The evolving epidemiology of chlamydial and gonococcal infections in response to control programs in Winnipeg, Canada

Reproductive system infections in women: lower genital tract syndromes

Gynecological and obstetrical infectious diseases are an important component of women's health. A system approach to gynecological and obstetrical infection helps unify and classify microbial etiology and pathogenesis within a clinical anatomical framework of lower and upper genital tract syndromes. The reproductive system of women includes the vulva, vagina, cervix, uterus, fallopian tubes and ovaries. During pregnancy, additional tissues include the chorioamnion and placenta together with the fetus and amniotic fluid. We review in two parts reproductive system infection syndromes in women using selected research results to illustrate the clinical utility of the system approach in terms of diagnosis, treatment and prevention. We conclude that a reproductive system perspective will lead to improvements in understanding, management and prevention of these diseases.

Antibiotic therapy for pelvic inflammatory disease

BACKGROUND

Pelvic inflammatory disease (PID) affects 4% to 12% of women of reproductive age. The main intervention for acute PID is broad-spectrum antibiotics administered intravenously, intramuscularly or orally. We assessed the optimal treatment regimen for PID.  OBJECTIVES: To assess the effectiveness and safety of antibiotic regimens to treat PID.

SEARCH METHODS

In January 2020, we searched the Cochrane Sexually Transmitted Infections Review Group's Specialized Register, which included randomized controlled trials (RCTs) from 1944 to 2020, located through hand and electronic searching; CENTRAL; MEDLINE; Embase; four other databases; and abstracts in selected publications.

SELECTION CRITERIA

We included RCTs comparing antibiotics with placebo or other antibiotics for the treatment of PID in women of reproductive age, either as inpatient or outpatient treatment. We limited our review to a comparison of drugs in current use that are recommended by the 2015 US Centers for Disease Control and Prevention guidelines for treatment of PID.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Two authors independently extracted data, assessed risk of bias and conducted GRADE assessments of the quality of evidence.

MAIN RESULTS

We included 39 RCTs (6894 women) in this review, adding two new RCTs at this update. The quality of the evidence ranged from very low to high, the main limitations being serious risk of bias (due to poor reporting of study methods and lack of blinding), serious inconsistency, and serious imprecision. None of the studies reported quinolones and cephalosporins, or the outcomes laparoscopic evidence of resolution of PID based on physician opinion or fertility outcomes. Length of stay results were insufficiently reported for analysis. Regimens containing azithromycin versus regimens containing doxycycline We are uncertain whether there was a clinically relevant difference between azithromycin and doxycycline in rates of cure for mild-moderate PID (RR 1.18, 95% CI 0.89 to 1.55; 2 RCTs, 243 women; I² = 72%; very low-quality evidence). The analyses may result in little or no difference between azithromycin and doxycycline in rates of severe PID (RR 1.00, 95% CI 0.96 to 1.05; 1 RCT, 309 women; low-quality evidence), or adverse effects leading to discontinuation of treatment (RR 0.71, 95% CI 0.38 to 1.34; 3 RCTs, 552 women; I² = 0%; low-quality evidence). In a sensitivity analysis limited to a single study at low risk of bias, azithromycin probably improves the rates of cure in mild-moderate PID (RR 1.35, 95% CI 1.10 to 1.67; 133 women; moderate-quality evidence), compared to doxycycline.  Regimens containing quinolone versus regimens containing cephalosporin The analysis shows there may be little or no clinically relevant difference between quinolones and cephalosporins in rates of cure for mild-moderate PID (RR 1.05, 95% CI 0.98 to 1.14; 4 RCTs, 772 women; I² = 15%; low-quality evidence), or severe PID (RR 1.06, 95% CI 0.91 to 1.23; 2 RCTs, 313 women; I² = 7%; low-quality evidence). We are uncertain whether there was a difference between quinolones and cephalosporins in adverse effects leading to discontinuation of treatment (RR 2.24, 95% CI 0.52 to 9.72; 6 RCTs, 1085 women; I² =  0%; very low-quality evidence). Regimens with nitroimidazole versus regimens without nitroimidazole There was probably little or no difference between regimens with or without nitroimidazoles (metronidazole) in rates of cure for mild-moderate PID (RR 1.02, 95% CI 0.95 to 1.09; 6 RCTs, 2660 women; I² = 50%; moderate-quality evidence), or severe PID (RR 0.96, 95% CI 0.92 to 1.01; 11 RCTs, 1383 women; I² = 0%; moderate-quality evidence). The evidence suggests that there was little to no difference in in adverse effects leading to discontinuation of treatment (RR 1.05, 95% CI 0.69 to 1.61; 17 studies, 4021 women; I² = 0%; low-quality evidence). . In a sensitivity analysis limited to studies at low risk of bias, there was little or no difference for rates of cure in mild-moderate PID (RR 1.05, 95% CI 1.00 to 1.12; 3 RCTs, 1434 women; I² = 0%; high-quality evidence). Regimens containing clindamycin plus aminoglycoside versus quinolone We are uncertain whether quinolone have little to no effect in  rates of cure for mild-moderate PID compared to clindamycin plus aminoglycoside (RR 0.88, 95% CI 0.69 to 1.13; 1 RCT, 25 women; very low-quality evidence). The analysis may result in little or no difference between quinolone vs. clindamycin plus aminoglycoside in severe PID (RR 1.02, 95% CI 0.87 to 1.19; 2 studies, 151 women; I² =  0%; low-quality evidence). We are uncertain whether quinolone reduces adverse effects leading to discontinuation of treatment (RR 0.21, 95% CI 0.02 to 1.72; 3 RCTs, 163 women; I² =  0%; very low-quality evidence). Regimens containing clindamycin plus aminoglycoside versus regimens containing cephalosporin We are uncertain whether clindamycin plus aminoglycoside improves the rates of cure for mild-moderate PID compared to cephalosporin (RR 1.02, 95% CI 0.95 to 1.09; 2 RCTs, 150 women; I² =  0%; low-quality evidence). There was probably little or no difference in rates of cure in severe PID with clindamycin plus aminoglycoside compared to cephalosporin (RR 1.00, 95% CI 0.95 to 1.06; 10 RCTs, 959 women; I²= 21%; moderate-quality evidence). We are uncertain whether clindamycin plus aminoglycoside reduces adverse effects leading to discontinuation of treatment compared to cephalosporin (RR 0.78, 95% CI 0.18 to 3.42; 10 RCTs, 1172 women; I² =  0%; very low-quality evidence).

