Estimating the prevalence of Trichomonas vaginalis, Chlamydia trachomatis, Neisseria gonorrhoeae, and human papillomavirus infection in indigenous women in northern Australia

Exploring the Molecular Pathogenesis, Pathogen Association, and Therapeutic Strategies against HPV Infection

The human papillomavirus (HPV), commonly documented as the cause of warts, has gained much interest recently due to its possible links to several types of cancer. HPV infection is discussed in this review from multiple angles, including its virology, epidemiology, etiology, immunology, clinical symptoms, and treatment. Recent breakthroughs in molecular biology have led to the development of new methods for detecting and treating HPV in tissue. There is no cure for HPV, and although vaccines are available to prevent infection with the most common HPV viruses, their utilization is limited. Destruction and excision are the primary treatment modalities. This review sheds light on the epidemiology, molecular pathogenesis, the association of several other pathogens with HPV, the latest treatment strategies available to treat the same, and an overview of the progress made and the obstacles still to be overcome in the fight against HPV infection.

Prevalence and spatial heterogeneity of Trichomonas vaginalis infection among the female population and association with climate in Guangxi Zhuang autonomous region, Southern China

BACKGROUND

Two cervical cancer screening (CCS) projects have been ongoing for years in Guangxi Zhuang autonomous region (Guangxi), and some Trichomonas vaginalis infection (TVI) cases have been found as an opportunistic finding. This study aimed to identify the high-risk population and expound the spatial epidemiological features of TVI in Guangxi.

METHODS

This study was based on CCS from 2012 to 2019. Adjusted odds ratio (AOR), and spatial analyses were used to identify the high-risk subgroups, as well as to depict the spatial epidemiological feature and its relationship with meteorological factors.

RESULTS

The infection rate of TVI was 0.38% in 873,880 samples. Significant association with a high risk of TVI was found in the following: females aged 40-49 years (aOR=4.464; 95% CI, 3.359-5.932; p<0.001), aged 50-59 years (aOR=3.169; 95% CI, 2.370-4.237; p<0.001), from urban (aOR=1.577; 95% CI, 1.471-1.691; p<0.001), from minority areas (aOR=1.183; 95% CI, 1.060-1.320; p=0.003), areas with GPD <41,500 CNY (aOR=1.191; 95% CI, 1.106-1.282; p<0.001), and inland areas (aOR=1.520; 95% CI, 1.339-1.726; p<0.001). Counties with higher infection rate were concentrated in northwest Guangxi's mountainous area (Z-score=3.9656, p<0.001), in the upper reaches of the Hongshui River and Yu River, and with a significant spatial autocorrelation (Moran's I=0.581, p=0.002). Spatial error model showed significantly negative regressions among temperature (B=-0.295, p=0.002), annual temperature range (B=-0.295, p=0.002), and TVI spatial distribution.

CONCLUSION

The spatial clustering and disparity of TVI in northwest Guangxi warrant further study, and meteorological conditions may play an important role in TVI in northwest Guangxi.

Absence of human papillomavirus in nasopharyngeal swabs from infants in a population at high risk of human papillomavirus infection

Maternal urogenital human papillomavirus (HPV) infection may place neonates at risk of HPV acquisition and subsequently lower respiratory infections as HPV can influence development of immunity. The respiratory HPV prevalence is not known in remote-dwelling Aboriginal infants, who are at high risk of respiratory infection and where the population prevalence of urogenital HPV in women is high. These data are necessary to inform HPV vaccination regimens. A retrospective analysis using PCR specific for HPV was performed on 64 stored nasopharyngeal swabs from remote-dwelling Aboriginal infants < 6 months of age, with and without hospitalised pneumonia. HPV DNA was not detected in any specimen. Despite the negative result, we cannot exclude a role for HPV in respiratory infections affecting infants in this population; however, our data do not support HPV as an important contributor to acute respiratory infection in remote-dwelling Aboriginal children.

Two Distinct Gonorrhea Trends and Risk Factors Among Women in Australia

BACKGROUND

In recent years, gonorrhea notifications have increased in women in Australia and other countries. We measured trends over time and risk factors among Australian Aboriginal and Torres Strait Islander ("Aboriginal") and non-Aboriginal women.

METHODS

We conducted a cross-sectional analysis of data from 41 sexual health clinics. Gonorrhea positivity at each patient's first visit (first-test positivity) during the period 2009 to 2016 was calculated. Univariate and multivariate analyses assessed risk factors for first-test positivity in Aboriginal and non-Aboriginal women.

RESULTS

Gonorrhea positivity decreased among Aboriginal women (7.1% in 2009 to 5.2% in 2016, P < 0.001) and increased among non-Aboriginal women (0.6%-2.9%, P < 0.001). Among Aboriginal women, first-test positivity was independently associated with living in a regional or remote area (adjusted odds ratio [aOR], 4.29; 95% confidence interval [CI], 2.52-7.31; P < 0.01) and chlamydia infection (aOR, 4.20; 95% CI,3.22-5.47; P < 0.01). Among non-Aboriginal women, first-test positivity was independently associated with greater socioeconomic disadvantage (second quartile: aOR, 1.68 [95% CI, 1.31-2.16; P < 0.01]; third quartile: aOR, 1.54 [95% CI, 1.25-1.89; P < 0.01]) compared with least disadvantaged quartile: recent sex work (aOR, 1.69; 95% CI, 1.37-2.08; P < 0.01), recent injecting drug use (aOR, 1.85; 95% CI, 1.34-2.57; P < 0.01), and chlamydia infection (aOR, 2.35; 95% CI, 1.90-2.91; P < 0.01). For non-Aboriginal women, being aged 16 to 19 years (aOR, 0.62; 95% CI, 0.49-0.80; P < 0.01) compared with those ≥30 years was a protective factor.

CONCLUSIONS

These findings highlight 2 different epidemics and risk factors for Aboriginal and non-Aboriginal women, which can inform appropriate health promotion and clinical strategies.

Impact of replacing cytology with human papillomavirus testing for cervical cancer screening on the prevalence of Trichomonas vaginalis: a modelling study

Objectives

Trichomonas vaginalis (TV) is the most common curable STI worldwide and is associated with increased risk of HIV acquisition and serious reproductive morbidities. The prevalence of TV infection is very low in Australian cities, and this is thought to be at least partly due to incidental detection and treatment of TV in women participating in the cervical cytology screening programme. In 2017, the national cervical screening programme will transition to a new model based on testing for high-risk (HR) human papillomavirus (HPV), with a reduced frequency and commencement at an older age. We model the potential impact of this transition on TV prevalence in Australia.

Methods

A mathematical model was developed to describe the transmission of TV in the general population and used to evaluate scenarios that capture the switch from cytology-based screening to HR HPV testing. Under these scenarios, individuals with asymptomatic TV who test negative for HR HPV will remain undiagnosed and untreated. We estimate the change in TV prevalence expected to occur due to the switch from cytology to HR HPV testing and changes to the frequency and age at commencement of screening.

Results

Our results suggest that with the transition to HR HPV testing, TV prevalence may increase from the current ~0.4% to 2.8% within 20 years if TV testing coverage is not increased and HR HPV prevalence does not decline further. If HR HPV prevalence continues to decline at its current rate with ongoing vaccination, TV prevalence is predicted to increase to 3.0% within this time frame.

Conclusions

Our modelling suggests that in a setting like Australia, where TV can be detected incidentally through cytology-based cervical screening, a transition to HPV testing is likely to result in increasing TV prevalence over time unless additional measures are implemented to increase TV testing and treatment.

