Serotype distribution and antimicrobial resistance patterns of nasopharyngeal and invasive Streptococcus pneumoniae isolates in Hong Kong children

A study was conducted to determine the vaccine coverage of prevalent carriage and invasive pneumococci from children aged less than 6 years in Hong Kong. A total of 383 nasopharyngeal carriage isolates and 88 invasive isolates from diverse sources were serotyped and their antimicrobial susceptibilities determined. The most common carriage serotypes were the same as the invasive isolates (6B, 14, 19F and 23F), although the rank order of specific serotypes was different. Serotypes in the 7-valent conjugate pneumococcal vaccine (4, 6B, 9V, 14, 18C, 19F and 23F) accounted for 89.7 and 66.1% of the invasive and carriage isolates, respectively. The same seven serotypes comprised 87.5% invasive isolates and 82.8% carriage isolates with resistance to penicillin, erythromycin and/or cefotaxime.