How common was pneumococcal bacteremia after cardiac transplantation?

Details

Bacterial infections cause substantial illness and death in cardiac transplant patients. Because Streptococcus pneumoniae is the most prominent bacterial pathogen of childhood, the study aimed to define its role as a pathogen in the cardiac transplant population.

Researchers reviewed the medical records of cardiac transplant patients from March 1990 through November 2000 to identify invasive pneumococcal infections after transplantation. They reviewed demographic, clinical and microbiologic data.

Nine of 80 patients (11%) had 12 episodes of pneumococcal bacteremia, an incidence rate of 39 cases per 1,000 patient-years. Being African-American, receiving a transplant before age 2, and receiving a transplant because of idiopathic dilated cardiomyopathy were associated with increased risk of invasive pneumococcal disease (P < 0.05).

Six patients were eligible for the 23-valent pneumococcal polysaccharide vaccine before their first invasive infection, but only one had received it at the recommended age. Most isolates (82%) were susceptible to penicillin, and no single serotype predominated. Two patients in the study group died, but neither death was related to infection. Three patients (33%) had recurrent invasive disease caused by a second serotype, on average 12 months after their first infection.

The researchers concluded that the incidence of pneumococcal bacteremia in cardiac transplant patients was higher than in the general pediatric population. They identified African-American race, age under 2 at transplantation, and transplantation because of idiopathic cardiomyopathy as infection risks. They considered it plausible that pneumococcal vaccination would reduce this risk.