Clinical and microbiological aspects of acute community-acquired pneumonia due to Streptococcus pneumoniae

The objectives of the present study were: (a) to describe the mortality rate and its associated variables in community-acquired pneumoniae (CAP) due to Streptococcus pneumoniae (S. pneumoniae), (b) to identify therapeutic issues to improve, (c) to describe the main serotypes of S. pneumoniae and (d) to know the potential coverage of antipneumococcal 23-valent vaccine.

Inclusion criteria were age >16 years-old hospitalized due to PAC. Pneumococcal PAC etiology was considered if S. pneumoniae was isolated from blood culture and/or positive capsular urinary antigen detected at hospital admission. Exclusion criteria were patients who refused participation and/or pneumococcal infection diagnosis was made within the last month before hospital admission.

A total of 192 patients were included, mean age 54.6 ± 19.2 years. The most frequent comorbidities were diabetes, COPD and immunosupression. There were 147 patients with bacteremia. The most frequent serotypes were 7F, 1 and 3. Beta-lactamic resistant microorganisms were not identified and only 8 (5.4%) strains were erythromycin-resistant. Potential anti-pneumococcal 23-valent vaccine coverage was 93%. Thirty-seven patients died. Variables associated with mortality were shock within the first 72 h of hospital admission (OR: 7.51; 95% CI: 2.94-19.17) and antibiotic delay ≥6 h (OR: 2.47; 95% CI: 1.00-6.17).

Pneumococcal pneumonia mortality was 19.3%. Septic shock and antibiotic delay ≥6 h since hospital admission were associated with hospital mortality. The most frequent serotype was 7F. The potential anti-pneumococcal vaccine coverage is almost 90%.