Risk of high-risk human papillomavirus infection and cervical precancerous lesions with past or current trichomonas infection: a pooled analysis of 25,054 women in rural China

BACKGROUND

Trichomonas vaginitis (TV) infection has obviously been implicated in gynecological morbidity but still unclear in cervical lesions.

OBJECTIVE

To evaluate the risk of hr-HPV infection and cervical intraepithelial neoplasia grade 2 or worse (CIN2 + ) by TV infection.

STUDY DESIGN

The pooled study was conducted among 12 population-based, cervical cancer screening studies throughout China (N = 24,054). HPV was detected by Hybrid Capture^®2 (HC2) test. Past TV infection was measured by self-reporting, current TV infection was diagnosed by liquid-based cytology (LBC), cervical lesions was diagnosed by histopathology.

RESULTS

Respective prevalence of hr-HPV and CIN2+ were 17.4% and 3.3%. Out of 24,054 women, 14.6% reported past TV infection, and out of 11,853 women, 9.9% had current TV infection. Current TV-positive women had an increased risk for hr-HPV (OR 1.31, 95%CI: 1.11-1.56). The risk of CIN2+ decreased for hr-HPV positive women with current TV infection (adjusted OR 0.50, 95% CI: 0.30-0.84) and past TV infection (adjusted OR 0.68, 95% CI: 0.54-0.86). Among hr-HPV negative women, no significant associations were observed between past or current TV infection and risk of CIN2+.

CONCLUSIONS

Women infected with HPV are more likely to be infected by other types of sexually transmitted diseases. Current TV-positive women had an increased risk for hr-HPV infection compared to currently TV-negative women. Both past and current TV-positive women had a decreased risk for CIN2+, especially among high-risk HPV positive women. More direct investigation into the interaction between TV, HPV, inflammatory signals, and risk of carcinogenesis are further needed.

Strategies for Prevention and Treatment of Trichomonas vaginalis Infections

The last estimated annual incidence of Trichomonas vaginalis worldwide exceeds that of chlamydia and gonorrhea combined. This critical review updates the state of the art on advances in T. vaginalis diagnostics and strategies for treatment and prevention of trichomoniasis. In particular, new data on treatment outcomes for topical administration of formulations are reviewed and discussed.

Detection of genital chlamydial and gonococcal infection using urine samples: A community-based study from India

Sexually transmitted infections (STI) have a major impact on the reproductive health of women. Among the different etiological agents of STIs, Chlamydia trachomatis and Neisseria gonorrhoeae are the main bacterial pathogens that cause sexually transmitted infections in women. The aim of the study was to estimate the prevalence of genital chlamydial and gonococcal infection among women in the age group of 18-65 years from a community-based setting. A community-based cross-sectional study was performed using the archived urine samples (n=811) of women in the age group of 18-65 years for C. trachomatis and N. gonorrhoeae using a multiplex conventional Polymerase Chain Reaction (PCR). Out of 811 samples tested in the present study, 2 (0.24%) were tested positive for C. trachomatis and none were positive for N. gonorrhoeae. The study demonstrates the very low prevalence of C. trachomatis and N. gonorrhoeae infection in a rural community. For large population-based screening, urine samples were observed to be more socially acceptable and cost-effective.

Detection of Trichomonas vaginalis in prostate tissue and serostatus in patients with asymptomatic benign prostatic hyperplasia

Background

Despite a worldwide common and progressive nature of benign prostate hyperplasia (BPH) in older men, no association has been observed between a causative pathogen and other etiology so far.

Methods

In this study, we investigated a causative association of Trichomonas vaginalis, a flagellate protozoan parasite, in 171 BPH cases presenting without symptoms of prostatitis at a surgical outpatient clinic in Kuwait. We detected T. vaginalis DNA by polymerase chain reaction (PCR) and T. vaginalis antigen by immunocytochemistry (ICC) in the prostate tissue of these cases. A total of 171 age-matched controls with no urinary tract symptoms were also included in the study. A detailed information regarding the sexual history and sexually transmitted infections (STIs) was enquired from all the enrolled subjects.

Results

We detected T. vaginalis DNA and T. vaginalis antigen in 42 (24.6 %) and 37 (21.6 %) of the 171 BPH cases respectively in their prostate tissue. Both these assays showed a very good agreement and statistically no significant difference in their sensitivities and specificities. A relatively higher seropositivity rate for antibodies to T. vaginalis was detected in BPH cases (53 of 171 cases, 31.0 %) than in the control group (26.9 %) [p: 0.19] and both were higher than in earlier reports but no significant association was observed between BPH and T. vaginalis serostatus. However, a greater proportion of seroreactive BPH cases had high IgG2 antibody absorbance score than in the control group (p:0.000). Furthermore, no significant association was observed between T. vaginalis seropositivity and presence of T. vaginalis DNA in the prostate tissue.

Conclusions

Our study documents T. vaginalis DNA and T. vaginalis antigen in 24.6 and 21.6 % respectively in the prostate tissue of the BPH cases. We also detected a relatively higher seropositivity rate for antibodies to T. vaginalis both in the BPH cases and in normal control group, 31 and 26.9 % respectively but no significant association was observed between BPH and T. vaginalis serostatus or presence of T. vaginalis DNA in the prostate tissue. Further epidemiological and case-controlled studies are needed to focus on local response to chronic asymptomatic retention of T. vaginalis in prostate tissue in the development of benign prostate hyperplasia.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-016-1843-1) contains supplementary material, which is available to authorized users.

Prevalence of Trichomoniasis by PCR in Women Attending Health Screening in Korea

Trichomoniasis is the most common curable sexually-transmitted infection (STI) worldwide. There are few reports on the prevalence of Trichomonas vaginalis in Korea. The purpose of this study was to examine the prevalence of trichomoniasis by PCR in Guri city, Korea. All adult women who visited Hanyang University Guri Hospital for health screening within the National Health Care Service were invited to participate in the study, and 424 women were enrolled between March and June 2011. PCR was used to detect Trichomonas vaginalis using primers based on a repetitive sequence cloned from T. vaginalis (TV-E650). Fourteen women (3.3%) were found to have T. vaginalis. All were over 50, and they were significantly older on average than the 410 Trichomonas-negative women (mean ages 63.4 vs 55.3 years). It seems that T. vaginalis infection is not rare in women receiving health screening, especially among those over 50.

Prevalence of chlamydia, gonorrhoea, syphilis and trichomonas in Aboriginal and Torres Strait Islander Australians: a systematic review and meta-analysis

Higher notification rates of sexually transmissible infections (STIs) are reported among Aboriginal and Torres Strait Islander (Aboriginal) compared with non-Aboriginal people in Australia. The aim of this study is to estimate the pooled prevalence of chlamydia, gonorrhoea, syphilis and trichomonas among Aboriginal people in Australia by sex, age-group, setting (clinic vs population/community-based) and population group [adults, pregnant females, young people (12-29 years) and prisoners]. The databases Medline, PubMed and Web of Science were searched in May 2015. A meta-analysis was conducted to estimate the pooled prevalence of the four STIs in Aboriginal people and if possible, by gender, age-group, setting and population group. A total of 46 studies were included. The pooled prevalence was 11.2% (95%CI: 9.4-13.0%) for chlamydia (36 studies), 12.5% (95%CI: 10.5-14.6%) for gonorrhoea (28 studies), 16.8% (95%CI: 11.0-22.6%) for syphilis (13 studies) and 22.6% (95%CI: 18.5-26.7%) for trichomonas (11 studies); however, there was significant heterogeneity between studies (I(2) <97.5%, P<0.01). In the subgroup analysis, a higher pooled prevalence occurred in females than males for chlamydia (12.7% vs 7.7%) and gonorrhoea (10.7% vs 8.1%). The prevalence of chlamydia was 12.4% in clinic-based compared with 4.3% in population-based studies. The highest pooled prevalence by population group was among pregnant females (16.8%) and young people (16.2%) for chlamydia, pregnant females (25.2%) for trichomonas; and young people for gonorrhoea (11.9%). This review highlights the need to decrease the prevalence of STIs among Aboriginal people through community-based programs that target asymptomatic young people.

