Scientists want to fight malaria by poisoning mosquitoes with human blood

Scientists may have found a solution to stop the spread of malaria: poisoning mosquitoes with human blood. New research suggests that the mosquito-borne malady can be curbed by getting the insects to consume the drug nitisinone. As malaria and other illnesses spread by mosquitoes become increasingly prevalent, nitisinone could help to reduce infections worldwide.

Brandishing the blood

Nitisinone can make human blood incredibly toxic to mosquitoes, according to a study published in the journal Science Translational Medicine. The research showed that the insects "die within a few hours of feeding on samples from patients who received even relatively low doses," said National Geographic. "What's more, the drug remains effective for up to 16 days after the initial dosing."

The drug is typically used to treat rare genetic disorders like alkaptonuria and tyrosinemia type 1. Nitisinone blocks the enzyme 4-hydroxyphenylpyruvate dioxygenase in the body. "While this helps patients with metabolic disorders, it disrupts digestion in mosquitoes that drink the blood of medicated individuals — ultimately killing them," said Interesting Engineering. The drug can cause side effects in humans — but the people with these rare disorders "typically have to take much higher quantities of the drug than would be needed for effective mosquito control," said National Geographic.

Nitisinone is not a preventative medication for malaria. But "by killing the mosquitoes before they can lay eggs, the drug might be able to knock down disease-transmitting mosquito populations to the point that it breaks the chain of infection," said National Geographic.

Double drugs

Ivermectin is another drug that is toxic to mosquitoes. It rose to fame following the false claim that it could treat Covid-19, but has long been used to kill the pesky insects. However, it can also be environmentally toxic and resistance to the drug "becomes a concern" when it is "overused to treat people and animals with worm and parasite infections," said a news release. By contrast, nitisinone "specifically targets blood-sucking insects, making it an environmentally friendly option," said Álvaro Acosta Serrano, a professor of biological sciences at Notre Dame and co-corresponding author of the study.

In addition, nitisinone is faster acting than ivermectin. "While ivermectin given to humans or cows can kill mosquitoes at lower concentrations than nitisinone, the new drug acts more quickly, often within a day," and it "does not target the nervous system, so it is less neurotoxic," said Science Alert. Ideally, "it could be advantageous to alternate both nitisinone and ivermectin for mosquito control," Lee R. Haines, an associate research professor of biological sciences at the University of Notre Dame, honorary fellow at the Liverpool School of Tropical Medicine and co-lead author of the study, said in the news release. "For example, nitisinone could be employed in areas where ivermectin resistance persists or where ivermectin is already heavily used for livestock and humans."

Climate change is expanding the range of mosquitoes, which allows for mosquito-borne diseases like malaria to spread wider. This makes it all the more important to take preventative measures. "You have more bites, more areas where they're able to live, more months when they're active, and more places for them to breed," Matthew Phillips, a research fellow in infectious diseases at Harvard Medical School and Massachusetts General Hospital, said to the Harvard Gazette. "That means larger populations."