AUTHORS' CONCLUSIONS

We are uncertain whether one treatment was safer or more effective than any other for the cure of mild-moderate or severe PID Based on a single study at a low risk of bias, a macrolide (azithromycin) probably improves the rates of cure of mild-moderate PID, compared to tetracycline (doxycycline).

Laboratory Detection of First and Repeat Chlamydia Cases Influenced by Testing Patterns: A Population-Based Study

Objectives:

The purpose of this study was to describe and explore potential driving factors of trends in reported chlamydia infections over time in Manitoba, Canada.

Methods:

Surveillance and laboratory testing data from Manitoba Health, Seniors and Active Living were analysed using SAS v9.4. Kaplan-Meier plots of time from the first to second chlamydia infection were constructed, and Cox proportional hazards regression was used to estimate the risk of second repeat chlamydia infections in males and females.

Results:

Overall, the number of reported infections found mirrored the number of tests conducted. From 2008 to 2014, the number of first infections found among females decreased as the number of first tests conducted among females also decreased. Between 2008 and 2012, the number of repeat tests among females increased and was accompanied by an increase in the number of repeat positive results from 2009 to 2013. From 2008 to 2016, the number of repeat tests and repeat positive results increased steadily among males.

Conclusions:

Chlamydia infection rates consistently included a subset composed of repeat infections. The number of cases identified appears to mirror testing volumes, drawing into question incidence calculations that do not include testing volumes.

Summary Box:

1) What is the current understanding of this subject? Chlamydia incidence is high in Manitoba, particularly among young women and in northern Manitoba.

2) What does this report add to the literature? This report suggests that incidence calculated using case-based surveillance data alone does not provide an accurate estimate of chlamydia incidence in Manitoba and is heavily influenced by testing patterns.

3) What are the implications for public health practice? In general, improving testing rates in clinical practices as well as through the provision of rapid services in non-clinical venues could result in higher screening and treatment rates. In turn, this could lead to a better understanding of true disease occurrence.

Antibiotic therapy for pelvic inflammatory disease: an abridged version of a Cochrane systematic review and meta-analysis of randomised controlled trials

OBJECTIVE

To assess the effectiveness and safety of antibiotic regimens used to treat pelvic inflammatory disease (PID).

DESIGN

This is a systematic review and meta-analysis of randomised controlled trials (RCTs). Risk of bias was assessed using the criteria outlined in the Cochrane guidelines. Quality of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation.

DATA SOURCES

Eight electronic databases were searched from date of inception up to July 2016. Database searches were complemented by screening of reference lists of relevant studies, trial registers, conference proceeding abstracts and grey literature.

ELIGIBILITY CRITERIA

RCTs comparing the use of antibiotics with placebo or other antibiotics for the treatment of PID in women of reproductive age, either as inpatient or outpatient treatment.

RESULTS

We included 37 RCTs (6348 women). The quality of evidence ranged from very low to high, the main limitations being serious risk of bias (due to poor reporting of study methods and lack of blinding), serious inconsistency and serious imprecision. There was no clear evidence of a difference in the rates of cure for mild-moderate or for severe PID for the comparisons of azithromycin versus doxycycline, quinolone versus cephalosporin, nitroimidazole versus no use of nitroimidazole, clindamycin plus aminoglycoside versus quinolone, or clindamycin plus aminoglycoside versus cephalosporin. No clear evidence of a difference between regimens in antibiotic-related adverse events leading to discontinuation of therapy was observed.

CONCLUSIONS

We found no conclusive evidence that one regimen of antibiotics was safer or more effective than any other for the treatment of PID, and there was no clear evidence for the use of nitroimidazoles (metronidazole) compared with the use of other drugs with activity against anaerobes. More evidence is needed to assess treatments for women with PID, particularly comparing regimens with or without the addition of nitroimidazoles and the efficacy of azithromycin compared with doxycycline.

Antibiotic therapy for pelvic inflammatory disease

BACKGROUND

Pelvic inflammatory disease (PID) is an infection that affects 4% to 12% of young women, and is one of the most common causes of morbidity in this age group. The main intervention for acute PID is the use of broad-spectrum antibiotics which cover Chlamydia trachomatis, Neisseria gonorrhoeae, and anaerobic bacteria, administered intravenously, intramuscularly, or orally. In this review, we assessed the optimal treatment regimen for PID.

OBJECTIVES

To assess the effectiveness and safety of antibiotic regimens used to treat pelvic inflammatory disease.

