Objective -To assess the value of CD4 T cell count in predicting Pneumocystis carinii pneumonia in infants born to mothers infected with HIV, with reference to the guidelines from the Centers for Disease Control on prophylaxis against pneumocystis.
Design -Prospective birth cohort study.
Setting -Hospitals in 10 European cities participating in the European collaborative study.
Subjects -924 children born to mothers known to be infected with HIV at or before delivery.
Main outcome measures -The incidence of P carinii pneumonia. CD4 T cell counts in children before diagnosis of the pneumonia. The proportions of children infected and uninfected with HIV who fulfilled the criteria for primary prophylaxis.
Results -Fourteen children were diagnosed with P carinii pneumonia. The cumulative incidence by the age of 6 years was 2% (95% confidence interval 0.9 to 3.0%). Of the 11 children with a CD4 T cell count predating diagnosis, only three fulfilled the criteria from the Centers for Disease Control for prophylaxis. Prophylaxis was indicated by 1 year of age for 62% of infected children who had not developed P carinii pneumonia and for at least 10% of uninfected children.
Conclusions -Monitoring CD4 T cell count seems to be of limited value in deciding when to start prophylaxis against P carinii pneumonia in children born to mothers infected with HIV. The alternative approach of giving prophylaxis to all children born to infected mothers would be difficult to justify given the low incidence of the pneumonia.