Q: My boyfriend has the dormant gene of TB. If I sleep with him, will I also get the dormant gene? If I do, will I be able to give blood and will it show up in all my blood test results?

A:You appear to be referring to dormant or latent TB infection, but have not mentioned your location. You do not have to worry about catching the infection from him, as long as it is dormant or latent. Not everyone infected with TB is capable of infecting others. Some of those infected with TB bacilli (Mycobacterium tuberculosis) have a dormant infection - meaning that it is inactive or latent and therefore have no symptoms. In these cases, a healthy immune system walls off the TB bacilli, which can then lie dormant in their bodies for years. Those with dormant or latent TB do not spread the disease, but they can become sick with active disease if and when their immune system is weakened - by poor nutrition, old age or HIV infection. Latent TB is diagnosed on the basis of a positive reaction to the TB skin test (Mantoux) or the QFT-G (Quantiferon TB gold). Your boyfriend's doctor would have done tests to rule out if he has active TB disease. These tests usually include a chest x-ray, and may also have included a test of sputum that he may cough up, as well as blood or urine tests if thought necessary. Many people who have latent TB infection never develop active TB disease. However, patients with active lung TB are capable of infecting others, and if your boyfriend develops symptoms that include persistent cough (for three weeks or more), coughing up mucus or blood, fever, night sweats and weight loss, you shall have to undergo testing as well. A person with dormant TB can receive prophylactic or preventive treatment to keep the infection from becoming active, and this involves taking a single drug (Isoniazid or INH) for six months.