This chapter provides the background discussion of sexually transmitted infections (STIs) focussing on Chlamydia trachomatis infection since the study is positioned within this area leading down to the specific research question and objectives. In addition, sexual health prevention and control strategies have been explored.
2.1 Introduction
Health has been defined by the World Health Organization (WHO) as "the science and art of preventing disease, prolonging life and promoting health through organised efforts of society" (WHO, n.d.). Sexual activity is known as an essential element of human health and well-being contributing to quality of adult partnerships and a requirement for natural creation. Yet it poses a lot of risks to health through transmission of STIs. Although syphilis, gonorrhoea and chancroid are generally considered as the main STIs, various other pathogens are transmissible including Herpes Simplex Virus type 2, Chlamydia trachomatis, Human immunodeficiency virus (HIV) Herpes Papilloma Virus, and Hepatitis B Virus (HPA, 2010) (Figure 1).
STIs affect people of all ages with the greatest occurrence amongst those under the age of 25 years (Nicoll, 1999; Johnson, 2001; NCSP, 2009). In the UK, certain groups of populations are affected more than others thus creating sexual health inequalities (HPA,2010; Marmott, 2010).
The research has delved into mainly secondary literature from peer reviewed journal articles, books, health agency or governing bodies' reports and articles to demonstrate what past researchers have established on CI. Moreover, sexual health prevention and control strategies have been explored in order to place CI in a context that engages with appropriate literature.
Figure 1: Number of diagnoses of selected STIs and HIV in the UK, females: 2000-2009
2.2 Chlamydia Infection Trends
Chlamydia trachomatis is the most widespread bacterial pathogen transmitted through infected secretions and mucous membranes of urethra, cervix, rectum, conjunctivae and throat following unprotected sexual contact with an infected partner. An infected pregnant woman can infect her baby during vaginal delivery.
Genital Chlamydial infection is currently the most common STI in the UK with prevalence's between 2% and 12% detected in studies of women attending general practice (Fenton et al., 2001; Creighton et al., 2003; HPA, 2010). Chlamydia infection rates are disproportionately high in under 25s (Low, 2001; HPA, 2010). Rate of infectivity for Chlamydia at national level for young people aged 15-24 is one in ten supporting the level of sexual activity in that group (HPA 2010; NHS Salford, 2010.
In 2001, women under 20 years of age had reported cases of 36% of Chlamydia. CI cases rose by 108% during 1998 to mid-2004 (Ryan, 2004). As reported by the Department of Health (DH), diagnosis of new Chlamydia and other STI diagnosed cases in the UK such as re-infections made in GUM showed a gradual rise in 1995-2009 (Figures 2, 3) (HPA, 2010).
Figure 2: Number of diagnoses of Chlamydia^, England: 1995-2009
Figure 3: Number of genital Chlamydia diagnoses by sex and age group, and number of laboratories using nucleic acid amplification tests (NAATs): 1999-2008 (females)
STI data from laboratory reports in England, Wales and Scotland and Chlamydia nucleic acid amplification test (NAAT) data from the UK National External Quality Assurance Scheme (NEQAS).
Most people infected with Chlamydia are asymptomatic (70% females and 50% males) until a diagnostic test is performed (HPA, 2010). Chlamydia infection is significant to women's reproductive health problems since 10-40% of those untreated infected women develop PID (Garside, 2001; Sweet & Gibbs, 2009; Pippa et al., 2010). If efficient and effective health measures are not administered, the disease has the potential of causing significant health complications to women's well-being including persistent pelvic pain, infertility, ectopic pregnancy, PID, Chlamydial pneumonia of the newborn, neonatal conjunctivitis, pre-term labour/delivery and neonatal death (Figure 4) (Golden, et al, 2000; Simms et al., 2000, 2007; Garnett, 2008; Oakeshott et al., 2010). There is also greater risk in those with recurring and untreated infections to spread to other reproductive organs resulting in chronic pelvic pains (La Montagne, et al, 2007; Evans et al., 2009; Hosenfeld et al., 2009). Sweet & Gibbs (2009) state that CI can also facilitate HIV transmission adding to the already long-term consequences it poses.
Figure 4: Chlamydial infection complications
Source: HPA communicable diseases surveillance centre.
The number of diagnosed episodes of Chlamydia infection has been rising over the past 10 years (Figures 5, 6). Because GUM clinic data is skewed towards symptomatic patients and Chlamydia is highly asymptomatic, prevalence is also used to describe the epidemiology.
