Epidemiology and clinical manifestations of unique Chlamydia trachomatis isolates that occupy nonfusogenic inclusions

Unique Chlamydia trachomatis strains characterized by multiple nonfusing in clusions were recently described. These strains lack evidence of the protei n IncA in the inclusion membrane and have mutations in the incA gene. This study evaluated the epidemiology and clinical manifestations of patients in fected with nonfusing mutant strains (case patients) and compared them with patients infected with wild-type fusing strains (control subjects). Both m ale and female case patients had fewer signs of infection than did control subjects (P =.016 and P =.019, respectively). Female case patients also had fewer symptoms of infection (P =.02). Median inclusion-forming unit (ifu) counts were lower in male and female case patients (P =.045 and P =.135, re spectively). Thus, nonfusing strains of C trachomatis more often produce su bclinical infections than do normal fusing strains and have lower median if u counts. From a prevention perspective, the data underscore the importance of screening programs to detect and treat inapparent C trachomatis infecti on.