We did four distinct clinical studies, mainly in the emergency department (ED) setting, to pragmatically evaluate the accuracy, feasibility and characteristics of different diagnostic tests in children with acute infections, and documented the etiology of febrile pharyngitis. 

The results of this study show that point-of-care tests (POCTs) for white blood cell count and C-reactive protein (CRP) were feasible and relatively accurate in comparison with standard laboratory methods. The occurrence of discrepant plasma procalcitonin (PCT) and CRP levels in acutely ill children was 29%. We confirmed an earlier finding that PCT rises more rapidly than CRP in bacteremic patients and made a new observation that PCT increases also in patients with acute diabetic ketoacidosis. In addition, a multianalyte antigen detection POCT for respiratory viruses was proven user-friendly and specific. It gave an overall sensitivity of 83% for influenza viruses, 89% for respiratory syncytial virus but only 25% for adenovirus in comparison with the polymerase chain reaction method. Finally, we found that febrile pharyngitis was caused solely by viruses in 59%, by viruses together with group A streptococcus (GAS) in 13% and solely by GAS in 10% of the children. Blood myxovirus resistance protein A (MxA) levels were increased in most of the pharyngitis patients with virus detection further supporting the causative role of viruses. 

These results highlight the usefulness of POCTs in ED setting. In addition, we completed the etiological picture of febrile pharyngitis.