Figure 5: Rates of genital Chlamydia infection women by age group (1995 - 2004)
Data sources: KC60 and STISS/ISD(D)5 returns from GUM clinics, United Kingdom (HPA, London)
Figure 6: Chlamydia positivity rates in screens performed by NCSP, 2007 (HPA, 2008)
Studies by Pimenta et al. (2003) and Adams et al. (2005) support findings of highest prevalence rates of Chlamydia infection in young women aged 16-24. Pimenta et al (2003) measured prevalence of Chlamydia infections in 16-24 year old females rather than just reported cases from GUM clinics (Figure 7). In Portsmouth there was a 9.8% prevalence of Chlamydia infection in 16-24 year old women, with the 18-year old women having the highest peak and Wirral had 11.2% with the 20-year old women having the highest peak (Pimenta et al., 2003). Most of these individuals from both sites would have been unaware of their infection and thus at risk of developing Chlamydial complications.
Figure 7: Prevalence of Chlamydial infections, 16-24 year old females, Portsmouth and Wirral, 1999-2000 (Pimenta, et al., 2003).
Furthermore, the economic impact of Chlamydia infections on the health service is enormous with high cost in the management of female health complications (Simms, 2006; Skinner, 2010; Land et al., 2010). UK costs to NHS are estimated at > £100 million per year (HPA, 2010). Because of the impact of CI on the health of young people, it is important to identify and treat infected patients and their partners and as a result reduce the burden of the disease on the people and health systems (Appleby et al., 2007; Adams et al., 2007; Low et al., 2009).
2.3 Chlamydia Awareness and Knowledge
Chlamydia rates of infection do vary in each region in the UK (HPA, 2010). This variation may reveal the provision of diagnostic services as much as disease prevalence. Unfortunately, Chlamydia trachomatis infection like most STIs brings about negative public health outcomes due to its contribution or causes to ill-health. In the UK and other parts of the world, CI pose enormous challenges for public health such as individual well-being, the burden of health costs or mental health. Chlamydia rate of infectivity at national level for young people aged 15-24 is one in ten supporting the level of sexual activity in that group. In the UK, certain groups of populations are affected more than others thus creating sexual health inequalities with young people bearing the greatest burden by being disproportionately affected by CI (Figure 8, Table 2-4) (NCSP, 2009; Marmott, 2010; HPA, 2010).
Figure 8: Age-specific distribution of the rate of diagnosed with Chlamydia at STI clinics, England: 2009
Source: STI data from genitourinary medicine clinics (HPA, 2010)
Table 2: Number of Chlamydia diagnoses by gender, male sexual orientation, age group and patient country: 2009
Source: STI data from genitourinary medicine clinics (HPA, 2010)
Table 3: Number of Chlamydia diagnoses by gender, male sexual orientation, age group and patient SHA: 2009
Source: STI data from genitourinary medicine clinics (HPA, 2010)
Table 4: Number of Chlamydia diagnoses by continent of birth: 2009
Source: STI data from genitourinary medicine clinics (HPA, 2010)
2.4 Sexual Behaviour: Chlamydia Infection
Although sex has become safer to a significant extent through the use of condoms, Chlamydia rates significantly increased in recent years in the UK predominantly from various factors like sexual risk behaviours and poor infection control. It has become a major public health concern as highlighted in the National Strategy for Sexual Health and HIV (DH, 2001). The 15-24 year age group comprises only 12% of the population but has the largest diagnosis of STI cases of almost 50% of newly acquired infections. Control of Chlamydia infection is complicated since it is asymptomatic.
The sexual behaviour of the population is an important determinant of the rates of STIs. The National Survey of Sexual Attitudes and Lifestyles II identified sexual behaviour as the risk of acquiring an STI in the young age groups (McDowall et al., 2006). The factors included low age at time of first sexual intercourse, frequent changing of partners, increased likelihood of being involved with concurrent partnerships, irregular use of condoms and the increased chances of being involved with a partner who comes from a part of the world other than UK that is regarded as high risk (Figure 9) (Hughes, 2000; Johnson, 2001, Mueller, 2008; Waylen, 2009; Skinner, 2010). The young people appear to be the central part of the risk of passing on the infection to other groups of the population. Thus prevention should be mostly targeted at this core group which would result in economic benefits.
