Children who have asymptomatic malaria are a hidden risk in the control measures against malaria, a research shows.
The research established that in Uganda, asymptomatic children were the biggest source of malaria parasites transmitted to mosquitoes. This finding followed two years of investigations on malaria transmission patterns in Eastern Uganda and mass public testing for evidence of malaria parasites.
The research was conducted by scientists from the Infectious Diseases Research Collaboration, London School of Hygiene & Tropical Medicine, Radboud University Medical Centre, and University of California, San Francisco.
Individuals who were asymptomatic were unknowingly responsible for most mosquito infections. People with symptomatic infections were responsible for less than one per cent of mosquito infections.
Children aged between five and 15 years were responsible for the highest number of infections at 59 per cent. Children under the age of five years contributed to 26 per cent of the infections whereas people aged 16 years and above contributed 16 per cent to the infections.
Malaria parasite reservoir
"We found that infections in school-aged children drive malaria transmission. Some children harboured billions of malaria parasites in their bloodstream without experiencing symptoms," said Prof Sarah Staedke, who co-authored the research.
She pointed out that children were a critical reservoir of malaria parasites that could be easily targeted for control interventions such as chemoprevention through intermittent preventive treatment.
"This will benefit individual children, reduce malaria transmission, and will help sustain malaria gains where intense vector control measures are deployed," Prof Staedke said.
According to the World Health Organization (WHO), malaria kills up to 400,000 people globally. Children under the age of five years are the most vulnerable. In 2018, for example, they accounted for 272,000 deaths out of the 405,000 malaria deaths recorded globally.
According to the WHO World Malaria Report 2020, Africa still carries the burden of malaria and accounts for 94 per cent of all malaria deaths. The deadliest parasite is known as Plasmodium falciparum and it accounts for over 75 per cent of all mortality worldwide.
In Kenya, up to 27 per cent of children aged five years and below have been infected with malaria.
In the same vein, according to data from the WHO, Kenya recorded the lowest number of malaria deaths in East Africa in 2018 with 2,000 deaths.
Tanzania had the most at 21,500 deaths followed by Uganda at 13,000. Rwanda recorded 3,200 malaria deaths. The low figures in Kenya were the fruits of 30 million bed nets that Kenya has distributed to high prevalence areas and indoor home spraying to prevent the risk of infection.
In the new research, Prof Staedke noted that asymptomatic cases were a risk in areas where control had been successful.
"Asymptomatic children that keep circulating at relatively low levels could be sufficient enough to cause infections to rebound swiftly if control measures are not sustained," said Prof Staedke in the findings published in the The Lancet Infectious Diseases journal