Tuberculosis Risk

Posted on June 3, 2007  Comments (2)

We have posted about the Tuberculosis risks previously: Extensively Drug-resistant Tuberculosis (XDR TB), May 2007Deadly TB Strain is Spreading, WHO Warns, Mar 2007Tuberculosis Pandemic Threat, Jan 2007‘Virtually untreatable’ TB found, Sep 2006. One USA citizen, while infected with XDR TB, flying to Europe and then to Canada and driving back into the USA has created a huge amount of publicity on this topic in the last week.

The risks are well known, given the extreme mobility in the world today, for TB, and other communicable diseases, becoming more troublesome, costly and deadly – often due to improper antibiotic use. But we continue to avoid giving this risk near the level of attention it seems to deserve. Deaths due to these diseases is likely to be very high in the next 20 years.

In fact there were 1.6 million TB deaths in 2005 (see WHO fact sheet below). Even if you only care about deaths in the USA (I am not advocating such a position, but even for those that hold such a position…) failing to address these issues will greatly increase the odds of large numbers of deaths in the USA (for TB and other diseases that become difficult or impossible to treat with antibiotics).

The current news will do little in my opinion (though it will help raise awareness). It will take a significant number of deaths in the USA, for significant policy changes to be implemented. Luckily scientists and policy makers have been giving these risks thought and so possible actions are already fairly well know. Unfortunately we seem very inclined to ignore problems for those out of sight (either continents away, or in the future) so until the consequences of the current action forces people to confront this issue little has been done (well actually good action is being taken, but much more is left to do).

One huge issue is quarantine. Personally, I try to use as a guide that people have the right to do what doesn’t infringe upon others rights. This allows plenty of room for debate about what level of trade-off is acceptable but I find it a useful guide to shape my thoughts. People don’t have the right to drive drunk and endanger others. People don’t have the right to pollute the air of others by smoking (or polluting the air with dangerous chemicals, CO2…). People don’t have the right to expose others to dangerous communicable diseases. Doctor’s don’t have the right to proscribe antibiotics when not medically justified (creating risks to those in the future)… But how society decides to define the social contract that everyone must agree to (rather that a way I find useful to help me analyze what is reasonable) is in need of some increased clarity in the light of health care issues today.

World Health Organization fact sheet on Tuberculosis:

Tuberculosis (TB) is a contagious disease. Like the common cold, it spreads through the air. Only people who are sick with TB in their lungs are infectious. When infectious people cough, sneeze, talk or spit, they propel TB germs, known as bacilli, into the air. A person needs only to inhale a small number of these to be infected.

Left untreated, each person with active TB disease will infect on average between 10 and 15 people every year. But people infected with TB bacilli will not necessarily become sick with the disease. The immune system “walls off” the TB bacilli which, protected by a thick waxy coat, can lie dormant for years. When someone’s immune system is weakened, the chances of becoming sick are greater.

It is estimated that 1.6 million deaths resulted from TB in 2005. Both the highest number of deaths and the highest mortality per capita are in the Africa Region. The TB epidemic in Africa grew rapidly during the 1990s, but this growth has been slowing each year, and incidence rates now appear to have stabilized or begun to fall.

While drug-resistant TB is generally treatable, it requires extensive chemotherapy (up to two years of treatment) with second-line anti-TB drugs which are more costly than first-line drugs, and which produce adverse drug reactions that are more severe, though manageable. Quality-assured second-line anti-TB drugs are available at reduced prices for projects approved by the Green Light Committee.

The emergence of extensively drug-resistant (XDR) TB, particularly in settings where many TB patients are also infected with HIV, poses a serious threat to TB control, and confirms the urgent need to strengthen basic TB control and to apply the new WHO guidelines for the programmatic management of drug-resistant TB.

Why TB Remains a Modern and Deadly Problem:

People with TB disease can spread the bacteria through coughing, sneezing or simply talking. But infection usually happens only after prolonged exposure, according to Dr. Martin Cetron, director of the global migration and quarantine division at the Centers of Disease Control and Prevention. “By and large, TB is spread through prolonged contact. This is not the type of pathogen that is transmitted by short, casual contact,” Cetron said. Only 10 percent of those infected with the germ go on to develop the disease.

When these so-called first line drugs don’t work, doctors resort to a second line of drugs. But these aren’t as fast-acting, cause more side effects and are more expensive. One U.S. case of drug-resistant TB last year cost nearly $500,000 to treat. When the bacteria become resistant to the second line of drugs, too, the disease is considered to be XDR-TB, or extensively drug-resistant TB. At that point, treatment options are seriously limited.

Related: Antibiotics Too Often Prescribed for Sinus WoesCDC Extensively Drug-Resistant Tuberculosis informationCDC Division of Tuberculosis EliminationExperts allay fears: TB is not easily spreadTB patient scornful of lawyer’s behaviorACLU files Arizona suit over TB caseTB carrier ignored health system until he feared for himselfAntibiotic Resistance and YouHow do antibiotics kill bacteria?

2 Responses to “Tuberculosis Risk”

  1. Curious Cat Science and Engineering Blog » Fighting Tuberculosis
    December 2nd, 2007 @ 6:53 pm

    “Though TB is a daunting foe, Alber remains confident about the prospects of beating the disease. ‘As a bacterium, it should be easier to treat than HIV or malaria. Those kinds of diseases-caused by viruses and protozoans-we generally don’t know how to cure,…”

  2. Curious Cat » Non-Vaccination Risks
    February 13th, 2008 @ 5:17 pm

    Freedom has responsibility for those that care about people and society. Choosing to risk others because of your actions is something I find uncivil, callous and disrespectful to those you put at risk…

Leave a Reply