Chlamydia screening programs: a review of the literature. Part 1: issues in the promotion of chlamydia testing of youth by primary care physicians.

Abstract: Rates of Chlamydia are highest among 15- to 24-year-old females. Often asymptomatic, untreated chlamydia can lead to Pelvic Inflammatory Disease (PID) and result in infertility, ectopic pregnancy, chronic pelvic pain, and increased susceptibility to HIV infection. Screening at risk women for chlamydia and treating those who test positive reduces the incidence of PID. This article reviews key data and research related to Chlamydia screening of youth by primary care physicians. These issues include the prevalence of chlamydia, the cost-effectiveness of chlamydia screening programs, the need to test males for Chlamydia, the discrepancy between guidelines for screening and the reality of physician screening practices as well as research on factors associated with the likelihood of physician Chlamydia screening of youth aged 15-24 and factors associated with the likelihood of physicians conducting sexual health risk assessments with their patients. The data and research reviewed in this article highlight the need for increased primary care physician Chlamydia screening of youth and identify issues that need to be addressed in interventions designed to increase and improve physician Chlamydia screening practices.

Key words: Chlamydia, youth, screening, physicians.

Introduction

Genital chlamydia is the most common reportable sexually transmitted infection (STI) in Canada with the highest rates occurring in females aged 20-24 and 15-19 years (Public Health Agency of Canada, 2005). The Public Health Agency of Canada (2005) notes that with respect to chlamydia rates, "The picture has changed drastically" (p. 1) with reported rates climbing steadily to an all-time high in 2002, the most recent year for which national rates are available. For example, the chlamydia rate among 15- to 19-year-old females increased from 971.3 per 100,000 in 1997 to 1,362.0 in 2002 (Public Health Agency of Canada, 2005). Although some of the increase in reported rates is likely due to the introduction of non-invasive testing such as NAAT, the Public Health Agency indicates that other factors, including risk behaviour, "point to a true increase in disease incidence" (p. 6). It has been firmly established that untreated chlamydia infection is a primary cause of Pelvic Inflammatory Disease (PID) (Scholes et al., 1996). Hu, Hook and Goldie (2004) estimated that 30% of women with untreated or uncured acute chlamydia infection develop acute PID within 6 months of an initial infection. It has also been firmly established that subclinical, asymptomtic chlamydia infection in women with no prior history of PID is a major cause of tubal infertility (Kelver & Nagamani, 1989; Sellors, Mahony, Chernesky, & Rath, 1988) and that untreated chlamydial infection is a major etiologic factor leading to ectopic pregnancy (Svensson, Mardh, Ahlgren, & Nordenskjold, 1985). According to the Public Health Agency of Canada (2005), ectopic pregnancy is a leading cause of maternal death in the first trimester and in 20% to 60% of cases leads to permanent sterility. In addition, chlamydia infection leading to PID is associated with the development of chronic pelvic pain in up to 25% of cases (Banikarin & Chacko, 2005). Infection with chlamydia increases the risk of HIV infection by a factor of 3 to 5 when a person is exposed to HIV, and recent studies have suggested that chlamydia infection can act as a co-factor to HPV infection that increases the risk of cervical cancer (Steben, 2004).

According to a Health Canada (1998) report, the costs of PID infections in Canada are substantial with calculations based on 1984/85 statistics suggesting that PID related inpatient and outpatients costs totaled more than $140 million. It is estimated that, in the United States, the average lifetime costs associated with an individual case of PID range from $1,060 to $3,180 (Yeh, Hook, & Goldie, 2003). More generally, it has been estimated that in the United States the reproductive health care costs associated with chlamydia infection are $3 to $4 billion annually (Institute of Medicine, 1997).

In sum, the negative health consequences for Canadian women (e.g., infertility, chronic pelvic pain, ectopic pregnancy) of undiagnosed, untreated chlamydia infection are substantial. In addition, although no precise cost estimates are available, it is very likely that the medical costs associated with untreated chlamydia infection among Canadians may well be in excess of $100 million per year. In the face of what appears to be a rising incidence of chlamydia, particularly among youth and young adults in Canada, strategies to reduce the incidence and negative outcomes of chlamydia are needed.

Using a randomized controlled trial design, Scholes et al. (1996) demonstrated that a screening strategy that identified, tested, and treated women at increased risk for chlamydia reduce the incidence of PID by 56% in one year of follow-up. Additional case studies have shown that screening programs significantly reduce the prevalence of genital tract infections and PID (Pimenta, et al., 2000). An effective population-based chlamydia control strategy involves a number of components including focused screening of high risk groups as well as partner notification protocols (Patrick, 1997). In addition, primary prevention efforts to increase condom use are an important behavioural target within a broader chlamydia control strategy (Patrick, 1997). Correct and consistent condom use has been shown to reduce the risk of chlamydial infection among adolescent women by 60% (Paz-Bailey et al., 2005).