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Test for latent infections: list, what to take
Last reviewed: 05.07.2025
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In the conditions of modern life, we increasingly have to deal with various diseases. The problems of combating infectious diseases have acquired special significance in medicine. They are capable of causing various pathological changes in the body, provoking the spread of infection throughout the body. They are quite difficult to diagnose and treat, quickly develop resistance to drugs, and rapidly multiply. But the main danger is that they often cause mass epidemics, transmitted from person to person. Despite the rapid development of medicine, diagnostics, problems have not decreased. Today, hidden infections that are asymptomatic pose a great danger. A person often does not even suspect that he has a disease, however, it progresses. In addition, a person is a carrier and becomes a source of infection, infecting other people. Fortunately, today it is possible to detect such diseases and take timely measures. An analysis for hidden infections will help with this.
Latent infections are a whole complex of diseases that are transmitted mainly sexually and proceed covertly, unnoticed. They may not bother you for a long time.
Should I get tested for latent infections?
They need to be taken periodically, since it allows to detect those infections that develop in the body asymptomatically. They allow to detect such diseases at early stages and prevent their further development. Despite the fact that the disease does not bother a person, it still develops in the body and causes corresponding pathological damage at various levels: cellular, tissue, organ. Someday the infection will still manifest itself. Most often, it manifests itself when serious changes have already occurred in the body, often irreversible. At such a late stage, the disease is often quite difficult to treat, and sometimes not at all. Effective treatment can only be in the early period of detection of the disease, since the pathologies that develop as a result of infectious damage are irreversible.
This type of infection always reduces immunity and can lead to serious complications. Most latent infections are sexually transmitted, affect the reproductive organs and lead to infertility. Many of them are capable of destroying the genetic information of germ cells, which entails various genetic pathologies and anomalies in the subsequent birth of a child.
In addition, infections are dangerous because they can be transmitted to the child, leading to intrauterine infection. It does not matter who is sick: the mother or the father. Some infections can provoke the development of cancerous tumors and immunodeficiency states. Secondary pathologies develop against the background of infection: severe kidney and liver diseases, heart failure.
Indications for the procedure
The tests are carried out both by doctor's prescription and on the patient's own initiative. The reason for taking the test should be unprotected sexual contact with a stranger, frequent and promiscuous sexual relations.
An analysis is considered mandatory before pregnancy. For any pathological symptoms, such as pain in the abdomen, burning and discomfort in the genital area, discharge, a strong odor. At the slightest suspicion of pathology or disorder, you need to take the test, as well as in the case of sudden weight loss and loss of appetite. Many concomitant diseases give the doctor a reason to suspect the presence of latent infections. For example, frequent colds can be caused by latent herpes.
Preparation
To obtain reliable and maximally accurate results for latent infections, it is necessary to prepare for them. First, it is necessary to stop taking immunomodulators, antibacterial, antiviral and other antibiotics, vitamins. Do not use antiseptics, even local ones. All these substances can significantly affect the results, distorting them. For example, antibacterial drugs can temporarily reduce the number of microorganisms, or transfer them to an inactive form in which they do not develop.
During the stimulation of the immune system, there is also a temporary deactivation and decrease in the activity of any infection, and false positive results are possible. Such results indicate the presence of an infection in the body, while in fact there is none. This is explained by the fact that the number of immune complexes increases sharply, which can erroneously react with the indicator that determines the presence of an infection. The amount of certain substances that often indicate infections can increase sharply and the doctor incorrectly interprets the result.
Before taking the test, refrain from sexual intercourse for 2-3 days, which will allow the patient's natural microflora to be examined without introducing transient (temporary) flora. Also, do not douche, use local contraceptives, anesthetics, or personal hygiene products 24 hours before the procedure. This will allow the microflora to be examined in its natural state, without introducing foreign flora or destroying the existing one. It is best for women to monitor their menstrual cycle and take the test on the 5th-6th day of the new cycle. This will give the most accurate results, since during this period all infections are maximally activated due to a slight decrease in immunity.
Unlike regular tests, when alcohol and non-dietary food are excluded, here everything is completely the opposite: doctors recommend drinking alcoholic beverages and eating unhealthy food: fatty, spicy, sauces, marinades, spices the day before the test. This trick facilitates detection, which is usually well masked. Immunity decreases, and the infection is activated, making it easier to detect. For the same reason, if you have a cold, this is the ideal time to take such a test.
