A community-derived outbreak of adenovirus type 3 in children in Taiwan between 2004 and 2005

An outbreak of respiratory adenovirus infection in children was observed in northern Taiwan between November 2004 and February 2005. Using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) to determine the serotype(s) of 172 adenovirus isolates in the outbreak period, we found that adenovirus type 3 (Ad3) was the predominant type (87.2%), followed by Ad2 (6.4%), Ad1 (4.1%), Ad7 (1.2%), Ad4 (0.6%), and Ad5 (0.6%). The genotype of Ad3 was analyzed for 15 isolates from the outbreak period by RFLP of the full-length genome. All these isolates belonged to genotype Ad3a2. Compared with the Ad3-infected patients in the baseline period, a significantly higher proportion of Ad3-infected patients in the outbreak period had severe infections (58.0% vs. 40.2%, P=0.01), which included bronchopneumonia (28.7%), exudative tonsillitis (24.1%), and tonsillitis (16.1%). Moreover, patients with severe infections were significantly younger than those without (4.10 vs. 8.15 years, P < 0.001). In summary, our study demonstrated that Ad3 was the predominant serotype responsible for the respiratory adenovirus outbreak in northern Taiwan during 20042005 and was associated with severe infections in the outbreak period.