Why is malaria so difficult to combat?

·2-min read

Each year on 25 April, World Malaria Day is marked to highlight the need for the prevention and control of the disease. The World Health Organization states that in 2019, the estimated number of deaths due to malaria was 409,000 while the number of cases stood at 229 million.

According to Professor Rachel Cerdan of the University of Montpellier, the big concern is the resistance of the parasite, Plasmodium falciparum, to antimalarial drugs.

"It's something that frightens everyone involved in research on malaria. Though there are treatments (artemisinin based combination therapy), there is a real worry that soon we won't have efficient ones," Cerdan told RFI. "The resistance was first found in Asia. Now, it's moving to Africa."

Professor Cerdan and her team are working on developing molecules for new antimalarial strategies. One of the strategies involves depriving the parasite the chance to reproduce in human red blood cells.

"Just like for every cell, the daughter cells of the malaria parasite need a membrane. Our research focuses on finding a chemical compound (or compounds) that can inhibit the metabolic pathways which allow the parasite to build this membrane. If the parasite fails to build the membrane, it will halt its ability to reproduce resulting in its death," Cerdan said.

Understanding the parasite

Her team's research remains fundamental, however, which means it may be a while before treatment based on such molecules can become available.

"We are deciphering the biology of the parasite to understand first how it works. After we understand the mechanism, we might be able to produce the right molecule with an inhibitory effect. Once we find a molecule, there are several steps before it is available as a drug. It requires a lot of time and plenty of funds."

Since the parasite grows in human red blood cells, it's important to develop drugs that only target the pathogen and not the host, Cerdan said.

Plasmodium falciparum, transmitted by a mosquito vector, first enters the liver of an infected individual. After about a week it migrates from the liver into the bloodstream. Symptoms such as fever start developing once the parasite reproduces in the red blood cells.

No vaccines have so far shown more than 50 percent efficacy. While efforts to develop better vaccines continue, Cerdan said there needs to me a multi-pronged approach to combat malaria, including research on vector mosquitoes and raising awareness about preventive measures.

"We have to take into account everything and to use everything we have in our arsenal in the fight against malaria. But in any case, we need effective treatments to cure the people who fall sick."