Spring is in the air and our worries about catching the seasonal flu or H1N1 are receding. Another airborne disease, however, is emerging as a global threat, largely because it is becoming resistant to the drugs that have fought it off for decades. In time for World Tuberculosis Day, March 24, the World Health Organization released a report calling attention to the global threat of multi-drug resistant tuberculosis.
Largely thought of as a disease of the past, or of other countries, tuberculosis still strikes in the U.S., including right here in King County, where 130-150 cases are found each year, according to Eyal Oren with the TB control program of Public Health - Seattle and King County.
Of those cases, 1-2 percent are multi-drug resistant, meaning they do not respond to the most commonly used antibiotics to treat TB. In such cases, longer courses of different antibiotics are required. Recently some strains of TB have shown resistance to even these second-line drugs, making the disease even more difficult to treat.
Easily spread and potentially deadly, TB is seen as a threat to domestic security, says Joanne Carter, board member of the Global Fund to Fight AIDS, Tuberculosis, and Malaria. She says the U.S. needs to lead the effort to control the spread of multi-drug resistant TB, yet President Obama's global health initiative actually would cut the U.S. contribution to the Global Fund.
In order to prevent strains of TB from becoming drug resistant, and to prevent the spread of such strains, patients must complete a full course of treatment. To ensure this happens, "directly observed therapy" is often used: here in King County, case workers drive to their patients' homes each day, give them the medicine and watch them take it.
In addition to the active cases, an estimated 100,000 King County residents are infected with the bacteria that causes TB but are not sick, says Oren. This is called latent TB, and will show up on a skin test but has no symptoms and is not contagious. Latent TB can turn into active disease at any time, even years after infection, if the immune system somehow becomes weakened.
Oren calls tuberculosis a disease of the poor and of immigrants from high-risk areas. He estimates 10 percent of King County's cases are among the homeless -- a rate, Oren says, akin to the disease's prevalence in the developing world. In 2002 there was a TB outbreak in the homeless shelters, and in about a third of the cases, the patients were also infected with HIV, says Oren. Tuberculosis is particularly deadly to people with HIV because of their weakened immune system.
The same drugs used in 1950 are still used to treat TB today, says Oren, but now with the resistant strains, new drugs are needed. Research and treatment cost money, though, and Obama has flatlined domestic funding for TB, says Carter, who considers it essential for Congress to restore this funding as well as contribute to global TB efforts.