Tuberculosis is a dangerous infectious disease that affects the internal organs of humans and animals. Mostly the lungs come under attack, but there is also tuberculosis of the kidneys, bladder, bones and other organs and systems.
Despite modern methods of diagnosis and treatment of this disease, statistics on the spread of tuberculosis remains sad. This is especially true of Russia. According to some reports, Russians are at ten times more likely to become infected than residents of developed countries. In addition, tuberculosis occurs even in members of wealthy families with a high standard of living. Therefore, it is so important to regularly undergo medical examinations and, if necessary, take a sputum test for tuberculosis.
Etiology of tuberculosis
The causative agent of this dangerous disease is Koch's wand. This is mycobacterium (lat. Micobacterium tuberculosis), which is transmitted by airborne droplets. The bacterium belongs to the class of fungi, has a small size and a dense shell, which allows it to survive in the environment and makes the microorganism very tenacious. This explains the prevalence of the disease - they can become infected during a normal conversation with the patient, especially if he sneezes or coughs at that time.
The insidiousness of the disease lies in the fact that in most cases it is asymptomatic. According to statistics, only one out of ten cases takes an active form.
What are the first signs of tuberculosis?
The first alarming symptoms will be:
- Prolonged lingering cough.
- The appearance in the sputum of traces of pus and blood.
- Subfebrile temperature values.
- Weight loss.
- Lack of appetite.
- Constant feeling of tiredness.
If you have one or more symptoms, you must pass an examination. Especially if there is a cough with a suspicious secretion. It is necessary to undergo fluorography, which every Russian should do once a year.
In the event that any formation is detected in the image, the diameter of which will exceed one centimeter, a person is required to be sent for additional tests.
What does sputum look like for tuberculosis?
In the initial stages, the patient has only a dumb secret. Usually it is white mucus , due to its high protein content.
In subsequent stages, streaks of blood and pus appear in the mucus. At this stage, the color of sputum can be yellow, green and even red. It all depends on the ratio of blood and pus in it. A photo of sputum in tuberculosis of the last stages is presented below.
In the initial stages, sputum is usually viscous and contains a lot of mucus. As the disease develops, a large amount of moisture appears in it, which makes it more liquid. Based on this, we can conclude that sputum with tuberculosis can be of very different consistency.
Diagnosis of tuberculosis
In medical diagnosis, there are several ways to determine the disease in patients. The most common of these is sputum bacteriological culture.
Sputum analysis for tuberculosis is carried out in two stages:
- External examination of sputum (macroscopy).
- Bacteriological culture (microscopy).
Sputum collection for tuberculosis
How to carry out the procedure for collecting biological material? A person with tuberculosis has a huge amount of Koch sticks in his sputum. In the study of mucous secretions, you can detect the pathogen and make a conclusion about the presence or absence of the disease in the patient.
However, for accurate and reliable results, the patient must properly prepare for the test and collect sputum for tuberculosis mycobacteria in accordance with all the rules:
- It is extremely important to carry out the analysis in the morning, since a large amount of secretion accumulates in the upper respiratory tract overnight. This will help him easily move away from the walls of the bronchi in the morning.
- The patient should postpone breakfast until the biomaterial is collected. The fact is that eating can change the composition of sputum with tuberculosis, as well as complicate its discharge.
- Some doctors advise patients to pre-take an expectorant to facilitate the passage of biomaterial.
- You should pay attention to the fact that it is necessary to collect sputum, and not saliva.
- Before taking the test, it is necessary to brush the oral cavity with a brush with toothpaste, and then rinse your mouth with boiled water. This will help prevent any foreign bacteria from getting into the sputum. Teeth should be brushed with a toothbrush with a hardness not higher than average. This will reduce the risk of injury to the gums and prevent blood from entering the sputum. With tuberculosis, it can be present in biological material only in the late stages of the disease.
- Biomaterial is rented in a special container, which can be purchased at any pharmacy. The container is sterile and has a screw cap that must be opened immediately before taking sputum. After collection, the container is immediately closed.
- For a more productive discharge of sputum, the patient should take three deep breaths, and then coughed effectively.
- The amount of material required for a successful analysis can usually be obtained in two to three expectorations.
