Epidemiology Of Chlamydia Trachomatis Infection Research Articles

Molecular epidemiology of genital Chlamydia trachomatis infection in Shenzhen, China

ObjectiveTo investigate molecular epidemiology of Chlamydia trachomatis infection among patients recruited from different clinic settings in Shenzhen, China.MethodsA total of 2534 patients from the sexually transmitted disease (STD) clinics, obstetrics...

Epidemiology of Chlamydia trachomatis infection in women and the cost-effectiveness of screening

The majority of Chlamydia trachomatis infections in women are asymptomatic, but may give rise to pelvic inflammatory disease (PID) and tubal infertility. Screening programmes aim at reducing morbidity in individuals by early detection and treatment, and at decreasing the overall prevalence of infection in the population. A number of modelling studies have tried to calculate the threshold prevalence of chlamydia lower genital tract infection above which screening becomes cost-effective. There is considerable debate over the exact complication rates after chlamydia infections, and more precise estimates of PID and tubal infertility are needed, for instance to be inserted in economic models. With reference to key studies and systematic reviews, an overview is provided focusing on the epidemiology of chlamydia infection and the risk-estimates of its late complications. In the literature, the generally assumed risk of developing PID after lower genital tract chlamydia infection varies considerably, and is up to 30%. For developing tubal infertility after PID the risks are 10-20%. This implies that the risk of test-positive women of developing tubal infertility would range between 0.1 and 6%. We included chlamydia IgG antibody testing in a model and estimated a risk of tubal infertility up to 4.6%. The risk of developing late complications after chlamydia lower genital tract infection appears low. High quality RCTs dealing with the transition from cervicitis to infertility are needed to broaden the evidence. In screening programmes, chlamydia antibody testing, as an intermediate marker for potential adverse sequelae, might enable more precise estimates.

Chlamydia trachomatis genital infection in apparently healthy adult population of Tamil Nadu, India: a population-based study.

Since the epidemiology of Chlamydia trachomatis infection in apparently healthy population has not been studied in India, a population-based study was conducted in the state of Tamil Nadu, India in order to analyse the prevalence of genital chlamydial infections in the community and to implement control programmes. A representative sample was taken from three randomly selected districts by using the 'probability proportional to size' cluster survey method. Households were the basic units of clusters. Adults aged 15-45 years, pre-identified from the selected households were enrolled during the medical camps conducted for a major study on community prevalence of sexually transmitted diseases in Tamil Nadu. Blood and urine samples collected from the study subjects were tested by enzyme-linked immunosorbent assay (ELISA) for anti-chlamydial IgM antibodies and by the commercial Amplicor polymerase chain reaction (PCR) test for chlamydial DNA. The prevalence of anti-C. trachomatis antibodies determined by IgM-ELISA was 2.4% (95% CI 1.6%-3.2%). The prevalence of genital chlamydial infection determined by PCR was 1.1% (95% CI 0.5%-1.7%). Majority of the detected infections (68.8%) were asymptomatic. This is the first Indian report on the prevalence of genital chlamydial infections in the general population. It is concluded that this study provides evidence for a substantial burden of approximately 10 million asymptomatic genital chlamydial infection cases in the sexually active age groups in the general population of India.

Prevalence of Chlamydia trachomatis infection in registered female sex workers in northern Mexico.

Little is known about the epidemiology of Chlamydia trachomatis infection in female sex workers (FSWs) in Mexico. The goal of the study was to determine the prevalence of C trachomatis infection in registered FSWs from northern Mexico and to determine the sociodemographic characteristics associated with the infection. An enzyme immunoassay was used to test 354 FSWs in three northern Mexican cities for cervical C trachomatis infection. All participants were registered in a government health office. Recruitment was consecutive and voluntary. The association between clinical and sociodemographic characteristics of FSWs and infection was evaluated. The overall prevalence of C trachomatis infection among participants in the three cities was 12.4%. Women of low socioeconomic level and those younger than 25 years were the most frequently infected. Among FSWs in Durango, a higher frequency of C trachomatis infection was found for those who did not use condoms. C trachomatis is an important pathogen in the sexually transmitted diseases of registered FSWs in northern Mexico.

