Recurrent Pneumococcal Bacteremia: Risk Factors and Outcomes

Background: Recurrent pneumococcal bacteremia receives infrequent mention in the literature, usually in association with patients who are immunocompromised. Objective: To examine recurrent cases of pneumococcal bacteremia to determine risk factors and outcomes (mortality rates and emergence of resistance) associated with recurrences. Methods: We retrospectively reviewed all cases of pneumococcal bacteremia identified by our microbiology laboratory from January 1,1992, through December 31, 1996. Demographic, clinical, and laboratory data were abstracted. Results: There were 462 bacteremic episodes in 432 patients; 23 of these patients had 30 recurrent episodes. The 5.3% recurrence rate (23/432) is greater than that previously described. The median time to recurrence was 200 days. The mean age of patients with recurrences was 34 years, 70% were women, all were black or Hispanic (in near equal numbers), and 87% were infected with the human immunodeficiency virus (HIV). Human immunodeficiency virus infection, coexistent cancer, and female sex were independent predictors of recurrence. Only patients who were HIV-infected had multiple recurrences. Isolates from recurrent bacteremias were more likely to be penicillin-resistant than were initial bacteremic isolates (relative risk, 2.0; P=.16). Patients with recurrences had a higher (although not statistically significant) mortality rate than those without recurrences (22% vs 16%; P=.33), There was an inverse relationship between severity of illness and likelihood of recurrence. Conclusions: Rates of recurrent pneumococcal bacteremia may be higher than previously reported. In patients with recurrent pneumococcal bacteremia, the presence of an underlying immunodeficiency should be investigated.