A swimming pool-associated outbreak of pharyngoconjunctival fever caused by human adenovirus type 4 in Beijing, China.

Patients with swimming pool-acquired human adenovirus (HAdV) infections usually manifest characteristic clinical features that include fever, pharyngitis, and conjunctival inflammation, syndromically referred to as pharyngoconjunctival fever (PCF). HAdV types 3, 4, and 7 are most commonly associated with PCF. This article reports an outbreak of PCF that involved 55 students and staff at a university in Beijing, China. Fifty patients had used the same swimming pool 2 weeks before the onset of symptoms. HAdV type 4 was identified from patient eye and throat swabs and concentrated swimming pool water samples. Partial hexon gene sequences obtained from the water samples were 100% identical to the sequences obtained from the swab samples, which clustered with HAdV-4 within species E. Swimming pool water contaminated with HAdV-4 was the most likely source of infection, although one instance of likely person-to-person transmission was noted.