Pneumococcal community-acquired pneumonia in hospitalized adults in México 2018-2021: serotype distribution and...

Community-acquired pneumonia (CAP) in adults represents a significant burden on the healthcare system in México, particularly among high-risk groups.

Adults hospitalized with chest X-ray-confirmed CAP (2018-2021) were prospectively enrolled across four cities in México (Mexico City, Durango, Mérida, and Tijuana). Urine samples were screened for Streptococcus pneumoniae (S. pneumoniae) using the BinaxNOW^® test and serotype-specific urine antigen detection (ssUAD) assays targeting 24 serotypes, and blood was obtained for pneumococcal culture.

Of the 1,275 patients screened for CAP, 389 had clinically or radiologically confirmed CAP (65.3% male; median age, 60 years; 39.3% aged ≥65 years). Pneumococcal CAP (pCAP) was identified in 12.1% of patients (47/389; 95% CI: 9.01-15.74). Based on CRB-65 scores, pCAP was more frequent among high-risk CAP patients (25.5%, 12/47) than among low- or moderate-risk CAP patients (10.2%, 35/342). Nevertheless, the 30-day mortality rate was 34.0% among pCAP patients versus 29.5% among S. pneumoniae-negative CAP patients. The most prevalent serotypes were 3 (13.0%), 6A (8.7%), and 19A (8.7%), and PCV20 would have covered 54.3% (25/46) of pCAP serotypes identified in this study.

During the study period, CAP was associated with a substantial mortality burden among hospitalized adult patients in México, with pCAP more frequent among high-risk patients. These findings underscore the needs for enhanced diagnostic approaches and risk group-targeted adult pneumococcal vaccination programs.