Methylene blue, an affordable synthetic dye, has been shown to be highly effective at blocking transmission of the malarial parasite Plasmodium falciparum from patients to mosquito hosts. David Fidock, PhD, and his colleagues, report this discovery in a study published online on October 31, 2011, in the Proceedings of the National Academy of Sciences.
Each year, the parasite causes severe malaria in over half a billion individuals and kills almost a million African children. Its ability to resist drug treatments and evade host immunity makes it particularly hard to eradicate. The problem is heightened in cases where the infection is asymptomatic and goes untreated, allowing undetected transmission.
This discovery of the dye’s ability to block transmission is an example of researchers finding a new use for something already well known. The famous chemist Paul Ehrlich first described the antimalarial properties of the compound in 1891.
Fidock and his lab recently received a nearly $1.5 million grant from the Bill & Melinda Gates Foundation for research on new drugs to block the transmission of malarial parasites from infected patients to the mosquito host. This work will build on knowledge of drugs already shown to be effective against the disease-causing stages of the parasite life cycle.