Why is diagnosing chlamydia often especially difficult




















Yes, chlamydia can be cured with the right treatment. It is important that you take all of the medication your doctor prescribes to cure your infection. When taken properly it will stop the infection and could decrease your chances of having complications later on.

You should not share medication for chlamydia with anyone. Repeat infection with chlamydia is common. You should be tested again about three months after you are treated, even if your sex partner s was treated. You should not have sex again until you and your sex partner s have completed treatment. If your doctor prescribes a single dose of medication, you should wait seven days after taking the medicine before having sex.

If your doctor prescribes a medicine for you to take for seven days, you should wait until you have taken all of the doses before having sex. The initial damage that chlamydia causes often goes unnoticed. However, chlamydia can lead to serious health problems. If you are a woman, untreated chlamydia can spread to your uterus and fallopian tubes tubes that carry fertilized eggs from the ovaries to the uterus.

This can cause pelvic inflammatory disease PID. PID often has no symptoms, however some women may have abdominal and pelvic pain. PID can lead to long-term pelvic pain, inability to get pregnant , and potentially deadly ectopic pregnancy pregnancy outside the uterus. Men rarely have health problems linked to chlamydia. This method is, therefore, recommended for low volume laboratories.

This test can also be applied to extragenital sites. It is reported to be more sensitive than culture for the detection of Chlamydia in endometrial or tubal specimen The enzyme immunoassay EIA tests have been reported to have a sensitivity of per cent and a specificity of per cent in comparison to cell culture This test is suitable for laboratories without access to cell culture.

Cytology : Cytology is an easily available, simple to use and cost-effective diagnostic test. The quality of the clinical specimen can be assessed by the microscopic technique and the technical procedures used in these tests are usually quicker and simpler to perform than culture.

Giemsa, immunoflourescence and iodine staining methods are most commonly used. Other stains like immunoperoxidase, immunoferritin, May Grunwald, Giemenez, Macchiavello and acridine orange can also be used for detecting chlamydial inclusion in exfoliated cells. The presence of intracytoplasmic inclusions is pathogonomic for chlamydial ocular infections in neonates, however, this method is not recommended for diagnosing conjunctivitis or genital infection in adults due to the lack of sensitivity.

Of the three methods, immunofluorescence offers the highest sensitivity followed by Giemsa and then iodine staining Molecular methods : The traditional methods of diagnosis have several limitations which include low sensitivity, long testing time and high cost. Once the DNA-rRNA hybrid is formed, it is adsorbed onto a magnetic bead and the chemiluminescent response is detected quantitatively with a luminometer.

Since actively dividing chlamydiae contain up to 10 4 copies of 16S rRNA, the PACE 2 test should theoretically be more sensitive than antigen detection systems. The sensitivity of PACE 2 relative to a DNA amplification standard has not yet been well evaluated but has been reported to be 77 to 93 per cent 48 in one study. The development of tests based on nucleic acid amplification technology NAAT has been the most important advancement in the field of chlamydial diagnosis since in vitro cell culture techniques replaced the yolk sac for culture and isolation of the organism from clinical specimens.

NAAT is at least per cent more sensitive capable of detecting as little as a single gene copy and per cent specific 49 , It offers the opportunity to use non-invasive samples like urine to screen for infections in asymptomatic individuals who would not ordinarily seek clinical care.

This is a critical advantage, since the majority of chlamydial infections in women and a significant proportion of infections in men are asymptomatic. PCR can be genus, species, group, or strain specific depending on the primer design. Genes targeted for diagnosis of C. Since all nucleic acid amplification technologies detect nucleic acid targets, these do not depend on either viability or an intact state of the target organism for a positive result.

Hence, transportation of sample is not a critical issue After this time, patient specimens become both culture and PCR negative. The PCR test for detection of C. Since , Amplicor PCR has been relatively well evaluated for both urogenital and urine specimens, with an overall sensitivity and specificity of 90 and 99 to per cent, respectively Amplicor PCR is approved for cervical, male urethral and male urine specimens.

Although popular in the developed countries, their high initial and maintenance cost prevent their use in resource-poor settings.

The burden of C. This is likely to influence the performance of different nucleic acid amplification tests, which do not routinely distinguish between people with high and low chlamydial loads. Differences in chlamydial load have been reported to be associated with the presence of clinical symptoms, the transmissibility and persistence of infection, and the risk of developing chronic sequelae Hence, there is a critical role of quantification in the diagnosis and treatment of chlamydial infections.

