Pulmonary bacterial coinfection in infants and children with viral respiratory infection.

The true incidence of pulmonary bacterial coinfection in infants and children hospitalized with a viral respiratory infection is difficult to ascertain but can vary widely from under 1 to 44%. For the same patient group admitted to pediatric intensive care units and/or requiring ventilatory support, the evidence is more convincing, with reported incidences of 17-39%. Studies covering influenza and respiratory syncytial virus infection dominate the recent literature. Whether treatment (or 'cover') with antibiotics is indicated/justified lies in the balance of risk of pulmonary bacterial coinfection (or risk of not diagnosing it), severity of disease and the patient setting. The balance between the overprescription of antibiotics and the possible sequelae associated with bacterial coinfection in infants and children continues to fuel debate.