Koay Hong Xin, Second Year Medical Student, Faculty of Medicine, Universiti Kebangsaan Malaysia.
Written By:
Reviewed By:
Dr. Zulkarnain Md Idris,
Assistant Head of Department of Parasitology and Medical Entomology,
Faculty of Medicine, Universiti Kebangsaan Malaysia.
The Culprit of Malaria
Generally, five species of Plasmodium can cause malaria in humans, namely
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P. falciparum,
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P. vivax,
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P. malariae,
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P. ovale
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P. knowlesii
From all of them, P. falciparum is the most prevalent and causes the highest mortality, particularly in the African region.
Malaria is transmitted when a female Anopheles mosquito bites a malaria patient; it becomes infected and subsequently transmits the parasite to the other individual via biting during a blood meal.
However, under certain circumstances, malaria could be transmitted from mother to child via blood transfusion or by sharing injecting drug needles.
Malaria cases in Malaysia
In Malaysia, significant progress towards the national elimination programme resulted in zero indigenous human malaria infections in 2018. However, zoonotic malaria caused by Plasmodium knowlesi, a parasite typically found in monkeys, has been increasing recently, accounting for most of the local cases in the nation.
A significant increase in the number of P. knowlesi cases from 376 in 2008 to 3575 cases was reported in 2021. Most cases of P. knowlesi infection were recorded in the states of Malaysian Borneo (i.e. Sabah and Sarawak).
The geographical topography of Sabah and Sarawak, which have vast forested areas are perfect habitats for the natural reservoir hosts (i.e. macaques) and the mosquito vector Anopheles.
Risk factors of malaria
With an increasing trend of zoonotic Malaria transmitted from monkeys to humansin Malaysia, populations living at greater risk include the indigenous population who mostly live in the jungle where female Anopheles mosquitoes infected with the parasite could be found easily.
Similarly, people working in forest-related sectors, including loggers and army personnel, are also at an increased risk. Other than that, the migrant population, for example foreign workers and displaced people, also have a greater risk, and it is difficult to track the malaria status of these populations.
Furthermore, deforestation results in the loss of habitat diversity, increasing forest fragmentation and decimation, which may affect the dynamics of P. knowlesi malaria transmission between macaques, vectors, and people and lead to an increase in the number of P. knowlesi cases in Malaysia.
Signs and symptoms of malaria
Fever, anaemia, and splenomegaly are the three main symptoms under the triad of signs of malaria.
Generally, fever is divided into the cold, hot, sweating, and apyrexia stages. Different species cause different fever patterns.
In severe cases, P. falciparum could cause cerebral malaria, mostly in children, while P. knowlesi can cause multiorgan failure, especially acute kidney injury and acute respiratory distress syndrome, particulary among older patients.
Treatment of malaria
The WHO recommends the use of artemisinin-based therapies (ACTs) for uncomplicated P. falciparum malaria in all endemic countries.
In Malaysia, except chloroquine for P. vivax and P. ovale, ACT is used as a first-line treatment for uncomplicated malaria from other Plasmodium species. Primaquine is also used as an anti-relapse for vivax and ovale malaria and to reduce falciparum malaria’s transmissibility.
Therefore, it is mandatory to admit all malaria patients, and case follow-up is required subsequently
Prophylaxis is better than cure
In a nutshell, malaria is a serious issue that should be given attention. As the saying goes, prevention is always better than cure.
Taking chemoprophylactic drugs when entering endemic areas, wearing protective clothing, using insecticide-treated nets (ITN) and long-lasting insecticidal nets (LLIN), and implementing fogging and indoor residual spray are among the ways to prevent the occurrence of malaria.
Last but not least, seek assistance from your healthcare provider if there are any signs or symptoms of malaria in your body​​
