Pneumococcal serotypes 19F and 1 were associated with mortality amongst adults and adolescents in the pre-vaccine era in South Africa (SA). We assessed the association of serotype with mortality in individuals aged ≥5 years with invasive pneumococcal disease (IPD) during the vaccine era.
We conducted surveillance for laboratory-confirmed IPD at 28 hospitals in SA during 2012-2018. We used multivariable logistic regression to compare the association of serotype with in-hospital outcome.
Of 3453 IPD cases with available serotype, age and outcome information, 1158 (34%) died (47% (458/970) with meningitis, 29% (643/2219) with bacteremia and 22% (57/264) with other invasive disease). Overall among IPD, compared to patients infected with serotype 8 (the most common serotype identified) and after adjusting for age, HIV status and specimen type, those with serotype 15B/C (OR:2.01, 95%CI: 1.16-3.48) were more likely to die. When restricting to meningitis cases, patients with serotype 23A (OR:0.31, 95%CI:0.10-0.95) were less likely to die compared to patients with serotype 8.
In the post-vaccine era, in ages ≥5 years, serotype 15B/C is associated with increased mortality, however this serotype is not included in the currently available conjugate vaccines.