a gin and tonic will not keep malaria at bay.

The term refers to marshy areas associated with the disease. An estimated 94% of malaria cases—215 million—occur in Africa.

Multiple species of a single-celled organism called a protozoa cause malaria infection when transmitted by a mosquito bite. But Plasmodium falciparum is the most widespread in Africa, and the most deadly.

Birds, rodents, monkeys, lizards, bats, apes, and livestock are among the species that can become infected with malaria. Infected animals' symptoms often resemble those of humans, including fever, lethargy, loss of appetite and difficulty breathing. Birds will also have ruffled feathers and drooped heads.

Two vaccines are currently recommended by world health experts for children living in areas where malaria transmission is common. The first, RTS,S/ASO1, formally became recommended for use by the World Health Organization in October 2021, and the second was approved by the WHO two years later. Both have faced logistical, financial, and uptake challenges.

Both of the currently recommended malaria vaccines have limited effectiveness, require multiple doses, and provide protection for only a short period of time. One, approved by the World Health Organization in 2021, is only about 30% effective, requires four doses, and protection fades within months. The other requires three shots, and some research indicates it is 75% effective for a year.

The English army surgeon Ronald Ross, who later won the Nobel Prize for his work, was the first to describe the transmission of malarial parasites by mosquitoes. He had lab mosquitoes suck blood from malaria-infected people and separately found the malaria parasite inside a mosquito's gut, confirming the bug's role in malaria transmission.

Charles Louis Alphonse Laveran won the Nobel Prize for his work "on the role played by protozoa" in causing diseases. His work included discovering and reporting the malaria-causing parasite in the blood of a patient suffering from malaria.

Using CRISPR, a team of international researchers is genetically modifying Anopheles in the lab to be malaria-resistant. The insects would be released into the wild to mate with the wild population, passing down this trait. As of early 2026 they had not yet released the mosquitoes into the wild for field trials. Separate CRISPR work seeks to reduce the Anopheles population altogether.