Who to contact?
Rules for taking tests for latent infections
The main rule is that you need to prepare for it in advance, approximately 3-5 weeks in advance. You need to stop taking any medications, especially those that affect the immune system, increase the body's resistance, and have a general strengthening effect. You cannot take medications that reduce inflammation or normalize microflora. You also cannot take sorbents and antitoxic drugs.
For 2 days, you must not swim, use local medications, or have sexual intercourse. It is better to take the test in a weakened state: under stress, hypothermia, fatigue, mild malaise. This will allow the infection to fully manifest itself, to become active.
What hidden infections are tested for?
Latent infections are a group of diseases that affect the body and develop in it latently. Most of them are STDs (sexually transmitted diseases). They affect both women and men. They are dangerous because if one partner gets sick, the other will definitely get sick too. There is also a risk of intrauterine damage to the fetus. They are called latent for another reason, because they are difficult to diagnose. It is almost impossible to detect them using conventional, traditional methods, specific diagnostic methods are required. The list consists of 31 pathogens. Among them, the most dangerous are mycoplasmas, chlamydia, gardnerella. The danger of these infections is that they are intracellular parasites. In this regard, they are very difficult to treat, since almost no medicine is able to penetrate the cell. They have developed a reliable defense system, with the help of which they can inactivate the drug and prevent its destructive effect. This gives them the opportunity to move freely in the extracellular space and actively reproduce. No less dangerous are herpes, syphilis, papillomas, cytomegalovirus, and fungi.
Analysis of latent infections in women
Usually blood and a smear are taken. Women need to undergo regular examinations, as the infection can cause the development of many diseases that subsequently lead to infertility. Below is a brief description of the main female hidden infections.
Mycoplasmosis is caused by microplasmas. It is a microorganism that occupies an intermediate position between viruses, fungi and bacteria. It is transmitted sexually, the first signs of the disease usually appear after 1.5-2 months. For men, such microorganisms are either harmless or can cause mild inflammation. In women, they cause numerous pathologies that are especially intense during pregnancy. Most often, they cause miscarriages and spontaneous abortions, stillbirths.
Chlamydia. The pathogen is chlamydia, an obligate intracellular parasite. In women, it causes inflammatory processes and erosions. It has the ability to penetrate the placental barrier, leading to fetal developmental abnormalities.
Herpes, cytomegalovirus. Significantly reduces immunity, provokes numerous infectious and inflammatory diseases. Causes frequent colds, tonsillitis, inflammation of the lymph nodes. It is mandatory to submit when registering for pregnancy, since it can complicate the course of pregnancy, can be transmitted to the child.
HPV – infection can develop latently throughout life. Often such infections manifest themselves only in old age in the form of numerous papillomas on the surface of the skin.
Candidiasis. The causative agent is a fungal microorganism that is activated by reduced immunity and dysbacteriosis. Candida are representatives of the normal intestinal microflora, but under unfavorable conditions they are capable of spreading throughout the body.
Actinomycetes occupy an intermediate position between fungi and bacteria. Representatives of the normal microflora of the oral cavity. In cases of excessive spread, they colonize other organs. They are the basis of sepsis.
Trichomonas cause inflammation and erosion. They do not show themselves for a long time. As a result, the woman infects her sexual partner. It can cause intrauterine infection of the fetus.
Hepatitis causes jaundice, a viral liver disease.
Bacterial vaginosis can occur as a result of infection or dysbacteriosis. It manifests itself as profuse discharge, burning, and pain.
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Analysis of latent infections during pregnancy
During pregnancy, a mandatory test for TORCH infections is taken, which includes a set of basic diseases that affect the fetus itself. This name encodes: toxoplasmosis, HIV, chickenpox, hepatitis, syphilis, chlamydia, gonococcal infection, rubella, cytomegalovirus infection. It is taken free of charge.
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Analysis of latent infections in men
The particular danger of latent infections in men is that they do not manifest themselves for a long time. The incubation period in this case is much longer than in women. Sometimes they manifest themselves only after years and even decades, causing latent inflammation and other serious disorders. Usually, diseases manifest themselves after a long incubation period with such dangerous diseases as prostatitis, prostate adenoma, various tumors, infertility. There are cases when the ability to fertilize is preserved, but the genetic information in them is still significantly affected. The fertilized fetus develops with genetic abnormalities. In addition, during sexual intercourse, both the expectant mother and the child are infected at the same time.
