• Question: Can humans catch TB from cows? If so is it the same as the deadly human TB virus, is it as bad? What would be the effects of cathcing TB from cows if possible?

    Asked by abihoulbrooke to Cat, Daz on 13 Jun 2011. This question was also asked by hifive5, poppy, macnaberz.
    • Photo: Cat O'Connor

      Cat O'Connor answered on 13 Jun 2011:

      Hi Abihoulbrooke, Great to hear from you again!
      So here’s a quick microbiology lesson 😀

      • TB in humans is caused by a bacteria called Mycobacterium tuberculosis or M. tb for short
      • TB in cattle (called bovine TB) is caused by a bacteria called Mycobacterium bovis or M. bovis for short
      • Both these bugs cause a similar chronic disease mostly of the respiratory system
      • Both of these bugs are also zoonotic which means that M. tb can make animals sick and M. bovis can make humans sick too

      So humans can catch bovine TB from cows and it’ll look very like a human TB infection. Doctors will take samples from the patients (normally phlegm or spit samples) and will grow the bugs in the lab to see which one the person is infected with. One kinda cool thing about these bugs is they are pretty slow, I like to think of them as like really really old people. In the lab when you try and grow them, they do everything really really slowly! It can take them up to three months to grow which most bugs will grow in 24-48 hours! Anyway, while these lads are growing in the lab the doctor will give you antibiotics to get rid of the infection. You often have to take antibiotics for a very long time to make sure you get rid of all the bug from your body. Thankfully, unlike the human type of TB, M. bovis is not as resistant to antibiotics so it can be treated easily enough.

      Now saying all this, a person getting sick from a cow is very very rare! Back in the days of your grandparents and great grandparents time, it used to be really common as you could get it from the milk. But now all milk is pasteurised or from herds that are testing very frequently to make sure they are not sick. So I wouldn’t worry too much about it 😀

      One thing that would happen if more people got TB from cows is that more would be done to control it in cows and wildlife but I wouldn’t wish that for the world!!