Mapping the pneumococcal disease landscape in India: a meta-analysis of literature from 2007 to 2024 on serotype prevalence and antimicrobial resistance patterns

Background Pneumococcal disease remains a major public health concern in India, with significant prevalence in both children and adults. Pneumococcal conjugate vaccine (PCV) 13 provides high serotype coverage in children and in adults; however, non-vaccine serotypes are emerging. Rising antimicrobial resistance and limited local serotype data hinder effective disease control and vaccine policy. This meta-analysis consolidates evidence on pneumococcal serotype distribution, antimicrobial resistance (AMR)/non-susceptibility trends, and PCV coverage in the Indian population across pediatric and adult age groups. Methods A systematic review and meta-analysis were conducted on pneumococcal serotype distribution and AMR/non-susceptibility patterns using Indian publications from 2007 to 2024. Comprehensive searches were performed in PubMed, Google Scholar, and EMBASE. Data were analyzed using a random-effects model in R (version 4.4.1), with heterogeneity assessed via the I² test. Serotype distribution was further stratified into invasive pneumococcal disease (IPD), carriage, and community-acquired pneumonia (CAP) subgroups. Results Twenty-six studies, comprising 4,253 Streptococcus pneumoniae (S. pneumoniae) isolates, were included with 24 studies from the pre-Universal Immunization program (UIP) period. Among pediatric IPD estimates supported by multiple studies, serotype 14 (14.15%), serotype 19F (11.39%), and serotype 6B (10.17%) were most frequent. Higher estimates for pediatric IPD serogroups 6 (25%), 18 (12.5%), and 19 (10%) were each derived from one 40-isolate study and were considered exploratory. In the adult IPD population, serotype 1 (11.69%), and serotypes 23F (6.84%), and 19F (6.71%) were the most common. Adult CAP estimates came from one 50-isolate study, in which serotype 19A (14%) and serotype 8 (10%) were most frequent. AMR/non-susceptibility was consistently highest for cotrimoxazole/trimethoprim-sulfamethoxazole across pediatric IPD (86.16%) and adult IPD (85.24%) populations as well as in adult CAP (74%). Penicillin non-susceptibility was estimated at 14.33% (95% CI: 5.22–33.72) in pediatric IPD, although considerable between-study heterogeneity was observed (I² = 97.15). Accordingly, this pooled estimate should be interpreted in the context of the substantial variability across the included studies. Conclusion Among pediatric IPD estimates supported by multiple studies, serotype 14, serotype 19F, and serotype 6B were most frequent. In the adult IPD population, serotype 1, and serotypes 23F, and 19F were the most common. Cotrimoxazole/trimethoprim-sulfamethoxazole showed the highest resistance. Among PCV formulations assessed, PCV20 showed the highest serotype coverage. There is a need for continuous, geographically broader surveillance of serotypes and AMR patterns in pneumococcal disease to guide the national vaccination policies and choice of PCVs.