The great challenge for the control of chlamydia is precisely in its diagnosis, because infected people usually do not show symptoms. About 50% of men and up to 70% of women are asymptomatic. This scenario makes it difficult to recognize the disease and treat it at an early stage. But even without showing any visible signs, there can be serious consequences, especially in the long term.
CHLAMYDIA: WHAT IS IT?
Chlamydia is an infection caused by the bacterium Chlamydia trachomatis , transmitted through direct sexual contact. They mainly affect sexually active adolescents and young adults. According to the World Health Organization, it is the most common of all bacterial STIs, with 131 million new cases every year. In Brazil, it is estimated that there is an annual incidence of 2 million new cases / year.
Not all people infected with chlamydia have symptoms, and the infection may go undetected for many years. Asymptomatic patients with chlamydia become permanent sources of contamination. The high numbers of cases are mainly due to those who transmit not knowing that they are infected and those who have been contaminated do not know who they got it from.
Although they cause curable infections, such as endocervicitis, in women, and urethritis, in men, these diseases can cause serious complications when not properly diagnosed and treated. The main complication of chlamydia infection in women is the progression of the bacteria towards the uterus, tubes and ovaries, as it can cause pelvic inflammatory disease (PID). As well as subsequent sequelae like ectopic pregnancy and infertility. In addition, studies suggest that C. trachomatis infection is an independent risk factor for the development of cervical cancer. In addition to increasing the risk of HIV acquisition and transmission by up to ten times.
Men can develop complications such as inflammation of the prostate (prostatitis) or inflammation in the testicles (orchiepididymitis), preventing the passage of sperm, as well as the possibility of infertility.
Another major concern is the risk of transmission from mother to baby during normal birth. The newborn may develop ocular (conjunctivitis) or pulmonary (pneumonia) infection. About a third of neonates exposed to the pathogen during delivery can be affected. In the mother, the infection can cause abortion, premature birth or even neonatal death.
SYMPTOMS OF CHLAMYDIA
When present, the most common symptoms in women are:
- yellowish or clear discharge
- spontaneous bleeding or during sexual intercourse
- pain when urinating, during intercourse or in the lower abdomen (bottom of the belly)
And in men, the most common symptoms are:
- burning when urinating
- urethral discharge with the presence of pus
- testicular pain
DIFFICULTIES IN CHLAMYDIA DIAGNOSIS
It is known that 35% to 50% of women infected with C. trachomatis are co-infected with N. gonorrhoeae , which makes this scenario even more worrying. Since both are mostly asymptomatic and, in the presence of symptoms, clinical syndromes may overlap.
Therefore, the clinical diagnosis is not very sensitive in such cases, which necessarily implies diagnostic confirmation by laboratory methods. There are several techniques like cell culture , direct immunofluorescence (IFD) , indirect immunofluorescence (IFI) and the immunoenzymatic assay ( EIA or ELISA ).
The immunoenzymatic assay is recommended for epidemiological studies and systemic infections, such as pneumonia in newborns, LGV, salpingitis, epididymitis, infertility, ectopic pregnancy, where IgG antibody titers are often elevated. It is not recommended for the diagnosis of urogenital infections because of the frequency of exposure to C. trachomatis serotypes and the occurrence of cross reactions with other species, especially C. pneumoniae , making it difficult to value antibody determinations in a single sample.
The technique considered as the gold standard is culture, but it requires a larger laboratory infrastructure, as it requires special care with the sample. The advantage of culture is the low probability of contamination and the preservation of the microorganism for further studies, such as the susceptibility test to antimicrobial therapy and genotyping.
Currently, the most accurate methodology is molecular diagnosis. Very well known and used in HPV research, molecular biology gains space to help in the analysis of agents that cause urogenital infections, many of them considered sexually transmitted infections. Among them, infection by Chlamydia trachomatis .
They are more complete in terms of sensitivity and specificity because they allow the identification of the infectious agent in samples with low concentration of the pathogen, without risk of false positive results. In addition to some molecular tests detecting in a single sample, different pathogens that cause the main STIs.