The NAATs are the most sensitive tests for the screening and diagnosis of chlamydial and gonococcal infections of the genital tract 54 , 55 , However, doubts regarding their performance in low prevalence areas are reported 57 , The CDC has also suggested several possible strategies for confirmation 59 which include i testing a second specimen with a different NAAT having equal or higher sensitivity to the first test, ii performing a different NAAT having equal or higher sensitivity to the first test targeting a different nucleic acid sequence on the original specimen, iii repeating the original test on the original specimen, and iv bringing the patient back for a retest.

The concept of confirmatory testing is not new However; it complicates the handling of a NAAT positive sample and adds cost to an already expensive screening test. Also, there is still room for improving the sensitivity of NAATs, perhaps by better specimen preparation, automation, or target concentration.

Leukocyte esterase LE test is a rapid dipstick test for use with urine specimens. This test is designed to detect urinary tract infections by detecting the enzyme produced by the polymorphonuclear PMN cells. Positive LE test results occur with infections caused by a number of different agents including C. The sensitivity of the LE test for detection of C. The LE test has been considered the best screening test for adolescent males and, according to most reports, should not be used for testing specimens from women or older men due to unsatisfactory performance.

Rapid tests are performed in physician's offices, do not require sophisticated equipment, and can be completed in about 30 min. Results are read visually and are thus qualitative. Though several kits are commercially available, but none has been well evaluated.

In general, the rapid tests are significantly less sensitive and specific than laboratory-performed EIAs. The rapid tests offer an advantage over conventional laboratory tests only when results are required immediately for patient management. Rapid tests should not be used in a low-prevalence population or for asymptomatic individuals due to the potential for false-positive results. The results of a rapid test should always be considered presumptive and, if positive, should be confirmed by a laboratory-performed test.

In conclusion, although culture is per cent specific, its estimated sensitivity may be as low as 50 per cent. Majority of laboratories have moved away from culture due to the expense involved, time and technical difficulties. The serological tests are generally not useful in the diagnosis of genital tract infections caused by C. Antibodies elicited by C. A new variant Chlamydia trachomatis nvCT strain has been recently isolated in Sweden 62 , which has a bps deletion in a portion of the plasmid that is the target area for some of the NAATs.

Consequently these tests often give false negative results when presented with this strain. Therefore, it is important to select primers for NAAT carefully particularly those targeting the endogenous plasmids. The symptoms and treatment of this strain do not differ from those for normal chlamydiae. So far, this strain has been found in Sweden and Norway. The clinicians and microbiologists should remain vigilant for suspicious negative results as well as unexplained fall in positive results.

Twenty per cent of the women with chlamydial lower genital tract infection will develop PID 63 and 4 per cent will develop chronic pelvic pain 2.

The clinical spectrum of chlamydial PID ranges from subclinical endometritis to frank salpingitis, tubo-ovarian masses, pelvic peritonitis, periappendicitis and perihepatitis.

However, symptomatic chlamydial infections represent only the tip of the iceberg of all chlamydial infections as majority of genital chlamydial infections are asymptomatic. Pregnant women with chlamydial infection are at increased risk for adverse outcomes of pregnancy and post-partum PID. Sequelae like still birth, low birth weight, neonatal death, decrease gestational periods, preterm delivery and premature rupture of membranes PROM have been reported Nine per cent of the women with chlamydial infection who develop PID have tubal pregnancy Early pregnancy loss or recurrent pregnancy loss may be induced by asymptomatic chlamydial infection through the operation of immune mechanism.

Chlamydial PID is the single most important preventable cause of infertility. Approximately, 3 per cent women with chlamydial genital tract infection develop infertility. After a single episode of PID, the risk of tubal factor infertility is approximately 10 per cent, each repeat episode doubles the risk The role of C. Though the role of this organism in prostatitis is controversial, but up to 50 per cent incidence has been reported in patients with prostatitis Infection of the testes and the prostrate is implicated in the deterioration of sperm decrease sperm motility, increase proportion of sperm abnormalities, significant reduction in sperm density, sperm morphology and viability and increased likelihood of leucocytospermia affecting fertility.

Chlamydial infection may also affect the male fertility by directly damaging the sperm as sperm parameters, proportion of DNA fragmentation and acrosome reaction capacity are impaired.

