A common but dangerous strain of malaria that hides in the liver, re-emerging years later to trigger new infections and is harder to prevent, diagnose and treat, can soon be treated.
According to Niraj Tolia, assistant professor of molecular microbiology and biochemistry at Washington University School of Medicine in St. Louis, they have found how a form of malaria – common in India, southeast asia and south America – attacks red blood cells by clamping down on the cells with a pair of proteins.
“More people live at risk of infection by this strain of malaria – called plasmodium vivax – than any other. We are now using what we have learned to create vaccines tailored to stop the infectious process by preventing the parasite from attaching to red blood cells,” Tolia added.
The study, appeared in the journal PLOS Pathogens, provides details that would help scientists design better vaccines and drug treatments for this strain.
Earlier studies had suggested that one P. vivax protein binds to one protein on the surface of red blood cells.
Tolia’s research reveals that the binding is a two-step process that involves two copies of a parasite protein coming together like tongs around two copies of a host protein.
“It’s a very intricate and chemically strong interaction that was not easily understood before,” Tolia said.
“We have had hints that other forms of malaria, including the African strain, may be binding in a similar fashion to host cells, but this is one of the first definitive proofs of this kind of attack,” he added.
Tolia suggested that blocking any of the proteins with drugs or vaccines will stop the infectious process.
“For example, some people have a mutation that eliminates the protein on red blood cell surfaces that P. vivax binds to, and they tend to be resistant to the parasite,” he added.
The parasite protein is very large, and human antibodies bind to it at many different points along its length.
The researchers observed that the ones that are most effective so far are the antibodies that bind to the protein at the region highlighted by the new findings,” the study said.
According to the world health organisation (WHO), there were more than 200 million malaria cases in 2012.
India records between 30,014 and 48,660 malaria deaths per year.
The deadliest form of malaria, Plasmodium falciparum, is most prevalent in Africa. But P. vivax can’t be ignored especially in India.