Figure 9: Chlamydia prevalence by risk factors 2003 - non GUM settings
(Montagne et al., 2004).
A study by Shiely et al. (2010) proved that expedited partner therapy (EPT) offer reductions in risks of recurring or continual CI in heterosexuals, and enhancing the percentage of those sex partners who obtain treatment. Thus EPT was revealed as better than standard partner referral over an extensive range of socio-demographic and behaviourally distinctive subgroups.
Behavioural interventions might be limited because choices about behaviour are controlled by local context and culture. Smedley and Syme (2000) state that, "It is clear that behaviour change is a difficult and complex challenge. It is unreasonable to expect that people will change their behaviour easily when so many forces in the social, cultural and physical environment conspire against such change." For example, Cohen et al. (2006) study found that when adolescents were exposed to sex education classes and parent-child communication about sex, they intended to practice safer sex; however, this did not actually lead to increased condom use. Rather, situational attributes, including partner attitudes about, or the availability of, condoms played a greater role in behaviour. However, the consequences of environmental risks like poverty and discrimination might be moderated by interventions focused on the individual: "But such efforts do little to address the broader social and economic forces that influence these risks" (Smedley & Syme, 2000).
Bandura (1986) developed the self-efficacy model which offers a degree of assurance for working with individuals in order to reduce risky behaviour. Since the women are young, they might not have the necessary skills to negotiate and manage condom use; Bandura's model may be specifically suitable for them. Bandura suggested that individuals beliefs in their competence to conduct certain behaviours impacts on the way they engage themselves, their willpower when faced with difficulties, and their attempt in conducting these behaviours. Foresight direct behaviour with regard to particularly expected outcomes, though self-control allows for the control of behaviour based on standards that are internal. Above all, self-reflection let individuals reflect on and become knowledgeable by learning from their experiences.
2.5 Sexual Health Prevention and Control: Chlamydia Infection
People's health and the social and economic success of the UK are extremely connected. The related economic and social costs of CI and other STIs to public health are enormous and surpass UK's future. Two of Marmott's (2010) six recommendations support the prevention and control of STIs in UK's population: "enabling all children, young people and adults to maximise their capabilities and have control over their lives" and "strengthening the role and impact of ill-health excellent well-being over their lives".
It is vital that the UK's population is educated on sexual health issues so that they are able to make well informed sex decisions that contribute to their well-being and reducing the burden caused by STIs. Marmott's report further emphasised other research work (Picket & Wilkinson, 2009) that "it is not only the poor who suffer from the effects of inequality, but the majority of the population". High priority should therefore be given to the integration of STI control measures into primary health care. The worldwide interest in and resources committed to preventing AIDS provide a unique opportunity for health workers to make considerable progress in controlling CI and other STIs.
2.5.1 Chlamydia infection: approaches to prevention and control
Although Chlamydia is a reportable infectious disease, easily treated with antibiotics, and largely prevented with condom use, challenges still exist globally in its prevention and control. Public health attempts to prevent and control Chlamydia and other bacterial STIs have been applied through surveillance, clinical services, partner notification strategies and behavioural intervention strategies.
Clinical services are an integral part of CI and other STIs prevention programmes implemented in all communities. Chlamydia clinical services are available in a variety of other settings such as community health centres, family planning clinics, GP surgeries, hospital emergency rooms, and prison settings. Increasingly, CIs are being diagnosed in settings other than public health clinics.
Surveillance is a fundamental public health responsibility which involves monitoring of Chlamydia or its effects, antimicrobial resistance, sexual behaviours, screening and healthcare quality and coverage. It is vital in detecting and monitoring discrepancies in Chlamydia and other STIs. It is insufficient to trace only Chlamydia infection case-associated demographics for getting insight into the dynamics of Chlamydia transmission and its persistence in the affected communities. However, consideration into how and when to apply the current strategies or to produce new ones is vital for an efficient decrease in Chlamydia infection rates in the risk groups. It is only out of using several surveillance approaches, routine data analysis and interpretation, and evaluation that the burden of these complex Chlamydia infections may be comprehended properly.
Primary prevention efforts include encouraging condom use and patient education about abstinence, delay of sexual intercourse, and monogamous sexual behaviour. Secondary prevention efforts include early and frequent screening, which have shown to reduce the prevalence of the disease (CDC, 2000; HPA, 2010).