Chlamydia trachomatis infection in asymptomatic men

Background The epidemiology of Chlamydia trachomatis infection in men is not well defined, especially among those who are asymptomatic or show no signs of infection. Established C. trachomatis screening programs for women have demonstrated the benefit of routine screening in reducing prevalence over time, but the yield and benefit of screening asymptomatic men are unclear. Methods Cross-sectional study of C. trachomatis prevalence and associated risk factors among men tested at sexually transmitted disease (STD) clinics in Alaska, Idaho, Oregon, and Washington. We analyzed data from 43,094 men universally tested from 1997 to 1999 at 103 STD clinics, and assessed age-specific prevalence of infection, controlling for signs of infection (urethritis diagnosed by clinician) and report of sexual contact to a person with an STD (defined as “contact”). Results Overall prevalence of C. trachomatis was 10.3%. Age-specific prevalence was highest among men aged 18 to 19 years and lowest among those aged >29 years, regardless of signs of infection upon examination or contact to a person with an STD. If these factors and age <25 years had been used to direct C. trachomatis testing at STD clinics, 59% of men would have been tested and 91% of positives would have been detected. Conclusions Using either the presence of clinical signs or report of a sex partner with an STD in combination with selective screening of all men aged <25 years detects the majority of infections and, in our population, would have considerably reduced the number of negative tests performed.

Epidemiology of infection due to Chlamydia trachomatis in Manitoba, Canada.

In a study of the epidemiology of Chlamydia trachomatis infection in Manitoba during 1981-1990, we retrospectively reviewed laboratory and clinical case notification records as well as hospital and health insurance data concerning pelvic inflammatory disease and ectopic pregnancy. After implementation of a control program in 1987, the annual incidence of chlamydial infection was highest among females aged 15-24 years (3,418 cases per 100,000 residents). Recurrent infection, which occurred in 13.4% of patients, was more common in women (P < .001), patients aged 15-24 years (P < .001), registered North American Indians (P < .001), and persons with concomitant gonorrhea (P < .001). Risk factors for dual (chlamydial and gonococcal) infection included male sex (P < .001) and young age (P < .001). Although the incidence of hospitalization and outpatient visits for pelvic inflammatory disease decreased (P < .001) from 1981 to 1990, the annual incidence of ectopic pregnancy increased from 10 to 16 cases per 1,000 reported pregnancies (P < .001). Control activities focusing on the primary prevention of C. trachomatis infection are presented. Strategies for improving secondary prevention (through case detection and treatment of lower genital infection) include the targeting of individuals with recurrent and multiple sexually transmitted diseases.

THE PREVALENCE OF CHLAMYDIA TRACHOMATIS INFECTION AMONG MOTHERS OF CHILDREN WITH TRACHOMA

The authors studied the epidemiology of Chlamydia trachomatis infection in a trachoma-endemic area of central Kenya. Children with abnormal ocular discharge were evaluated for clinical evidence of trachoma and were cultured for C. trachomatis. Isolated strains of C. trachomatis were immunotyped with monoclonal antibodies. Overall, 221 children from 207 families were evaluated. Clinically, 91 children (41%) had trachomatous follicular inflammation, and 130 (59%) had papillary hypertrophy without visible follicle and were labeled as having mucopurulent conjunctivitis. C. trachomatis was isolated from 31 of 91 children with trachoma (34%) and 17 of 130 children with conjunctivitis (13%) (p less than 0.001). Twenty-two C. trachomatis strains were immunotyped: 17 were from children with trachoma (nine type A, one A/L2, five B, one Ba, and one E) and five were from children with conjunctivitis (two A, one Ba, one D, and one F). A total of 168 mothers were evaluated for cervical C. trachomatis infection, and seven (4%) were culture-positive. Two strains were immunotyped as serovar E. The authors conclude that C. trachomatis ocular infections are due to heterogeneous serovars in this area, that most cases of trachoma are due to C. trachomatis infection with the classic trachoma serovars (A, B, or Ba), and that cervical C. trachomatis infection is uncommon among mothers of children with trachoma.