- It is very important to take sputum in a well-ventilated area. Entrance to it must be marked with a special sign, which means that outsiders are strictly forbidden to enter here. Doctors should have a certain level of protection in the form of a mask or respirator.
Analysis
Even at the initial stages of the disease, the sputum of a patient with tuberculosis externally differs from the norm. It acquires a grayish or greenish color, pieces of mucus or pus are present in it. In the first stages, the presence of blood is completely optional, this is more characteristic of the cavernous stage, when the integrity of the vessels is already violated.
When examined under a microscope, oval or slightly curved sticks are found. The length of which is from 1 to 10 microns, and the diameter is from 0.2 to 0.6. Mycobacterium tuberculosis in sputum is as follows: pay attention to the photo below.
In addition, using a microscope, you can detect calcium salts, cholesterol, elastic fibers. All these are products of the breakdown of lung cells. Finding them in the analysis suggests that the process of organ damage has already begun.
Then bacteriological culture of sputum is carried out for tuberculosis:
- The laboratory assistant conducts sputum culture on a nutrient medium placed in a Petri dish.
- At the second stage of the work, the preparation is stained using the Ziehl-Nelson method. This method involves clarification with a fuchsin carbolic solution. After that, the drug is exposed to a number of chemicals (hydrochloric acid, sulfuric acid).
- The next step is to stain the drug with methylene blue.
- As a result, the entire drug turns blue, and tuberculous bacilli do not stain. Therefore, in case of infection, they will be very clearly visible. If the whole preparation is blue, then this will mean the absence of tuberculosis in the patient.
How many times is this analysis required?
It is worth considering that the first negative result is not a guarantee of health. The fact is that, although this method is very sensitive, it guarantees the reliability of the result only if at least 100 thousand mycobacteria are present in 1 ml of the sample. Therefore, if there is a suspicion of tuberculosis in the patient, he needs to pass sputum two more times with an interval of 1 month.
The sensitivity of the first analysis is 80%, while the second and third are 90% and 97%, respectively.
If all three analyzes are negative, we can safely conclude that the patient is healthy. A sputum test for tuberculosis lasts about two to five weeks. So much time is required to identify pathogens in sputum.
Bronchoscopy Another method for diagnosing tuberculosis
However, bacteriological analysis is not always possible. There are times when expectoration of biomaterial is ineffective. What to do in such situations? In medical diagnostics, there is a method of bronchoscopy, when a specialist using the device takes samples of bronchopulmonary tissue.
This procedure is done after local anesthesia to the patient. If the patient is a child who cannot lie calmly during the procedure, then general anesthesia will be required. Bronchoscopy lasts several minutes, during which the specialist introduces a small manipulator through the nasal or oral cavity. At the end of the device there is a probe capable of capturing the right amount of sample.
One of the advantages of this method is the ability to remove the pathological secretion from the patient's bronchi.
PCR The most advanced method for diagnosing tuberculosis
One of the most modern methods for diagnosing tuberculosis is to carry out a polymer chain reaction, which consists in isolating a mycobacterium DNA fragment from the biomaterial, which allows us to conclude that the patient is infected.
Its main plus is expressiveness. The result of the analysis is ready in 3-5 hours, which means that you do not need to wait a few weeks, as is the case with bacteriological culture. The advantages of the method can also include:
- High reliability of the results.
- Small amount of material needed for analysis.
- The ability to conduct analysis in any biological material.
The disadvantages of the method are:
- Its high cost.
- Inefficiency analysis after anti-TB treatment. The fact is that a recovered person has dead mycobacteria in the body. In this case, PCR will still give a positive result, despite the fact that the person is already healthy.
Conclusion
In the modern world, tuberculosis has ceased to be considered a fatal disease, as it was recently. This disease is treated, and quite successfully. The main thing is to timely detect the pathogen in your body. For this, in medical diagnostics there are several effective methods for detecting mycobacterium tuberculosis: fluorography, bacteriological culture of sputum for tuberculosis, bronchoscopy, PCR and others. Do not neglect this opportunity. You need to regularly undergo medical examinations, monitor your general well-being, and try to improve your standard of living.