Rapid blood test by GPs can rule out serious infections in children

The researchers from Belgium and Oxford, led by Dr Jan Verbakel, an Honorary Clinical Lecturer in Oxford University's Nuffield Department of Primary Care Health Sciences, say their findings are important for improving the accuracy of diagnosis of unwell children in primary care, which could reduce the number of unnecessary hospital referrals, and, ultimately, the strain on secondary health care services.

The research is published in BMC Medicine.

In the early stages, serious infections such as meningitis, pneumonia, kidney or bone infections, 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. We asked ourselves how rapid diagnostic tests might help solve this problem,' said Dr Verbakel, who is also a Belgium-based GP and a postdoctoral researcher at KU Leuven Faculty of Medicine, where the clinical study was carried out.

The rapid point-of-care blood test for the inflammatory marker C-reactive protein (CRP) takes only four minutes and, in this study, was able to rule out serious infection in nearly 40% of children who presented as being at-risk by the usual clinical assessment. This includes at least one of the following symptoms: breathlessness, a temperature of 40°C and above, or diarrhoea if the child is aged between 12-30 months.

In their randomised trial involving 78 general practices and 3,100 unwell children across Flanders in Belgium, the researchers showed that the usual clinical assessment would flag 57 children for referral to hospital, out of which only one would be found to have a serious infection. Including the CRP test in these cases could reduce the number of referrals to 35.

Dr Verbakel said: 'Point-of-care CRP testing cannot replace a general practitioner. 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 point-of-care 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.'

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