Invasive Pneumococcal Disease in Neonates Prior to Pneumococcal Conjugate Vaccine Use in South Africa: 2003 - 2008.

BACKGROUND: Neonatal invasive pneumococcal disease (IPD) in developing countries is poorly described. We provide a baseline description of neonatal IPD in South Africa, prior to implementation of the seven-valent pneumococcal conjugate vaccine (PCV7) in 2009.

METHODS: Data from children (age ≤ 2 years) with IPD (pneumococcus identified from a normally sterile specimen) from January 2003 - December 2008 were extracted from a national laboratory-based surveillance database. Clinical and laboratory characteristics of IPD amongst neonates (0-27 days old) was compared to IPD amongst young children (≥28 days ≤ 2 years). Early-onset IPD (EOD) (0 - 6 days old) was compared with late-onset IPD (LOD) (≥7 - 27 days old). Isolates were serotyped using the Quellung reaction.

RESULTS: Overall 27 630 IPD cases were reported. Of the 26 277 (95%) with known ages, 6583 (25%) were ≤ 2 years of age, of which 4.5% (294/6583) were neonates. The estimated annual incidence of neonatal IPD in 2008 was 5 per 100 000 live births. Fifty-one percent of neonates with IPD presented with EOD. Case-fatality ratios (CFR) were high in both groups, 31% (28/89) in neonatal IPD vs 26% (614/2383) in non-neonatal IPD (p = 0.18). Among neonates the meningitis cases (15/37, 41%) were associated with the highest CFR. The thirteen-valent pneumococcal conjugate vaccine (PCV13) serotypes accounted for 69% (134/194) of neonatal IPD isolates.

CONCLUSIONS: Pneumococcal neonatal disease in South Africa was not uncommon prior to PCV introduction, and is associated with a high CFR. The indirect effect on neonatal IPD of PCV rollout requires further evaluation.