Incidence of respiratory viral infections and associated factors among children attending a public kindergarten in Taipei City.

BACKGROUND: Kindergarteners frequently encounter various infectious diseases, so surveillance of viral infectious diseases would provide information for their health promotion. METHODS: We enrolled kindergarten attendees, age 2-5 years, during the academic years of 2006 and 2007 in a Taipei City kindergarten. Daily monitoring of illness and regular biweekly physical examinations were undertaken. Multiple infections were defined as one child having two or more laboratory-confirmed viral infections with different viruses or different serotypes during one academic year. RESULTS: The overall laboratory-confirmed incidence rate of respiratory viral infection was 239 per 100 person-years in the 2006 academic year and 136 per 100 person-years in the 2007 academic year. The attack rate for seasonal influenza was 17% in the 2006 academic year and 27% in the 2007 academic year. Boys and children with allergies had significantly higher risks to get multiple viral infections [odds ratio (OR) 1.81, 95% confidence interval (CI) 1.20-2.75; OR 1.56, 95% CI 1.00-2.39, respectively]. Boys also tended to get enterovirus infections (OR 1.56, 95% CI 1.02-2.38) while children with allergies tended to acquire adenovirus infections (OR 1.71, 95% CI 1.12-2.66). CONCLUSION: Boys and children with allergies were more susceptible to multiple viral infections, so they should be more cautious about viral infections.

Viral infections associated with Kawasaki disease.

BACKGROUND/PURPOSE: Kawasaki disease (KD) is a disease of unknown cause. To investigate the infectious etiology of Kawasaki disease, we initiated a prospective case-control study to investigate possible links between common viral infections and Kawasaki disease. METHODS: We enrolled 226 children with KD and 226 age- and sex-matched healthy children from February 2004 to March 2010. Throat and nasopharyngeal swabs were taken for both viral isolation and polymerase chain reaction (PCR) for various viruses. RESULTS: The mean age of the 226 KD cases was 2.07 years, and the male to female ratio was 1.43 (133 boys to 93 girls). Their mean fever duration was 7.5 days with a mean peak temperature of 39.7°C. In addition to the typical symptoms of fever, neck lymphadenopathy, lip fissure and/or strawberry tongue, skin rash, nonpurulent bulbar conjunctivitis, palm/sole erythema, and induration followed by periungual desquamation, these KD cases also exhibited cough (69%), rhinorrhea (58%), and diarrhea (45%). Cases of KD had a significantly higher positive rate of viral isolation in comparison with the control group (7.5% vs. 2.2%, p = 0.02). Compared with the control group, cases of KD were more likely to have overall positive rates of viral PCR (50.4% vs. 16.4%, p < 0.001) and for various viruses including enterovirus (16.8% vs. 4.4%, p < 0.001), adenovirus (8.0% vs. 1.8%, p = 0.007), human rhinovirus (26.5% vs. 9.7%, p < 0.001), and coronavirus (7.1% vs. 0.9%, p = 0.003). CONCLUSION: We found that some common respiratory viruses, such as adenoviruses, enteroviruses, rhinoviruses, and coronaviruses, were associated with KD cases.

Seroprevalence of enterovirus 71 and no evidence of crossprotection of enterovirus 71 antibody against the other enteroviruses in kindergarten children in Taipei city.

BACKGROUND/PURPOSE: Enterovirus 71 (EV71) infection may cause severe neurological and cardiopulmonary complications, especially in preschool children. This study is to investigate the seroprevalence and seroconversion of EV71, and the crossprotection of EV71 antibody against other enteroviruses among kindergarteners. METHODS: Overall 228 children in a public kindergarten were enrolled during two academic years, 2006 and 2007, in Taipei, Taiwan and we measured their EV71 neutralizing antibody. When the participants had herpangina; hand, foot and mouth disease (HFMD); febrile illness or respiratory symptoms, throat swabs were sampled and processed for viral culture and enterovirus real-time reverse transcriptase polymerase chain reaction (RT-PCR). Questionnaires, completed by the participants' guardians, surveyed the history of allergy and annual incidence of symptoms related to enterovirus infection. RESULTS: Seropositive rates of EV71 were 20% (32/163) in 2006 and 6% (4/65) in 2007. The rate of EV71 seropositivity increased with age (p < 0.01) in 2006 but it did not differ between genders (p = 0.14). No seroconversion was observed from 2006 to 2007. Herpangina occurred in 64% of children with EV71 seropositivity and 48% of those without EV71 antibodies (p = 0.12). Non-71 enterovirus infection, confirmed by viral study, occurred in 53% (19/36) of the EV71-seropositive children and in 53% (102/192) of EV71-seronegative children (p = 0.89). No participants had EV71 infection during the study period. CONCLUSION: EV71 did not frequently circulate in Taipei City from September 2006 to June 2008. Presence of EV71 neutralizing antibody was not associated with lower incidence of enterovirus infection caused by non-71 serotypes.

Household transmission of Pandemic (H1N1) 2009 Virus, Taiwan.

During August-November 2009, to investigate disease transmission within households in Taiwan, we recruited 87 pandemic (H1N1) 2009 patients and their household members. Overall, pandemic (H1N1) 2009 virus was transmitted to 60 (27%) of 223 household contacts. Transmission was 4× higher to children than to adults (61% vs. 15%; p<0.001).