Objective: --To study the natural history of Chlamydia trachomatis infections in infants.
Design: --Bacteriologic and serologic study of an inception cohort.
Setting: --University of Washington Medical Center, Seattle.
Participants: --Twenty-two infants with C trachomatis infections either not treated early in life or recurring after antimicrobial treatment.
Main outcome measures: --Persistence of infection in various anatomic sites, antibody responses to specific serovars (serologic variants) of C trachomatis, and serovars of isolates from mothers and infants.
Results: --The cumulative proportion of infants still infected at the age of 1 year was 35%. Infection persisted in the conjunctiva, nasopharynx, and oropharynx in one child for as long as 866 days (28.5 months), when she was cured by treatment. In none of the infants did serologic tests suggest acquisition of infection other than at birth. Isolates of C trachomatis from mothers and their respective infants were always of the same serovar.
Conclusions: --Many infants infected with C trachomatis at birth remain infected for months or years in the absence of specific antimicrobial therapy. Such infections may be confused with those acquired by sexual abuse.