Across various studies that have identified the aetiology of CAP in adults in India, S. pneumoniae has been identified as the most common causative pathogen accounting for about 30% to 55% of cases (where diagnosis was possible).^1-6 
​​​​​A systematic review and meta-analysis evaluated the contribution of S. pneumoniae in the causation of CAP infection in the Indian population. This study revealed that approximately one-fifth of the Indian adult population with CAP had S. pneumoniae infection. Therefore, this study further validated the notion that S. pneumoniae is the leading causative organism of CAP in the Indian adult population and is responsible for a significant burden of CAP in India.⁷ 

Age Association and Percentage of S. pneumoniae in CAP in the Indian Adult Population^1-6 

In a 10-year retrospective study of community-acquired acute bacterial meningitis in India, S. pneumoniae accounted for >60% of cases in adults.⁸ According to the IBIS study, the CFR in IPD has been found to be the highest in adults aged above 50 years (28%) in India.⁹ A prospective 15-year  hospital surveillance in adults also documented similar CFR (30.2% in patients aged 50-60 years and 26.1% in patients aged >60 years).¹⁰ A single-centre study from India including 72 consecutive CAP patients, evaluated the prognostic factors and clinical profile of CAP, with emphasis on the elderly patients. This study reported that the mortality from CAP in the elderly patients aged ≥50 years (35%) was significantly higher (P = 0.04) than in adults aged <50 years (14%).¹

​​​​​​​Adapted from Dey AB, et al. 1997.
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As observed by Dey AB, et al in a study on 72 adult patients hospitalised for CAP in India, adults aged ≥50 years had a 2.5-fold higher rate of mortality due to CAP than compared to adults aged <50 years.¹

In a surveillance study between 2007 and 2011 conducted at the Christian Medical College, Vellore, PCV13 and PPSV23 provided serotype coverage of 77% and 83%, respectively, in adults aged ≥60 years.¹¹

IPDs continue to be a major global concern of illness and death. The at-risk patients for pneumococcal diseases are adults aged over 50 years and younger adults with specific chronic health conditions.¹²

A previous prospective surveillance study of IPD in individuals aged >18 years across 7 centres in India between 1993 and 2008 assessed the seroepidemiology among older adults who were admitted to hospitals. A total of 1037 subjects with suspected invasive bacterial infection were enrolled in the study. S. pneumoniae was identified in 43.3% of patients recruited in the study. The most common clinical conditions associated with IPD were pneumonia (33.9%) and meningitis (34.3%). Across all the age groups, 25% to 30% CFR was observed.¹⁰

A recent laboratory-based surveillance study from a tertiary care hospital in South India investigated the epidemiology of IPD and the prevalent serotypes in Indian adults aged >18 years between January 2007 and July 2017. Out of the total 408 IPD cases studied, the overall CFR was 17.8%. In individuals aged ≥66 years, the CFR was highest, that is, 34.9%. Although the CFR in the overall study population (17.8%) was lower than the previously reported Indian rates (25%-30%), the CFR in older individuals aged ≥66 years was higher than that reported between 1993 and 2008 (26%), thereby raising a concern. The most common clinical conditions associated with IPD were pneumonia (39%), meningitis (24.3%) and septicaemia (18.4%). The serotype data obtained from this study helped in the accurate estimation of PCV13 and PPSV23 protective coverage against IPD-causing serotypes in India. The coverage of PCV13 and PPSV23 was 58.7% and 67.4%, respectively. This study also evaluated the pattern of AMR in Indian adults.¹³ 

Adapted from Jayaraman R, et al. 2019.