Malaria is a well-known infectious disease caused by Plasmodium parasites and spread through the bites of Anopheles mosquitoes. However, a new form of malaria has emerged in recent years—zoonotic malaria. This type of malaria originates from wild animals—especially monkeys—and can be passed on to humans. It has become a growing concern in many forested areas of Southeast Asia, including Indonesia. People who live near or work in forest areas are at higher risk of what scientists call “spillover infection,” where diseases jump from animals to humans.
This research aimed to identify monkey species and Plasmodium parasites that have the potential to infect humans, study forest mosquitoes that could carry and spread these parasites, explore how the parasites interact with human blood cells, and assess whether people in these areas have already developed some immunity to the infection.
The study was conducted in three regions: Sabang (Aceh), Palangkaraya (Central Kalimantan), and Buton Utara (Southeast Sulawesi). Researchers collected blood samples from 366 people and 46 wild monkeys, captured and identified forest mosquitoes, examined the genetic material in the blood and mosquitoes, and tested for malaria antibodies.
The results showed that many wild monkeys were infected with malaria, especially Plasmodium inui, P. cynomolgi, P. knowlesi, and P. simiovale. While no active malaria cases were found in people, antibody tests showed that many had been exposed to malaria in the past—particularly in Southeast Sulawesi—suggesting both past infection and some level of immunity. The study also examined a gene in humans called DARC, which helps the parasite enter red blood cells. This gene varies between individuals and regions, and these differences may affect how vulnerable someone is to zoonotic malaria. Some forest mosquitoes, such as Anopheles sulawesi and An. letifer, were found carrying malaria parasites, proving their role as potential vectors.
In conclusion, zoonotic malaria is real and present, especially in areas close to forests. Even though no outbreak has occurred yet, the risk of transmission is high due to the presence of infected monkeys, forest mosquitoes, and ongoing human activity in natural habitats. These findings highlight the importance of a One Health approach—one that sees human, animal, and environmental health as connected. This research paves the way for better malaria prevention strategies that not only focus on humans but also protect ecosystems and monitor wildlife health.