Clinical and molecular features of adenovirus type 2, 3, and 7 infections in children in an outbreak in Taiwan, 2011

OBJECTIVES: We studied paediatric patients with human adenovirus (HAdV) infection during the 2011 outbreak in northern Taiwan to define the clinical features of different HAdV genotypes in children. METHODS: Between January and December 2011, 637 patients <19 years of age exhibited culture-confirmed adenoviral infection in Chang Gung Memorial Hospital, and provided specimens available for genotyping by multiplex real-time PCR. Clinical data were collected retrospectively. RESULTS: Excluding five cases with multiple genotypes, 632 cases were included for analysis. Three genotypes were identified, including HAdV-3 (429/632; 67.6%), HAdV-7 (144/632; 22.6%) and HAdV-2 (59/632; 9.8%). Median age was 4.58 years (range 2 months to 18 years), with children infected with HAdV-3 significantly older (82.9% >3 years; p <0.001). Of the 621 inpatients, 98.2% had fevers and all exhibited respiratory symptoms, 75 patients (12.1%) had lower respiratory tract infections, 20 (3.2%) required intensive care (HAdV-2: 1; HAdV-3: 8; and HAdV-7: 11), and three died (all HAdV-7-infected). HAdV-3-infected patients were significantly more likely to have upper respiratory symptoms and a high serum C-reactive protein level >100 mg/L, whereas leucocytosis (white blood cell count >15 000/mm(3)) was more common in HAdV-2-infected patients (p 0.007). HAdV-7 infections were significantly associated with a longer duration of fever, leucopenia (white blood cell count <5000/mm(3)), thrombocytopenia (platelet count <150 000/mm(3)), lower respiratory tract infections, a longer length of hospital stay, and requiring intensive care (all p <0.001). CONCLUSION: Childhood HAdV-2, HAdV-3 and HAdV-7 infections may exhibit different clinical manifestations. Although HAdV-3 was the most prevalent genotype observed during the 2011 Taiwan outbreak, HAdV-7 caused more severe disease characteristics and outcomes.