Chlamydia trachomatis infections
Rates of chlamydia infection have doubled in the last decade. Adherence to screening guidelines for the infection is important for identifying cases, initiating treatment, and reducing maternal and neonatal morbidity
Compared with previous culture and antigen detection techniques, NAAT’s advantages include excellent sensitivity and specificity (>90% and ≥99%, respectively), enabling detection of a low inoculum of organisms in a sample obtained by noninvasive methods, such as first-void urine collection or vaginal swab.2,4,5 Furthermore, NAAT does not impose any specific storage regulations on collected specimens, is cost effective, and can jointly test for Neisseria gonorrhoeae, which commonly co-infects with C trachomatis.6
Screening in pregnancy. In 2012, Blatt and colleagues examined testing patterns in nearly 1.3 million obstetric patients and found that only 59% (761,315) of women were tested for chlamydia at least once in pregnancy.7 Only 1 in 3 women were tested during the first prenatal visit, as CDC guidelines recommend. Testing rates declined with increasing age. Of women screened, 3.5% tested positive for chlamydia.7 Of these, 3 of 4 were retested at least once, with almost 20% having at least 1 subsequent positive result.7
Of note, in a study of women who reported receptive anal intercourse (n = 2,818), 292 women tested positive for chlamydia; 10.4% tested positive in genital-only sites, 58.6% in genital and rectal sites, and 20.5% at the rectal site only.8
It is alarming that only 59% of pregnant women are screened for chlamydia given the significant perinatal complications associated with this infection. Barriers to screening pregnant women may include clinician discomfort in discussing STDs and patient refusal of screening. Furthermore, clinicians should routinely ask women about receptive anal sex. Women who report this risk factor should be tested for chlamydia in both the endocervix and rectum.
Retesting and follow-up. After the initial diagnosis of chlamydia, a test of cure 3 weeks after treatment is an important aspect of care. Thus, identifying and overcoming barriers to retesting is important. Clinicians should educate patients about the importance of follow-up. Also consider incorporating the use of home-based, self-obtained vaginal swabs for retesting. Results from 2 randomized trials showed that eliminating a patient’s transportation barriers and providing a home-based alternative to a follow-up visit significantly increased rescreening rates by 33% in STD clinic patients and by 59.2% in family planning clinic patients.9
Reinfection risk. The rate of venereal chlamydia transmission in heterosexual partners is 70%. Since sexually active chlamydia-positive patients are at risk for reinfection by their partner after treatment completion, clinicians should refer the sex partners for evaluation. If the sex partners are reluctant to have testing, it is reasonable to provide empiric antibiotic treatment to decrease the risk of re-infection in the patient.7 Before doing so, however, make certain that state law permits this practice, and be sure to document the prescribed treatment in the patient’s record.