Coinfection with Chlamydia trachomatis, Neisseria gonorrhoeae and Trichomonas vaginalis: a cross-sectional analysis of positivity and risk factors in remote Australian Aboriginal communities

OBJECTIVES

To determine the co-occurrence and epidemiological relationships of Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG) and Trichomonas vaginalis (TV) in a high-prevalence setting in Australia.

METHODS

In the context of a cluster randomised trial in 68 remote Aboriginal communities, we obtained laboratory reports on simultaneous testing for CT, NG and TV by nucleic acid amplification tests in individuals aged ≥16 years and examined relationships between age and sex and the coinfection positivity. ORs were used to determine which infections were more likely to co-occur by demographic category.

RESULTS

Of 13 480 patients (median age: 30 years; men: 37%) tested for all three infections during the study period, 33.3% of women and 21.3% of men had at least one of them, highest in patients aged 16-19 years (48.9% in women, 33.4% in men). The most frequent combination was CT/NG (2.0% of women, 4.1% of men), and 1.8% of women and 0.5% of men had all three. In all co-combinations, coinfection positivity was highest in patients aged 16-19 years. CT and NG were highly predictive of each other's presence, and TV was associated with each of the other two infections, but much more so with NG than CT, and its associations were much stronger in women than in men.

CONCLUSIONS

In this remote high-prevalence area, nearly half the patients aged 16-19 years had one or more sexually transmitted infections. CT and NG were more common dual infections. TV was more strongly associated with NG coinfections than with CT. These findings confirm the need for increased simultaneous screening for CT, NG and TV, and enhanced control strategies.

TRIAL REGISTRATION

Australian and New Zealand Clinical Trials Registry ACTRN12610000358044.

Incidence of curable sexually transmissible infections among adolescents and young adults in remote Australian Aboriginal communities: analysis of longitudinal clinical service data

OBJECTIVES

To undertake the first comprehensive analysis of the incidence of three curable sexually transmissible infections (STIs) within remote Australian Aboriginal populations and provide a basis for developing new control initiatives.

METHODS

We obtained all results for Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG) and Trichomonas vaginalis (TV) testing conducted during 2009-2011 in individuals aged ≥16 years attending 65 primary health services across central and northern Australia. Baseline prevalence and incidence of all three infections was calculated by sex and age group.

RESULTS

A total of 17 849 individuals were tested over 35 months. Baseline prevalence was 11.1%, 9.5% and 17.6% for CT, NG and TV, respectively. During the study period, 7171, 7439 and 4946 initially negative individuals had a repeat test for CT, NG and TV, respectively; these were followed for 6852, 6981 and 6621 person-years and 651 CT, 609 NG and 486 TV incident cases were detected. Incidence of all three STIs was highest in 16-year-olds to 19-year-olds compared with 35+ year olds (incident rate ratio: CT 10.9; NG 11.9; TV 2.5). In the youngest age group there were 23.4 new CT infections per 100 person-years for men and 29.2 for women; and 26.1 and 23.4 new NG infections per 100 person-years in men and women, respectively. TV incidence in this age group for women was also high, at 19.8 per 100 person-years but was much lower in men at 3.6 per 100 person-years.

CONCLUSIONS

This study, the largest ever reported on the age and sex specific incidence of any one of these three curable infections, has identified extremely high rates of new infection in young people. Sexual health is a priority for remote communities, but will clearly need new approaches, at least intensification of existing approaches, if a reduction in rates is to be achieved.

Could point-of-care testing be effective for reducing the prevalence of trichomoniasis in remote Aboriginal communities?

High prevalence of trichomoniasis is reported for many remote Indigenous communities despite intensive screening and treatment programs. Mathematical modelling has previously been used to show that point-of-care (POC) testing for gonorrhoea and chlamydia has the potential to increase the impact of screening in reducing the prevalence of these sexually transmissible infections. The study was extended to estimate the impact of a rapid POC test for trichomoniasis. The results suggest that POC testing in place of conventional testing will also provide additional reductions in trichomoniasis prevalence. However, more emphasis should be placed on testing for trichomoniasis in older women due to the high prevalence observed in this group.

Inflammatory response of prostate epithelial cells to stimulation by Trichomonas vaginalis

BACKGROUND

Trichomonas vaginalis is known as the most common cause of sexually transmitted infection. However, its prevalence may have been underestimated. Trichomonads are detected in prostatic tissue in benign prostatic hyperplasia, prostatitis, and prostate cancer. Our objective was to investigate whether T. vaginalis could induce an inflammatory response in prostate epithelium.

METHODS

The cytokine production by human prostate epithelial cell (RWPE-1) activated with T. vaginalis was determined by ELISA and real-time PCR. Intracellular ROS was evaluated by flow cytometry or spectrofluorometry. The protein levels of MAP kinase, NF-κB were analyzed by Western blot. The migration of neutrophil and monocyte were performed in 24-well microplates with filter insert.

RESULTS

Incubation of cells of a human prostate epithelial cell line with a live T. vaginalis T016 isolate increased expression of the inflammatory mediators IL-1β, CCL2, and CXCL8. In addition, ROS, MAPK, and NF-κB activities increased, while inhibitors of ROS, ERK, and NF-κB reduced IL-1β production. Medium conditioned by incubation of RWPE-1 cells with T. vaginalis contained IL-1β and stimulated the migration of human neutrophils and monocytes (THP-1 cell line).

CONCLUSIONS

We conclude that T. vaginalis may increase IL-1β expression in human prostate epithelium through activation of ROS, ERK, and NF-κB, and this in turn may induce the migration of neutrophils and monocytes and lead to an inflammatory response. This research is the first attempt to confirm inflammatory reaction caused by T. vaginalis in prostate epithelial cell.

'Young clean and safe?' Young people's perceptions of risk from sexually transmitted infections in regional, rural and remote Australia

This paper examines young people's perceived vulnerability to sexually transmitted infections (STIs) and their efforts to create a sense of personal safety within an environment in which risks may be high and where STIs are highly stigmatised. The paper reports on findings from research involving both Indigenous and non-Indigenous 16- to 25-year-olds from remote, rural and regional Australia, including communities in the Northern Territory, Western Australia and South Australia. The study used qualitative methods, including body mapping and scenario based interviewing, to explore how young people made decisions about potential sexual partners and how STIs were understood within the context of young people's everyday social worlds. The paper has important implications for the design and implementation of sexual-health education programmes by documenting the stigmatisation of young people with STIs and the protective mechanisms peer groups employ to create perceptions of personal safety.

Use of health services for sexually transmitted and blood-borne viral infections by young Aboriginal people in New South Wales

The objective of the present study was to describe use of health services for sexually transmitted infections (STI), blood borne viral infections (BBV) and drug and alcohol issues by young Aboriginal people in New South Wales (NSW). A cross-sectional survey was conducted at two Aboriginal sports and cultural events in NSW, in 2007 and 2008, among Aboriginal people aged 16-30 years to ascertain their knowledge of STI, BBV, associated risk behaviours and health service access in NSW. A total of 293 young Aboriginal people completed the survey; 58% were female, the mean age was 20 years, and almost 70% were single. Just over one-third (34%) of participants had been tested for an STI in the past 12 months, and over half (58%) reported that they had ever had an STI test (including HIV). Of respondents who had had an STI test in the past 12 months, 54.0% had done so at an Aboriginal Community Controlled Health Service (ACCHS) and 29% by a GP. Just over one-third (36%) of participants had ever had a test for hepatitis C, 45% of whom had received their test at an ACCHS. Participants were also asked about the types of services they had used for advice about STI and BBV. Of the 69% who had sought STI advice, ACCHS was the most common clinical location for doing so (36% for STI and 26% for hepatitis C). This study highlights the important role that ACCHS play in the provision of STI and BBV testing care and management for a cohort of young Aboriginal people in NSW.

