Malaria is one of the most common infectious diseases in tropical regions, including Nigeria. It is caused by parasites of the Plasmodium group and is mainly transmitted through the bite of an infected female Anopheles mosquito.
Although many people simply refer to every infection as malaria, there are different types of malaria. The type depends largely on the Plasmodium parasite responsible for the infection, while malaria can also be described according to how severe the illness becomes.
The distinction matters because some forms are more likely to cause severe disease, while others can remain in the body and cause repeated episodes if not properly treated.
In this article, Tribune Online highlights seven types and forms of malaria everyone should know.
Plasmodium falciparum malaria
Plasmodium falciparum is the most dangerous malaria parasite and the dominant cause of malaria in Africa. It can multiply rapidly in the blood and cause severe illness if treatment is delayed. In some patients, the infection can progress to complications affecting the brain, kidneys, lungs and other organs.
Severe P. falciparum malaria can cause impaired consciousness, seizures, severe anaemia, breathing difficulties, jaundice and other life-threatening complications. This is why fever and other symptoms suggestive of malaria should not simply be treated casually at home, particularly in young children and pregnant women. P. falciparum is recognised as the deadliest malaria parasite and says it is the most prevalent malaria parasite on the African continent.
Plasmodium vivax malaria
Plasmodium vivax is another major cause of malaria, particularly in regions outside sub-Saharan Africa. One important feature of P. vivax is its ability to form dormant stages in the liver. These parasites can become active again later, causing another episode of malaria.
This means treating the initial symptoms alone may not always be enough. Where P. vivax is confirmed, treatment may need to address both the parasites in the blood and the dormant liver stages to prevent relapse. Repeated infections can also contribute to anemia and other health problems, particularly in vulnerable patients.
Plasmodium malariae malaria
Plasmodium malariae is less common than P. falciparum but can infect people in several parts of the world, including Africa. The infection can sometimes persist in the body for a long period without causing dramatic symptoms.
Although it is generally less likely than P. falciparum to cause severe disease, it should not be dismissed. Chronic infection has been associated with complications such as kidney-related problems. Proper testing is therefore important rather than assuming that all malaria infections behave in exactly the same way.
Plasmodium ovale malaria
Plasmodium ovale is another malaria parasite that can infect humans and is found particularly in parts of Africa and some other tropical regions. Like P. vivax, P. ovale can form dormant stages in the liver. These can reactivate later and cause relapse.
There are actually two recognised P. ovale species, P. ovale curtisi and P. ovale wallikeri, although they are commonly discussed together as P. ovale malaria. Because the parasite can remain dormant, identifying the type of malaria is important when deciding on appropriate treatment.
Plasmodium knowlesi malaria
Plasmodium knowlesi is different from the other malaria parasites commonly discussed because it normally infects certain monkeys. However, it can also infect humans, particularly in parts of Southeast Asia.
It can multiply rapidly and may cause severe illness. Because of this, P. knowlesi infection can sometimes be mistaken for other forms of malaria, making accurate diagnosis important. It is not a major cause of malaria in Nigeria, but it is important to know about because of its potential severity and its role as a zoonotic malaria parasite.
Uncomplicated malaria
Uncomplicated malaria refers to malaria that has not developed into severe disease. A person may have symptoms such as fever, chills, headache, weakness, muscle aches, nausea or vomiting.
The symptoms can initially appear similar to other common infections, which is why testing is important. Uncomplicated malaria can become severe if it is not treated appropriately, particularly when caused by parasites capable of rapidly progressing to serious disease.
It’s recommended to confirm suspected malaria with parasite-based testing, such as microscopy or a rapid diagnostic test, where testing is available. The appropriate medicine depends on factors including the parasite species, local drug resistance patterns, the patient’s age and weight, and whether the person is pregnant.
Severe malaria
Severe malaria is the most dangerous form of the disease. It occurs when malaria causes serious complications involving vital organs or other major problems in the body. It can include impaired consciousness, repeated seizures, severe breathing difficulties, severe anaemia, jaundice, abnormal bleeding and other complications.
Severe malaria requires urgent hospital treatment. Children under five, pregnant women, travellers who have not developed immunity and people with certain health conditions are among those at increased risk of severe malaria.