2.5.1 National chlamydia screening programme and partners
The National Chlamydia Screening Programme (NCSP) was established back in 2003 in the UK to provide opportunistic screening tests targeting sexually active women and men under 25 years of age who attend health and non-health care settings. Systematic screening in the UK is performed only at GUM clinics. The introduction of the NCSP in 2003 and other health screens in England, Wales and Northern Ireland and in Scotland in 2005 resulted in an increase of sexual health screens from 759,770 to 1,219,308. The programme was rolled out to the rest of England in 2007 and it aims at screening young women attending GUM, family planning and termination of pregnancy clinics; first cervical smear, youth clinics, colleges, schools and universities. Pharmacies are also offering screening tests to young women seeking emergency hormonal contraception (Brabin et al., 2009).
The HPA was appointed in November 2005 by the DH to administer the NCSP which is delivered by 152 PCTs in England. However, this was rolled out by the Greater Manchester health authority region in Salford in December 2006 by setting up RUClear programme which works in collaboration with NCSP and all registered screening sites. Its partners include health care providers and laboratories in providing high-quality CI surveillance data required by the health protection agency which is essential for identifying and monitoring CI health disparities. RUClear coordinates screening services through easy accessibility of screening and treatment services as well as finding ways of persuading the young population to use these services (Appendix B). Diagnosis of Chlamydia cases increased by 7%, 217,570 in 2009 from 203,773 in 2008 (Table 6) (HPA, 2010). NCSP has national targets for which by 31st March 2010, 25% of all 15-24 year olds were screened and from 1st April 2010 to 31st March 2011 the target was raised to 35% (anonymous, 2010).
Table 6: Total number of Chlamydia diagnoses in genitourinary medicine clinics and community-based settings by gender, UK and England, 2008-2009
The asymptomatic nature of CI results in significant under detection by case reporting. Those who are asymptomatic might not obtain care and hence are not likely to produce a case report. Furthermore, CI may be distributed differently in similar racial or ethnic group.
Figure 11: NCSP testing venues by sex: England April - December 2010 (HPA, 2011).
The screening and treating of Chlamydia is placing a lot of pressure for the Primary Care Trusts (PCTs) that have to deliver in case the young people are unwilling to visit clinical services. The challenge is to get innovative methods that would persuade the young people to take on screening services.
The criteria for screening Chlamydia, although more broadly applicable, are mainly for sexually active women and men aged under 25 years. In order for Chlamydia screening to be effective, HAs should closely monitor adherence to screening criteria. For instance, when there is evidence of high rates of pregnant women accessing healthcare service but screening numbers are low, then it means the recommended care is not being received by these women.
Provision of regular screening services for asymptomatic young people-at-risk and prompt diagnosis and accurate treatment for young people infected with or exposed to CI are vital components of effective clinical CI infection prevention and control. Correct identification and appropriate treatment are key elements of CI clinical care but partner notification services and counselling are also critical in risk reduction. However, even with commercial accessibility of good diagnostic tests, effective medications, and screening and treatment guidance for preventing and curing Chlamydia, several challenges restrict the full potential of these tools in providing quality care for the young women.
Given the reported high incidence rates of CI, the burden is much more for young people (Figure 12, Table 5) (Fenton et al., 2005). It is imperative to ascertain effective prevention programmes. Although enhancing access to Chlamydia testing has been an important and urgent focus of Chlamydia awareness programmes and has led to renewed efforts to increase access to Chlamydia testing (WHO, 2001; Santer, 2000, 2003; HPA, 2010). As more people including this identified group aged under 25 learn their Chlamydia status, and in recognition of the long latent period of the disease before symptoms prevail, factors related to Chlamydia awareness remain crucial to identify in order to design comprehensive Chlamydia management services that meet the needs of the population at risk of infection (Wight, 2000, 2002; Low, 2007; Brabin et al., 2009).
Figure 12: Proportion of positive cases by age and sex: April - December 2010
Table 5: Total number of Chlamydia diagnoses by patient PCT: 2009
Source: STI data from genitourinary medicine clinics (HPA, 2010)
2.7 Summary
In summary, the above review form a background for understanding Chlamydia trachomatis infection and a yardstick for evaluating the sexual health prevention and control strategies whilst carefully considered and acknowledged the reported high incidence rates of infection. This chapter has vindicated many challenges and concerns that public health face today. Following is Chapter 3 describing the adopted research methodology to gathering pertinent research data.
