View Full Version : TB

08-06-2008, 15:38
Hello,Throughout my time serving in various regioins, it came to pass that before my discharge I was diagnosed with having been "exposed" to TB. Therefore on the routine PPD test I will always test positive. Upon my discharge during the final physical I was told I had nothing to worry about. I know others had to take the course of antibiotics (Rifampicin?) as a precautionary measure. I did not. I have been out for over 4 years now and had a recent chest x-ray and it came back clear. My worry is I have a baby on the way near the end of this month (August). Should I worry about contagiousness or anything? Should I get another x-ray and blood test to confirm I'm not active? Please advise because I don't want to jeopordize my offsprings well being. Any info you guys can pass on is most helpful. I now live in a foreign country and I think there is some sort of vaccination I can give my newborn (Bacillius Calmette Guerin BCG) as per Google, Wikipedia, etc., which they do not usually admisister stateside. I have a pending hospital visit with my wife so I will be asking the OBGYN, but any info the medics who I know have seen this epidemic firsthand out there and the best course of action to take I will trust their word in order to push the issue here with the health care professionals I currently have to deal with.

08-07-2008, 20:42
No, I don't think you really have to worry for the sake of your child, but you need to see the doctor about this. Positive PPD tests usually trigger initiation of 9 months of therapy with isoniazid (no beer for you during that time) and follow-up chest xrays, but we generally do testing and treatment only in patients who have a high risk of exposure to TB or spreading it, i.e., health care workers, humanitarian aid workers, corrections officers, etc.

If you received the BCG vaccine, which is used in many countries with high TB prevalence, it may forever lead to positive PPD tests. If you live in an area with high TB prevalence, then go ahead with the BCG at the right time for your kid, but if not, then skip it. We don't do it in the US because of the low prevalence of TB, the variable effectiveness of the vaccine, and the fact that it will later be difficult to determine with PPD testing if the patient has been exposed to TB or if the test is positive just because of vaccination. Consult a doc in that area or a travel medicine doc stateside that can give you good advice on it.

The vast majority of exposures to TB don't lead to active disease, but the bacilli are walled off in the lung by immune cells, where a sort of mexican stand-off ensues. The TB is isolated and can't grow, but the cells can't destroy it because of the thick waxy coating on the bacteria.

There is no good blood test to see if you have active TB. There are sputum tests, which are stained for TB (acid fast bacilli, or AFB smear) or tested with immunological tests, but they take some time to come back (~3 weeks) and are not recommended in asymptomatic folks with normal chest xrays. They are generally not performed unless you have symptoms such as cough, shortness of breath, night sweats, unexplained fever, or chest pain, or have a cavitary lesion seen on chest xray (there is a form of TB, called milliary TB, that does not have this xray pattern, but can look like a regular pneumonia).

If you are immunosuppressed (HIV+, other diseases), then treatment with rifampin and pyrazinamide is recommended rather than isoniazid. This also changes the definition of a "positive" PPD test.

CDC Recommendations on TB testing and treatment (http://www.cdc.gov/mmwr/preview/mmwrhtml/rr4906a1.htm)


08-08-2008, 01:42
'Zilla,Thanks for the info. We had a hospital visit yesterday at the hospital. I asked and the doc said pretty much the same thing as you. He seemed in shock when I told him they do not vaccinate for it in the U.S. as it is SOP here. Therefore, when the time comes I'll get him innoculated just to be on the safe side. Again, thanks for the help. ;)Regards,Jason

Red Flag 1
08-08-2008, 10:43
I had BCG in 1964 and have been pos ever since. Always screened with CXR.

The downside of BCG is that it does take away PPD, and Tine, as a diagnostic indicator.

With yearly CXR, and hours of C-arm time in the OR, my wife says I am easier to find in the dark now. :D

RF 1