Clinical and epidemiological characteristics of respiratory syncytial virus and influenza virus associated hospitalization in urban Thai infants.

BACKGROUND

Respiratory syncytial virus (RSV) and influenza infections are among the leading cause of hospitalized lower respiratory tract infections (LRTI) in children especially among those younger than 1 year of age. Few descriptions of these 2 important viruses in Thai children less than 1 year of age have been published.

MATERIAL AND METHOD

The authors conducted a prospective study of children 1-12 months old hospitalized at a pediatric tertiary-care hospital in Bangkok with LRTI during the period December 2007 to August 2009. Respiratory specimens were tested for influenza A/B virus and RSV using a reverse-transcriptase polymerase chain reaction (RT-PCR).

RESULTS

Twenty-six (7.3%) had RT-PCR positive for influenza and 104 (29.4%) for RSV from 354 infants. Clinical diagnoses included pneumonia (73.4%), bronchiolitis (17.55%), croup (6.5%) and bronchitis (2.5%) and were similar among groups except the proportion of croup was significantly lower in RSV (p = .018). The proportion of RSV infection was highest between July and October (42-76%). RSV patients were more likely to present with higher temperature than the negative RT-PCR patients (p = .031). Oseltamivir was prescribed in 7.7% of influenza infections. Intravenous antibiotics were prescribed in 69.2%, 56.7% and 60.7% of the influenza, RSV and negative group respectively (p = .736). Percentages of patients requiring mechanical ventilation were 3.8, 6.7 and 6.3% among the influenza, RSV and negative group respectively (p = .861). Three patients died: 2 from RSV and 1 from the negative group. All three fatality cases had existing co-morbidity.

CONCLUSION

A high proportion of RSV was detected in infants hospitalized with LRTI especially during July to October. High proportion of antibiotic prescription and relatively low rate of oseltamivir treatment were identified. Surveillance data and the availability of a rapid and reliable viral diagnostic test may help guide treatment, thereby improve outcome of this vulnerable population.