Doc: M. marinum bacteria exposure comes via water
Dear Dr. Roach: I read your recent column about “flesh-eating bacteria.” Is it in any way related to Mycobacterium marinum?
My son is having multiple surgeries due to this, which was finally and correctly diagnosed after many weeks. It came on slowly over months, and has caused his hand to swell up greatly.
He remembered that he did get a cut on his hand while fixing a home water line that was in soil. He was told that it is rare, but it occurs all over this country. There is a creek near us, and recently a local newspaper announced that there was a “life-threatening” bacteria discovered in that creek, which empties into a local waterway.
His treatment was intravenous continuously for over a week, and now three strong antibiotics need to be taken for at least a year. Meanwhile, he continues with some surgery.
Dear N.F.: Mycobacterium marinum is a bacteria species closely related to tuberculosis. It is not related to the type of “flesh-eating” bacteria you read about periodically in the newspaper; those are group A streptococcus, which grows very rapidly (people can go from appearing well to being dead in hours) and needs immediate identification and surgery to treat; M. marinum grows slowly. It is uniquely related to water exposure, especially from fish tanks (both fresh and saltwater).
However, it has been reported after exposure to oysters and fish spines, and occasionally in swimming pools.
Treatment for M. marinum usually includes two or more antibiotics taken for months. Your son’s infection is worse than I have heard of, requiring surgery and antibiotics lasting over a year.
I looked up your local creek: It is contaminated by fecal bacteria (presumably from untreated sewage), not by M. marinum. I hope your son does well.
Dear Dr. Roach: Why do I get lightheaded just before I have a bowel movement?
This happens during the day or in the evening.
Dear R.E.: This is due to stimulation of the vagus nerve, which provides the nerves to your gut, but which also can slow down the heart. Yours is an exaggeration of a normal reflex. It can be extreme, with some people fainting when going to the bathroom.
Making sure you have adequate fluid and avoiding straining are the first steps in treatment.
Email questions to ToYourGoodHealth@med.cornell.edu.