Mosquitoes are more than pests. They’re also a mortal threat, contributing to millions of cases of malaria a year. Fortunately for humans, however, a team of researchers has recently identified a medication that could curb mosquito populations, controlling their spread of malaria.
Revealing their results in a paper published in Science Translational Medicine, the researchers report that the medication nitisinone makes human blood deadly to mosquitoes.
“One way to stop the spread of diseases transmitted by [mosquitoes] is to make the blood of animals and humans toxic to these blood-feeding insects,” said Lee R. Haines, a paper author and an associate research professor of biology at the University of Notre Dame, according to a press release. “Our findings suggest that using nitisinone could be a promising new complementary tool for controlling insect-borne diseases like malaria.”
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Fighting Malaria-Infected Mosquitoes
In 2023 alone, the world saw some 263 million cases of malaria, a deadly disease that causes fever, fatigue, and sometimes seizures (in the most severe cases). Caused by one of five malaria parasites, this disease is mostly spread by bites from malaria-infected mosquitoes.
Scientists say that the trick to controlling the spread of malaria is to curb mosquito populations. Over the years, they’ve identified several medications that could serve such a purpose, including ivermectin. This medication shortens the lifespan of mosquitoes when it is ingested through human or animal blood, limiting the insects’ ability to spread malaria. But ivermectin is toxic to the environment and is likely to lose its efficacy if it is overused as a treatment for parasitic infections.
Setting out to find a complementary method for curbing mosquitoes, researchers turned to nitisinone, a medication that blocks the enzyme 4-hydroxyphenylpyruvate dioxygenase (HPPD) in the body. In humans, this medication treats rare inherited diseases like alkaptonuria and tyrosinemia type 1. But in mosquitoes, it’s deadly.
“We thought that if we wanted to go down this route, nitisinone had to perform better than ivermectin,” said Álvaro Acosta Serrano, another paper author and a professor of biology, also at the University of Notre Dame, according to the press release. “Indeed, nitisinone performance was fantastic.”
When mosquitoes consumed blood containing nitisinone, they died quickly. And when compared to ivermectin, nitisinone lasted a lot longer in human blood, improving its mosquitocidal ability to curb mosquitos and, thus, malaria. “This is critical when applied in the field for safety and economical reasons,” Acosta Serrano said in the release.
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The Ivermectin-Nitisinone Combination
To arrive at their results, the researchers tested the effects of nitisinone blood on the Anopheles gambiae mosquito, a common carrier of malaria parasites in Africa. Taken from patients who were already using nitisinone as a treatment for alkaptonuria, the blood had a “hidden superpower,” Haines said in the release. Deadly to mosquitoes both young and old, the blood was also fatal to insecticide-resistant insects.
“In the future, it could be advantageous to alternate both nitisinone and ivermectin for mosquito control,” Haines said in the release. “For example, nitisinone could be employed in areas where ivermectin resistance persists or where ivermectin is already heavily used.”
While fatal for mosquitoes, nitisinone is safe for the environment and could serve as an insecticide. “What’s particularly interesting is that it specifically targets blood-sucking insects, making it an environmentally friendly option,” Acosta Serrano said in the release.
Even a small amount of the drug is deadly to mosquitoes in the lab, but additional tests are needed to determine what dosages would be best for managing mosquitoes in the outside world. With wider use, the combination of ivermectin and nitisinone could mitigate malaria while also increasing the availability of drugs for people with alkaptonuria and tyrosinemia type I — a dual benefit for fighting diseases with parasites and without.
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Article Sources
Our writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:
Science Translational Medicine. Anopheles Mosquito Survival and Pharmacokinetic Modeling Show the Mosquitocidal Activity of Nitisinone
World Health Organization. Malaria
MedlinePlus. Alkaptonuria
MedlinePlus. Tyrosinemia
Sam Walters is a journalist covering archaeology, paleontology, ecology, and evolution for Discover, along with an assortment of other topics. Before joining the Discover team as an assistant editor in 2022, Sam studied journalism at Northwestern University in Evanston, Illinois.
