Q: Is tuberculosis a contagious, or "catchy" thing? Can you get it if you have sexual relations with a person who has tuberculosis? If someone does this, should he or she see a doctor for a TB test?
A: Tuberculosis is contagious but it is not one of the diseases transmitted through sexual relations. The explosive problem of sexually transmitted diseases includes AIDS, syphilis, gonorrhea, herpes simplex, chlamydia, lymphogranuloma venereum, chancroid, granuloma inguinale, condyloma acuminata (genital warts), hepatitis, and Trichomonas.
The tuberculosis bacillus is transmitted through droplets expelled into the air by an infected person during normal breathing, while talking or sneezing, but especially when coughing. The number of TB organisms excreted into the air is greatest when the disease is extensive. The risk of "catching" tuberculosis is promptly reduced once an infected person starts anti-TB treatment.
It is very unlikely that you would get tuberculosis during a single sexual encounter with an infected person; a trip to the doctor for a TB test seems unnecessary.
OC Q: Could you please settle a family dispute? Does cracking your
knuckles cause any kind of problems, such as arthritis or enlarged knuckles?
A: Arthritis experts tell me there are no physical ill effects from cracking your knuckles.
Several readers have called with further questions about snake bites and snakes in Maryland. The On Call column of Nov. 20 was based on an excellent article by Drs. Gold and Barish in the September issue of the Maryland Medical Journal, which is available at the Enoch Pratt Library.
Dr. Margolis is professor of medicine and biological chemistry at the Johns Hopkins School of Medicine and associate dean for academic affairs at the school.