Cookies on this website
We use cookies to ensure that we give you the best experience on our website. If you click 'Continue' we'll assume that you are happy to receive all cookies and you won't see this message again. Click 'Find out more' for information on how to change your cookie settings.

About one-third of children diagnosed with severe malaria may instead have an alternative cause of illness, but simple blood tests could help researchers distinguish between the two and speed up research on new treatments.

A healthcare worker with gloved hands draws blood from a child's finger. © 2020 MORU. Photographer: Gerhard Jørén.

Using simple blood tests could help researchers identify children who have been misidentified as having severe malaria, according to a study published today in eLife.

Researchers are working to develop better ways to treat severe malaria, which kills about 400,000 children in Africa each year. The discovery could help expedite such research by helping them more accurately identify children with severe malaria. It also reinforces the importance of the World Health Organization’s recommendation that all children being treated for severe malaria also receive antibiotics to ensure any misdiagnosed children receive life-saving care.

Diagnosing severe malaria in children in Africa is challenging because the parasites that cause malaria can be found in both healthy and severely ill children. This makes it difficult to tell if the parasites or some other condition is causing illness. In fact, many children diagnosed with severe malaria may have other life-threatening infections. In addition to potentially delaying life-saving antibiotic care, misdiagnosis can skew the results of studies of new treatments for malaria because children misdiagnosed with malaria will not respond, which could make drugs that work look ineffective.

“Inaccuracy in the diagnosis of severe malaria negatively impacts clinical studies, especially those trying to understand which genes may make people more vulnerable to severe disease, or which treatments are most effective,” says co-first author James Watson, Senior Scientist at the Mahidol Oxford Tropical Medicine Research Unit (MORU) in Bangkok, Thailand. “We wanted to know whether complete blood count data, notably platelet counts and white blood cell counts, could help make the diagnosis of malaria more accurate.”

Watson, along with co-first author Carolyne Ndila, a researcher at The Kenya Medical Research Institute-Wellcome Trust Research Programme (KWTRP), in Kilifi, Kenya, and their colleagues developed a statistical model that could distinguish between severe malaria and other severe illnesses that can be mistaken as severe malaria. To develop the model they included data from over 1,500 children and adults diagnosed with severe malaria in Thailand and Bangladesh. In these countries, people are rarely misdiagnosed with severe malaria because it is much less common for healthy people to have malaria parasites in their blood.

They applied this model, which relied on platelet and white blood cell counts, to a large cohort of Kenyan children diagnosed with severe malaria. Based on their analysis, they estimate that in approximately one-third of the children, severe malaria was in fact a misdiagnosis.

“Our results support the current guideline that all children with suspected malaria should be given both antimalarials and broad-spectrum antibiotics, as many of the misdiagnosed children will likely have had bacterial sepsis, a severe blood infection,” Ndila says.

Using their new model to reanalyse data from clinical studies that looked for potential genetic factors that protect against severe malaria, the team also found that people with glucose-6-phosphate dehydrogenase deficiency probably have some protection from malaria. This benefit was likely obscured in previous studies by the high rate of misdiagnoses.

“We hope our new model can be used by other scientists and clinicians to improve the accuracy of diagnosis in children suspected of having severe malaria,” concludes senior author Nicholas White, Professor of Tropical Medicine at Mahidol University. “This will help studies trying to identify better treatments for these patients.”

 

For full paper:

Improving statistical power in severe malaria genetic association studies by augmenting phenotypic precision. Nyutu G, Mohammed S, Ngetsa C, Mturi N, Peshu N, Tsofa B, Rockett K, Leopold S, Kingston H, George EC, Maitland K, Day NP, Dondorp AM, Bejon P, Williams T, Holmes CC, White NJ. Elife. 2021 Jul 6;10:e69698. doi: 10.7554/eLife.69698. Epub ahead of print. PMID: 34225842.

Similar stories

Laos’ first Pint of Science: warty newts, COVID, AI for Instagram, and more!

Organised by a grass-root community of thousands of scientists across the world, Pint of Science 2022 allowed researchers in 25 countries and over 800 cities to share their latest findings with lay folk in interesting, informal settings. Lao PDR joined the global Pint of Science family on Monday 9 May, when the first-ever Pint of Science Laos kicked off!

Modelling the Cost-Effectiveness of COVID-19 Vaccination Strategies in Kenya

The KEMRI-Wellcome Trust Research Programme today released the results of its latest modelling on COVID-19 vaccine scale-up within the country. The analysis found that the country’s COVID-19 vaccination campaign can achieve greater value for money if it focuses on the elderly, rather than a strategy that pursues scaling up vaccines to the whole population.

Patient recruitment on track in Oxford-led DeTACT trial of safe, effective drug combinations to prevent the spread of artemisinin and multi-drug resistant malaria in Africa

Today is World Malaria Day. The global fight against malaria is at a critical point. No new antimalarial drugs are expected in the near future, and if multi-drug resistant falciparum malaria becomes established in East Africa and spreads to other parts of Africa, millions will be at risk of drug-resistant malaria infection and death. The development of triple artemisinin-based combination therapies aims to prevent or delay the emergence of artemisinin and multi-drug resistant malaria in Africa.

PRIORITISE study team publishes results, now seeks partners

In regions where few people have received Covid-19 vaccines, health systems remain vulnerable to surges in SARS-CoV-2 infections. During the delta-wave of COVID-19 in India, for example, healthcare facilities and staff across the country struggled to cope with the surge in the number of cases of COVID-19 due to a shortage of hospital beds for people with severe cases, plus shortages of medicines and limited human resources.

Emelda Okiro awarded Wellcome Senior Research Fellowship

Dr Emelda Okiro has been awarded the prestigious Wellcome Senior Research Fellowship. Emelda’s fellowship is the first African Senior Research Fellowship awarded in the KEMRI-Wellcome Research Programme and among the less than five SRFs awarded to researchers in Africa.

Large African and South Asian research network finds half of deaths among children admitted to hospital happens after discharge

Young children in sub-Saharan Africa and South Asia who become sick or malnourished continue to have a high risk of death in the six months after being hospitalized, according to findings by researchers in the Childhood Acute Illness & Nutrition (CHAIN) Network. Appearing in The Lancet Global Health, the study of 3,101 acutely ill children at nine hospitals in six countries across sub-Saharan Africa and South Asia found that 48% of the 350 deaths recorded occurred within six months after discharge from hospital.