It is very important to take timely measures, to detect the disease at an early stage, so you need to undergo preventive examinations with a urologist. You need to prepare for the tests in advance. About a month before, stop taking any medications. You can urinate only a few hours before the test. For 3 days, you cannot swim, use anesthetics and antiseptics, or have sexual intercourse.
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Analysis of latent infections in children
Children often get sick due to hidden infections. The test should be taken if the child often gets colds, has a weakened immune system, or has a respiratory disorder. The test should also be taken if the child has been diagnosed with infectious mononucleosis.
The main clinically significant infections for a child are: measles, rubella, whooping cough, scarlet fever, meningococcal infection, hepatitis, acute intestinal infections. The analysis is prescribed by a pediatrician after a preliminary examination.
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Methods of analysis for latent infection
There are many methods that can be used to analyze latent infections. Conventionally, all methods can be divided into three large groups: bacteriological, immunological, molecular genetic.
A smear or scraping is usually taken to conduct a bacteriological examination. Most often, the material for the study is the secretion of the genitals, various secretions, sperm. The scraping is taken from the mucous membranes of the genitals. First, a preliminary microscopic examination is carried out, which makes it possible to detect signs in the smear that could indirectly indicate the presence of an infection. Most often, such signs are protein, mucus, fibers. Sometimes, the microorganism itself, which is the causative agent of the disease, can be seen under the microscope. Based on its appearance, one can roughly assume which group it represents.
Then the obtained material is sown on a nutrient medium. First, the seeding is done on a regular nutrient medium, incubated for several days in a thermostat. Then one or more colonies are isolated, immunological studies are carried out with them, which make it possible to approximately identify the microorganism. Then the grown colonies are transferred to selective nutrient media and to slants for further biochemical analysis. Incubated in a thermostat for a certain time, depending on the type and growth rate of the microorganism.
Biochemical studies and microscopy are conducted, which makes it possible to identify the organism by determining its species and genus. The degree of contamination, i.e. the concentration of microorganisms, is also determined. The advantage of this method is that it is possible to immediately select a drug that will be most effective against a given microorganism, and its exact dosage. Accordingly, it is possible to select a treatment that will be maximally effective and safe.
Immunological methods include a wide range of techniques. The principle of the method in most of them is to identify specific antigen-antibody complexes that are formed as a result of interaction between the antigen and the antibody. The antigen is a microorganism, or genes, proteins, metabolic products that are produced by it. The point is that they are foreign to the body.
The immune system is immediately activated, begins to produce antibodies against them - proteins aimed at destroying and eliminating the foreign agent. Antibodies attack antigens, stick to them, forming a complex immune complex, which is detected during the reaction.
Blood is needed to conduct the analysis. Blood serum is separated from the blood using centrifugation. The serum is then poured into test tubes and antigen is added to it. Incubate for several hours. As a result of the reaction, complexes are formed that precipitate. The concentration of antigen in the blood is judged by the turbidity of the solution.
Antigen-antibody complexes that precipitate are formed only if there is an antigen (infection) in the blood. In the absence of infection, complexes are not formed. The test tubes are compared with the international turbidity standard, and the turbidity is used to judge the number of microorganisms in the blood. A spectrophotometer can be used to more accurately determine the quantitative indicators. The liquid is poured into special cuvettes and placed in the device. Light rays are then passed through. Based on the refractive indices of light in the liquid, the device calculates the extinction indices. Based on these data, a recalculation is performed in a special computer program. The result is obtained as a concentration of infectious cells. A calibration graph is also plotted, which clearly presents all the data.
There is a similar method that detects antibodies rather than antigens. The method is no different, except that antigens are added to the solution instead of antibodies. A similar complexation reaction occurs if antibodies to a given infection are present in the body. But this method is less accurate, since the risk of false positive results increases. The fact is that antibodies can form to another infection, and even with normal inflammation. Despite the high specificity, the reaction can occur erroneously.
Of interest is the immunofluorescence method (IF), in which the obtained biological material is stained with a special fluorescent dye. The samples are studied under a fluorescence microscope. In this case, the cells of infectious agents and the products of their vital activity acquire a glow. The sensitivity of the method is 70%. Most often used to study syphilis.
The radioisotope method makes it possible to identify similar complexes in a flow of radioactive radiation.
