Malaria: Causes, Symptoms, and Control

Malaria is a mosquito-borne infectious disease caused by single-celled protozoan parasites of the genus Plasmodium. The parasites infect red blood cells and cause various symptoms, including fever, headache, and muscle pain. Malaria has a complex life cycle that involves both human and mosquito hosts. The disease is transmitted through the bites of infected female Anopheles mosquitoes, which inject sporozoites into the bloodstream. These sporozoites then travel to the liver, where they mature into liver schizonts. The liver schizonts divide and produce merozoites, which invade red blood cells, causing the onset of clinical symptoms. A fraction of merozoites also differentiate into male and female gametocytes, which are ingested by the mosquito host during a blood meal. The parasite then undergoes sexual reproduction in the mosquito, and the resulting sporozoites are injected into another human host when the mosquito bites again.

There are five species of Plasmodium that naturally infect humans and cause malaria in large areas of the world: P. falciparum, P. vivax, P. malariae, P. ovale, and P. knowlesi. While the first four species are specific to humans, P. knowlesi is naturally maintained in macaque monkeys and causes zoonotic malaria widely in Southeast Asia.

Malaria can have severe consequences for individuals and communities. It can lead to anemia, organ damage, and even death. Malaria can also have long-term detrimental effects on non-health-related quality of life, intensifying poverty by limiting education opportunities and reducing productivity at work.

Despite the challenges, progress has been made in controlling malaria. Malaria transmission has been eliminated in many countries, including the United States, but the potential for reintroduction of active transmission exists in many non-endemic parts of the world. The development of antimalarial drugs and vaccines has improved the ability to prevent and treat malaria. However, resistance to antimalarial drugs and the lack of a highly efficient vaccine continue to pose challenges in controlling the disease, particularly in African regions.

The World Health Organization (WHO) aims for malaria incidence and mortality to decrease by 90% over the next 15 years, with increasing numbers of countries that eliminate the disease. Despite these efforts, there is still a child dying of malaria every 10 minutes in 2030 [210]. It is crucial to continue focusing on new and innovative approaches to reduce malaria's burden and save lives.

Learn about the causes and symptoms of malaria, a mosquito-borne infectious disease that affects millions of people worldwide. Discover the different species of Plasmodium, the transmission cycle, and the efforts to control and eliminate malaria.