Trichomonas vaginalis: underdiagnosis in urban Australia could facilitate re-emergence

Abstract

Objectives Trichomonas vaginalis (TV) has a low profile in urban sexually transmitted infection (STI) clinics in many developed countries. The objective of this study was to determine the true prevalence of TV in an Australian urban sexual health setting using sensitive molecular diagnostic techniques. Methods A cross-sectional study investigating the aetiology of cervicitis in women attending two urban sexual health clinics in Sydney, Australia, enrolled 356 consecutive eligible women from 2006 to 2008. The diagnostic yield from the standard clinical practice of discretionary high vaginal wet preparation microscopy in women with suspicious vaginal discharge was compared with universal use of nested PCR for TV of cervical samples. Results TV was detected by PCR in 17/356 women (4.8%, 95% CI 2.8 to 7.5%), whereas only four cases (1.1%, 95% CI 0.3 to 2.8%) were detected by discretionary wet preparation microscopy. Eleven of the 17 women (p¼0.003) were of culturally and linguistically diverse background. Additionally, cervicitis was found to be significantly associated with TV, RR 1.66 (1.14 to 2.42), p¼0.034. Conclusions Traditional TV-detection methods underestimate TV prevalence in urban Australia. The TV prevalence of 4.8% by PCR testing in this study exceeds previously reported urban Australian TV rates of <1%. An increase in trichomoniasis-associated adverse reproductive outcomes and enhanced HIV transmission poses a salient public health threat. Accordingly, TV warrants a higher profile in urban STI clinic settings in developed countries, and we suggest that priority be given to development of standardised molecular TV detection techniques and that these become part of routine STI testing.

Cervicitis aetiology and case definition: a study in Australian women attending sexually transmitted infection clinics

“…Study protocol and laboratory methods are described previously 12 21. In brief, 558 women enrolled in a cross-sectional study in three STI/HIV clinics in Sydney, Australia, between July 2006 and February 2010.…”

“…Lower genital tract inflammation (cervicitis or leucorrhoea) is thought to be a sensitive indicator of endometritis and subclinical pelvic infection 5 6 . Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) have been consistently associated with cervicitis,7 8 with variable evidence for Mycoplasma genitalium (MG),9–11 Trichomonas vaginalis (TV)7 9 12 and bacterial vaginosis (BV) 9 13 14. Most cervicitis diagnoses occur in the absence of these pathogens, referred to as non-chlamydial and non-gonococcal cervicitis,7 non-specific cervicitis4 or cervicitis of unknown aetiology 15…”

Trichomoniasis in older individuals: a preliminary report from Iran

“…Increasing numbers of T. vaginalis infection cases have been recorded in recent years. Development of novel diagnostic methods, especially molecular methods, can be main accountable for such a trend (Lusk et al 2010). …”

Inducing Immune Protection Against Trichomonas vaginalis: A Novel Vaccine Approach to Prevent HIV Transmission

“…These tests may be conducted years after sample collection depending on proper storage conditions unlike wet mount which results in much less sensitivity unless maintained under strict time and temperature conditions (Van Der Pol et al, 2006). Despite high sensitivity for both male and female samples (Seña et al, 2007), greater than wet mount and culture (Crucitti et al, 2003;Lusk et al, 2010;Roth et al, 2011), in the range of 70-98% and specificity from 94-100% (Huppert et al, 2007;Nye et al, 2009;Seña et al, 2007;Wendel et al, 2002) this method is problematic as it is not point of care and remains unconfirmed for use in clinical settings.…”

“…Ignoring the latter issue yet another problem arises. Diagnosis of cases investigated from clinical suspicion of trichomoniasis are at mercy of low sensitivity of current diagnostic standards as recent evaluations over the past decade have come to find (Lusk et al, 2010;Roth et al, 2011;Seña et al, 2007;Van Der Pol, 2007;Wendel et al, 2002). The most prevalent and most promising techniques will be reviewed below while a more detailed overview of guidelines for laboratory diagnosis and the methodology can be found in Domeika et al (2010).…”