Surveillance of pneumococcal-associated disease among hospitalized children in Khanh Hoa Province, Vietnam.

BACKGROUND: To understand the epidemiology of childhood bacterial diseases, including invasive pneumococcal disease, prospective surveillance was conducted among hospitalized children in Nha Trang, Vietnam.
METHODS: From April 2005 through August 2006, pediatricians at the Khanh Hoa General Hospital used standardized screening criteria to identify children aged <5 years who had signs and symptoms of invasive bacterial disease. All cerebrospinal fluid (CSF) and blood specimens collected were tested by bacterial culture. Selected culture-negative specimens were tested for Streptococcus pneumoniae by antigen detection or for Haemophilus influenzae, Moraxella catarrhalis, Neisseria meningitidis, and S. pneumoniae by polymerase chain reaction (PCR).
RESULTS: A total of 987 children were enrolled (794 with pneumonia, 76 with meningitis, and 117 with other syndromes consistent with invasive bacterial disease); 84% of children were aged 0-23 months, and 57% were male. Seven (0.71%) of 987 blood cultures and 4 (15%) of 26 CSF cultures were positive for any bacterial pathogen (including 6 for H. influenzae type b and 1 for S. pneumoniae). Pneumococcal antigen testing and PCR identified an additional 16 children with invasive pneumococcal disease (12 by antigen testing and 4 by PCR). Among children aged <5 years who lived in Nha Trang, the incidence rate of invasive pneumococcal disease was at least 48.7 cases per 100,000 children (95% confidence interval, 27.9-85.1 cases per 100,000 children).
CONCLUSIONS: S. pneumoniae and H. influenzae type b were the most common causes of laboratory-confirmed invasive bacterial disease in children. PCR and antigen testing increased the sensitivity of detection and provided a more accurate estimate of the burden of invasive bacterial disease in Vietnam.