Predictors of Chlamydia trachomatis infection among women attending rural Midwest family planning clinics

Mathematical modeling study of school-based chlamydia screening: potential impact on chlamydia prevalence in intervention schools and surrounding communities

Background

Chlamydia screening in high schools offers a way to reach adolescents outside of a traditional clinic setting. Using transmission dynamic modeling, we examined the potential impact of high-school-based chlamydia screening programs on the burden of infection within intervention schools and surrounding communities, under varying epidemiological and programmatic conditions.

Methods

A chlamydia transmission model was calibrated to epidemiological data from three different settings. Philadelphia and Chicago are two high-burden cities with existing school-based screening programs. Rural Iowa does not have an existing program but represents a low-burden setting. We modeled the effects of the two existing programs to analyze the potential influence of program coverage and student participation. All three settings were used to examine a broader set of hypothetical programs with varying coverage levels and time trends in participation.

Results

In the modeled Philadelphia program, prevalence among the intervention schools’ sexually active 15–18 years old population was 4.34% (95% credible interval 3.75–4.71%)after 12 program years compared to 5.03% (4.39–5.43%) in absence of the program. In the modeled Chicago program, prevalence was estimated as 5.97% (2.60–7.88%) after 4 program years compared to 7.00% (3.08–9.29%) without the program. In the broader hypothetical scenarios including both high-burden and low-burden settings, impact of school-based screening programs was greater in absolute terms in the higher-prevalence settings, and benefits in the community were approximately proportional to population coverage of intervention schools. Most benefits were garnered if the student participation did not decline over time.

Conclusions

Sustained high student participation in school-based screening programs and broad coverage of schools within a target community are likely needed to maximize program benefits in terms of reduced burden of chlamydia in the adolescent population.

Chlamydia trachomatis, Mycoplasma genitalium, and Trichomonas vaginalis infections in men with nongonococcal urethritis: predictors and persistence after therapy

BACKGROUND

Chlamydia trachomatis (CT), Mycoplasma genitalium (MG), and Trichomonas vaginalis (TV) are sexually transmitted infections (STIs) associated with nongonococcal urethritis (NGU). We assessed their predictors and persistence after treatment.

METHODS

We analyzed data from an NGU treatment trial among symptomatic heterosexual men aged 16-45 years from STI clinics. Nucleic acid amplification tests detected CT, MG, and TV at baseline and at 1 and 4 weeks after therapy. Associations between variables and STI detection were investigated.

RESULTS

Among 293 participants, 44% had CT, 31% had MG, and 13% had TV at baseline. In multivariate analysis, CT infection was associated with young age and STI contact. Young age was also associated with MG, and having ≥ 1 new partner was negatively associated with TV. We detected persistent CT in 12% and MG in 44% of participants at 4 weeks after therapy, which were associated with signs and symptoms of NGU. Persistent CT was detected in 23% of participants after azithromycin treatment vs 5% after doxycycline treatment (P = .011); persistent MG was detected in 68% of participants after doxycycline vs 33% after azithromycin (P = .001). All but 1 TV infection cleared after tinidazole.

CONCLUSIONS

Persistent CT and MG after treatment of NGU are common, and were associated with clinical findings and drug regimen.

Importance of physicians in Chlamydia trachomatis control

INTRODUCTION

During 2002-2006, reported rates of Chlamydia (CT) increased 17.3% nationally, with 43.6% of guideline eligible females screened in 2006. Annual costs associated with CT exceed $1.88 billion. We sought to determine the importance of private medical doctors (PMDs) and hospitals as screening venues in Illinois, USA and if this varied by county Rural-Urban Continuum Code (RUCC).

METHODS

A retrospective analysis of all CT cases reported in Illinois during 2002-2006. Counties were stratified by RUCC and eighteen provider types were condensed into nine venues. Venue positivity rates were derived from laboratory data.

RESULTS

PMDs and hospitals reported 247,725 CT cases (33.1% and 25.4%, respectively). Sample positivity rates were 6.2% and 6.1%, comparable to 5.7% for family planning clinics (FPC). Distribution of cases within these venues (and STD clinics) by RUCC was highly significant (p<0.001).

DISCUSSION

Even though screening guideline compliance is low, PMDs identify the majority of cases in Illinois and are consistently important screening venues at all levels of urbanization. As PMDs (and/or hospitals) exist in every Illinois county, it may be more efficient to augment screening rates at these venues rather than create new venues of other types which may be cost-ineffective in rural or low-prevalence areas.

Use of the internet and self-collected samples as a sexually transmissible infection intervention in rural Illinois communities

BACKGROUND

In the USA, reported cases of chlamydia (Chlamydia trachomatis) continue to rise despite substantial funding for screening. National gonorrhoea (Neisseria gonorrhoeae) rates have remained relatively stable, with clusters associated with metropolitan areas. Rural areas are no exception, as every county in Illinois reported cases of chlamydia in 2007. Morbidity associated with infection remains a public health concern, with costs of $US2.5+ billion annually. Novel screening interventions must be examined for their ability to reach those at risk who are missed by traditional methods.

