Detailed description of the study
The study is performed using the polymerase chain reaction (PCR) method and makes it possible to detect viral particles in the biomaterial being studied. The analysis is carried out both to establish the primary infection and exacerbation (reactivation) of the infection, and to monitor the effectiveness of therapy.
Cytomegalovirus infection (CMVI) is a disease caused by herpesvirus type 5 Cytomegalovirus (family Herpesviridae). Cytomegalovirus is one of the most common causative agents of congenital infection. It can affect all organs and systems of the human body, penetrate the placenta and cause severe impairment of the physical and mental development of the fetus. The virus persists in lymphoid organs for life and is activated under the influence of endo- and exogenous factors.
The source of infection is a sick person or a carrier of the virus. The pathogen is found in biological fluids:
- saliva;
- discharge from the nasopharynx;
- tear fluid;
- blood;
- urine;
- kale;
- sperm;
- breast milk;
- amniotic fluid;
- vaginal secretion;
- cerebrospinal fluid.
The main routes of transmission are airborne, household contact, sexual and parenteral. The virus remains in the human body throughout life. It does not cause disease in persons with normal immunity. But when it decreases, it can manifest itself. Therefore, CMV is especially dangerous for patients with immunodeficiencies and pregnant women. There are congenital and acquired forms of cytomegalovirus infection. Acquired forms of the disease occur in the form of pneumonia, hepatitis, infectious mononucleosis, pancreatitis, chorioretinitis, thrombocytopenia.
Based on clinical symptoms, there are 3 forms of CMV infection:
- latent;
- subclinical;
- clinically expressed.
Testing for cytomegalovirus infection is of greatest importance in the diagnosis of perinatal pathology. Intrauterine infection of the fetus in women with asymptomatic CMV infection is 30-50%. In 5-18%, a severe course of the disease is observed, often ending in death.
Most survivors still have severe organ damage, which leads to disability and low quality of life:
- mental retardation;
- cerebral paralysis;
- somatosensory insufficiency;
- visual impairment;
- hearing loss.
Therefore, when planning a pregnancy, it is recommended to get tested for CMV. It is also included in the complex of research on TORCH infections. Don't worry about a positive result. Even if the disease worsens during pregnancy, this form does not pose a great danger. If the result is negative, the woman is at risk and must follow the rules of caution.
Clinical manifestations of cytomegalovirus
The incubation period for cytomegalovirus ranges from 20 to 60 days. The acute phase of the disease lasts from 2 to 6 weeks: an increase in body temperature and the appearance of signs of general intoxication, chills, weakness, headache, muscle pain and bronchitis. In response to the initial introduction, immune restructuring of the body develops. After the acute phase, asthenia and sometimes autonomic-vascular disorders persist for many weeks. Multiple damage to internal organs.
Most often, CMV infection manifests itself as:
- ARVI (acute respiratory viral infection). In this case, patients complain of weakness, general malaise, fatigue, headaches, runny nose, inflammation and enlargement of the salivary glands, with copious amounts of saliva and whitish deposits on the gums and tongue.
- A generalized form of CMV infection with damage to internal (parenchymal) organs. Inflammation of the liver tissue, adrenal glands, spleen, pancreas, and kidneys is observed. This is accompanied by frequent “causeless” pneumonia and bronchitis, which are difficult to respond to antibiotic therapy; There is a decrease in immune status, and the number of platelets in the peripheral blood decreases. Damage to the blood vessels of the eye, intestinal walls, brain and peripheral nerves is common. Enlargement of the parotid and submandibular salivary glands, inflammation of the joints, skin rash.
- Damage to the genitourinary system in men and women is manifested by symptoms of chronic nonspecific inflammation. If the viral nature of the existing pathology is not established, the diseases do not respond well to antibiotic therapy.
Pathology of pregnancy, fetus and newborn are the most serious complications of CMV infection. The maximum risk of developing this pathology occurs when the fetus becomes infected during pregnancy. However, it must be remembered that problems often arise in pregnant women with the activation of a latent infection with the development of viremia (the release of the virus into the blood) with subsequent infection of the fetus. Cytomegalovirus is one of the most common causes of miscarriage.
Intrauterine CMV infection of the fetus leads to the development of severe diseases and damage to the central nervous system (mental retardation, hearing loss). In 20-30% of cases the child dies.
Sowing (method accuracy 95–100%)
A diagnostic method in which the test material, taken from blood, saliva, semen, discharge from the cervix and vagina, amniotic fluid, is placed in a special nutrient medium favorable for the growth of microorganisms. The disadvantage of this method is that obtaining results requires a lot of time: a week or more.
Cytomegalovirus tests are especially recommended for women planning pregnancy. It is also worth getting checked for those people who consider themselves to be quite healthy, but who are plagued by constant colds - this may be one of the manifestations of CMV. Timely diagnosis of cytomegalovirus infection will help not only to avoid the development of the disease, but also to prevent the possibility of transmitting the virus to family and friends.
Do you care about your health and the health of your family, are you planning a healthy and desired pregnancy? Our medical specialist offers you to undergo diagnostics for sexually transmitted infections, including cytomegalovirus. If necessary, our specialists, doctors of the highest category, will treat these infections.
