Tuberculosis is a very troublesome disease. Whether it is for respiratory medicine, infectious diseases or even emergency departments, tuberculosis is a very, very troublesome disease.

This is not only the long treatment period and the longer period of the disease, but also the diagnosis.

Yes, tuberculosis is one of the most difficult diseases in the world to diagnose.

There used to be a popular joke among respiratory physicians, which probably goes something like this - if you are asked by an old professor to diagnose the patient's condition during the general consultation, and you are unlucky to be distracted and don't hear the patient's condition clearly, don't worry, you just need to cough lightly and then put on a very calm face and answer "tuberculosis cannot be ruled out".

No old professor can deny this diagnosis, and basically all respiratory diseases can be diagnosed with "tuberculosis cannot be ruled out". This can also show how many different manifestations of tuberculosis are present.

20% of tuberculosis patients have no symptoms or only mild symptoms, and even if they do, they are basically limited to "cough", "chest pain", "dyspnea", and "fever". In other words, people with tuberculosis are either asymptomatic or have no specific symptoms.

What about the introduction of imaging tests?

The situation is just as bad. There are no characteristic changes in the chest X-ray manifestations of pulmonary tuberculosis, and the doctors in the imaging department can only put forward the opinion of "suspicion of tuberculosis, please combine it with clinical practice" through some calcified spots, lesions occurring in the posterior segment of the apical non-upper lobe, dorsal segment of the lower lobe, and posterior basal segment, spherical lesions, and slow absorption of lesions.

CT has a certain complementary diagnostic value, but it is only for some lesions in occult sites, or lesions that are difficult to diagnose. CT scans, like X-rays, do not give a direct opinion on the diagnosis.

After two waves of unreliable diagnoses of symptoms and imaging, if doctors still think that it is possible tuberculosis (or because they simply can't think of other types of disease), they will diagnose the patient with an etiology.

The next most unreliable place appeared, because the diagnosis of tuberculosis is generally based on the detection method of sampling smear staining. The likelihood of a negative staining of a tuberculosis smear is too high in clinical testing. So much so that the diagnosis and treatment guidelines recommend that patients need to be tested for at least three consecutive sampling smear staining tests to minimize the possibility of false negatives - worse still, a positive smear is not necessarily tuberculosis, and nontuberculous Divergent bacterium, Divergent leprosy, Nukajun and Actinomycetes may also show false positives under staining.

As a result, the current "gold standard" recommends the use of fractionation for a more accurate diagnosis – but the positive rate of fractionation is still not ideal, and the overall period of time is not average. The modified Roche culture method commonly used in China needs to be cultured for four to six weeks, that is, one month to one and a half months, and about 30 to 45 days.

The well-known PCR technology can be used in the detection, which can amplify the DNA of the tuberculosis bacteria in a small amount of time, and amplify it hundreds of times in a short time to facilitate detection. However, the defects of false negatives and the inability to distinguish between Mycobacterium tuberculosis and non-tuberculous Divergent bacteria not only do not improve, but there are even more troubles such as the inability to distinguish between dead and live bacteria and the inability to determine clinical efficacy.

The tuberculin skin test (TST), which is also more specific, is even worse – after the age of three, the effect of this test is basically meaningless. The reason is simple, TST cannot tell whether the patient has a current infection or a history of infection. However, due to the widespread BCG vaccination for infants and young children in China, its reference is even worse. The devil knows if an adult who is positive for TST is vaccinated with BCG, or because they have been infected in the past, or if they are being infected.

Putting aside the advantages and disadvantages of the detection technique for the time being, can the patient be ruled out as having tuberculosis infection if three consecutive sputum smears are added and the test of one isolation and culture of Mycobacterium tuberculosis is negative?

The answer is no.

In the field of tuberculosis treatment, there is something called "bacterio-negative tuberculosis".

Even if the differentiatorium tuberculosis cannot be detected, if the patient has clinical symptoms of pulmonary tuberculosis (i.e., those that are not specific, and has lung x-ray findings) - the diagnosis of "bacterial negative pulmonary tuberculosis" can only be made if antituberculosis therapy is effective, other nontuberculous lung diseases have been excluded, a positive PCR test, a positive TST test, extrapulmonary histopathological examination confirms tuberculosis lesions, and bronchial or pulmonary histopathology confirms tuberculosis lesions.

Not to mention the differences in the manifestations of tuberculosis under various underlying diseases. Immunocompromised patients, extremely immunocompromised patients, AIDS patients, diabetic patients have different progression and various manifestations of pulmonary tuberculosis, and even pulmonary tuberculosis caused by bronchial tuberculosis is also different from the symptoms of primary pulmonary tuberculosis patients.

Tuberculosis is simply a huge psychedelic cube edifice. As long as you set foot in this area, you have to struggle to find out who I am, where I am, and where I am going.

Sun Lien has been working on diagnosis wholeheartedly for almost a year. He never found diagnosis a problem – as long as it didn't involve TB.

He even gave some face in the prayer status column, and when he met a tuberculosis patient, he directly prompted a "tuberculosis bacillus infection". Don't give some symptoms to reason about. But now it looks ...... The status bar doesn't seem to intend to give Sun Lien this face.

Liu Baoguo's symptoms are indeed somewhat similar to tuberculosis, although it is not certain why the high fever and the "low-grade fever in the afternoon" that usually occur with tuberculosis are different, but it is true that the possibility of tuberculosis cannot be denied on this basis. There are so many symptoms of tuberculosis that it is not surprising to have a high fever.

"Mr. Liu, you used to ...... Have you ever coughed like this?" Sun Lien instantly raised his vigilance to the highest level, and out of the sensitivity of a doctor who is engaged in diagnosis, he decided to make some inquiries about tuberculosis first, "In addition to back pain and high fever, have you ever had chest pain, difficulty breathing or coughing up blood during this time?"

"Ahem...... No, no, nothing. Liu Baoguo finally gasped for breath, he glanced at Sun Lien a little helplessly, and seemed to understand that his cough scared the young doctor, "I'm fine, I just accidentally choked on tea just now." ”

Choking on drinking water may have been just an accident, but it may also indicate that Liu Baoguo has a soft palate swallowing dysfunction — which may indicate a central nerve lesion, possibly some kind of infection, or a luminal infarction — some ischemic microinfarct that occurs deep in the brain.

"Then how many times have you choked on water in the past month?" Sun Lien was still a little uneasy, Liu Baoguo seemed to be the kind of patient who didn't like to cooperate with the doctor. Since he didn't want to take the initiative to say it himself, he could only ask little by little.

"Good guy, how can you pay it back if you choke on water every day?" Liu Baoguo glanced at Sun Lin very dissatisfied, "Don't say it's been a month, I haven't been choked in the past few years!"