In tuberculosis, the disease formerly known as consumption, patches or tubercules take up residence in your body and destroy tissue. You can catch TB when a person sick with untreated active tuberculosis of the lungs, not the latent form like I had, coughs, sneezes or spits — or sometimes just speaks or sings — in close proximity to you and you inhale their Mycobacterium tuberculosis. According to the Centers for Disease Control, you cannot get TB from toilet seats, sharing a drink or food, shaking hands, kissing or even sharing toothbrushes.
Certain segments of the population are more at risk of succumbing to any TB bacteria with which they come in close contact. Those are people with compromised immune systems, people with HIV infection, drug users, as well as those coming from developing countries where it is common. Also, people who live or work in prisons, homeless shelters and some nursing homes should be tested regularly.
The forms of this test have evolved over the years. I remember that staple-like tine test they gave out when I was a kid, when TB was more common. We’d be sent home with a card to compare our arm with and send in later. Currently the most accurate of the simple skin tests is the Mantoux, in which one cc of tuberculin is injected just under the skin of your forearm. The area may itch, burn or turn red but those aren’t signs of TB. After 48 to 72 hours, no more and no less, you must return to the healthcare professional who administered the test to get checked for an induration, or hardening, of a certain size. If it is over that size, you may have been exposed. It does not mean you are sick with active TB. A couple of blood tests such as QuantiFERON and T-SPOT, which are even more accurate, can test in cases when it may be unlikely that the person will return in two or three days to have a skin test checked, or to avoid false positive skin tests in the case of patients who have received the BCG (Bacille Calmette-Guèrin) vaccine against TB (usually overseas, where it’s much more commonly given than in this country).
Symptoms of active pulmonary TB can show up two or three months or even years after exposure. Generally the person may experience a persistent cough that lasts three weeks or longer, coughing up blood, chest pain, weakness, fatigue, chills, fever, night sweats, lack of appetite or weight loss. Each of these can be a symptom of other things, of course.
Pulmonary TB isn’t the only kind. The bacteria can also invade the brain, spine or kidney. A resistant strain, multidrug-resistant tuberculosis or MDR-TB, requires more aggressive treatment, like a two-year course of chemotherapy. Such drug-resistant TB is becoming more common, with hundreds of thousands of new cases worldwide each year. Rarer is extensively drug-resistant tuberculosis (XDR-TB).
