Tuberculosis (TB) Test

A tuberculosis test detects whether there has been contact with the bacteria. There are two ways to do it, and which one applies depends on what you need it for.

PPD or blood test: which applies

• PPD (skin test): a small amount is injected under the skin of the forearm and you must return in 48 to 72 hours to have it read. It is the usual one for work, school or daycare
• IGRA (blood test): a single visit, with no need to return. It is the one used for the immigration medical exam, and it is not affected by the BCG vaccine

If you received BCG in your home country, say so: the PPD can come back positive for that reason, and the blood test clears up the doubt.

What is it requested for?

• Employment requirements, especially in healthcare, education and caregiving
• School or daycare enrollment
• Immigration medical exam I-693
• Contact with someone who has tuberculosis
• Symptoms: cough lasting more than three weeks, fever, night sweats, weight loss

If the test is positive

Positive means contact with the bacteria, not necessarily active disease. Most people with a positive test have a latent infection: they are not contagious and have no symptoms. Telling them apart requires a chest X-ray and an assessment. You are told the next step and given the report.

With the PPD, keep in mind

• You must return in 48 to 72 hours, without exception: if it is not read in that window, it is repeated
• Do not scratch the area or cover it with bandages
• Some redness is normal; what is measured is the firmness, not the color

Walk-in and no insurance

Monday through Sunday, 9 AM to 9 PM.