The prevalence of Trichomonas vaginalis detected by wet mount and polymerase chain reaction in Sydney women

Objectives Although Trichomonas vaginalis (TV) has a low profile in urban Australia, local data has estimated the prevalence in women to be 10 times higher when using polymerase chain reaction (PCR) versus wet mount microscopy (4.8% v. 0.4%). Our aim was to determine the prevalence of TV in Sydney women using both wet mount and PCR. Methods: A cross-sectional study was conducted of women requiring sexually transmissible infection screening at the Sydney Sexual Health Centre. Vaginal swabs were examined for TV using PCR and wet mount microscopy. Results: In total, 781 of 1263 eligible women were tested; 3 out of 781 tested positive by PCR and 1 out of 781 by wet mount, giving a prevalence of 0.38% (95% confidence interval (CI): 0.14–1.12%) and 0.13% (95% CI: 0.03–0.71%) respectively. There was not enough power to compare PCR and wet mount. Conclusions: The results of this analysis indicate that in our female urban population, TV is a very rare sexually transmissible infection,with 0.38% prevalence, and routine screening by PCR is not indicated.

Trends in testing and notification for genital gonorrhoea in a northern Australian district, 2004 - 2008

Background The study aimed to examine the trends in notification and testing for genital gonorrhoea (Neisseria gonorrhoeae) in the Darwin Remote District of Northern Territory, Australia, between 2004 and 2008. Methods: Using laboratory testing data and notification data, we calculated the annual sex- and age-specific notification rates, testing rates and positivity rates, and examined their trends. A deterministic matching method was used to identify unique individuals tested in order to estimate the number of years out of five in which each individual was tested. The correlation between testing rates and notification rates was calculated. Results: The notification rates for the 15–24 year age group increased sharply from 2004 to 2005, and then trended downwards between 2005 and 2008, with a decrease of 48.2% in females and 59.9% in males. No evident trends were found in testing rates. The positivity rates for this age group decreased by 46.3% in females (from 8.9% to 4.8%), and by 70.4% in males (from 10.8% to 3.2%) between 2004 and 2008. Over 76% of the population in this age-group had been tested at least once during the study period. A moderate correlation was found between notification rates and testing rates in both sexes. Conclusions: There was a significant decreasing trend in the notification rate of gonorrhoea between 2005 and 2008, which was most probably due to a decrease in prevalence. This study demonstrates the importance and utility of population-level testing data in understanding the epidemiology of common bacterial sexually transmissible infections such as gonorrhoea.

Cervical cancer in Indigenous women: The case of Australia

Globally, health inequities between Indigenous and non-Indigenous populations exist. The disparity in health outcomes between Indigenous and non-Indigenous Australians is exemplified by cervical cancer. Current evidence suggests that Indigenous women have higher age standardised incidence and mortality than non-Indigenous women when adjusted for stage at diagnosis and co-morbidities; however, there is little information pertaining to national estimates of cervical cancer in Indigenous women. In this paper we review available evidence on the difference in occurrence and case fatality of cervical cancer among Indigenous and non-Indigenous Australian women. The Australian Bureau of Statistics, Australian Institute of Health and Welfare, and State- or Territory-based Cancer Registries were utilised to collect surveillance data. To corroborate existing data, further available journal literature was identified through Medline and Embase. All papers selected for review were cross-referenced to identify further relevant studies. The most recent national estimate of age-standardised cervical cancer incidence rate was 16.9 and 7.1 per 100,000 women-years in Indigenous and non-Indigenous women respectively (incidence ratio 2.4). The Indigenous age-standardised mortality rate was 9.9 per 100,000 women years (95% CI 7.1-13.3), over 5 times the non-Indigenous rate. Cervical cancer incidence, in both Indigenous and non-Indigenous women, has decreased since 1991. Despite the decline, age-standardised incidence among Indigenous women is still higher than non-Indigenous women. The pattern of cervical cancer incidence and survival corroborates the health inequities that exist in Australia. Indigenous women are more likely than non-Indigenous women to develop cervical cancer and are less likely to survive it. Similar patterns exist in Indigenous populations worldwide, such as New Zealander Maoris and Canadian Aboriginals, suggesting that high rates of cervical cancer incidence and mortality may be a symptom of social and economic inequity.

Safer sex and condom use: a convenience sample of Aboriginal young people in New South Wales

BACKGROUND

This paper examines condom use in a sample of Aboriginal young people in New South Wales (NSW) aged 16-30 years.

METHODS

Cross-sectional data were collected using hand-held computer devices from 293 Aboriginal people attending two Aboriginal events in NSW.

RESULTS

Almost two-thirds of respondents reported having had a casual sex partner in the previous 6 months. Of these, 39.2% reported always using a condom with casual partners. Having always used a condom with casual partners varied among respondents, and was more likely among younger respondents (adjusted odds ratio (AOR): 2.7, 95% confidence interval (CI): 1.2-6.1) and less likely among those who used illicit drugs (AOR: 0.2, 95% CI: 0.1-0.7).

CONCLUSIONS

In comparison to published studies of other Australians, casual sex appears to be more common among this sample of Aboriginal young people; however, the proportion who report having always used condoms with casual partners is very similar. This suggests that although casual sex is more common, Aboriginal young people do not engage in risky behaviour any more often than other young Australians. Further work should be conducted with those who do not always use condoms, such as those who are older and who use illicit drugs, particularly with regards to how abstinence from drug use supports protective behaviours such as condom use among this population of Aboriginal young people.

Trichomonas vaginalis infection among women in a low prevalence setting

Objectives: Trichomonas vaginalis has become rare in Australian cities but remains endemic in some remote regions. We describe the prevalence and associations of infection among women attending an urban Australian sexual health clinic. Methods: A retrospective case control study was conducted with women diagnosed with T. vaginalis at Sydney Sexual Health Centre between January 1992 and December 2006. Proforma medical records for all women were reviewed to extract demographic, behavioural and diagnostic variables using a predefined data collection instrument. Results: Over the 15-year period, 123 cases of T. vaginalis were diagnosed, with a prevalence of 0.40%. Factors independently associated with infection were older age, vaginitis symptoms (adjusted odds ratio (AOR) 6.47; 95% confidence interval (CI), 3.29–12.7), sex with a partner from outside Australia (AOR 2.33; 95% CI, 1.18–4.62), a concurrent (AOR 3.65; 95% CI, 1.23–10.8) or past (AOR 2.67; 95% CI, 1.28–5.57) sexually transmissible infection, injecting drugs (AOR 7.27; 95% CI, 1.43–36.8), and never having had a Papanicolaou smear (AOR 7.22; 95% CI, 2.81–18.9). Conclusions: T. vaginalis infection was rare in women attending our urban clinic. Rarity, combined with an association with sex outside Australia, points to imported infections accounting for a large proportion of T. vaginalis infections in an urban population. The association with never having had cervical cancer screening, along with injecting drug use, likely reflects an increased prevalence in those with reduced access to health services or poor health seeking behaviours.

