Chlamydia trachomatis infections in infants – co-infections and treatment

The purpose of this report was to look at C. trachomatis infections in infants by focusing on co-infection, severity of the clinical picture, length of hospitalization and the possibility of antibiotic treatment. Between December 1994 and April 2001, thirty infants diagnosed with Chlamydia trachomatis were treated for an acute respiratory system infection at the University Infectious Diseases Hospital Zagreb. Whereas in 26(86.7%) subjects Chlamydia was demonstrated using the DNA-RNA hybridization method, in 4(13.3%) subjects this was done by isolation on cell culture. The clinical and laboratory studies were performed on admission to the ward, with the findings not differing from those in other reports. While in the examined infants respiratory syncytial virus (RSV) infection was shown in 11(84.6%) cases, Bordetella pertussis (BP) and dual RSV-BP infection were shown in one each, both accounting for 7.7%. In infants affected by co-infection, pneumonia was more common, i.e. 9/13(69.2%), than among cases of chlamydial monoinfection, 6/17 (35.3%). General respiratory insufficiency with a need for mechanical ventilation occurred in four infants of the 13 (38.8%) having co-infections versus in one of the 17(5.9%) co-infection-free infants. The median length of hospitalization was much greater in infants with a co-infection than among those with chlamydial monoinfection (25 vs 13 days). Of the 30 infants studied, 16(53.3%) and 14 (46.7%) were treated with azithromycin, respectively erythromycin. Length-of-hospitalization medians were smaller for azithromycin-treated infants, especially in the co-infection subgroup, compared with the medians in erythromycin-treated infants (14 vs 33 days). Azithromycin proved clinically more effective in the treatment of infantile infections caused by C. trachomatis.