Can a diagnostic test designed for athletes help save the lives of children with malaria? A new study from researchers at the University of Alberta shows that a handheld device could help predict risk so that limited resources can be directed to the children who need it most.
According to the World Health Organization, 96 percent of malaria deaths happen in Africa. And of those deaths, 80 percent are children under five years old. Each year, this adds up to nearly half a million pediatric deaths.
In the hospitals where these children are treated, resources are limited, putting many diagnostic tests out of reach.
To help identify which patients need care most urgently, researchers at the University of Alberta demonstrated a way to identify high-risk cases. The study, led by professor of medicine Michael T. Hawkes, was published in Microorganisms.
The study was developed around a portable, low-cost blood test originally developed for athletes. A simple fingerstick blood sample, just like what is used by people with diabetes to measure blood sugar, is all that is needed to run the test and obtain results in seconds.
When people are physically active, lactic acid builds up in their muscles, reaching high levels when they work hard enough to transition from aerobic to anaerobic exercise, where the activity is using up oxygen so quickly that it isn’t being fully replenished. Athletes can use their lactic acid levels to definitively find out whether that limit has been reached.
Hawkes showed that the same blood test can pick up cases where children with malaria aren’t getting enough oxygen because they are experiencing respiratory distress. The malaria-causing parasites themselves can also produce lactic acid, and they can physically block blood flow if there are enough of them in the body, triggering even greater lactic acid production in further oxygen-deprived tissues.
Moreover, malaria affects multiple organs, and if the kidneys and liver begin to decline it can prevent them from clearing excess lactic acid effectively. This makes a lactic acid test a good overall indicator of malaria severity.
It can be difficult to triage patients based on their clinical symptoms alone, but using a lactic acid test at the bedside could make this distinction clear. Being able to get answers within seconds is particularly attractive here, as about half of cases that lead to death become fatal within eight hours of hospital admission.
Looking at the outcomes of over 1,000 pediatric cases of malaria with respiratory distress in Uganda, the researchers found that children with lactic acid over 5 mmol/L concentration at the time they were admitted to hospital were three times more likely to die of their illness.
Used as a predictive triage tool, a bedside lactic acid blood test could inform decisions on care given limited resources. The next step is for the team to verify that outcomes can be improved with modified resource management by following patients identified as being at high risk. The hope is that having a straightforward way to identify the most critically ill children will be the first step in making lifesaving choices on care.
