Background:
Recent reports of rectal lymphogranuloma venereum (LGV) in Europe and California underscores the importance of performing OmpA genotyping on rectal Chlamydia trachomatis (CT) isolates for LGV surveillance. CT OmpA genotype G has been reported to be a common rectal (in men), but not urethral or cervical, isolate. Data on rectal CT OmpA genotypes in women are sparse.

Objective:
To determine CT OmpA genotypes of rectal isolates and the associated patient characteristics in women and MSM in Birmingham, AL.

Method:
In this ongoing study, patients seen at 2 Birmingham clinics (STD and HIV clinic) with a CT-positive rectal specimen (defined as culture-positive or as culture-negative with 3 positive nucleic acid amplification tests) are identified and their rectal isolates genotyped by amplification and sequencing of the CT OmpA gene. Medical records are reviewed.

Result:
To date, 55 patients with rectal CT have been identified and OmpA genotyping has been completed for 29 specimens: 15 women (7% HIV-positive) and 14 MSM (50% HIV-positive); 72% black; median age 22; all culture-positive. The overall CT OmpA genotype distribution was: E (28%), D/Da (17%), F (17%), J/Ja (14%), G (7%), Ia (7%), K (7%), and mixed (3%); LGV genotypes were absent. MSM were less often infected by E (14% vs. 40%) and more often by G (14% vs. 0%). Only one patient reported rectal symptoms.

Conclusion:
Our initial findings indicate that women and MSM in Birmingham with rectal CT were infected with non-LGV strains and were mostly asymptomatic. OmpA genotype G was absent in women.

Implications:
Rectal CT OmpA genotyping enhances LGV surveillance and monitoring of non-LGV genotype distributions, which may be of epidemiological importance in the event of a rectal CT outbreak.