SEARCH METHODS

We searched the Cochrane Sexually Transmitted Infections Review Group's Specialized Register, which included randomized controlled trials (RCTs) from 1944 to 2016, located through electronic searching and handsearching; the Cochrane Central Register of Controlled Trials (CENTRAL), Ovid platform (1991 to July 2016); MEDLINE (1946 to July 2016); Embase (1947 to July 2016); LILACS, iAHx interface (1982 to July 2016); World Health Organization International Clinical Trials Registry Platform (July 2016); Web of Science (2001 to July 2016); OpenGrey (1990, 1992, 1995, 1996, and 1997); and abstracts in selected publications.

SELECTION CRITERIA

We included RCTs comparing the use of antibiotics with placebo or other antibiotics for the treatment of PID in women of reproductive age, either as inpatient or outpatient treatment. We limited our review to comparison of drugs in current use that are recommended for consideration by the 2015 US Centers for Disease Control and Prevention (CDC) guidelines for treatment of PID.

DATA COLLECTION AND ANALYSIS

At least two review authors independently selected trials for inclusion, extracted data, and assessed risk of bias. We contacted investigators to obtain missing information. We resolved disagreements by consensus or by consulting a fourth review author if necessary. We assessed the quality of the evidence using GRADE criteria, classifying it as high, moderate, low, or very low. We calculated Mantel-Haenszel risk ratios (RR), using either random-effects or fixed-effect models and number needed to treat for an additional beneficial outcome or for an additional harmful outcome, with their 95% confidence interval (CI), to measure the effect of the treatments. We conducted sensitivity analyses limited to studies at low risk of bias, for comparisons where such studies were available.

MAIN RESULTS

We included 37 RCTs (6348 women). The quality of the evidence ranged from very low to high, the main limitations being serious risk of bias (due to poor reporting of study methods and lack of blinding), serious inconsistency, and serious imprecision. Azithromycin versus doxycyclineThere was no clear evidence of a difference between the two drugs in rates of cure for mild-moderate PID (RR 1.18, 95% CI 0.89 to 1.55, I² = 72%, 2 RCTs, 243 women, very low-quality evidence), severe PID (RR 1.00, 95% CI 0.96 to 1.05, 1 RCT, 309 women, low-quality evidence), or adverse effects leading to discontinuation of treatment (RR 0.71, 95% CI 0.38 to 1.34, 3 RCTs, 552 women, I² = 0%, low-quality evidence). In a sensitivity analysis limited to a single study at low risk of bias, azithromycin was superior to doxycycline in achieving cure in mild-moderate PID (RR 1.35, 95% CI 1.10 to 1.67, 133 women, moderate-quality evidence). Quinolone versus cephalosporinThere was no clear evidence of a difference between the two drugs in rates of cure for mild-moderate PID (RR 1.04, 95% CI 0.98 to 1.10, 3 RCTs, 459 women, I² = 5%, low-quality evidence), severe PID (RR 1.06, 95% CI 0.91 to 1.23, 2 RCTs, 313 women, I² = 7%, low-quality evidence), or adverse effects leading to discontinuation of treatment (RR 2.24, 95% CI 0.52 to 9.72, 5 RCTs, 772 women, I² = 0%, very low-quality evidence). Nitroimidazole versus no use of nitroimidazoleThere was no conclusive evidence of a difference between the nitroimidazoles (metronidazole) group and the group receiving other drugs with activity over anaerobes (e.g. amoxicillin-clavulanate) in rates of cure for mild-moderate PID (RR 1.01, 95% CI 0.93 to 1.10, 5 RCTs, 2427 women, I² = 60%, moderate-quality evidence), severe PID (RR 0.96, 95% CI 0.92 to 1.01, 11 RCTs, 1383 women, I² = 0%, moderate-quality evidence), or adverse effects leading to discontinuation of treatment (RR 1.00, 95% CI 0.63 to 1.59; participants = 3788; studies = 16; I² = 0% , low-quality evidence). In a sensitivity analysis limited to studies at low risk of bias, findings did not differ substantially from the main analysis (RR 1.06, 95% CI 0.98 to 1.15, 2 RCTs, 1201 women, I² = 32%, high-quality evidence). Clindamycin plus aminoglycoside versus quinoloneThere was no evidence of a difference between the two groups in rates of cure for mild-moderate PID (RR 0.88, 95% CI 0.69 to 1.13, 1 RCT, 25 women, very low-quality evidence), severe PID (RR 1.02, 95% CI 0.87 to 1.19, 2 studies, 151 women, I² = 0%, low-quality evidence), or adverse effects leading to discontinuation of treatment (RR 0.21, 95% CI 0.02 to 1.72, 3 RCTs, 163 women, very low-quality evidence). Clindamycin plus aminoglycoside versus cephalosporinThere was no clear evidence of a difference between the two groups in rates of cure for mild-moderate PID (RR 1.02, 95% CI 0.95 to 1.09, 2 RCTs, 150 women, I² = 0%, low-quality evidence), severe PID (RR 1.00, 95% CI 0.95 to 1.06, 10 RCTs, 959 women, I² = 21%, moderate-quality evidence), or adverse effects leading to discontinuation of treatment (RR 0.78, 95% CI 0.18 to 3.42, 10 RCTs, 1172 women, I² = 0%, very low-quality evidence).

