Streptococcus pneumoniae as a Cause of Community-Acquired Pneumonia in Portuguese Adults: A single-center retrospective study

Abstract

Pneumococcal pneumonia is considered a major cause of mortality in adults worldwide. Vaccination is an effective method for preventing severe forms of Pneumococcal pneumonia like invasive pneumococcal disease.

Characterization of patients diagnosed with community-acquired pneumonia and microbiology identification of Streptococcus Pneumoniae.

Retrospective study of patients diagnosed with community-acquired pneumonia over a period of 2 years. Collection of data was made by review of the medical records and identifying the serotypes.

Total sample of 87 patients;mean age 67.8 years;51.8% current smokers or former smokers. The most frequently identified comorbidities were COPD (29.9%) and heart failure (18.4%). The most frequent symptoms were cough (65.6%), sputum (59.7%) and dyspnea (56.3%). 9.2% had leukopenia (<4000 / µL),51.7% leukocytosis (> 14,000/µL),42.5% lactate >2 mmol/L, 17,3% acidemia and 75.3% pO2/FiO2 ratio <300mmHg. 42.5% had invasive pneumococcal disease. 19.5% of patients were admitted to the intensive care unit and 18.3% required invasive mechanical ventilation. The serotype involved was identified in 55.2% of cases, of these, 14.5% serotype 8, 12.5% serotype 3, 8.3% serotype 22F and 8.3% serotype 6C. There was 17.2% total mortality rate. Only 10.3% of the patients had undergone anti-pneumococcal vaccination, mostly the 13-valent polysaccharide conjugate vaccine.

The high prevalence of invasive pneumococcal disease highlights the fundamental role of vaccination. These results reinforce the potential for improvement with the increase in vaccination coverage. In conclusion we must improve adherence and implementation of this preventive strategy.