METHODS

The website Iwantthekit.org was modified to allow residents from 25 contiguous counties in Central Illinois to request a self-collected sample kit. Returned kits were tested for chlamydia and gonorrhoea. The initial study period was 12 months.

RESULTS

During the study period, 343 kits were requested from 20 counties and 39.9% were satisfactorily returned for analysis. Positivity rates for chlamydia and gonorrhoea were 5.8% and 1.2%, respectively, for females and 1.9% and 0% for males. Males comprised 37.7% of all internet samples (compared with 23.4% for traditional screening venues) and 40.4% of all internet samples submitted by whites (compared with only 17.2% of traditional screening).

CONCLUSIONS

The female positivity rate was comparable to those seen in other screening venues and the method successfully engaged at-risk males. Overall, participation was low and the costs associated with the program outweighed the averted costs associated with the few cases identified. While this methodology resulted in sample requests from a wide area, it must be utilised by more individuals to become cost-effective.

A training program for nurses and other health professionals in rural-based settings on screening and clinical management of HIV and other sexually transmitted infections

Populations at risk for HIV and other sexually transmitted infections (STIs) include those living in rural areas. The authors describe a statewide training program that targeted rural-based health professionals. This program focused on HIV, STIs, and viral hepatitis and was designed to (a) enhance participants' ability to conduct sexual histories and risk assessments, (b) educate clients about risk reduction and prevention, (c) screen for and diagnose these infections, (d) clinically manage clients with positive screening test results, (e) access prevention and other educational materials, and (f) conduct other clinical and public health activities. A total of 122 participants reflecting a wide variety of practice settings attended training at five sites throughout Minnesota; 74% of participants were nurses and 81% characterized employment settings as rural. Nurses and other health professionals in rural settings are an important training priority and can play an important role in education, prevention, screening, and clinical care for HIV and other STIs.

Developments in the screening for Chlamydia trachomatis: a review

Many studies have evaluated selective screening criteria for women in various settings. Most have concluded and all guidelines recommend that all women aged < 25 be screened yearly for C. trachomatis infection. Behavioral criteria, such as the number of sex partners, new or more than one sex partners, and previous infection, also can serve as criteria for screening women aged > 25. Because re-infection rates are high and occur within a few months, complications may be reduced further if partners are treated and women rescreened 4 to 6 months after initial infection. Revised recommendations for C. trachomatis screening programs have stated that more frequent screening may be considered among women < 20 and those with recent infection. Screening in nontraditional settings and careful evaluation of local prevalence and risk factor information should be encouraged. Private providers and emergency room providers should discuss screening recommendations and adopt a C. trachomatis screening policy for the population they serve. The HEDIS measure should serve to encourage at least annual screening of 15- to 25-year-old sexually active females through providers linked to managed care organizations. In general, high yields (ie, percentage of tests that are positive) in nontraditional settings and enhanced feasibility and acceptability of urine-based tests may encourage further innovative approaches to reach and screen populations at risk. Several issues remain to be addressed to increase the effectiveness of screening efforts. If more sensitive amplification tests are used widely, more infected persons will be identified and treated, and transmission patterns may change, particularly if partner treatment also occurs. Current screening criteria should continue to be re-evaluated. An important issue that affects testing methods includes the possible need for confirmation testing when using NAATs if the prevalence of C. trachomatis is less than 2%. If the sensitivity of an NAAT is 85% and specificity is 99%, in a hypothetical population of 10,000 with a prevalence of 2%, the positive predictive value is 170/268 (63%). A second important issue affecting testing methods and feasibility of using NAATs for screening large numbers of individuals is the pooling of urine specimens, which has been evaluated in several studies and found to be very effective for reducing costs. A research issue for pooling is the determination of the most cost-effective prevalence levels for pooling. An additional research question is in which populations should a NAAT be used for detection of C. trachomatis and N. gonorrhoeae. There are no recommendations for the routine screening of men because of the paucity of data showing that this strategy can reduce sequelae. The CDC is conducting a multisite study to examine the feasibility, acceptability, and usefulness of screening of asymptomatic men. There are a few studies have determining cost-effective prevalence threshold levels, particularly with NAATs. A recently developed decision analysis model by CDC designed to maximize the effectiveness of screening strategies for C. trachomatis infections may be useful for decision makers. It is intended to serve as an easy and flexible tool to determine cost effectiveness at a local level and takes into account positivity rates and test performance characteristics (SOCRATES). It is unclear if recurrent infection is caused by true re-infection by the same or a different partner or recurrence of initial infection. Recurrence may be caused by persistence of C. trachomatis or antibiotic resistance. This distinction is of scientific interest because the appropriate intervention differs (eg, identification of risk factors for the former and microbiologic investigations for the latter). Effective partner management and retesting are critical to reducing sequelae of C. trachomatis infection. Screening for C. trachomatis infection remains an essential component of C. trachomatis control. It is cost effective, most infections are asymptomatic, and symptom-based health care seeking and testing identify few of those infected. The likelihood that opportunities for screening are missed is high particularly in non-STD clinic settings. Local studies using NAATs to determine C. trachomatis prevalence and risk factors are helpful to health care providers so they can make evidence-based decisions on who to screen. The use of nontraditional, non-clinic-based test settings should be explored further. We have focused on summarizing the medical evidence regarding recommendations for screening for C. trachomatis. High-risk populations for C. trachomatis infection may overlap with populations for other STDs, and comprehensive STD prevention programs that involve a range of STD service providers are needed to successfully reduce the STD-related health burden in the population.