AUTHORS' CONCLUSIONS

We found no conclusive evidence that one regimen of antibiotics was safer or more effective than any other for the cure of PID, and there was no clear evidence for the use of nitroimidazoles (metronidazole) compared to use of other drugs with activity over anaerobes. Moderate-quality evidence from a single study at low risk of bias suggested that a macrolide (azithromycin) may be more effective than a tetracycline (doxycycline) for curing mild-moderate PID. Our review considered only the drugs that are currently used and mentioned by the CDC.

Examining Chlamydia trachomatis and Neisseria gonorrhoeae rates between 2010 and 2015: a population-based observational study

Bacterial sexually transmitted infections including Chlamydia trachomatis and Neisseria gonorrhoeae remain an important public health concern. We aimed to assess the population-based incidence of C. trachomatis and N. gonorrhoeae in an age-standardized cohort over time. A retrospective study of a large Canadian health region was undertaken between 2010 and 2015 using linked census and digital laboratory data. C. trachomatis and N. gonorrhoeae tests were linked to patient data. Sex and age-standardized incidence rates (IR) and ratios (IRR) were calculated for cases and testing rates. The annual mean population was 1,150,556 individuals (50.1% female). A total of 15,109 cases of chlamydia and 981 cases of gonorrhoea occurred. The overall IR for chlamydia ranged from 18.81 to 25.63 cases per 10,000 person-years. The IRR was 1.27 (95% CI 1.20-1.34, p < 0.001) for the comparison of 2015 and 2010 rates. For gonorrhoea, overall rates ranged from 0.92 to 1.86 cases per 10,000 person-years. The IRR for gonorrhoea was 2.02 (95% CI 1.56-2.59, p < 0.001) for 2015 and 2010 rates. In our large population-based study spanning six years, we observed increasing rates of C. trachomatis and N. gonorrhoeae with low testing rates.

A review of antibiotic therapy for pelvic inflammatory disease

Pelvic inflammatory disease (PID) is a gynaecological inflammatory disorder with a high incidence that can lead to sequelae such as infertility, ectopic pregnancy and chronic pelvic pain. The International Union against Sexually Transmitted Infections (IUSTI) and the US Centers for Disease Control and Prevention (CDC) have issued treatment recommendations for the management of PID. The purpose of this review is to summarise the available evidence for the use of IUSTI- and CDC-recommended antibiotic therapies for PID. The main differences between recommendations concern alternative regimens for inpatient treatment and the use of oral moxifloxacin as an alternative outpatient regimen in the IUSTI guidelines. There is evidence supporting the use of the recommended antibiotic regimens, although with some variation in reported cure rates. This variation can be explained, in part, by the different diagnostic and evaluation criteria used in different trials. Adverse events that require discontinuation of antibiotic therapy are rarely observed. The main limitation of the current available evidence is the short-term follow-up, which does not allow full evaluation of the risks of long-term sequelae.

Incorporating geospatial capacity within clinical data systems to address social determinants of health

Linking electronic health record (EHR) systems with community information systems (CIS) holds great promise for addressing inequities in social determinants of health (SDH). While EHRs are rich in location-specific data that allow us to uncover geographic inequities in health outcomes, CIS are rich in data that allow us to describe community-level characteristics relating to health. When meaningfully integrated, these data systems enable clinicians, researchers, and public health professionals to actively address the social etiologies of health disparities.This article describes a process for exploring SDH by geocoding and integrating EHR data with a comprehensive CIS covering a large metropolitan area. Because the systems were initially designed for different purposes and had different teams of experts involved in their development, integrating them presents challenges that require multidisciplinary expertise in informatics, geography, public health, and medicine. We identify these challenges and the means of addressing them and discuss the significance of the project as a model for similar projects.

Mapping the core: chlamydia and gonorrhea infections in Calgary, Alberta

OBJECTIVES

To examine the spatial patterning of the individuals with gonorrhea or chlamydia infection in the Calgary Health Region (CHR) to target prevention and control activities.

METHODS

A Geographic Information System was used to map the prevalence rates of gonorrhea and chlamydia infection in the CHR to 2001 Census Tracts in the CHR. Data from the 2001 Canadian Census were used to describe the socioeconomic status (SES) of these areas.

RESULTS

Low SES indicators correlated with each other (low median household income, lower education, single mothers) as did high SES indicators (married, owning a dwelling, high median income, university education). A correlation was detected between areas of low SES and areas of high prevalence rates for gonorrhea and for chlamydia. These areas clustered primarily downtown and in the northeast part of the city.

CONCLUSIONS

Nodes and corridors of activity in Calgary were detected in correlation studies of the 2001 Census variables used. The core (high prevalence) areas should be the areas targeted for sexually transmitted infection prevention and control. This can be done at the community level through measures such as more sexually transmitted infection clinics operating with longer hours in areas identified from this mapping.

Geospatial methods for identification of core groups for HIV/AIDS

OBJECTIVES

Disease transmission dynamics among members of a sexual network's core group make the group an ideal target for prevention for positives. Identifying the geographic territory of an HIV/AIDS core group is complicated by the numerous factors that may spatially structure cases including alcohol availability. We employ spatial analytic methods in an attempt to identify the geographic distribution of the core HIV/AIDS group.

METHODS

Five year HIV/AIDS detection rates were analyzed for each HIV/AIDS risk category (i.e., MSM, IDU, HRH) at the census tract level (n = 164) in New Orleans using spatial analytic techniques in multivariate models.

