Incidence of Chlamydia pneumoniae infection in vertically HIV-1 infected children.

The rate of seroconversion for antibody to Chlamydia pneumoniae was analysed in blood samples of 26 vertically HIV-1 infected children and 14 seroreverter children (HIV-negative children born to HIV-positive mothers) during a 3-year study period. Seroconversion for Chlamydia pneumoniae was found in 13 of 26 HIV-1 infected children and in 1 of 14 in the seroreverter group (P=0.013). A lower mean CD4+ cell count and p24 antigen positivity at enrolment were significantly associated with seroconversion for Chlamydia pneumoniae. Signs and symptoms of acute respiratory infection were recorded in the 30 to 40 days preceding collection of the blood samples showing seroconversion for Chlamydia pneumoniae in 8 of 13 HIV-1 infected children and in the single seroreverter. This study confirms the potential role of Chlamydia pneumoniae in the pathogenesis of respiratory tract infections in HIV-1 infected subjects.