by Dr. Adele Visser

Introduction

Although malaria is a preventable and treatable disease, there were still an estimated 241 million cases reported with 627 000 deaths worldwide in 2021. Of these deaths, approximately 80% occur in sub-Saharan Africa2 and 70% in children under the age of 5 years3.

Pathogenesis

Malaria is a parasitic infection caused by Plasmodium spp. as transmitted by the infected female Anopheles mosquito.

Of the five species of the parasite, P. falciparum remains the most predominant in sub-Saharan Africa, however P. vivax, P. ovale, P. malariae and P. knowlesi also contribute to the disease burden worldwide, albeit with milder symptoms.

The disease requires two hosts for propagation. The female Anopheles mosquito bites a human and inoculates them with the sporozoites.

Following a maturation cycle within the human, which varies depending on the species of malaria in question, merozoites are present in the bloodstream where it infects red blood cells.

A portion of the parasites develop to the gametocyte stage, where the cycle is continued through retransmission to the mosquito upon feeding from human blood3.

Disease Progression and Clinical Manifestations

Certain patients are at risk of severe infection. These include non-immune travellers to endemic areas, pregnant women, young children, the elderly, splenetomised and immunocompromised patients, including patients with HIV-1 infection (figure 1).

 

Figure 1
Figure 1.

Summary of the disease progression of malaria.

 

Treatment

Treatment is dependent on the type of species a patient is infected with, as well as the local resistance profiles.

This should best be approached using National Guidelines as established by the National Institute of Communicable Diseases (NICD)3 and the Department of Health (DOH)2.

Important Notes

Malaria remains to have a significant disease burden in South Africa and active prevention and effective treatment regimens are essential in reducing its mortality (figure 2).

 

Figure 2
Figure 2.

Essential steps in reducing the disease burden of malaria.

 

References

  1. https://www.who.int/news-room/fact-sheets/detail/malaria
  2. https://www.health.gov.za/malaria/
  3. https://www.nicd.ac.za/wp-content/uploads/2019/03/National-Guidelines-for-prevention-of-Malaria_updated-08012019-1.pdf