Background: The HIV infection and the development of penicillin-resistant pneumococci justify the review of the epidemiologic features of pneumococcal pneumonia in the last years.
Method: A retrospective chart review of all patients admitted between 1987 and 1990 with a positive blood culture to Streptococcus pneumoniae was conducted. Different epidemiologic variables were selected ad compared.
Results: Streptococcus pneumoniae was isolated in 147 blood cultures from 147 patients. The estimated incidence of pneumococcal bacteremia was 10 cases per 100,000 inhabitants/year. The figure increases from 7 to 12 cases during the study period. The risk factors identified were: HIV infection, 27 patients (19%); cancer, 14 patients (10%); cirrhosis of the liver, 13 patients (9%). In 56 cases (38%) no special risk factors were identified. All bacteremic episodes were from a pulmonary source. In 66% of patients, no special complications were recorded. Mortality outcome was related to age (28% if aged more than 60 years, 7% if less; p = 0.001, chi 2, and with the underlying condition (p = 0.034, chi 2). Resistance to penicillin increases from 0.0% to 21% during the study period (p = 0.03, chi 2) but it seems not to have any impact in mortality nor in the nosocomial origin of the bacteremia.
Conclusions: In the last 4 years we have observed an increase in the incidence of pneumococcal bacteremia related to an increase in cases among HIV infected patients, and also the emergence of penicillin-resistant strains. However, none of the two mentioned conditions seems to have any impact on mortality.