**2. Diagnostic methods and detectability of chlamydia infection in the light of a socio-psychological approach**

Laboratory diagnostic method of chlamydia infection is of paramount importance due to the frequent absence of specific clinical manifestations. The gold standard for the diagnosis of chlamydia infection is currently considered to be the nucleic acid amplification test (NAAT), which is positioned as highly sensitive (99%) and specific (WHO 2016). Its undoubted advantages are accessibility, speed, and the possibility of mass examination of a large group of patients. The quality of diagnostics depends on the quality of test systems used, the quality of sampling, and storage of biomaterial.

Other diagnostic methods are culture, direct fluorescence of antibodies, enzyme immunoassay, and immunohistochemical assays.

#### *Organizational and Socio-Psychological Difficulties of Management of Patients with Chlamydia… DOI: http://dx.doi.org/10.5772/intechopen.109748*

The cultural method, previously considered a reference due to its high specificity, has receded into the background. This is due to the labor intensity, high cost, strict rules for the transportation of clinical samples, high requirements for the qualification of medical personnel, as well as low sensitivity (33–85%). The detection rate of chlamydia is low in inactive stage and chronic ascending infection. Currently, it is not used in routine diagnostics, but is carried out mainly for special indication.

The method of direct immunofluorescence of antibodies is highly specific, fast, but "good in the right hands." It depends on the quality of the test systems used, the quality of biomaterial sampling, and requires high professionalism of a specialist in luminescent microscopy. This method is highly sensitive and highly specific mainly when performed correctly by an experienced laboratory technician. Otherwise, it is impossible to exclude both false-positive and false-negative results of the study.

Enzyme immunoassay determines the presence and titer in the blood of antibodies to chlamydia—Ig G, Ig M, Ig A. It allows us to find out the stages and nature of the course of infection, its activity. However, chlamydia antigens have weak immunogenicity, so the production and accumulation of antibodies to them occur in small quantities. Antibodies to chlamydia are found only in about half of patients. The absence of immunoglobulins does not allow us to talk about the absence of chlamydia infection in the body. If only Ig G to chlamydia is detected, it is impossible to diagnose an existing disease, but only to assert that the body has met with the pathogen. Enzyme immunoassay may be appropriate for verification of persistent infection.

All these methods are among the additional ones and in most countries are not included in the most common health insurance programs. The clinical guidelines recommend a single method, nucleic acid amplification test (NAAT), for suspected chlamydial urogenital infections. It is positioned as highly sensitive and highly specific, and available and adequate. Has the problem of diagnosis of chlamydia infection been solved?

Unfortunately, it is not that simple. The detectability of chlamydia infection has sharply decreased with the transition exclusively to the NAAT method. This is particularly true in cases of ascending infection, chronic persistent course, and fibrosis processes in women (chronic cervicitis and endometritis, adhesions in the pelvis, obstruction of the fallopian tubes, reproductive losses). Many researchers note the difficulties when diagnosing widespread forms of chlamydia infection with a prolonged, recurrent nature of the course. Persistent forms of chlamydia are difficult to verify by microbiological methods due to changes in metabolism and antigenic structure. The pathogen is often inaccessible for diagnosis in complicated ascending infection. In these cases, in order to reliably verify the pathogen, it is necessary to expand the list of clinical specimens obtained not only from the cervical canal and urethra, but also from other organs.

An important diagnostic criterion may be an enzyme immunoassay that determines antibodies to chlamydia in the blood. Unfortunately, a suppressed immune response may also limit the possibilities of serodiagnosis. Against this background, the focus of specialists has shifted toward viruses, bacterial films, and non-specific opportunistic flora identified in such patients. However, the possibility of a chronic persistent chlamydial infection undetected by NAAT cannot be excluded. The latter assumption may be supported by cases of C. trachomatis isolation in such patients using a culture method and its detection also by a culture method in partners. In clinical practice, patients with recurrent exacerbations of chronic genital inflammatory diseases and negative NAAT of urethral and cervical duct material are often found to have C. trachomatis Ig A, indicating an active course of chlamydial infection,

C. trachomatis Ig G, and C. trachomatis heat shock protein Ig G (cHSP60) in their blood by enzyme immunoassay [6, 7].

The problems of diagnosing chlamydia infection are related to the fact that there is currently no unified algorithm for examining patients with suspected chronic, persistent chlamydia infection. It is this form that occurs most often. A comprehensive competent approach to the diagnosis of chlamydia using several methods and a scientifically based assessment of the results obtained may be optimal. Detection of chlamydia, determination of the nature of the infectious and inflammatory process, and the extend of the lesion are important for the correct choice of therapy.

What happens in practice? The possibilities of using the entire set of tests for the diagnosis of chlamydia infection are small. This is expensive, not covered by health insurance programs. Doctors who work in insurance medicine cannot use additional tests if the NAAT test is negative. Ethical and financial problems are also important. Is it ethical to offer patients additional tests if they are not included in clinical guidelines, there are no other approved algorithms of examination in chronic ascending processes, and NAAT methods are positioned as highly effective?

It is also worth noting the psychological problems of patients. When several diagnostic tests are used and a chlamydial infection is found in only one of them or in only one of the partners, questions almost always arise. Why focus on tests that show the presence of a chlamydial infection and not those that do not? Why was one partner diagnosed with chlamydia, and the other did not? What does all this mean? These questions cause patients to doubt the correctness of the diagnosis, the competence of the physician and medicine in general, and difficulties in achieving compliance with the physician about the therapy. The result can be refusal of therapy, violation of doctor's recommendations, development of stress and anxiety disorders in patients, conflicts between partners (each may have his own opinion and his own motivation for treatment), and lack of faith in the cure.