Diagnosis of CMV infection
Diagnosis of herpesvirus (HSV and CMV) infections:
- The diagnosis of HSV and CMV infections can be made (especially in asymptomatic, atypical and latent forms of herpes) only on the basis of detecting the virus in biological fluids of the body (blood, urine, saliva, genital tract secretions) using the PCR method or with special culture of cells. PCR answers the question: the virus is detected or not, but does not answer the activity of the virus.
- Sowing a cell culture not only detects the virus, but also provides information about its activity (aggressiveness). Analysis of culture results during treatment allows us to draw a conclusion about the effectiveness of the therapy.
- IgM antibodies may indicate either a primary infection or an exacerbation of a chronic infection.
- IgG antibodies only indicate that a person has encountered the virus and an infection has occurred. IgG in herpesvirus infections persists for life (unlike, for example, chlamydia). There are situations in which IgG has diagnostic value.
Read more about taking tests to diagnose CMV infection.
Chlamydia trachomatis, DNA [real-time PCR]
A study to identify the causative agent of urogenital chlamydia (Chlamydia trachomatis), during which the genetic material (DNA) of chlamydia is determined using the real-time polymerase chain reaction (RT-PCR) method in a sample obtained from the urogenital tract.
Synonyms Russian
Chlamydia, the causative agent of chlamydia.
English synonyms
Ch. trachomatis, DNA (qPCR, Real-time PCR, RT-PCR), Chlamydia trachomatis by Amplified Detection.
Research method
Real-time polymerase chain reaction.
What biomaterial can be used for research?
Urogenital smear (with prostate secretions), the first portion of morning urine, ejaculate, rectal smear, smear from the gingival pocket, smear from the conjunctiva.
How to properly prepare for research?
- Women are recommended to take the test before menstruation or 2 days after it ends.
- Men should not urinate for 3 hours before taking a urogenital smear or urine.
General information about the study
Chlamydia trachomatis is a bacterium, an intracellular parasite, the causative agent of several human diseases. In particular, some serovars of this species cause trachoma and lymphogranuloma venereum. In Russia, the most common chlamydial infection of the genitourinary system (urogenital chlamydia). It is transmitted sexually, as well as from mother to child during childbirth. Contact-household transmission is also possible. Chlamydia trachomatis is the most common causative agent of nongonococcal urethritis. Chlamydia is more common in women than in men.
The incubation period ranges from 2 weeks to 1 month. Often (in about half of the cases) chlamydia is asymptomatic.
Initial symptoms of infection: burning and pain when urinating, mucous discharge, cloudy urine, weakness, slightly elevated temperature, in men - inflammation of the urethra, which lasts a long time, in women - mucous or purulent discharge from the vagina. In the future, various complications may occur: epididymitis, endometritis, conjunctivitis, arthritis, etc.
It is believed that chlamydial infection is dangerous during pregnancy, as it can lead to premature birth, miscarriage, low birth weight of newborns and even fetal death.
In addition, a newborn baby sometimes becomes infected with chlamydia from the mother when passing through the birth canal, which is why he develops conjunctivitis or pneumonia.
To diagnose chlamydia, serological methods (for example, ELISA), chlamydia culture, and detection of bacterial DNA (for example, PCR) are used.
Serological methods and culture have a number of limitations, so PCR-based tests are considered the most convenient and sensitive.
Real-time PCR (RT-PCR) is a laboratory method that allows you to find the DNA of a pathogen in a sample: if Chlamydia trachomatis is present in the sample, then real-time PCR will detect the DNA of this bacterium. The principle is that the DNA of the pathogen that they want to identify is copied many times using special enzymes (DNA polymerases). Typically, several dozen cycles take place and during each cycle the desired DNA is doubled. As a result, the amount of DNA being studied increases millions of times and can be detected using a fluorescent dye.
With real-time PCR, the amount of DNA is detected during the copying process, after each cycle. But at the same time, using RT-PCR it is impossible to distinguish between forms of infection (for example, newly acquired or old infection).
The best material for analysis is considered to be morning urine (in men) or a vaginal smear.
What is the research used for?
To diagnose Chlamydia trachomatis infection and monitor its treatment.
When is the study scheduled?
- To diagnose urogenital chlamydia with the following symptoms: burning and pain when urinating,
- redness in the area of the external urethral opening in men,
- mucous discharge from the genital tract,
- cloudy urine
- weakness,
- low-grade fever.
What do the results mean?
Reference values: negative.
Negative result
- There is no chlamydial infection. The inflammation is caused by another pathogen.
Positive result
- Chlamydial infection is present. If there is inflammation, it is likely caused by chlamydia. In this case, the DNA content in the sample is high.
- Chlamydia is present, but inflammation may be caused by another pathogen. In this case, chlamydia DNA was detected in small quantities.
Also recommended
- Chlamydia trachomatis, IgM, titer
- Chlamydia trachomatis, IgG, titer
- Chlamydia trachomatis, IgA, titer
- Culture for Chlamydia trachomatis
- Culture for Chlamydia trachomatis with determination of sensitivity to antibiotics
Who orders the study?
General practitioner, therapist, infectious disease specialist, gynecologist.
Literature
- Goldman's Cecil Medicine. 24th ed. Goldman L, Schafer AI, eds. Saunders Elsevier; 2011.
- Howie SE Chlamydia trachomatis infection during pregnancy: known unknowns. Disco Med. 2011; 12(62): 57 – 64.