Seroprevalence of herpes simplex virus type 1 and type 2 among the Indigenous population of Cape York, Far North Queensland, Australia

BACKGROUND

The objective of this study was to obtain representative seroprevalence data for the Indigenous population of Far North Queensland by measuring the age- and sex-specific seroprevalence of the herpes simplex viruses (HSV-1 and HSV-2) in Cape York.

METHODS

A cross-sectional seroprevalence study was conducted using de-identified serum samples collected from Indigenous patients living in Cape York, aged 16 years or older, who sought medical care between August 2007 and May 2008. An age- and sex-stratified random sample of 270 sera was tested for the presence of antibodies to HSV-1 and HSV-2 using commercially available enzyme-linked immunosorbent assays. Indeterminate results were resolved with western blot.

RESULTS

The overall seroprevalence for the Indigenous population of Cape York was 97.8% for HSV-1 and 58.5% for HSV-2. There was a statistically significant difference in HSV-2 seroprevalence according to sex (P < 0.001). Females were more likely to be HSV-2 seropositive compared with males (72.1% and 43.8%, respectively).

CONCLUSIONS

This is the first study to report on the seroprevalence of HSV-1 and HSV-2 among the Indigenous population of Cape York. This study has identified a population with an extremely high prevalence of HSV-1 and HSV-2 infection. The seroprevalence of HSV-2 in this population was found to be five times higher than that reported for the general adult Australian population. These results will be invaluable to the implementation of appropriate prevention and control strategies against HSV infection and are especially important considering the strong association between HSV-2 and the acquisition and transmission of HIV.

Chlamydia at an inner metropolitan sexual health service in Sydney, NSW: Australian Collaboration for Chlamydia Enhanced Sentinel Surveillance (ACCESS) Project

BACKGROUND

Australia has a widely dispersed network of public sexual health services that test large numbers of people from high prevalence populations for genital Chlamydia trachomatis infection. These populations include young sexually active heterosexuals, men who have sex with men, sex workers and Aboriginal and Torres Strait Islander people. The Australian Collaboration for Chlamydia Enhanced Sentinel Surveillance (ACCESS) Project was established to monitor chlamydia testing rates and positivity rates at a national level, which in turn will help interpret trends in chlamydia diagnoses reported through passive surveillance. The ACCESS Project is the first time that chlamydia-related data including priority population and testing denominators has been collated at a national level. The present paper reports on chlamydia testing and positivity rates in a sexual health service in the inner west of Sydney between 2004 and 2008 and compares these to published national data from the ACCESS Project in sexual health services.

METHODS

Chlamydia positivity and testing rates at an inner western Sydney sexual health service were compared with aggregate data from the ACCESS Project obtained from 14 sexual health services across Australia. Using a standardised extraction program, retrospective de-identified line-listed demographic and chlamydia testing data on all patients were extracted from patient management systems.

RESULTS

Over the 5-year period, 5145 new patients attended the inner-west sexual health service. Almost 66% had a chlamydia test at first visit and there was no significant difference in this testing rate when compared with the ACCESS Project national rate for sexual health services (67.0%; odds ratio [OR] 0.94, 95% confidence intervals 0.88-1.00). The testing rate increased over time from 61% in 2004 to 70% in 2008. There were 281 chlamydia diagnoses at this service, giving an overall chlamydia positivity rate of 9.3%, significantly higher than the ACCESS Project national rate of 8.2% (OR 1.16, 95% confidence intervals 1.02-1.32).

DISCUSSION

Testing rates were similar and positivity rates for Chlamydia trachomatis were higher in this sexual health service in Sydney than national trends.

Prevention or treatment: the benefits of Trichomonas vaginalis vaccine

Trichomoniasis (infection with Trichomonas vaginalis) is the most common non-viral sexually transmitted disease (STI) in the world. Although treatment is available, most cases occur in developing countries, where accessing healthcare is difficult and facilities are limited. Additionally, infection is often asymptomatic and as such goes untreated, creating reservoirs of T. vaginalis that allow the disease to spread within the community. Because of this there has been little success in controlling the incidence of trichomoniasis, especially amongst the underprivileged. The development of a vaccine against T. vaginalis could reduce the human costs (pregnancy complications, infertility), medical costs (repeated doctor visits, increased susceptibility to human immunodeficiency virus (HIV) infection), and societal costs (stigma of STI, cycles of untreated infection) associated with trichomoniasis.

Metronidazole resistance in Trichomonas vaginalis from highland women in Papua New Guinea

BACKGROUND

The prevalence of the sexually transmissible protozoan parasite Trichomonas vaginalis in the highlands of Papua New Guinea (PNG) has been reported to be as high as 46% and although not previously studied in Papua New Guinea, clinical resistance against metronidazole (Mz), the drug most commonly used to treat trichomoniasis, is well documented worldwide. This study was primarily aimed at assessing resistance to Mz in T. vaginalis strains from the Goroka region.

METHODS

Consenting patients presenting at the Goroka Base Hospital Sexually Transmitted Diseases (STD) Clinic and local women were asked to provide two vaginal swabs: one for culturing of the parasite; and one for polymerase chain reaction detection of T. vaginalis, Chlamydia trachomatis and Neisseria gonorrhoeae. T. vaginalis isolates were assayed for Mz susceptibility and a selection was genotyped.

RESULTS

The prevalence of T. vaginalis was determined to be 32.9% by culture and polymerase chain reaction of swabs among 82 local women and patients from the STD clinic. An unexpectedly high level of in vitro Mz resistance was determined with 17.4% of isolates displaying unexpectedly high resistance to Mz. The ability to identify isolates of T. vaginalis by genotyping was confirmed and the results revealed a more homogeneous T. vaginalis population in Papua New Guinea compared with isolates from elsewhere.

CONCLUSION

T. vaginalis is highly prevalent in the Goroka region and in vitro Mz resistance data suggest that clinical resistance may become an issue.

Neisseria gonorrhoeae infection in urban Sydney women: prevalence and predictors

Background: The notification rate of female gonorrhoea in urban Sydney is very low. With the increasing use of nucleic acid amplification tests (NAAT), demonstrating a low prevalence of gonorrhoea in women would have important implications for the reliability of positive results. We determined the prevalence of female cervical gonorrhoea in our urban sexual health clinic and identified associated clinical, behavioural and demographic variables that may allow more targeted screening practices. Methods: The Sydney Sexual Health Centre database was used to identify women tested for cervical gonorrhoea between 1997 and 2007. Diagnostic, demographic and behavioural information were extracted to ascertain the prevalence of gonorrhoea and describe variables associated with infection. Additionally, a case control study was conducted of cervical gonorrhoea cases from January 2000 to December 2005, with two gonorrhoea negative women selected for each case as controls. A blinded researcher examined each medical record to determine genital symptoms, being a contact of gonorrhoea, sex work, sex outside of Australia, injecting drug use. Results: Between 1997 and 2007, 77 women were diagnosed with cervical gonorrhoea, a prevalence of 0.37%. Results of the case control study reveal that women with gonorrhoea were more likely to be symptomatic [odds ratio (OR) 3.7, 95% confidence interval (CI) 1.7–8.4], be a known contact of gonorrhoea (OR 264, 95% CI 149–470), or have had recent sex overseas, or with a partner from overseas (OR 1.75, 95% CI 1.11–2.75). Conclusion: Cervical gonorrhoea infection is rare in our urban sexual health clinic, and even more unlikely in asymptomatic women without risk factors. This low prevalence of gonorrhoea, particularly in asymptomatic women, decreases the reliability of positive NAAT test results. This has important implications for the screening of asymptomatic women presenting to urban sexual health clinics in Australia.