RESULTS

MSM was the most common risk category for newly detected HIV cases. Both MSM and IDU cases appeared to decline or enter an endemic phase. Each risk category exhibited unique spatial structure. Among IDUs and HRHs nearly all the spatial structure was explained in terms of the independent variables. However, among MSMs residual spatial structure remained after controlling for independent variables.

CONCLUSIONS

Residual spatial structure in the MSM HIV/AIDS detection rates after controlling for social structure could be explained by the presence of core group members. The study's limitations are noted.

Socio-economic factors and adolescent sexual activity and behaviour in Nova Scotia

PURPOSE

Little is known about associations of adolescents' socio-economic status (SES) and their sexual activity and risk behaviours. This study examined these associations in Nova Scotia adolescents aged 15-19.

METHODS

Students at four high schools in northern Nova Scotia completed surveys examining relationships of family SES factors and: 1) sexual activity (having had vaginal or anal intercourse, intercourse before age 15 (early intercourse)); and 2) risk behaviours (use of contraception/condoms, number of partners and unplanned intercourse after substance use).

RESULTS

Of students present when the survey was administered, 2,135 (91%) responded. Almost half (49%) had had vaginal intercourse, and 7% anal intercourse. In univariate analysis for young women, non-intact family structure and lower parental education were associated with having vaginal, anal and early intercourse. Female risk behaviours showed no significant univariate associations with SES. Young men had univariate associations of family structure, lower maternal education and paternal unemployment with early intercourse, and lower paternal education with anal intercourse. Condom use was higher for young men with employed fathers; those living with both parents less often had >1 sexual partner. In multivariate analysis, most SES associations with females' sexual activities held, while most for males did not, and few associations of SES and risk behaviours were seen for females.

CONCLUSIONS

Indicators of lower SES are associated with sexual activity in young women. Sexual risk behaviours are not often associated with SES in females, though they are more so in males. These findings have implications for sexual health promotion and health services.

Prognostic relevance of census-derived individual respondent incomes versus household incomes

BACKGROUND

Census-based measures of income derived from median income of a geographic area are often used in health research. Many national census surveys gather information on both the respondent's individual income and the income for the entire household, giving researchers a choice of census income measures. We compared the extent to which individual respondent income and household income (both obtained from census data) are associated with outcomes in a cohort of patients with cardiac disease.

METHODS

We used data from the Alberta Provincial Project for Outcome Assessment in Coronary Heart Disease (APPROACH), where postal codes were linked to the Postal Code Conversion File (PCCF) to determine each patient's census Dissemination Areas (DA). DA-derived median household income and median individual income were obtained from the 2001 Canadian Census and survival outcomes were then directly determined for income groupings defined by quintile. Two-year survival adjusted for age and sex was described with a proportional hazards analysis.

RESULTS

There were 9,397 patients undergoing cardiac catheterization between January 1, 2001 and March 31, 2002, with complete DA-level median income measures. Household income quintiles yielded a wider spread of survival across quintiles (range of 2-year estimated survival, 91.8% to 95.9% for household income versus 92.8% to 95.6% for respondent income), as well as a more progressive decline in survival as income decreased. This progressive decline was not seen for the respondent income measure.

CONCLUSIONS

The greater spread and progressive decline of survival for household income relative to respondent income leads us to conclude that household income is the better socio-economic determinant of health in our data and for the outcome measure we studied.

Prognostic relevance of census-derived individual respondent incomes versus household incomes

BACKGROUND

Census-based measures of income derived from median income of a geographic area are often used in health research. Many national census surveys gather information on both the respondent's individual income and the income for the entire household, giving researchers a choice of census income measures. We compared the extent to which individual respondent income and household income (both obtained from census data) are associated with outcomes in a cohort of patients with cardiac disease.

METHODS

We used data from the Alberta Provincial Project for Outcome Assessment in Coronary Heart Disease (APPROACH), where postal codes were linked to the Postal Code Conversion File (PCCF) to determine each patient's census Dissemination Areas (DA). DA-derived median household income and median individual income were obtained from the 2001 Canadian Census and survival outcomes were then directly determined for income groupings defined by quintile. Two-year survival adjusted for age and sex was described with a proportional hazards analysis.

RESULTS

There were 9,397 patients undergoing cardiac catheterization between January 1, 2001 and March 31, 2002, with complete DA-level median income measures. Household income quintiles yielded a wider spread of survival across quintiles (range of 2-year estimated survival, 91.8% to 95.9% for household income versus 92.8% to 95.6% for respondent income), as well as a more progressive decline in survival as income decreased. This progressive decline was not seen for the respondent income measure.

CONCLUSIONS

The greater spread and progressive decline of survival for household income relative to respondent income leads us to conclude that household income is the better socio-economic determinant of health in our data and for the outcome measure we studied.

Sexually transmitted disease thresholds in Manitoba, Canada

PURPOSE

Persistence of sexually transmitted infections (STI) in a population is due to the activities of a small proportion of the population with STI, who transmit infection on average to one or more susceptible sex partners during an infectious period. Within these groups, the average number of transmissions by infectious people to susceptible people in a closed group is measured by the reproductive number; a threshold, above which endemic infection is likely occur and below which, in the rest of the population, it is unlikely to occur. We hypothesized that people with repeated bacterial STI's and their sex partners include the theoretical core group and that they differ from singly infected noncore individuals.

METHODS

Data on infected individuals and nominated sex partners for the years 1990-1992 were extracted from the notifiable disease and health insurance registries in Manitoba, Canada. Individuals with repeated gonorrhea, chlamydia and coinfected infections were compared using logistic regression, and reproductive numbers were calculated using sex partner data.

