Spontaneous Resolution of Genital Chlamydia trachomatis Infection in Women and Protection from Reinfection

Abstract

The natural history of chlamydia is variable and may include persisting asymptomatic infection, complications, or spontaneous resolution before treatment. Reinfection is common. We evaluated whether spontaneous resolution was associated with decreased reinfection in women returning for treatment of a positive chlamydia screening test. At enrollment, participants were tested for chlamydia, treated with azithromycin, and scheduled for a 6-month follow-up visit for repeat testing. Two hundred participants returned 1 to 12 months after treatment. Spontaneous resolution at enrollment was demonstrated in 44 (22.0%). Reinfection at follow-up occurred in 33 (16.5%), being more frequent in those with persisting infection at enrollment versus spontaneous resolution (31 of 156 [19.9%] vs 2 of 44 [4.5%]; P = .016). Adjusting for age, the odds of reinfection was 4 times higher for participants with persisting infection at enrollment (odds ratio 4.0, 95% confidence interval, 1.1-25.6; P = .034). Chlamydia treatment may attenuate protective immunity in some patients.

Immunoglobulin-Based Investigation of Spontaneous Resolution of Chlamydia trachomatis Infection

“…The potential clinical significance of spontaneous resolution is that patients who clear CT infection before treatment have a lower reinfection risk than those with persisting infection [5]. It has been suggested this may be because patients whose infections spontaneously resolve develop protective immunity, in contrast to those with persisting infection having "arrested" immunity if treated too early in their infection [6].…”

Lower Levels of Cervicovaginal Tryptophan Are Associated With Natural Clearance of Chlamydia in Women

“…resolving infection before treatment) occurs in 5 approximately 11-44% of women in the interval between a positive Ct screening test and returning for treatment [10]. Although the mechanisms involved in natural clearance are poorly understood, one study reported that women who naturally cleared Ct infection were 4-fold less likely to be re-infected within 6 months, suggesting adaptive immunity (perhaps via IFN--mediated tryptophan depletion) may contribute to natural clearance and protective immunity [11]. The primary objective of our study was to determine whether tryptophan, indole, and IFN- concentrations were associated with natural clearance of Ct infection in humans.…”

“…Adaptive immunity likely contributes to this process, evidenced by the association between natural clearance of Ct infection and reduced Ct reinfection rates [11]. IFN- is crucial for effective Ct clearance in animal models [2], and likely humans [3,4], by signaling tryptophan depletion, as shown in vitro [6].…”

Development of a chlamydial vaccine for koalas (Phascolarctos cinereus)

“…As koala chlamydial infection is widespread and often asymptomatic in free ranging animals, a prophylactic vaccine is of paramount importance. Recent studies showed that women with C. trachomatis infection without clinical disease, and treated with antibiotic, had a significant level of subsequent reinfections within a 1 year time period [83]. This clearly suggests that some individuals receiving antibiotic treatment did not develop protective immunity [84].…”

“…Chronic disease is associated with cystic changes in the oviduct and ovarian bursae and in some cases thickening of the uterine wall. Prostatic abscess formation is the prominent pathological finding for male koalas [83,84]. Ocular infections result in inflammation, characterised by conjuctival hyperplasia and progressing to fibrosis.…”