Temporal associations with declining Trichomonas vaginalis diagnosis rates among women in the state of Victoria, Australia, 1947 to 2005

BACKGROUND

To investigate the temporal associations between Trichomonas vaginalis (TV) diagnoses in women at a large urban sexual health clinic and a major Papanicolaou (Pap) smear screening laboratory in Victoria, Australia with Pap smear screening rates and the introduction of nitroimidazole treatments.

METHODS

An ecological analysis of TV diagnosis rates at the Melbourne Sexual Health Centre and the Victorian Cytology Service, Pap smear screening rates and nitroimidazole prescription data.

RESULTS

Diagnoses of TV at the Melbourne Sexual Health Centre peaked in the 1950s at 20% to 30% and then rapidly declined through the 1960s and 1970s to below 1% in 1990. A similar pattern was observed at the Victorian Cytology Service. Metronidazole prescribing and opportunistic Pap smear screening began in Victoria in the 1960s coinciding with declining TV. The availability of tinidazole in 1976 led to further declines in TV in the late 1970s. A national cervical screening program introduced in 1991 was temporally associated with further declines in TV.

CONCLUSIONS

Our analyses suggest that the introduction of metronidazole was associated with a large reduction in TV among Victorian women in the 1960s. The subsequent availability of tinidazole and increased Pap smear screening may have contributed to the current low TV prevalence in Victoria.

Structural details and composition of Trichomonas vaginalis lipophosphoglycan in relevance to the epithelial immune function

Trichomonas vaginalis causes the most common non-viral sexually transmitted infection linked to increased risk of premature birth, cervical cancer and HIV. This study defines molecular domains of the parasite surface glycoconjugate lipophosphoglycan (LPG) with distinct functions in the host immunoinflammatory response. The ceramide phospho-inositol glycan core (CPI-GC) released by mild acid had Mr of approximately 8,700 Da determined by MALDI-TOF MS. Rha, GlcN, Gal and Xyl and small amounts of GalN and Glc were found in CPI-GC. N-acetyllactosamine repeats were identified by endo-beta-galactosidase treatment followed by MALDI-MS and MS/MS and capLC/ESI-MS/MS analyses. Mild acid hydrolysis led to products rich in internal deoxyhexose residues. The CPI-GC induced chemokine production, NF-kappaB and extracellular signal-regulated kinase (ERK)1/2 activation in human cervicovaginal epithelial cells, but neither the released saccharide components nor the lipid-devoid LPG showed these activities. These results suggest a dominant role for CPI-GC in the pathogenic epithelial response to trichomoniasis.

Global epidemiology and control of Trichomonas vaginalis

PURPOSE OF REVIEW

Trichomonas vaginalis is the most common curable sexually transmitted infection. Despite a number of serious health consequences including facilitation of HIV transmission, pelvic inflammatory disease and adverse outcomes of pregnancy it remains an under-recognized condition. This review aims to update the reader on the global epidemiology and control of T. vaginalis.

RECENT FINDINGS

The burden of T. vaginalis infection is found in resource-limited settings and high-risk groups in industrialized settings. Utilization of polymerase chain reaction-based diagnostics has enhanced our understanding of the epidemiology of T. vaginalis both at the population level and in sexual partners. High rates of asymptomatic infection in male partners of infected females and subsequent re-infection have significant implications for control programmes. Further studies investigating the role of T. vaginalis in facilitating HIV transmission has highlighted its significance and the need to develop and implement control interventions.

SUMMARY

Future research to develop cheap, point-of-care diagnostic tests will allow a greater understanding of T. vaginalis epidemiology. In addition, the effect of treatment on outcome of pregnancy and HIV acquisition requires further study. This will in turn facilitate operational studies evaluating optimal control strategies and their impact on the complications of T. vaginalis.

Sex in Australia: Sexually transmissible infection and blood-borne virus history in a representative sample of adults

OBJECTIVE

To describe the lifetime and recent history of STIs and BBV, including place of seeking treatment, in a representative sample of Australian adults.

METHODS

Computer-assisted telephone interviews were completed by a representative sample of 10,173 men and 9,134 women aged 16-59 years from all States and Territories. The overall response rate was 73.1% (69.4% among men and 77.6% among women).

RESULTS

Overall, 20.2% of men and 16.9% of women had ever been diagnosed with an STI or BBV, and 2.0% and 2.2% respectively had been diagnosed in the past year. The participant's usual general practitioner was the most common location of treatment. Sexual health clinics accounted for a small proportion of treatment locations. Predictors of recent STI or BBV diagnosis in men included homosexual or bisexual identity, a history of sex work as a worker or client, a history of injecting drugs and having more than one partner in the past year. In women, predictors included bisexual identity, history of sex work as a worker, injecting drug use, and having more than one partner in the past year. Around 40% of men and women had been tested for HIV and in homosexually identified men, 77% had been tested.

CONCLUSION

STIs and BBVs are common infections in Australia and care is mostly received from general practitioners. Although a variety of predictors, including homosexual or bisexual identity, injecting drug use and sex work were related to STI diagnosis, STIs were not uncommon among people without these risk factors.

IMPLICATIONS

General practitioners in Australia require a high level of expertise to recognise, offer testing, and manage common STIs and BBVs.

Sex in Australia: The rationale and methods of the Australian Study of Health and Relationships

OBJECTIVE

To describe the methods and process of the Australian Study of Health and Relationships.

METHODS

A computer-assisted telephone interview was developed and applied to a stratified sample of the Australian population. After initially weighting to reflect the study design, the sample was further weighted to reflect the location, age and sex distribution of the 2001 Census.

RESULTS

Interviews were completed with 10,173 men and 9,134 women aged 16-59 years from all states and Territories. The overall response rate was 73.1% (69.4% among men and 77.6% among women). After accounting for the survey design and weighting to the 2001 Census, the sample appears broadly representative of the Australian population.

CONCLUSION

The combination of methods and design in the Australian Study of Health and Relationships, coupled with the high response rate, strongly suggests that the results of the study are robust and broadly representative of the Australian population.

Age-specific prevalence of high-risk human papillomavirus infection in a Hungarian female population with positive cytology

OBJECTIVE

Patients with positive screening results and persistence of high-risk human papillomavirus (HPV) infection represent the population at the highest risk for developing cervical cancer. To describe the epidemiology in this high-risk population, data were collected and analysed at the referral centre for patients with positive cytology.

STUDY DESIGN

Between January 1997 and December 2002 the authors performed 3480 virus identifications using the Digene Hybrid Capture system in a female population with positive cytology at cervical cancer screening. Age-specific prevalence data were evaluated and compared between the age groups by running the chi(2) and Pearson chi(2) tests. Subgroup analysis was performed to estimate monthly clearance rates among eligible women with positive HR-HPV results.

RESULTS

Low-risk (LR), high-risk (HR) and double infections were detected in 91 cases (2.6%), 1072 cases (30.8%) and 59 cases (1.7%), respectively. A significantly higher incidence of high-, rather than low-risk HPV infections was found in all age groups (p<0.001). Also, in this high-risk population with positive screening a significant decrease was detected in the prevalence of both high- and low-risk infections beyond 35 years of age (p<0.001). However, the decline in the HR-HPV types occurred later than in the case of LR infections, and HR-HPV was of remarkable frequency in the older age groups, which might represent both incidental and prevalent cases. Subgroup analysis for estimating monthly clearance rates revealed no significant differences between the various age groups and between women with various cytology results.

CONCLUSIONS

In a population with positive cytology the prevalence of HPV drops with age while the relative frequency of high-risk HPV infection remains at the same level as that of the youngest age group.

