© 2015 Cohen et al.This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Background: An association between pneumococcal serotypes and mortality has been suggested. We aimed to investigate this among individuals aged ≥15 years with invasive pneumococcal disease (IPD) in South Africa. Methods: IPD cases were identified through national laboratory-based surveillance at 25 sites, prepneumococcal conjugate vaccine (PCV) introduction, from 2003-2008. We assessed the association between the 20 commonest serotypes and in-hospital mortality using logistic regression with serotype 4 (the third commonest serotype with intermediate case-fatality ratio (CFR)) as referent. Results: Among 3953 IPD cases, CFR was 55% (641/1166) for meningitis and 23% (576/2484) for bacteremia (p<0.001). Serotype 19F had the highest CFR (48%, 100/207), followed by serotype 23F (39%, 99/252) and serotype 1 (38%, 246/651). On multivariable analysis, factors independently associated with mortality included serotype 1 (OR 1.9, 95%CI 1.1-3.5) and 19F (OR 2.9, 95%CI 1.4-6.1) vs. serotype 4; increasing age (25-44 years, OR 1.8, 95%CI 1.0-3.0; 45-64 years, OR 3.6, 95%CI 2.0-6.4; ≥65 years, OR 5.2, 95%CI 1.9-14.1; vs. 15-24 years); meningitis (OR 4.1, 95%CI 3.0-5.6) vs. bacteremic pneumonia; and HIV infection (OR1.7, 95%CI 1.0-2.8). On stratified multivariate analysis, serotype 19F was associated with increased mortality amongst bacteremic pneumococcal pneumonia cases, while no serotype was associated with increased mortality in meningitis cases. Conclusion: Mortality was increased in HIV-infected individuals, which may be reduced by increased antiretroviral therapy availability. Serotypes associated with increased mortality are included in the 10-and-13-valent PCV and may become less common in adults due to indirect effects following routine infant immunization.
Cohen, C., Naidoo, N., Meiring, S., Gouveia, L. D., Von Mollendorf, C., Walaza, S., … Von Gottberg, A. (2015). Streptococcus pneumoniae serotypes and mortality in adults and adolescents in South Africa: Analysis of national surveillance data, 2003-2008. PLoS ONE, 10(10). https://doi.org/10.1371/journal.pone.0140185