Using a simple decision rule and a finger prick to test blood, general practitioners can detect serious infections in children very quickly, according to a new study.1 The method ensures that seriously ill children don’t have to wait for a diagnosis until they’re hospitalized—a delay that may have fatal consequences. The procedure also prevents unnecessary hospital referrals for less serious cases.

In the early stages, serious infections such as kidney or bone infections, meningitis, pneumonia, or dangerous inflammations of the skin have symptoms that resemble those of more common viral infections. They are also very rare.

“As a result, serious infections tend to stay off the general practitioner’s radar for too long,” says Jan Y. Verbakel, MD, PhD, a general practitioner and postdoctoral researcher in the faculty of medicine at Katholieke Universiteit Leuven (KU Leuven). “We asked ourselves how rapid diagnostic tests might help solve this problem.”

Testing is not a very common practice among general practitioners yet. “Testing is often complex, expensive, and most of all time-consuming: it usually takes a few days for the lab results to come in,” Verbakel continues. “But recently various so-called point-of-care (POC) tests have become available. These simple diagnostic tests can be performed in the general practitioner’s office and provide results within minutes. For the detection of serious infections, POC C-reactive protein (CRP) testing by means of a finger prick holds potential.” The test measures the level of CRP in a drop of blood. The concentration of this protein increases in response to a pathogen.

A 1-year study involving more than 3,100 ill children from across Flanders showed that 5 mg of CRP per liter of blood is a good threshold value to rule out serious infections—but only after the general practitioner has performed a clinical evaluation of the patient’s symptoms and vital functions.

“POC CRP testing cannot replace a general practitioner,” Verbakel says. “Does the GP sense that something is off? Is the child short of breath, or running a fever of more than 40°C? If the answer to any of these questions is yes, it’s useful to perform a POC CRP test. Our study showed that with this procedure, all serious infections were detected during the first visit to the general practitioner. But there’s no need to test all ill children.”

“Thanks to the combination of a clinical examination of the patient, possibly followed by a POC CRP test, general practitioners can detect serious infections more quickly and more objectively,” Verbakel adds. “And for children who are less seriously ill, the procedure prevents unnecessary hospital referrals and anxiety. The POC CRP test is a valuable tool for general practitioners, but it has to be used responsibly.”

The Ernie 2 study was funded by Belgium’s National Institute for Health and Disability Insurance and Research Foundation Flanders. The foundation is a collaboration encompassing Ghent University, Ghent University Hospital, KU Leuven, University Hospitals Leuven, pediatricians affiliated with various Flemish hospitals, and general practitioners all across Flanders.


  1. Verbakel JY, Lemiengre MB, De Burghgraeve T, et al. Should all acutely ill children in primary care be tested with point-of-care CRP: a cluster randomized trial. BMC Med. 2016;14:131; doi: 10.1186/s12916-016-0679-2.