Once you have a positive skin test, it's necessary to rely on symptoms to determine if you have tuberculosis. A chest radiograph should be obtained if you have a cough lasting for 2 to 3 weeks, if you are bringing up mucus with blood in it or if you have fever or weight loss. Routine yearly chest radiographs usually are not necessary. Some people think that once they've been infected with the bacteria that causes tuberculosis, they don't need to take precautions or wear a mask when dealing with tuberculosis patients. Since there have been rare instances of persons being reinfected with a new tuberculosis strain, however, you should continue to take precautions.
Most adults are immune to varicella, even if they have no history of the disease.
If your test is negative, you should have the 2-shot varicella vaccine series. If you aren't vaccinated, you're at risk of getting chickenpox and spreading it to patients. A history of chickenpox infection usually means that you are immune. However, some people do get chickenpox a second time. This can happen even if a blood test is positive for immunity.