There is no reliable evidence that primaquine reduces the transmission of P. falciparum malaria in malaria-endemic communities, the Cochrane Review on this topic shows. Primaquine, a drug with anti-malarial properties, does not cure P. falciparum infection but does kill P. falciparum gametocytes, which is a stage of the malaria parasite in the blood that infects mosquitoes. The mosquitoes then go on to spread the disease by infecting others (completing the transmission cycle).
Side effects of Primaquine
Primaquine has long been given as a single dose or short course add-on to P. falciparum infection treatment regimens and is now recommended by the World Health Organization (WHO) and several national malaria programmes, with the intention of reducing malaria transmission. However, primaquine also has potentially serious side effects in people with glucose-6-phosphate dehydrogenase (G6PD) deficiency, where it may cause haemolysis (disintegration of red blood cells) which can be serious. There is also the risk of the parasite developing resistance to primaquine as it acts as a monotherapy against gametocytes.
An assessment of the evidence
In this new review, the authors assess whether a single dose or short course of primaquine, added to standard treatments for P. falciparum malaria, reduces malaria transmission and is safe. The review includes 11 Randomized Controlled Trials (RCTs) with a total of 1776 individuals. None of the trials assessed effects on malaria transmission, and only one small study suggested it reduces the infectiousness of the parasite present in infected people to the mosquito. The trials do not provide enough evidence about safety. In conclusion, the findings of this review do not support using primaquine to reduce malaria transmission.
The Cochrane Infectious Diseases Group (CIDG)
The Cochrane Infectious Diseases Group (CIDG) is a partner of the Effective Health Care Research Consortium, funded by the UK Government. The editorial base of the CIDG is located at the Liverpool School of Tropical Medicine. CIDG has been preparing systematic reviews on the benefits and harms of healthcare interventions for infectious diseases, particularly malaria, tuberculosis, diarrhoea, and tropical diseases, since 1994.