RESULTS

Of the three groups, the coinfected were youngest, and they were largely of aboriginal descent and had the lowest incomes. Repeaters were older; they had higher incomes, and there were fewer aboriginal people in this group. Chlamydia repeaters had even higher incomes, and this group comprised the least number of aboriginal people. The reproductive numbers showed the same gradient; (1.09, 1.01, and 2.41, respectively.)

CONCLUSIONS

These data show that these groups do not contribute equally to STI endemicity and indicate that sexual network structure affects epidemic thresholds.

Socio-economic factors and adolescent sexual activity and behaviour in Nova Scotia

PURPOSE

Little is known about associations of adolescents' socio-economic status (SES) and their sexual activity and risk behaviours. This study examined these associations in Nova Scotia adolescents aged 15-19.

METHODS

Students at four high schools in northern Nova Scotia completed surveys examining relationships of family SES factors and: 1) sexual activity (having had vaginal or anal intercourse, intercourse before age 15 (early intercourse)); and 2) risk behaviours (use of contraception/condoms, number of partners and unplanned intercourse after substance use).

RESULTS

Of students present when the survey was administered, 2,135 (91%) responded. Almost half (49%) had had vaginal intercourse, and 7% anal intercourse. In univariate analysis for young women, non-intact family structure and lower parental education were associated with having vaginal, anal and early intercourse. Female risk behaviours showed no significant univariate associations with SES. Young men had univariate associations of family structure, lower maternal education and paternal unemployment with early intercourse, and lower paternal education with anal intercourse. Condom use was higher for young men with employed fathers; those living with both parents less often had >1 sexual partner. In multivariate analysis, most SES associations with females' sexual activities held, while most for males did not, and few associations of SES and risk behaviours were seen for females.

CONCLUSIONS

Indicators of lower SES are associated with sexual activity in young women. Sexual risk behaviours are not often associated with SES in females, though they are more so in males. These findings have implications for sexual health promotion and health services.

Comparative geographic concentrations of 4 sexually transmitted infections

OBJECTIVES

We measured and compared the concentration of primary and secondary syphilis, gonorrhea, chlamydial infection, and genital herpes in a large county with urban, suburban, and rural settings.

METHODS

We geocoded sexually transmitted infections reported to King County, Washington health department in 2000-2001 to census tract of residence. We used a model-based approach to measure concentration with Lorenz curves and Gini coefficients.

RESULTS

Syphilis exhibited the highest level of concentration (estimated Gini coefficient = 0.68, 95% confidence interval [CI] = 0.64, 0.78), followed by gonorrhea (estimated Gini coefficient=0.57; 95% CI=0.54, 0.60), chlamydial infection (estimated Gini coefficient = 0.45; 95% CI = 0.40, 0.43), and herpes (estimated Gini coefficient=0.26; 95% CI=0.22, 0.29).

CONCLUSIONS

Geographically targeted interventions may be most appropriate for syphilis and gonorrhea. For less-concentrated infections, control strategies must reach a wider portion of the population.

The interrelation of demographic and geospatial risk factors between four common sexually transmitted diseases

OBJECTIVES

To examine the interrelation between demographic and geospatial risk factors for gonorrhoea, chlamydia, genital warts, and genital herpes.

DESIGN

We analysed age, sex, ethnicity, socioeconomic status, and area of residence for Leeds residents aged 15-54 with Neisseria gonorrhoeae, genital Chlamydia trachomatis, first episode genital herpes, and first episode genital warts during 1994-5. The 1991 UK census provided denominator population information.

RESULTS

Regression analysis showed that young age (15-24 years), ethnicity (with a gradient of risk black >white >Asian), and residence in inner city areas of deprivation were independent risk factors for all STDs. There were highly significant correlations in the geospatial distribution of incidence rates between the four infections. However, there was variation in the degree of central urban clustering, with gonorrhoea having the most restricted, and genital warts and chlamydia the widest distribution. 31% of all disease occurred in the four inner city census wards, representing 15% of the population.

CONCLUSION

These results are in keeping with core group theory applying in a unified manner to the four most common UK sexually transmitted diseases in this urban area. Population based studies are needed to clarify whether ethnicity is associated with differing sexual behavioural or mixing patterns. Our data suggest that chlamydia screening in women <25 years of age could detect 70% of cases in the community, that such programmes should give particular emphasis to implementation in core group areas, and that they could function as unifying strategies for the control of most common STDs within urban areas.

Surveillance for Repeat Gonorrhea Infection, San Diego, California, 1995???2001

BACKGROUND

Persons with repeat gonorrhea (GC) infection often participate in sexual networks that maintain and spread GC throughout the community. However, there are no established methods for collecting repeat GC surveillance data that are needed to monitor trends and risk factors for repeat infection.

GOAL

The goal of this study was to evaluate definitions and methods for establishing surveillance for repeat gonorrhea infection.

STUDY DESIGN

During a 7-year period (1995-2001), all reported GC cases in San Diego County, California, were reviewed to identify persons with >2 GC infections that occurred >30 but <365 days apart. Various matching criteria and definitions of repeat infection were evaluated.

RESULTS

Overall, 12,287 GC infections were reported; 509 persons accounted for 551 episodes of repeat infection and 9.7% of all GC infections. The mean annual repeat GC case rate was 2.8 per 100,000 population (range, 1.5-4.1) and repeat cases were 4.5% of total GC (range, 2.7-5.5%). Temporal trends in both repeat measures mirrored the overall county reported GC case rate. Young, inner-city males were more likely to have reported repeat GC infection.

