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Working with Mycobacterium tuberculosis

  1. Mar 1, 2005 #1
    i will work with this bacteria, but am afraid of get infected and eventually get tuberculosis. are there any people who work within this area who can calm me down? should i work with it or not?

    thanks. :smile:
  2. jcsd
  3. Mar 1, 2005 #2
    my boss gives me 2 days to think about it. so please, give me your thoughts. thanks. :smile: :smile:
  4. Mar 1, 2005 #3


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    It will depend if you will be working in a lab or in the "field". Mycobacterium tuberculosis is a biosafety class 3 microorganism and labs working with it will have sufficient protection that reduce the odds of infection to a very low level. It is possible that you get infected but it will depend on people and you respect the safety codes. If everything is respected and good pratices are used, it is near impossible to get infected.

    For guideline for lab biosafety, http://www.who.int/csr/resources/publications/biosafety/en/Biosafety7.pdf

    As far as working in the field (with patients), you are more prone to get infected. Patient are infectious only during certain periods of time (i.e. when people cough). Also, you have, if you are healthy, a 10% of developing TB once infected. The antibiotic treatment is efficient but it is a long treatment (6 month to 2 years). Antibiotic resitance is starting to spread. As far as vaccine goes, it does not protect adults but they working on improve candidate. So in the field you are more at risk but it is low and acceptable.
  5. Mar 1, 2005 #4


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    I work with this bug (I'm a microbiologist). Ian is correct, it is a BSL 3 level bug, transmissible by airborne spread (droplet nuclei), and that means there is a significant risk of laboratory acquired infection *if* you work with it without following correct safety procedures. The type of work done with the bug is very important in determining risk. If all you're doing is manipulating "inactivated" organisms in small quantities, then the risk is low. If OTOH, you're working with live cultures, you have to be very, very careful.

    You have to look at it in terms of :

    a) the facility design :

    A BSL 3 facility has to have a particular design, including negative pressure within the lab, with the exhaust being HEPA (high efficiency particulate air) filtered and discharged away from other buildings. There is nothing much you can do about the design of the overall facility, but you can assure yourself that it meets some basic requirements.

    b) Work practices :

    For actual manipulation of live cultures, you need to work within a Biosafety Cabinet (BSC), and Class II is the minimum. You need to understand that this is not absolute protection and it works only as long as you respect the airflow pattern (don't block the vents, no sudden violent movements within the cabinet, minimise aerosolisation of liquids), etc.

    In addition, you need to be careful when doing basic lab things : e.g. centrifugation should ALWAYS be carried out within safety cups, and preferably within the BSC. Same thing for vortexing, always covered, and in the BSC.

    c) Personal protective eqpt :

    Personal protective equipment is VERY important. Since this is an airborne bug, you need respiratory protection, like a filtering respirator of grade at lease N95 (N97 and N99 are also fine). You must be properly fit tested for the respirator you're using. Or you can use a PAPR hood which looks like the top of a space suit and pumps air downward through your head area so you're relatively protected. You need to wear front closing impermeable gowns, shoe covers and gloves. Use goggles or (even better) a face shield if working with infectious fluids. You need eye protection all the time if using contact lenses.

    Apart from all that, just use your common sense. Be cautious and alert, but don't get paranoid and refuse to touch anything to do with it. We all have to face our fears and our worries sometime, and all you need to do is equip yourself with knowledge.

    Good luck.
    Last edited: Mar 1, 2005
  6. Mar 1, 2005 #5


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    Iansmith and Curious have already given the advice I'd have given. The most important thing is to make sure all possible safety measures are being employed, to be certain you feel confident EVERYONE in the lab who will have access to the bug is extremely meticulous and careful about preventing contamination, to make sure there is a health plan for monitoring you for exposure to ensure you haven't become accidentally infected.

    Working in a laboratory environment can be very safe, as long as everyone follows all the rules. To work with a BSL 3 organism, there has to be a biosafety plan in writing. Get this from your boss and read it thoroughly and make sure every part of the plan is being followed. If you see any aberrations, 1) don't work with it in that lab, 2) report it to whoever is in charge of a biosafety committee because it's dangerous to more people than just you.
  7. Mar 2, 2005 #6


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    If this laboratory has been working with this agent previous to your arrival, I would imagine they would have a record of their activities, i.e. any saftey violations, warnings, etc. If the lab manager doesn't have this, or isn't forthcoming, you should be able to check up on their history with your institutional biosafety group. This should give you an idea of how well they execute standard safety protocols. This assumes you are working at a university-type institution, I'm not sure about private industry and who they answer to.
  8. Mar 2, 2005 #7
    I am not a biologist...but not to burst any bubbles, I read an article that 1 in 3 people in the world have TB - either actively or in the dormant form in their lungs. Some heavily urbanised areas in the developed world rival TB hotspots like India and mainland China. Even the BCG "vaccination" is not 100% effective against TB.

    Your best bet on top of the usual safety protocols is to stay healthy and not get HIV, since you'd probably be exposed to it in the open anyway.
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