Scientists have found that a drug-resistant parasite that causes malaria can infect the most common type of mosquito in Africa. The parasite has not yet spread to the African continent, but the concern is that it could and that, if it does, it might undo at least a decade's worth of work to eliminate the disease.
A laboratory study by the U.S. National Institutes of Health shows that Plasmodium falciparum is the deadliest species among malaria parasites, and it is spreading rapidly in Southeast Asia.
The parasite is resistant to artemisinin, the main drug used to treat malaria. This is not the first time that malaria causing parasites have become resistant to drugs used to treat the disease, but artemisinin plays a major role in fighting malaria.
Until now, scientists didn't know that these parasites could infect species of mosquitoes outside Southeast Asia.
In the study, scientists infected various mosquito species from Southeast Asia and Africa with artemisinin-resistant parasites from Cambodia in a laboratory setting.
They discovered the parasites easily infected the main malaria carrying mosquito in Africa. They also discovered a shared genetic background among artemisinin-resistant parasites that may enable them to infect different species of mosquitoes. The study was published in the journal Nature Communications.
The researchers plan to investigate other potential genetic determinants of parasite infection of mosquitoes and to study which species from Cambodia are naturally transmitting artemisinin-resistant parasites in the wild.
The World Health Organization reports that malaria that kills more than 400,000 people each year, most of them in sub-Saharan Africa, where malaria is the leading cause of death for children under five. WHO statistics show that between 2000 and 2015, new cases of the disease fell by 37 percent globally. During the same period, deaths from malaria decreased worldwide by 60 percent.
The disease is caused when a mosquito infected with the malaria-causing parasite bites a human being. Once the parasite is introduced into the human body, it invades the person's red blood cells. The infected blood cells can then block blood flow to the brain and other critical organs and cause death.
Earlier this month, Dr. Youyou Tu was recognized by the Nobel Committee for discovering artemisinin, the drug that has saved millions of lives, and is now threatened with becoming ineffective.