Current priorities for adolescent sexual and reproductive health in Australia

The sexual health needs of teenagers differ from those of adults. Young sexually active teenagers are at high risk of Chlamydia trachomatis genital infection and its complications. Teenage pregnancy continues to be a problem in Australia. Current preventive strategies and clinical services in this domain of adolescent health in Australia are deficient. Australia can learn from the innovative and effective strategies developed in various countries for preventing high-risk sexual behaviours in teenagers.

Adolescence and other risk factors for Chlamydia trachomatis genitourinary infection in women in Melbourne, Australia

OBJECTIVE

To establish the prevalence of and risk factors for Chlamydia trachomatis infection to determine the role of universal versus targeted testing.

METHODS

A prospective study of 1107 women attending two sexual and reproductive health clinics in Melbourne, Australia, was carried out. A questionnaire was used to establish risk factors. Urine samples were tested for C. trachomatis by PCR. The main outcome measures were prevalence of and risk factors for C. trachomatis infection.

RESULTS

Of 1107 recruitable women, 851 (76.9%) consented and were successfully tested. C. trachomatis was detected in 18 (4.8% (95% CI 2.9 to 7.5)) of 373 women in the inner city and eight (1.7% (95% CI (0.7 to 3.3)) of 478 women in the suburban clinic. Of women under 25 years, 17 (6.2% (95% CI 3.7 to 9.8)) of 273 in the inner city in contrast with three (1.7% (95% CI 0.4 to 5.0)) of 174 in the suburban clinic were infected. In the inner city clinic, age under 25 years (OR 5.4 (95% CI 0.7 to 41.5)), vaginal discharge (OR 4.1 (95% CI 1.5 to 11.1)), and recent change of sexual partner (OR 4.6 (95% CI 1.6 to 12.9)) were associated with C. trachomatis. In contrast, in the suburban clinic, only vaginal discharge (OR 3.5 (95% CI 0.9 to 14.3)) and recent change of sexual partner (OR 3.4 (95% CI 0.8 to 15.7)) were identified as risk factors. Multivariate analysis showed that recent change of partner (OR 4.5 (95% CI 1.5 to 13.8)) was the most strongly associated independent risk factor for infection in the inner city clinic.

CONCLUSION

The high prevalence of C. trachomatis indicates that universal testing should be undertaken in the inner city clinic. Young age may not be a risk factor for C. trachomatis in more affluent populations with lower prevalence rates. No risk factors were identified with sufficient sensitivity and specificity to be useful for targeted testing. Prevalence and identifiable risk factors for C. trachomatis are not transferable between populations, even in the same city.

Is the prevention of genital chlamydial infections by community involvement possible?

This chapter presents different means by which community initiatives have been undertaken to reduce the prevalence and incidence of genital and allied infections caused by Chlamydia trachomatis. As most of these infections in the majority of infected individuals do not produce symptoms that are likely to urge them to attend any health care unit, screening programmes are mandatory to be able to influence the epidemic of infections with this agent. In many societies there has been a skewed gender distribution in the number of chlamydia-positive persons; this probably indicates that diagnostic service activities have been directed more against one gender than the other. The important role of partner notification, as in the case of other sexually transmitted infections, has been documented. Different means of community initiative have included counselling of school children and groups of persons more likely to be infected. Counselling by the pharmacy has an important role in many societies. Selected cohorts have been offered - via the mass media, Internet, radio and television programmes - sampling kits which can be mailed to a laboratory for testing. The establishment of youth clinics has been found effective for detecting teenagers harbouring C. trachomatis, similarly to screening at antenatal clinics. The offer of free consultations, aetiological tests and therapy has been a part of community initiatives, mimicking the services offered for some of the classic sexually transmitted infections. This chapter considers the usefulness of different test methods and stresses the need to retest those found to be positive. Barriers to the successful introduction of screening activities and diagnostic services are also considered.

Chlamydia screening in primary care: is it useful, affordable and universal?

Genital chlamydial infection, with its possible long-term morbidity, is a serious public health problem. The number of new diagnoses is rising rapidly and, in the UK, recent evidence suggests that the infection rate in young women exceeds 10%. Screening programmes can reduce the population prevalence of infection, but uncertainty remains as to the ideal screening model. This may prove to be opportunistic screening of sexually active young women, less than 25 years of age, in primary care settings, and contact tracing of the partners of those with chlamydia. Recent literature on the practicalities of genital chlamydia screening is reviewed.