CONCLUSION

Simple, uniform repeat GC measures can be used to establish a surveillance system for monitoring trends, risk factors, and the impact of interventions directed toward preventing repeat GC infections.

Outbreak of Neisseria gonorrhoeae in Northern Alberta, Canada

BACKGROUND

In January 2001 we investigated an outbreak of Neisseria gonorrhoeae in a northern region of Alberta, Canada, and here we report on the epidemiology of the outbreak.

GOAL

The goal was to examine the outbreak etiology and make recommendations for strengthening regional STD programs.

STUDY DESIGN

Provincial STD notification forms were reviewed to identify cases, and a case-control study was undertaken to identify risk factors for infection.

RESULTS

Gonorrhea was reported among 81 individuals, aged 15 to 60 years, between January 1999 and March 2001 in 8 neighboring communities. Attendance at a public bar in one community was associated with infection (P < 0.01). Cases were predominantly Aboriginal (96.3%) and aged less than 30 years (77.6%), and at least 39% of cases reported multiple sex partners. Casual partnering and extended sexual networks are believed to have influenced the spread of infection.

CONCLUSION

This study emphasizes the importance of site-specific health interventions to effectively target at-risk individuals at high-risk locations, with preventive measures aimed at members of high-risk sexual networks. Effective interventions must ensure the availability of and access to appropriate health services for all residents of northern regions in Alberta.

Risk factors for genital chlamydial infection

OBJECTIVE

To discuss the occurrence of genital chlamydia in developed countries and review the literature assessing the potential risk factors for this sexually transmitted disease.

DATA SOURCES

A MEDLINE search was performed for all English citations from 1985 to 2000 that contain the keywords "Chlamydia trachomatis", "chlamydial infections", "risk factors" and "sex behaviour". All relevant references cited in articles that were obtained from the search were also included.

DATA EXTRACTION

ALL ARTICLES OBTAINED FROM THE ABOVE SOURCES WERE EXAMINED, AND WERE INCLUDED IN THE REVIEW IF THEY MET THE FOLLOWING CRITERIA: primary study examining sociodemographic or behavioural risk factors associated with genital chlamydial infection using multivariate analysis; study subjects 12 years of age and older; and study setting in a developed country.

DATA SYNTHESIS AND CONCLUSIONS

Genital chlamydial infection has become the most commonly reported bacterial infection in North America over the past decade. Thirty-eight cross-sectional studies and six cohort studies were included in the present review. Most studies demonstrated that young men and women are at higher risk of being infected with chlamydia than older subjects. Chlamydia seems to be found in a diverse group of people, and unlike gonorrhea, is not concentrated in low income, minority core groups with high rates of partner change. However, a number of studies have shown that communities with well-established control programs are beginning to demonstrate this pattern. There is no clear evidence that chlamydia is associated with type of partners, contraceptive use, or age at first intercourse. Future research should follow this sexually transmitted disease as it evolves through the epidemiological stages to ensure that preventive and treatment services are reaching those people who are most likely to be infected.

Sexual networks and sexually transmitted infections: a tale of two cities

Research on risk behaviors for sexually transmitted infections (STIs) has revealed that they seldom correspond with actual risk of infection. Core groups of people with high-risk behavior who form networks of people linked by sexual contact are essential for STI transmission, but have been overlooked in epidemiological studies. Social network analysis, a subdiscipline of sociology, provides both the methods and analytical techniques to describe and illustrate the effects of sexual networks on STI transmission. Sexual networks of people from Colorado Springs, Colorado, and from Winnipeg, Manitoba, Canada, infected with chlamydia during a 6-month period were compared. In Winnipeg, 442 networks were identified, comprising 571 cases and 663 contacts, ranging in size from 2 to 20 individuals; Colorado Springs data yielded 401 networks, comprising 468 cases and 700 contacts, ranging in size from 2 to 12 individuals. Taking differing partner notification methods and the slightly smaller population size in Colorado Springs into account, the networks from both places were similar in both size and structure. These smaller, sparsely linked networks, peripheral to the core, may form the mechanism by which chlamydia can remain endemic, in contrast with larger, more densely connected networks, closer to the core, which are associated with steep rises in incidence.

Strategies for improving sexual health in ethnic minorities

In many developed countries, ethnic minority communities bear the brunt of poor sexual health outcomes, with high rates of HIV/AIDS, sexually transmitted infections and their sequelae. Economic disadvantage, social exclusion and racism experienced by these communities all contribute to the observed inequalities. However, culturally prescribed attitudes and behaviours also play an important role. A review of the literature suggests that multifaceted and sustained approaches are needed to improve the sexual health of ethnic minority communities. Chief among these approaches are improving sexually transmitted infection surveillance and research tools; creating collaborative partnerships with communities; targeting high-risk groups and networks; and improving access to, and the utilization of, proven effective interventions.

Patterns of chlamydia and gonorrhea infection in sexual networks in Manitoba, Canada

BACKGROUND

The use of sexual network analysis has the potential to further our understanding of sexually tranmitted disease (STD) epidemics and contribute to the development of more effective targeted control strategies.

GOAL

To use sexual network analysis to study transmission patterns of chlamydia and gonorrhea in Manitoba, Canada.