Real-time PCRs for detection of Trichomonas vaginalis beta-tubulin and 18S rRNA genes in female genital specimens

Trichomonas vaginalis is the cause of one of the most common types of vaginitis, trichomoniasis. The incidence of trichomoniasis in developed countries has decreased substantially during the past decade, but high prevalence of this disease can still be found in rural and remote areas of Australia. Clinical manifestations of symptomatic women are generally non-specific, but include vaginal discharge, vaginitis and irritation. T. vaginalis infection has also been linked to the increased risk of human immunodeficiency virus transmission. Current diagnosis of T. vaginalis relies on the visualization of motile organisms in a wet-mount preparation. Culture is used mainly in reference laboratories. The latter two methods require viable organisms and would not be suitable for use where transportation of specimens can be delayed. Two real-time fluorescence resonance energy transfer (FRET) hybridization probe PCR assays were used in this study to test for T. vaginalis DNA, targeting the beta-tubulin and 18S rRNA genes. We tested 500 randomly selected female patients, in an STD setting, for T. vaginalis DNA. The FRET PCRs targeting the beta-tubulin gene and the 18S rRNA gene detected 96 % (85/89) and 100 % (89/89) , respectively, of the positive specimens (first-void urine sample or genital swabs). Wet-mount microscopy was performed on 76 of these PCR-positive specimens and showed a sensitivity of 38 % (29/76). The prevalence, by PCR, of trichomoniasis was 18 % in this study. The two real-time PCRs developed in this study, targeting different genetic regions of the organism, provide a rapid, sensitive and specific diagnosis of T. vaginalis infection.

Predicting antitrichomonal activity: A computational screening using atom-based bilinear indices and experimental proofs

Existing Trichomonas vaginalis therapies are out of reach for most trichomoniasis people in developing countries and, where available, they are limited by their toxicity (mainly in pregnant women) and their cost. New antitrichomonal agents are needed to combat emerging metronidazole-resistant trichomoniasis and reduce the side effects associated with currently available drugs. Toward this end, atom-based bilinear indices, a new TOMOCOMD-CARDD molecular descriptor, and linear discriminant analysis (LDA) were used to discover novel, potent, and non-toxic lead trichomonacidal chemicals. Two discriminant functions were obtained with the use of non-stochastic and stochastic atom-type bilinear indices for heteroatoms and H-bonding of heteroatoms. These atomic-level molecular descriptors were calculated using a weighting scheme that includes four atomic labels, namely atomic masses, van der Waals volumes, atomic polarizabilities, and atomic electronegativities in Pauling scale. The obtained LDA-based QSAR models, using non-stochastic and stochastic indices, were able to classify correctly 94.51% (90.63%) and 93.41% (93.75%) of the chemicals in training (test) sets, respectively. They showed large Matthews' correlation coefficients (C); 0.89 (0.79) and 0.87 (0.85), for the training (test) sets, correspondingly. The result of predictions on the 15% full-out cross-validation test also evidenced the robustness and predictive power of the obtained models. In addition, canonical regression analyses corroborated the statistical quality of these models (R(can) of 0.749 and of 0.845, correspondingly); they were also used to compute biological activity canonical scores for each compound. On the other hand, a close inspection of the molecular descriptors included in both equations showed that several of these molecular fingerprints are strongly interrelated with each other. Therefore, these models were orthogonalized using the Randić orthogonalization procedure. These classification functions were then applied to find new lead antitrichomonal agents and six compounds were selected as possible active compounds by computational screening. The designed compounds were synthesized and tested for in vitro activity against T. vaginalis. Out of the six compounds that were designed, and synthesized, three molecules (chemicals VA5-5a, VA5-5c, and VA5-12b) showed high to moderate cytocidal activity at the concentration of 10 microg/ml, other two compounds (VA5-8pre and VA5-8) showed high cytocidal and cytostatic activity at the concentration of 100 microg/ml and 10 microg/ml, correspondingly, and the remaining chemical (compound VA5-5e) was inactive at these assayed concentrations. Nonetheless, these compounds possess structural features not seen in known trichomonacidal compounds and thus can serve as excellent leads for further optimization of antitrichomonal activity. The LDA-based QSAR models presented here can be considered as a computer-assisted system that could potentially significantly reduce the number of synthesized and tested compounds and increase the chance of finding new chemical entities with antitrichomonal activity.

Genotyping Trichomonas vaginalis

A genotyping method has been developed to distinguish each Trichomonas vaginalis isolate and has provided the first genome mapping studies of this protist with an estimated 180Mb genome. The technique was developed using high molecular weight DNA prepared from five laboratory isolates from Australia and USA and 20 clinical isolates from South Africa. Inhibition of the notorious T. vaginalis endogenous nucleases by addition of potent inhibitors was essential to the success of this study. Chromosomal DNA larger than 2.2Mb was macrorestricted to a minimum segment size of approximately 50kb, separated by pulsed field gel electrophoresis and hybridised with a variety of gene probes. Each isolate generated a unique pattern that was distinguished by each of the probes. Four single copy gene probes (fd, hmp35, ibp39 and pfoD) were identified but probes which identified several bands (pfoB and alpha-scs) per isolate were most informative for genotyping. The pyruvate:ferredoxin oxidoreductase B gene probe identified two to seven copies of pfoB (or its closely related homologue pfoA) per genome in different isolates and is an obvious candidate probe to identify epidemiological linkage between infections by this genotyping method. Cleavage of the genomes into smaller fragments failed to distinguish isolates from diverse locations indicating the proximal regions of genes are conserved.

Trichomoniasis and its treatment

Trichomonas vaginalis has long been recognized as a cause of infectious vaginitis in women. More recently, studies have demonstrated a significant burden of disease in men with urethritis or men at high risk for sexually transmitted diseases. There is increasing interest in this pathogen as more data accumulates linking it to HIV transmission and perinatal morbidity. New diagnostic methods have emerged that may increase sensitivity of diagnosis or improve point-of-care access to testing. Nitroimidazoles remain the mainstay of therapy. Metronidazole and tinidazole are highly effective as single-dose therapy. Unfortunately, despite the link between T. vaginalis infection and perinatal morbidity, nitroimidazole therapy during pregnancy remains controversial. Although metronidazole resistance is currently uncommon, pharmacological features and nitroimidazole resistance patterns suggest that tinidazole may be more effective in treating patients with metronidazole treatment failure. Alternatives to nitroimidazole therapy are few, and most have limited efficacy and significant toxicity.

Antiparasitic properties of homoallylamines and related compounds

A study of some antiparasitic properties of several homoallylamines and related tetrahydroquinolines and quinolines, previously described, was carried out using in vitro activity assays against the epimastigote form of Trypanosoma cruzi and against Trichomonas vaginalis. Unspecific cytotoxicity against murine macrophages was also studied. Although the antichagasic and trichomonacidal activities are not comparable to those of the standard drugs, nifurtimox and metronidazole, some of the compounds exhibit an interesting specific antiparasitic activity.

Use of an immunochromatographic assay for rapid detection of Trichomonas vaginalis in vaginal specimens

Trichomonas vaginalis infection is estimated to be the most widely prevalent nonviral sexually transmitted infection in the world. Wet-mount microscopy is the most common diagnostic method, although it is less sensitive than culture. The OSOM Trichomonas Rapid Test (Genzyme Diagnostics, Cambridge, Mass.) (referred to here as OSOM) is a new point-of-care diagnostic assay for T. vaginalis that uses an immunochromatographic capillary flow (dipstick) assay and provides results in 10 min. The purpose of this study was to determine the test characteristics of OSOM compared to those of a composite reference standard (CRS) comprised of wet-mount microscopy and T. vaginalis culture. This multicenter cross-sectional study enrolled sexually active women > or =18 years of age who presented with symptoms of vaginitis, exposure to T. vaginalis, or multiple sexual partners. Vaginal-swab specimens were obtained for T. vaginalis culture, wet mount, and rapid testing. The prevalence of T. vaginalis in this sample was 23.4% (105 of 449) by the CRS. The sensitivity and specificity of OSOM vaginal-swab specimens were 83.3 and 98.8%, respectively, while wet mount had a sensitivity and specificity of 71.4 and 100%, respectively, compared to the CRS. OSOM performed significantly better than wet mount (P = 0.004) and detected T. vaginalis in samples that required 48 to 72 h of incubation prior to becoming culture positive. The performance of the rapid test was not affected by the presence of coinfections with chlamydia and gonorrhea. The OSOM Trichomonas Rapid Test is a simple, objective test that can be expected to improve the diagnosis of T. vaginalis, especially where microscopy and culture are unavailable.