Molecular genetic methods are based on the detection of the microorganism genome or the microorganism itself in the sample being studied. This group includes the genome sequencing method, PCR, and other methods.
General analysis for latent infections
A general idea of the processes occurring in the body can be obtained from a general blood test. It reveals the blood formula in detail, after reading which you can find signs indicating an inflammatory or infectious process, its severity. For example, an increased ESR, an increased content of leukocytes and neutrophils may indicate the presence of an infection. The leukocyte formula shifts to the left. Of course, such an analysis cannot show which specific microorganism caused such changes. Moreover, these indicators do not always indicate the presence of an infection. Similar indicators can be found in colds, inflammatory diseases, during the recovery period, in the presence of tumors. But this gives the doctor the opportunity to suspect violations and conduct a detailed study to find the causes.
Blood test for latent infections
Blood tests are performed mainly by immunological methods, which identify antigen-antibody complexes. The method is highly specific and makes it possible to detect the presence of infection at early stages. This test is taken if there is a suspicion of infection, if a person is often ill, does not recover for a long time, during pregnancy. This test should also be taken for prevention in order to timely detect pathology, in case of questionable sexual contacts, to exclude the possibility of infection, if any disease or discomfort in the genital area appears.
Urine analysis for latent infections
Urine analysis can be used to detect an infection of the genital tract and urinary organs. Normally, urine is a sterile fluid. Detection of microorganisms in it indicates the development of an infectious process. The study is carried out using a bacteriological method. Goleman culture is most often used. It makes it possible to isolate the pathogen, conduct its complete identification, and determine the concentration. If necessary, an effective drug can be selected and its dosage determined.
PCR analysis for latent infections
PCR, or polymerase chain reaction, is a molecular genetic research method, the essence of which is to detect DNA or RNA of a microorganism in the sample being studied. It is also possible to determine its quantity. The method is highly specific, the accuracy reaches 100%.
To detect, the material being studied is placed in a reactor, the necessary enzymes are added, which bind DNA and build a copy of it. The method is based on genome replication. Any type of infection can be determined, including hidden ones.
Smear analysis for latent infection
During a gynecological examination or consultation with a urologist, a smear is taken from the mucous membranes of the genitals. For detection, a microscopic method is most often used, in which a micropreparation is prepared from the obtained sample and studied under a microscope. The smear is also analyzed by other methods, such as PCR, ELISA. PCR is considered the most informative and accurate.
Sperm analysis for latent infections
The PCR method is used to test sperm for infection. Before taking the test, you must abstain from sexual intercourse for 2-3 days and not take any medications. Latent infection significantly reduces the ability of sperm to fertilize. At the early stages, you can take the necessary measures to detect the infection.
Express analysis for latent infections
The fastest method for detecting an infection is immunological methods. But it should be taken into account that they are used rather for general screening and monitoring. It makes it possible to detect an infection at an early stage and take the necessary measures. To detail the information, it is necessary to conduct parallel and other studies. If the test is performed incorrectly or the preparation rules are not followed, false positive and false negative methods are possible. To increase the reliability of the study, it is better to use several methods at once. For example, PCR and ELISA. On average, these tests take 1-2 days, depending on the workload of the laboratory. If necessary, they can be accelerated to 3-4 hours.
Normal values
It is impossible to judge normal values for a whole group of infections. Each specific infection has its own normal values. For example, opportunistic microorganisms should normally be present in the normal microflora. Both their decrease and increase lead to the development of the disease. On average, normal values for this group vary from 10 2 to 10 4 CFU/ml. Many pathogenic microorganisms should not be detected in the body at all. Their detection indicates infection.
Also, the norm indicators depend on the individual characteristics of the organism, the state of immunity, age. Some liquids should normally be sterile, while others, on the contrary, should contain microflora.
Decoding the analysis for latent infections
It all depends on the method used to conduct the analysis for latent infections. If a bacteriological analysis was performed, the result will be indicated as the name of the detected infection. The amount of infection in the body is indicated next to it. When conducting immunological and molecular genetic methods, the result may be positive if the pathogen is detected and negative if it is absent. When conducting two analyses in parallel, you can get contradictory information (at first glance). A negative PCR and a positive ELISA may indicate a recovery period after recovery from the infection. A positive PCR and a negative ELISA may indicate a chronic form of infection.