However, the role of C. Chlamydial infection of the genital tract facilitates the transmission of HIV. This is confirmed by various studies 12 , 15 , The combined epidemiology of these infections may partly be due to the fact that STDs including C.

But, C. The possible inter-relationship between HIV infection and C. On the other hand, immunosuppression due to HIV may lead to more aggressive chlamydial disease conditions like PID in those who are infected. Thus, early diagnosis and treatment of chlamydial infections are important to prevent HIV risk and devastating clinical consequence. Clinical findings need to be corroborated with the laboratory investigations as the signs and symptoms of both are indistinguishable.

Therefore, in the syndromic approach used in resource-limited settings, urethral discharge UD is simultaneously treated for both. In individuals with gonorrhoea, there exists a per cent higher risk of acquiring Chlamydia. Further, individuals infected with both C. These data suggest that acquisition of a gonococcal infection either reactivates a persistent chlamydial infection or increases the susceptibility of the host to Chlamydia. Post-gonococcal urethritis is often due to C.

Co-infection of C. The co-infection of C. However, co-infection with N. Two cases with multiple infections were also reported i. In another study, the prevalence of C.

Thirty per cent of the Chlamydia infected cases had HIV infection, while the analysis revealed that 50 per cent of the HIV positive cases happened to be proven C.

The control of STD is a public health priority and the importance of these infections has increased in salience over the past decade, with the growing evidence of co- transmission of HIV. The CDC guidelines 59 for the prevention and control of STDs are based on five major concepts: i Education and counselling on safer sexual behaviour in persons at risk.

However, screening for chlamydial infection is not recommended for men, including those who have sex with other men Prevention of C.

Primary prevention involves preventing both exposure to and acquisition of chlamydial infection through lifestyle counselling and health education. Clinicians play an important role by enquiring about the risk taking sexual behaviour, by encouraging screening tests for those at risk, by ensuring that partners are evaluated and treated and by counselling about safe sex practices. Effective school based health programmes should be implemented among adolescents. Unfortunately, primary prevention has not gained popularity especially in the developing world Secondary prevention means early detection of asymptomatic disease by screening in order to prevent the drastic sequelae of chlamydial infection.

Chlamydial infection fills the general pre-requisite for disease prevention by screening, since these are highly prevalent, are associated with significant morbidity, can be diagnosed, and are treatable. Recent advances like testing non-invasive specimen, utilization of nucleic acid amplification tests and single dose therapy using azithromycin further enhance the efforts to prevent chlamydial infection. Tertiary prevention of acute and chronic chlamydial infection of the upper genital tract has largely failed because by the time patient becomes symptomatic substantial tubal damage already occurs.

The treatment of chlamydial infection depends on the site of infection, the age of the patient, and whether the infection is complicated or not. Treatment also differs during pregnancy.

Uncomplicated infection : The CDC recommends 1 g azithromycin orally in a single dose, or mg doxycycline orally twice a day bd for seven days for uncomplicated genito-urinary infection. Alternate regimens include erythromycin mg orally four times a day qid or ofloxacin mg orally bd for seven days. People showing signs and symptoms mentioned above can consult a general practitioner GP or family doctor. Women can also consult their gynaecologist. Most STDs are diagnosed with a simple swab test, wherein a sample liquid taken from the rectum, vagina, penis or mouth is tested in a laboratory.

A standard urine test is also commonly done. The disease responds very well to antibiotics. Many patients are able to fully recover from their condition a week after their antibiotic therapy. It is important for patients not to have sex until the infection has cleared up.

References :. Stevenson, Angus Oxford dictionary of English. ISBN Definition and Overview Chlamydia is one of the most common sexually transmitted diseases STDs that affects millions of people around the world. Contrary to what other people believe, it cannot be transmitted by: Sharing a sauna and swimming pool with infected individuals Using utensils used by an infected person Touching a surface that an infected person has touched or sneezed on Key Symptoms Many people with the disease do not show symptoms.

Women whose sex partners have not been properly treated are at high risk for re-infection. Retesting should be considered for women, especially teens, three to four months after treatment.

This is especially true if a woman does not know if her sex partner received treatment. If untreated, chlamydia can develop into serious reproductive and other health problems with both short-term and long-term effects. In women, untreated infection can cause pelvic inflammatory disease PID. This happens in 10 percent to 15 percent women with untreated chlamydia. PID can damage the fallopian tubes enough to cause infertility or increase the risk of ectopic pregnancy life-threatening pregnancy outside the uterus.



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