Re-testing for Chlamydia trachomatis Infection in Massachusetts Family Planning Clinics

Background:
Because a high prevalence of chlamydia re-infection has been observed in women following treatment for chlamydia infection, the CDC has recommended re-testing of all women approximately 3 months after treatment for chlamydia infection. Little is known about factors influencing a woman's return for re-testing.

Objective:
To examine factors associated with chlamydia re-testing after treatment for chlamydia infection.

Method:
A case was defined by first positive chlamydia test in a woman seen between 1/1/05-12/31/05 at one of 8 Massachusetts family planning organizations. Data available for review included age at diagnosis, clinic organization, race/ethnicity, and history of prior chlamydia infection. Multivariate logistic regression was performed to identify factors associated with chlamydia retesting 3-<12 months after the initial positive test.

Result:
Of 402 chlamydia cases in women identified during the study period, 116 (29%) had re-testing within 3-<12 months; 29 (25%) were diagnosed with repeat infection. In cases <=18 years old, 43/104 (41%) were re-tested, versus 73/297 (25%) in cases >18 years old. The two clinic organizations handling highest number of chlamydia infections re-tested 62/161 (39%), versus 9/56 (16%) in two clinic organizations with lowest number. Younger age (OR 1.8, 95% CI 1.1-3.0) and highest number (OR 3.3, CI 1.3-10.0) were associated with retesting in a logistic regression model including age, race/ethnicity, clinic organization, and prior history of chlamydia infection. No significant associations with re-testing were found with race/ethnicity or prior history of chlamydia infection.

Conclusion:
Repeat chlamydia infection was common in women re-tested for chlamydia 3-<12 months after incident chlamydia infection. Younger age and certain clinic organizations were associated with greater chlamydia re-testing amongst women seen at Massachusetts family planning organizations.

Implications:
Given how common chlamydia re-infection appears to be, more study is needed to identify factors that influence chlamydia re-testing rates.