Talk:Tuberculosis

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Center for Disease Control Division of Tuberculosis Elimination uses form "TB" rather than "T.B." (see link on Tuberculosis)

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From the article:

Primary tuberculosis is a person's first exposure to T.B. Assuming the infection was not completely cleared by the immune system (which sometimes happens if the bacterial load was small enough), post primary tuberculosis can occur - this is a reactivation of T.B. following primary tuberculosis (symptomatic or asymptomatic). In 40% of patients with primary T.B., this may take more than 10 years.

The last sentence is strange and unclear. Certainly, in 100% of patients, this may take more than 10 years. But in what percentage does it actually take more than 10 years? Also, it is not clear what exactly this refers to. The post primary tb lasts for more than 10 years? AxelBoldt 21:06 Jan 2, 2003 (UTC)

It is unclear to me too. I've removed the 40% figure from the article and rephrased. I think part of the problem is the use of the term "post primary tuberculosis", (which first of all needs a hyphen), as opposed to "reactivation tuberculosis" which I think is clearer. Also added on some other missing info about staining characteristics, which remains an important diagnostic technique. Should add info about use of DNA testing of culture results, (permitting rapid, rather than 6 week cultures), too. -- Someone else 21:59 Jan 2, 2003 (UTC)

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Few random questions that someone else (or indeed Someone else...) may have some insight into:

• So what: "In Australia, the incidence of T.B. is currently 6 per 100,000, while for Australians born in Australia, the rate is 1.8 per 100,000."

Is this just giving an idea of what the infection rate in a first-world country is? Is this making a point about health factors for first-generation immigrants, and if so what? Is there something specific to Australia? For that matter, if anyone knows infection rates in countries in which TB is more prevalent, that'd be nice to know.

I've removed this statement, it does sound a bit Pauline Hanson. If they mean that TB is coming into countries with low rates from countries with high rates, then say it. Not just stats that could mean anything. (i'm not saying this was intended, but it's how it sounds). Tristanb 08:13 2 Jun 2003 (UTC)

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TB is a disease of poverty, crowding, homelessness, social neglect, and inadequate public health systems. Persons inclined to blame immigrants and immigration for TB can find statistics to support their views: the Journal of the American Medical Association (JAMA) <POV on>a rag, not a journal</POV off>claimed, in 1994, that the foreign-born living in the United States were responsible for sixty percent of the total increase in cases from 1985 to 1992. The New York City Task Force of TB's simultaneous analysis showed that increased TB rates were mainly attributable to HIV infection, homelessness, and inadequate health care, which affected immigrants disproportionately. The remedy proposed (on the one hand, to keep immigrants out, and on the other hand to assure them appropriate living conditions and health care on their arrival) depends more on the proposer's political views than on science. -- Someone else 08:27 2 Jun 2003 (UTC)

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• "The cause of tuberculosis, Mycobacterium tuberculosis is a Gram-positive aerobic bacterium that divides every 16-20 hours."

Is this in the human body, or is this in the lab. I know that TB takes a long time to grow in the lab (like 2-3 weeks to get a visible colony), but I thought this is because people don't know the optimal conditions in the lab -- and that it grows faster in its natural environment, i.e. humans. Seems to me that E. coli divides in about 20 minutes, and takes I'd say ~ 8 hours to form colonies. TB's division time is thus 60x longer, and 60*8 hours = 480 hours = 20 days = ~ 2-3 weeks. I'd suspect that the division time is different in human vs. in lab, but I don't know the #s. Anyone?

• "For example, T.B. cases in Britain, numbering around 50,000 in 1955, had fallen to around 5,500 in 1987, but for 2001 there were over 7,000 confirmed cases."

This statistic is meaningless without knowing what the change in population in the UK was from 1987 to 2001. Anyone know cases per 100,000 in 1987 and 2001 (or other nearby dates)?

Speak the name of the devil, and he will drop by to italicize species names. <G>. Seriously, all good questions, especially the one on division rate (which varies (obviously) with the virulence of the various specific strains, and depends not only on in vitro vs in vivo, but also is higher in lungs in vivo than in other tissues in vivo, presumably as a function of oxygen tension, and one suspects therefore on a great many other variables), but sadly, no answers here. -- Someone else 00:44 Mar 27, 2003 (UTC)

P.S. FWIW: Infect Immun 1999 Jan;67(1):74-9 "Mycobacterium tuberculosis catalase and peroxidase activities and resistance to oxidative killing in human monocytes in vitro". Manca C, Paul S, Barry CE 3rd, Freedman VH, Kaplan G. [1] found doubling times of about 27-32 hrs intracellularly (in monocytes) and 16-22 hrs extracellularly (acellular culture medium). -- Someone else 00:58 Mar 27, 2003 (UTC)

Most common?

The first sentence of the article says that tuberculosis is "the most common infectious disease in the world today". Really? More common than the Common cold? That sounds astounding and counterintuitive. Some explanation, please! -- Wondering simply, Infrogmation 06:05, 22 Aug 2004 (UTC)

explanation and clarification - could have stated: most common major infectious disease (ID) in the world, (the top 3 ID killers are HIV/AIDS (3 Million), TB (2 Million), malaria (1 Million)), mostly in developing countries). Stats from WHO, one-third of world has infection (>90% latent TB infection LTBI), about 9 million new cases active disease annually (mostly reactivation from LTBI - 10% lifetime, if HIV 10% annually) with 2 million deaths. Since the common cold is actually caused by several different classes of viruses Virus classification and one-third of the world has been infected by only one species Mycobacterium tuberculosis, TB could still be called the most common ID even more than the common cold. The adjective "major" has been added to the article. Petersam 09:08, 22 Aug 2004 (UTC)