Procalcitonin Levels Detect Bacterial Infections in Children

According to the results of a study by scientists in Taiwan, the level of procalcitonin is the most precise parameter to exclude a bacterial infection in children.

In a report in Annals of Emergency Medicine, researchers note that after taking a history and physical exam, about 20% of newborns and young children with fever are diagnosed with fever of unclear origin. However, 20% of them can have serious bacterial infections, such as lobar pneumonia or bacteremia. The chest x-ray and a general urinalysis, of course, are important in the diagnosis of these diseases, but currently there are not enough reliable markers of their presence.

To assess the quality of existing indicators, a team of scientists studied the data from 8 studies. In total, the researchers selected 1,883 patients who determined procalcitonin levels, 1,265 patients who measured C-reactive protein (CRP) levels, and 1,649 patients who had white blood cell counts.

The corresponding prevalence rate of bacterial infection was 18.1%, 19.6% and 18.8%. Further analysis has shown that markers differ in their prognostic capacity for serious bacterial infections. The odds ratio for procalcitonin was 10.6, for CRP - 9.83 and for leukocytosis - 4.26.

The overall sensitivity of the indicators in the groups was 0.83, 0.74 and 0.58, respectively, while the specificity of these markers was 0.69, 0.76 and 0.73.

Thus, given the relatively small group of patients with a positive likelihood ratio and the acceptable volume of patients with a negative likelihood ratio, procalcitonin is the most informative indicator for the exclusion of bacterial infections than for their detection.

According to the researchers, carrying out additional analyzes and examinations increases the information content of this indicator. However, existing studies do not determine how to combine the diagnostic significance of the level of procalcitonin with other clinical data to improve the accuracy of diagnosis of infections.