by Dr. Adele Visser
Overview
The 6th of November marks the SADC Malaria Day. Despite the decline in incidence over recent decades, it remains an important preventable cause of death and morbidity in South Africa.
There are five species of Plasmodia, of which Plasmodium falciparum is endemic to the north-eastern border of South Africa, accounting for › 90% of cases. Infection with this species also carries the highest risk of complication, as compared to other species.
Prevention
The mainstay of malaria prevention remains to be bite avoidance. Bites typically occur between dusk to dawn and are notoriously asymptomatic. Therefore, the lack of an itchy bite does not preclude exposure. If not contra-indicated, chemoprophylaxis is advisable for all visitors to malaria-endemic areas.
Drug | Schedule | Dose | Specific indications | Contra-indications |
---|---|---|---|---|
Mefloquine | Weekly. From one week before to 4 weeks after. |
Adults: 250 mg Children: 5 mg/kg |
Can be used in all trimesters of pregnancy. Children › 3 months or › 5 kg. Long-term prophylaxis up to 3 years. |
|
Doxycycline | Daily. From 1 day before. To 4 weeks after. |
Adults: 100 mg | Only used in children › 8 years. Long-term prophylaxis up to 2 years. HIV on HAART. |
Pregnancy |
Atovaquone-proguanil | Daily. From 1 day before. To 1 week after. |
Adults: 1 tab Children: as per weight categories. |
Paediatric dose from 11 kg. Long-term prophylaxis up to 1 year. |
Pregnancy (lacking data) |
Diagnosis
Key to the early and successful diagnosis of malaria is a high index of suspicion, despite season, use of prophylaxis or prevalence of malaria at the time. Any patient with a positive travel history, presenting with flu-like symptoms and/or fever should be tested. Progression to severe disease is typically rapid, particularly in immune-compromised patients, children or pregnant women.
Malaria rapid diagnostic tests (RDTs) may be specific to the P. falciparum histidine-rich protein 2, or be generic to Plasmodium spp. This test may remain positive for up to 30-days after infection, despite treatment.
In addition, Malaria smears of peripheral blood, as performed on an EDTA-sample, can be used in the diagnosis and speciation of malaria, based on the parasite morphology. It can also be used to quantify the parasitaemia, which can be used in the follow up monitoring of patients. Molecular testing and speciation can be performed but is not offered in a routine diagnostic setting.
For further information about diagnostic testing, please call 031 201 4647.
References
- Blumberg, L. 2015. Recommendations for the treatment and prevention of malaria: Update for the 2015 season in South Africa. SAMJ. 105(3):175-178.
- Raman, J., Blumberg, L., Ukpe,I.S. 2021. Maintaining focus on administering effective malaria treatment during the COVID-19 pandemic. SAMJ. 111(1):13-16.