the TB test dilemma

Ruby is again in Manila seeing a doctor for a third opinion  if she needs treatment for a positive skin test for Tuberculosis with a negative x ray.

usually in the Philippines, you get a BCG vaccine, which primes the immune system against TB, and lowers your risk of infection, especially miliary (widespread) TB, where the germ in a person without immunity spreads all over the place . So your skin test is weakly positive. (1 cm)

But if you have been in contact with a case, the skin test is very very positive. (over a 1 cm lump)

So what do you do?

usually you check a Chest x ray to see if there is active infection, and maybe check the newfangled blood test for TB.

Treatment recommendations keep changing. Latest CDC recommendations here.

Both me and my son got INH treatment when this happened: It is to kill any latent germs behind after your body fights off the infection.

What to do is controversial: without treatment, often the latent germ goes active after you get pregnant, old, cancer, diabetes or some other reason that your immune system gets weak. Malnutrition used to be the main risk factor in the disease becoming active, but now it is HIV.

When I left the IHS, they had just decided to treat all our diabetics with a positive test (which is common in AmerIndians).

The problem? INH can cause hepatic damage in a small percentage of people... so it used to be you didn't treat them if they were over 30 and at higher risk for this.

With the HIV problem, and with multi drug resistant TB, there is a real danger of reoccurring epidemics of TB. Indeed it already is a major health problem in third world countries: 1.8 million died of it last year and one third of the world's population has been infected, although most of the time the body has fought off the infection so they don't have active disease.

Full CDC summary here.

the problem? HIV, which affects the immune system means your chance of the active disease goes way up.

cdc summary.

one problem? if you had the disease and have scar tissue, it is hard to see if the disease is old or active.

CT scans help with this problem.

so no, she is not sick, and does not have TB. The question is how to keep her from getting it later in life.

usually here, since positive tests are so frequent, you only treat the latent patients if they are high risk cases (e.g. children). Because it would mean time, expense, and side effects of treating most of the population who have had contact with tuberculosis but no active disease.

Usually in the US they check this if you work in the health care field (why me and my son got tested), or start college.