Chlamydia trachomatis infections in Greece: first prevalence study using nucleic acid amplification tests

The present retrospective study was initiated to determine the prevalence of Chlamydia trachomatis and to assess the risk factors for infection in adult women and men presenting to general practitioners, gynecologists, dermatologists, and family-planning centers in Greece. The study was carried out in four different Greek hospital centers using highly sensitive nucleic acid amplification techniques. Altogether, 16,834 women and 1,035 men were enrolled from October 1998 to April 2004. Two types of specimens were collected from each patient: cervical swabs from women, urethral swabs from men, and first-catch urine from women and men. All specimens were examined with the Cobas Amplicor C. trachomatis polymerase chain reaction assay (Roche Molecular Systems, Branchburg, NJ, USA) or the LC x C. trachomatis ligase chain reaction assay (Abbott Laboratories, Abbott Park, IL, USA). Demographic and behavioral data were collected by clinicians using a standardized questionnaire. A total of 704 (3.9%) patients were infected with C. trachomatis. The prevalence among female patients was 3.5% and that among male patients 11.2%. Among infected patients, 88% were under 30 years of age, 71% reported more than one sexual partner, and 91% reported a new sexual partner within the last year. In conclusion, the prevalence of C. trachomatis infection in Greece is low. Young age and new and multiple sexual partners within the last year were factors consistently associated with an increased risk of chlamydial infection.

Genetic typing of the porin protein of Neisseria gonorrhoeae from clinical noncultured samples for strain characterization and identification of mixed gonococcal infections

Molecular methods that characterize the Neisseria gonorrhoeae porin protein Por are needed to study gonococcal pathogenesis in the natural host and to classify strains from direct clinical samples used with nucleic acid amplification-based tests. We have defined the capabilities of por variable region (VR) typing and determined suitable conditions to apply the method to direct clinical specimens. Nested PCR from spiked urine samples detected 1 to 10 copies of template DNA; freezing spiked whole urine greatly reduced the ability to amplify porB. In a laboratory model of mixed gonococcal infections, the por type of one strain could be determined in the presence of a 100-fold excess of another. por VR typing was used to examine clinical samples from women enrolled in studies conducted in Baltimore, Md., and Madagascar. por type was determined from 100% of paired cervical swab and wick samples from 20 culture-positive women from Baltimore; results for eight individuals (40%) suggested infection with more than one strain. In frozen urine samples from Madagascar, porB was amplified and typed from 60 of 126 samples from ligase chain reaction (LCR)-positive women and 3 samples from LCR-negative women. The por VR types of 13 samples (21%) suggested the presence of more than one gonococcal strain. Five por types, identified in >45% of women with typed samples, were common to both geographic areas. Molecular typing is an important adjunct to nucleic acid amplification-based diagnostics. Methods that utilize direct clinical samples and can identify mixed infections may contribute significantly to studies of host immunity, gonococcal epidemiology, and pathogenesis.

Sexually transmitted infections, blood-borne viruses and risk behaviour in an Australian senior high school population—the SHLiRP study

Objectives: To determine the feasibility and acceptability of screening for sexually transmitted infections and blood-borne viruses and to study the profile of sexual activity and other risk behaviours in a senior high school population. Methods: In this descriptive study we provided sexual health education and screening to students from two senior high schools in the Australian Capital Territory. We collected behavioural data using a self-administered questionnaire. Urines and swabs were tested for Chlamydia trachomatis (Ct), Neisseria gonorrhoea (Ng), Trichomonas vaginalis (Tv) and human papilloma virus (HPV). Blood specimens were tested for hepatitis B and C, HIV, herpes simplex viruses (HSV-1 and HSV-2) and syphilis. Results: A total of 795 students participated (31% of the enrolled population; female to male ratio 60 : 40) and 67.0% were sexually active. Of 795 students, 644 (81.0%) were screened. Rates of infection were Ct 1.1% (95% CI: 0.4–2.6), HPV 11.7% (95% CI: 7.4–17.3), HSV-1 32.5% (95% CI: 28.9–36.3), HSV-2 2.4% (95% CI: 1.3–3.9), hepatitis B surface antigen 0.3% (95% CI: 0.04–1.1) and hepatitis C antibodies 0.7% (95% CI: 0.07–1.6). Only 22.3% (95% CI: 19.3–25.7) of students had immunity to hepatitis B. There were no cases of HIV, gonorrhoea, trichomoniasis or syphilis. Of the sexually active students, 49.2% (95% CI: 38.9–59.2%) reported never or only sometimes using condoms, 41.5% (95% CI: 32.2–52.3%) reported unsafe drinking, 33.3% (95% CI: 23.9–43.1%) were smokers and 1.9% (95% CI: 0.2–7.0%) reported injecting drug use. Conclusions: Rates of STI and blood-borne viruses and immunity to hepatitis B were low in this population, but unsafe sex and other risk behaviours were common. We have demonstrated that STI screening, including serological testing, was well accepted in a senior high school population.

The prevalence of genital Chlamydia trachomatis in Australia 1997 - 2004: a systematic review

Objectives: To determine by systematic review the prevalence of genital chlamydial infection in Australia between 1997 and 2004. Methods: Electronic literature databases, reference lists, and conference proceedings were searched and health agencies and jurisdictions were contacted for published and unpublished reports. Studies were eligible if they offered a diagnostic nucleic acid amplification test to consecutive individuals presenting during the study period. As a summary measure of the available data, mean prevalence rates, weighted by sample size and irrespective of participant age, were calculated for the population sub-groups. Results: 40 studies of 50 populations and 40587 individuals met the inclusion criteria, but only one of these was population-based. The use of non-systematic methodologies prevented an assessment of time trends and a statistical comparison of population sub-groups. The mean overall prevalence of genital chlamydial infection was 4.6% (95% CI 4.4–4.8%), reflecting over-sampling of high-risk groups. The mean community-based rates were 7.5% (95% CI 6.4–8.6%) and 8.7% (95% CI 7.9–9.7%) for Indigenous men and women, and 1.5% (95% CI 1.1–1.9%) and 1.4% (95% CI 0.9–2.0%) for non-Indigenous men and women. The overall mean estimates for other groups were 3.3% (95% CI 3.0–3.7%) for female attendees of sexual health and related clinics, 5.6% (95% CI 4.9–6.4%) for adolescents and young adults, 3.3% (95% CI 2.8–3.9%) for sex workers, and 1.6% (95% CI 1.2–2.0%) for urethral infection in men who have sex with men. Clinic-based estimates were generally, although not consistently, higher than community-based estimates. There is no serial population-based data for sexually active young men and women, but the available age-specific rates suggest under-ascertainment by the routine surveillance systems. Conclusions: The prevalence of genital chlamydial infection in Indigenous Australians and young adults is unacceptably high and quality epidemiological studies are urgently required to supplement the routinely collected national notification data.