A Swiss team studied 134 young children who were experiencing unidentified high fevers and were able to find at least one virus in 35% of those patients. The two biggest culprits were enterovirus (14%) and HHV-6 (11%).
Arnaud Gregoire L'Huillier and his team at the Geneva University Hospitals and Medical School in Switzerland also explored possible relationships with serious bacterial infections. Children presenting with “fever without a source” are sometimes subject to invasive procedures to treat or rule-out a bacterial infection.
The authors note that clinical presentation alone cannot distinguish whether a patient has a viral infection or a bacterial infection. Yet, treatment and invasive diagnostic procedures against bacterial infections appears to be the default. 73% of virus positive patients were treated with antibiotics compared to 63% without virus.
Patients with any virus detected had an 8-fold reduced risk of a serious bacterial infection.
This study confirms the findings of Colvin et al. (2012) who observed a similar association between viral infections and “fever without a source” diagnoses. That study identified HHV-6 in 17% of their cohort.
The percentage of viruses detected increased with age, ranging from less than 30% in the first few months to 47% of children 12-36 months of age.