STUDY DESIGN

Routinely collected case/contact information gathered by public health nurses was used to construct the sexual network.

RESULTS

Components within the sexual network ranged in size from 2 to 82 people. Two types of components, designated radial and linear, were described. Large linear components resembled the theoretical structure of STD core groups. Geographic analysis of the largest components demonstrated the potential for STD transmission between isolated rural communities and within different areas of an urban center.

CONCLUSIONS

The application of sexual network analysis on a provincial basis demonstrated the importance of a centralized, coordinated approach to STD control. The analysis highlights the need for a greater understanding of the causative factors promoting the formation of different component types, the homogeneity and heterogeneity of behaviors within and between components, and the temporal stability of these patterns.

A prospective social and molecular investigation of gonococcal transmission

BACKGROUND

Gonorrhoea is a common infectious disease, poorly controlled despite effective treatments. Tracing chains of transmission is difficult, because sexual partners are commonly difficult or impossible to identify. We assess the use of gonococcal opa-typing in identifying transmission links not revealed through interview.

METHODS

Epidemiological data and gonococcal isolates were collected prospectively from patients at two UK clinics in London and Sheffield. Social and epidemiological data were combined with molecular typing of gonococcal isolates by a new methodology based on the polymorphisms of the opa gene.

FINDINGS

In London, interview data and opa-typing on samples from 215 cases showed a diverse population with few links. In Sheffield, interview data identified links between 51 (43%) of 120 cases, whereas opa-typing suggested a more connected population: 95 (79%) of cases had shared profiles. There was a highly significant correlation between the two distributions with epidemiological clusters appearing as a subset of the opa clusters. Two large opa clusters, of 18 and 43 cases, accounted for 50% of local cases of gonorrhoea. Discordance between epidemiological and opa-typing data was observed at highly connected points in the sexual network.

INTERPRETATION

Opa-typing is a more powerful tool for epidemiological investigation of gonorrhoea transmission than earlier methods. Opa-typing can link infections that would otherwise remain unlinked, and may aid interventions to control endemic disease.

Sexually transmitted disease clinic clients at risk for subsequent gonorrhea and chlamydia infections: possible 'core' transmitters

BACKGROUND

From an sexually transmitted disease (STD) intervention perspective, developing a practical way to identify persons in core transmitter groups has been difficult. However, persons who have repeated STD infections may be in such groups.

GOAL

To evaluate a self-administered risk assessment approach that would identify STD clinic clients who were at an increased risk of being involved in gonorrhea (GC) or chlamydia (CT) transmission in the subsequent year.

STUDY DESIGN

Prospective cohort of consecutive STD clinic clients with a 1-year follow-up period.

RESULTS

During a 6-month period in 1995, 2576 STD clinic clients in San Diego completed a risk assessment. Of those clients, 204 (7.9%) had a subsequent STD and 79 (3.1%) had a subsequent GC or CT infection during the 1-year follow-up period. The strongest predictor of a subsequent GC/CT was having a recent history or current clinic visit diagnosis of GC or CT (6.1% subsequent GC/CT rate). The more past episodes of GC or CT, the higher the subsequent GC/CT rate. Unsafe sexual behavior had little effect on further increasing subsequent GC/CT risk.

CONCLUSION

STD clinic clients with a recent history of GC or CT and a high risk of subsequent GC/CT may be core transmitters who could likely benefit from risk reduction, periodic screening for GC/CT, symptom recognition counseling, and preventive treatment-the essential elements of STD-prevention case management.

Assessment of a geographically targeted field intervention on gonorrhea incidence in two New York State counties

BACKGROUND AND OBJECTIVES

Using study findings that demonstrated the importance of core group members in gonorrhea transmission, in 1984, one New York State county changed its approach toward gonorrhea control by targeting its field intervention activities toward infected persons from a geographic core area. In late 1988, New York State experienced an epidemic increase in the number of syphilis cases. In response, the New York State sexually transmitted disease (STD) control program enacted a Syphilis Initiative, which required the diversion of field staff from gonorrhea to syphilis control activities for a 3-year period. Each of these events held the possibility of impacting gonorrhea incidence in this county.

GOAL OF THIS STUDY

To evaluate the impact of core interventions on reducing gonorrhea incidence as compared to traditional nontargeted field intervention methods and to determine the influence on gonorrhea incidence of diverting field activities from gonorrhea to syphilis case finding.

STUDY DESIGN

A Poisson regression method was used to estimate gonorrhea incidence for a 22-year period in two similar counties: one county that used core intervention and one that applied traditional case-finding methods. The impact of core intervention was estimated in terms of the reduction in the gonorrhea incidence rate from the preintervention incidence rates.

RESULTS

After initiation of the core intervention, the relative risk of gonorrhea decreased by 61%. Between 30 % to 40% of the total reported cases were interviewed for contacts annually during the intervention period. In the control county, the relative risk was reduced by 50% despite a significantly higher percentage of annual case interviews (60%-70%). In addition, a small change in the definition of core (from census tracts encompassing 50% of gonorrhea cases to 30%-35%) during the Syphilis Initiative led to a significant increase (16%) in the relative risk of gonorrhea.

CONCLUSION

Targeting partner notification activities toward a geographic core area population appears effective in reducing the risk of gonorrhea, and it was more efficient because the overall percentage of cases interviewed was smaller than in a county using a nontargeted approach. Diversion of staff during a syphilis epidemic, combined with a narrowing of the geographic scope of the core intervention, was associated with an increase in gonorrhea incidence.