Chlamydia trachomatis (Microbiology)
Chlamydiae are obligate intracellular bacteria. They have a unique biphasic life cycle in which the elementary body represents the infectious, transmissible form and the reticulate body is the replicative, intracellular form of the organism. They have small genomes and are dependent on the host cell for many essential molecules. There are four species, Chlamydia pecorum, Chlamydia psittaci, Chlamydia pneumoniae and Chlamydia trachomatis.
C. trachomatis causes ocular trachoma and genital infections. The latter are widespread and are said to be the most common, bacterial sexually-transmitted infections in the UK. Many cases are asymptomatic but infection can also result in major complications. Natural infection seems to provide, at best, partial immunity against re-infection. Complications include pelvic inflammatory disease, ectopic pregnancy and tubal infertility. In addition infection can lead to complications in pregnancy and conjunctivitis and pneumonia in newborns. Asymptomatic cases can often go undetected and this has obvious implications for the spread of infection. Click here to view the Natural History section.
Laboratory diagnosis is currently achieved using nucleic acid amplification tests (NAATs) which, in general, are highly sensitive and specific. In low prevalence populations high specificity is particularly important to ensure high positive predictive values or the probability that a positive test is a true positive. Since these tests allow the use of non-invasive samples such as urine and self-taken vulvo-vaginal swabs, they are seen as ideal for use in screening programmes as they remove the need for pelvic examination and invasive swabs. Vigilance is required to identify any unexpected changes in epidemiology as variants have been described which evade detection in some detection systems.
It is likely that most untreated infections eventually resolve although in some cases C. trachomatis has been shown to persist. However, infection can be treated successfully with appropriate antibiotics and partner notification is regarded as an integral part of good management.
The possibility of other sexually transmitted infections should always be considered although many tests for chlamydia now incorporate detection of Neisseria gonorrhoeae as a dual assay. Preventive strategies such as inducing behavioural change should be implemented and screening has been identified as a way of finding infected patients and interrupting spread by appropriate management. The use of non-invasive samples has facilitated this approach.
Chlamydiae are obligate intracellular bacteria. They have a unique biphasic life cycle in which the elementary body represents the infectious, transmissible form and the reticulate body is the replicative, intracellular form of the organism. They have small genomes and are dependent on the host cell for many essential molecules. There are four species, Chlamydia pecorum, Chlamydia psittaci, Chlamydia pneumoniae and Chlamydia trachomatis.
C. trachomatis causes ocular trachoma and genital infections. The latter are widespread and are said to be the most common, bacterial sexually-transmitted infections in the UK. Many cases are asymptomatic but infection can also result in major complications. Natural infection seems to provide, at best, partial immunity against re-infection. Complications include pelvic inflammatory disease, ectopic pregnancy and tubal infertility. In addition infection can lead to complications in pregnancy and conjunctivitis and pneumonia in newborns. Asymptomatic cases can often go undetected and this has obvious implications for the spread of infection. Click here to view the Natural History section.
Laboratory diagnosis is currently achieved using nucleic acid amplification tests (NAATs) which, in general, are highly sensitive and specific. In low prevalence populations high specificity is particularly important to ensure high positive predictive values or the probability that a positive test is a true positive. Since these tests allow the use of non-invasive samples such as urine and self-taken vulvo-vaginal swabs, they are seen as ideal for use in screening programmes as they remove the need for pelvic examination and invasive swabs. Vigilance is required to identify any unexpected changes in epidemiology as variants have been described which evade detection in some detection systems.
Eurosurveillance, Volume 11, Issue 45, 09 November 2006
BMJ - No evidence of new variant Chlamydia trachomatis in England and Wales
HPA - No evidence of new variant Chlamydia trachomatis in England and Wales
It is likely that most untreated infections eventually resolve although in some cases C. trachomatis has been shown to persist. However, infection can be treated successfully with appropriate antibiotics and partner notification is regarded as an integral part of good management.
The possibility of other sexually transmitted infections should always be considered although many tests for chlamydia now incorporate detection of Neisseria gonorrhoeae as a dual assay. Preventive strategies such as inducing behavioural change should be implemented and screening has been identified as a way of finding infected patients and interrupting spread by appropriate management. The use of non-invasive samples has facilitated this approach.
The National Chlamydia Screening Programme (NCSP) is a control and prevention programme targeted at the highest risk group for chlamydia infection in England, young people under 25 who are sexually active.
Chlamydia is often asymptomatic so a large proportion of cases remain undiagnosed, but infection can be diagnosed easily (young people can do the test themselves), and treated effectively.
To find your local Chlamydia Screening Office or to register with us enter your post code or select your region on the map
Chlamydia is often asymptomatic so a large proportion of cases remain undiagnosed, but infection can be diagnosed easily (young people can do the test themselves), and treated effectively.
To find your local Chlamydia Screening Office or to register with us enter your post code or select your region on the map
© 2010 National Chlamydia Screening Programme
