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

All-nighter: staying up to fight malaria

Featured in Nature, Victor Chaumeau collects mosquitoes in Myanmar to better understand how to control malaria.

Antibiotic accountability: how countries and companies perform

Patients in north Africa and the Middle East are using antibiotics in sharply rising quantities far beyond the global average, raising concerns over the escalating risks of resistance to medicines to treat bacterial infections. Estimated antibiotic consumption for 204 countries between 2000 and 2018 shows a 46 per cent increase in global antibiotic usage, with a surge in nations including India and Vietnam.

Overusing antibiotics? Find out with Antibiotic Footprint Calculator

To mark WHO World Antimicrobial Awareness Week, 18-24 Nov 2021, and help reduce the overuse of antibiotics, MORU researchers have released a new, easy to use online tool – Antibiotic Footprint Calculator – that could make an important contribution in the fight against antimicrobial resistance (AMR), one of the world’s most significant emerging threats to public health.

GRAM study provides the first longitudinal estimates of global antibiotic consumption in 204 countries from 2000 to 2018

Global antibiotic consumption rates increased by 46 percent in the last two decades, according to the first study to provide longitudinal estimates for human antibiotic consumption covering 204 countries from 2000 to 2018, published in Lancet Planetary Health by the Global Research on Antimicrobial Resistance (GRAM) Project.

Peter Macharia wins RSTMH Emerging Leader Award

Peter Macharia is a spatial epidemiologist and a postdoc interested in disease mapping, healthcare access and mapping population vulnerabilities at KEMRI Wellcome. He received the RSTMH 2021 Emerging Leader Award, which recognises significant contributions in leadership, mentoring and capacity building in those who are early in their careers.

Lack of evidence is key barrier to using portable devices to detect poor quality medicines

A series of papers which reviewed portable devices to detect poor quality medicines has concluded major gaps in scientific evidence remain a key barrier for regulators to implement surveillance systems using such devices.