Prevalence and predictors of cervicitis in female sex workers in Peru: an observational study

Cervicitis is a syndrome of cervical inflammation and a common manifestation of sexually transmitted infections (STI) such as Chlamydia trachomatis (CT) and Neisseria gonorrhoea (GC) [1, 2]. Vaginal discharge or intermenstrual bleeding are frequent symptoms of cervicitis, although it may be asymptomatic [1, 3]. Cervicitis can progress to pelvic inflammatory disease (PID) with severe reproductive sequelae, even in asymptomatic cases [3]. Cervicitis may also affect sexual health at a population level, as it increases shedding of other STI such as Human Immunodeficiency Virus (HIV) and Human T-cell Lymphotropic Virus (HTLV) [4, 5].

While cervicitis is considered to arise as a consequence of STI, understanding of its etiology and pathogenesis is still evolving. Even with advanced microbiological assays, no causative pathogen is identified in the majority of cervicitis cases. When a pathogen is detected, CT and GC are the usual culprits. Less commonly, Mycoplasma genitalium, Trichomonas vaginalis (TV) and Herpes simplex Virus (HSV) are implicated [1, 2]. More recently, bacterial vaginosis (BV) has been linked to cervicitis, in addition to an increased risk of HIV acquisition, adverse pregnancy outcomes and gynaecological surgery complications [3, 6]. Although not an STI per se, BV is an endogenous vaginitis associated with sexual activity and characterized by an overgrowth of vaginal anaerobic flora and reduction of H₂0₂-producing lactobacilli [3].

Cervicitis is a common condition in FSW, with prevalences as high as 20% [7]. In studies of cervicitis in FSW living in Africa, CT, GC, M. genitalium and TV were common pathogens [7–9]. Factors such as lower education level, greater numbers of clients and decreased condom usage were associated with cervical infection in FSW working in Madagascar [10]. Although cervicitis has been reported in Peruvian FSW, detailed data regarding the prevalence, etiologies and risk factors for cervicitis in FSW working in Peru or other Latin American countries is lacking [4, 11]. As FSW may receive only intermittent healthcare and advanced diagnostics in low resource settings are limited, cervicitis in FSW, when diagnosed, is most often treated syndromically [12]. Syndromic management has drawbacks such as the underdiagnosis of subclinical STI and a potential overuse of antimicrobials [13]. Since FSW are particularly vulnerable to STI, and cervicitis may increase rates of STI transmission to the general population, accurate local epidemiological data is essential for guiding syndromic management of cervicitis in FSW.

The objectives of this observational, cross-sectional study were to describe the prevalence and etiologies of cervicitis in FSW receiving care at a public health clinic and associated mobile clinic in Callao-Lima, Peru. We also sought to identify sociodemographic, behavioral and biological factors associated with cervicitis. In particular, we sought to determine if an association between BV and cervicitis existed in these women, particularly given the high reported rates of BV in Peruvian FSW [11].

Further analyses were conducted to examine the association between cervicitis and regular clinic attendance, Ecuadorian nationality, and BV. The most common STI associated with cervicitis, namely CT, GC and TV, were less common in regular clinic attendees (OR = 0.39 [0.15, 0.99], p = 0.04). BV was also less common in regular clinic attendees (OR = 0.39, 95% [0.24, 0.62] p < 0.001). Regular clinic attendance was more common in Ecuadorian FSW (OR = 2.72, [1.49, 4.94], p = 0.001).

Almost one quarter of FSW in this study had cervicitis, second only to vaginal discharge as the most common syndrome. Cervicitis in this study was predominantly non-gonococcal, non-chlamydial in etiology, and no pathogen was detected in cervical samples in over 90% of participants with cervicitis. Cervicitis that is not associated with chlamydial or gonoccocal infections is the most common type of cervicitis overall and is referred to as ‘non-specific cervicitis’ (NSC) [1]. The rate of NSC determined here was higher than some rates reported in non-FSW women [6].

Studies in other FSW populations have demonstrated a strong association between gonoccoal, chlamydial or Trichomonas infection with clinical manifestations of cervicitis [8, 9]. No such association was found in the women studied here, and this likely reflects the low overall prevalence of STI diagnosed, in contrast to the higher STI prevalence reported in FSW in other Latin American countries, Asia and Africa [8, 9, 11, 16, 17].

Other potential reasons for the high frequency of NSC and lack of association with typical cervicitis-causing organisms may include ongoing inflammation of the cervix after previously treated chlamydial or gonorrhoeal infections, perhaps mediated by an abnormal immune response [2]. Data was unfortunately not collected on prior antimicrobial treatment for cervicitis or other genital tract syndromes in these women, which is a significant limitation to this study.

Cervical irritation due to douches and spermicides may also have contributed to high NSC rates [2]. While no data was collected on the use of spermicides or frequency of douching, douching is common in this population (personal observation by authors). Additionally, testing for other potential pathogens associated with cervicitis such as HSV-2 and M. genitalium were not performed in this study [1]. Furthermore, microscopy was used for the detection of trichomoniasis in this study, a method that is less sensitive compared to culture-based, molecular and immunochromatographic methods [3]. This relatively insensitive method of TV detection is a limitation of this study, and future studies should consider the use of newer generation diagnostic methods such as PCR.

Bacterial vaginosis may play a causative role in some NSC cases. BV was the second most common genital tract infection in our study and was present in over a third (36.9%) of cervicitis cases. On bivariate analysis, the association between BV and cervicitis failed to reach significance, but this may reflect insufficient power due to the number of FSW enrolled. There is growing evidence from other studies that BV is an independent risk factor for cervicitis [6]. Bacterial vaginosis could lead to cervicitis through a loss of bactericidal H₂0₂-producing lactobacilli, reduced levels of protective vaginal mucins, and increased pro-inflammatory enzymes and cytokines, which in turn may decrease the cervical mucus barrier [6].

Regular clinic attendance was associated with a 46% reduced risk of cervicitis, possibly due to the reduced rates of STI and BV noted in the regular clinic attendees. This may reflect frequent and early antibiotic treatment of genital tract syndromes and infections, although the exact frequency of antibiotic treatment was not determined. Self-treatment with antimicrobials was also considered as a confounding factor in women who attended clinics, however only one participant reported receiving treatment outside of clinics (data not shown). Preventative STI education delivered during clinic attendance may also contribute to the protective effect associated with regular clinic attendance. Regardless of the mechanism, the current Peruvian Ministry of Health program of free monthly health checks for FSW may be effective for reducing rates of cervicitis, BV and cervicitis-causing STI noted in FSW with regular clinic attendance.

Ecuadorian nationality was also protective against cervicitis, even after controlling for regular clinic attendance, which was more common in the Ecuadorian participants. The effect of Ecuadorian nationality may reflect unmeasured cultural differences in sexual practices, douching or other risk behaviors for cervicitis and STI.

In conclusion, cervicitis was a common condition in Peruvian FSW and in the context of very low STI rates was predominately non-specific cervicitis. Our findings may not be generalizable to other populations of FSW, particularly those with higher rates of STI, but encourage further evaluation of the etiologies and treatment of cervicitis in FSW populations. The protective effect of Ecuadorian nationality is intriguing, and future studies could examine the effect of migration upon the sexual health and risk behaviors of FSW. Defining the role of M. genitalium, HSV and other emerging pathogens such as Ureaplasma urealyticum, adenovirus and cytomegalovirus in FSW with cervicitis may also reveal new associations [2, 3].