20 18 examination methods of pulmonary tuberculosis in American immigrants' physical examination

# American Immigration # Introduction Tuberculosis examination is an important item of physical examination before entering the United States, which directly affects whether you can pass the visa. So how to check tuberculosis? Next, let's take a look at the 20 18 introduction of tuberculosis examination methods for American immigrants. A, TuberculosisSkinTest (tuberculosis skin test)

Inject 5 units of tuberculin into the skin and observe the results after 48-72 hours. If there is no response, it is negative. For high-risk groups, if there is a red mass larger than 5mm, it is considered positive; For people at moderate risk, masses larger than 10mm are regarded as positive; Low-risk people with a mass greater than 15 mm are considered positive. See WebMd instructions.

Second, if the skin test of tuberculosis is positive.

You can arrange a chest X-ray to check whether there are shadows in the lungs. If there is no abnormality, there may be two situations: (a) many people in China have been vaccinated with BCG, and there will be false positive reactions; (two) have been exposed to tuberculosis, but cured by autoantibodies or other reasons, there is no active tuberculosis in the body.

Third, if the chest radiograph is normal.

However, if you want to further confirm whether it is (a) or (b) mentioned above, you can do another blood test, QuantiFERON-TBGoldTest, which is a new detection method approved by FDA in 20065438+0, without interference from BCG.

You may have noticed that tuberculosis skin test is obviously subjective (including how to define high-risk groups and accurately measure tumor size), and it is interfered by false positives such as BCG, and the accuracy is low. So, can you do a chest X-ray directly, or even QuantiFERONTBGoldTest?

It should be possible (please consult a doctor), but the immigration physical examination includes free TB skin test, while the chest X-ray is charged (35~65 dollars), and you may need to go to the radiology center. QuantiFERONTBGoldTest is going to the laboratory, and the charge is relatively expensive (about $350). Therefore, most people still do a free tuberculosis skin test first: everything will be fine if there is no problem; If there is any problem, pay for further inspection.