Scientists Build One Tool to Track Two Types of Malaria at Once

Scientists have created a new computer model that can track two types of malaria parasites at the same time. The two parasites are called Plasmodium falciparum and Plasmodium vivax. Researchers hope this tool will help health workers plan better ways to fight malaria in places where both types exist. Malaria is a serious disease spread by mosquito bites, and it still sickens millions of people every year around the world.

Malaria is caused by tiny parasites that mosquitoes carry. When an infected mosquito bites a person, the parasite enters the body and can make that person very sick. P. falciparum is the most deadly type and is most common in Africa. P. vivax is more common in Asia and the Americas, and scientists have been working hard to wipe it out in those regions.

The two parasites behave very differently inside the human body, which makes them hard to fight with the same tools. P. falciparum stays active in the blood, but P. vivax can hide in the liver as sleeping cells called hypnozoites. These sleeping cells can wake up weeks or even months later and cause the person to get sick again. This is called a relapse, and it makes P. vivax much harder to fully cure.

To treat P. vivax, doctors need to use special drugs that kill the sleeping liver cells. These drugs are called 8-aminoquinolines, and two common ones are primaquine and tafenoquine. However, these drugs can be dangerous for some people who have a condition called G6PD deficiency, which affects how their red blood cells work. Doctors must test patients for this condition before giving them the medicine.

In Africa, most people carry a blood type called Duffy-negative, which protects them from P. vivax. The parasite cannot easily enter their red blood cells. This is why P. vivax is rare across most of Africa, but it is found in places like Ethiopia and Madagascar where fewer people have that protection. Recently, scientists have found small amounts of P. vivax in areas they did not expect, which suggests the parasite may be more widespread than anyone thought.

Another problem is that lab workers sometimes mix up the two parasites when looking at blood samples under a microscope. A person might actually have P. vivax, but it gets recorded as P. falciparum, or the other way around. This is called misidentification, and it can lead to patients getting the wrong treatment. If a P. vivax infection is missed, the patient will not receive the special drug needed to clear the sleeping liver cells.

A team of researchers at Imperial College London decided to combine an older P. vivax model with their existing P. falciparum model, called malariasimulation. Now, both parasites can be studied together in one shared computer system. This lets scientists run simulations that are fair and consistent for both types of malaria. When researchers tested the new model, it matched real-world data collected from countries around the globe.

The model showed that P. falciparum tends to dominate in areas with lots of mosquitoes. P. vivax, on the other hand, does better in areas with fewer mosquitoes because its sleeping liver cells help keep it alive. This means P. vivax can survive in places where P. falciparum would die out. The model also showed that control tools like bed nets work better against P. falciparum than against P. vivax.

When health efforts stopped in the simulation, P. vivax came back faster and stronger than P. falciparum. This is because of those sleeping liver cells, which act like a hidden backup supply of the parasite. Scientists say this shows that standard malaria tools are not enough on their own to eliminate P. vivax. Special strategies aimed directly at P. vivax will be needed.

Scientists say this new unified model is a big step forward for fighting malaria. It gives health officials in different countries a smarter way to plan their anti-malaria campaigns. Because the model can account for local differences like Duffy blood type and relapse rates, it can give more tailored advice. The goal is to help countries eliminate malaria once and for all.