Search

Abstract: This study analyzed 828 isolates causing invasive pneumococcal disease (IPD) before (1995–2001, n =265) and after (2007–2009, n =563) the introduction of the 7-valent pneumococcal conjugate vaccine (PCV7) in Hong Kong. In children <5 years, serotype 14 had declined (36–15.7%, P <0.01) while 19A had increased (0–12.9%, P <0.01) in the before and after periods, respectively. In children aged <5 years, the proportion of PCV7 serotypes declined from 89.5% to 65.7% (72.8% if included cross protection against 6A) with time but that of PCV13 serotypes remained stable (91.4–93.2%). In elderly ≥65 years, 9V and 23F decreased from 3.8% to 0.3% (P =0.01) and from 18.9% to 7.4% (P <0.01), respectively while 7F increased significantly from 0% to 4.1% (P =0.04) over the same periods. Among isolates from aged <5 years, dual penicillin/erythromycin resistance increased from 44.1% to 64.2% (P =0.01). The types that often had dual penicillin/erythromycin resistance were 6B, 14, 19F, 23F, 6A and 19A. The emergence of serotype 19A was associated with expansion of sequence type 320. [Copyright &y& Elsevier]

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. [Copyright &y& Elsevier]