A team of researchers have found that pre-existing malaria prevents secondary infection by another Plasmodium strain - the parasite responsible for malaria - by restricting iron availability in the liver of the host.
This discovery was published in Nature Medicine and has important implications for the management and prevention of malaria, a condition which affects millions of individuals worldwide.
After a mosquito bite, malaria parasites first travel to the liver, multiply, then escape and invade red blood cells. It was previously understood that parasites in both the liver and in blood need iron in order to grow. This new study shows that a second mosquito bite in an individual who is already carrying blood parasites does not lead to a full-blown second infection.
The superinfection is blocked in the liver by the first infection.
This protective effect is due to the blood parasites causing the parasites in the liver to be starved of iron, so that they cannot grow. In that respect, the results challenge the biological concept that infection of distinct host cells (liver hepatocytes or red blood cells) occur independently from each other, which may also have an impact in the research area of infection (beyond malaria).