Plasmodium knowlesi

Plasmodium knowlesi

Plasmodium knowlesi is a species of malaria parasite that primarily infects macaque monkeys. It is also known to infect humans, causing a severe form of malaria known as knowlesi malaria. This species was first identified in 1931 by Robert Knowles and Biraj Mohan Das Gupta in a long-tailed macaque in Malaysia.

Taxonomy

Plasmodium knowlesi belongs to the genus Plasmodium, which includes various species of malaria parasites. It is classified under the subgenus Plasmodium (Plasmodium) and the family Plasmodiidae. The species name "knowlesi" is derived from the name of the scientist who first discovered it, Robert Knowles.

Life Cycle

The life cycle of Plasmodium knowlesi involves both humans and macaque monkeys. The parasite is transmitted through the bite of infected Anopheles mosquitoes. When an infected mosquito bites a human or a macaque, the parasite enters the bloodstream and travels to the liver. In the liver, the parasite multiplies and forms merozoites, which are released into the bloodstream. These merozoites invade red blood cells, where they continue to multiply and cause the characteristic symptoms of malaria.

Symptoms and Diagnosis

Knowlesi malaria caused by Plasmodium knowlesi can lead to severe illness and even death if not treated promptly. The symptoms of knowlesi malaria are similar to those of other types of malaria and include fever, chills, headache, muscle aches, and fatigue. Diagnosis is typically done through microscopic examination of blood samples, where the presence of Plasmodium knowlesi can be detected.

Distribution

Plasmodium knowlesi is primarily found in Southeast Asia, particularly in Malaysia, Thailand, the Philippines, and Indonesia. However, cases of knowlesi malaria have also been reported in other parts of the world, including India and some countries in Africa. The increasing number of cases outside of Southeast Asia has raised concerns about the potential global spread of this parasite.

Prevention and Treatment

Preventing knowlesi malaria involves taking measures to avoid mosquito bites, such as using insect repellents, wearing protective clothing, and sleeping under mosquito nets. In areas where knowlesi malaria is prevalent, efforts are also made to control mosquito populations through insecticide spraying and environmental management.

The treatment of knowlesi malaria typically involves the use of antimalarial drugs, such as chloroquine or artemisinin-based combination therapies (ACTs). Prompt diagnosis and treatment are crucial to prevent complications and reduce the risk of severe illness or death.

Research and Future Directions

Research on Plasmodium knowlesi is ongoing to better understand its transmission dynamics, pathogenesis, and drug resistance patterns. Efforts are also being made to develop new diagnostic tools and effective vaccines against knowlesi malaria. Understanding the biology and epidemiology of this parasite is essential for implementing effective control strategies and reducing the burden of knowlesi malaria.

See Also

• Malaria
• Plasmodium falciparum
• Plasmodium vivax

References

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  Plasmodium knowlesi blood smears showing intraerythrocytic developmental cycle

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  Life cycle of Plasmodium species

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  Plasmodium knowlesi merozoite

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  Plasmodium knowlesi blood smears

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  Photograph of Robert Knowles