Efficacy of primary chemoprophylaxis against Pneumocystis carinii pneumonia during the first year of life in infants infected with human immunodeficiency virus type 1

To evaluate the efficacy of primary chemoprophylaxis in preventing Pneumocystis carinii pneumonia (PCP) in infants with perinatal human immunodeficiency virus-1 infection during the first year of life, we conducted a retrospective chart review of infants with human immunodeficiency virus-1 infection born at New York University Medical Center-Bellevue Hospital Center, in New York. Between March 1989 and March 1993, 24 infants received primary chemoprophylaxis with trimethoprim-sulfamethoxazole in the first year of life and 24 infants did not receive primary prophylaxis. The CD4⁺ T-lymphocyte counts in the two groups did not differ during the first year of life. The median age at the time of initiation of prophylaxis was 3 months, and the average duration of prophylaxis was 5.5 months. Among the infants who had not recelved prophylaxis, five cases of PCP were diagnosed at a median age of 5 months; in contrast, no cases of PCP were observed in the infants receiving prophylaxis (log-rank test, p=0.017). The probability of surviving after 1 year of age was 92% for the children who recelved prophylaxis and 74% for those who did not (long-rank test, p=0.035). These data indicate that chemoprophylaxis is highly effective in preventing primary PCP and improving survival time in infants with human immunodeficiency virus-1 infection.