Extensively Drug Resistant Tuberculosis (XDR-TB)

Extensively Drug Resistant Tuberculosis (XDR-TB)

The news story seemed reminiscent of a Keystone Kops cinema: police and health officials chasing a handsome, healthy-looking 31-year-old globe-trotting attorney Andrew Speaker, and his beautiful bride, through city after city in at least 5 countries, being eluded at hotels, airports, and border checkpoints, only to have the gentleman turn himself in at a New York City hospital, and finally having agents of the Centers of Disease Control and Prevention (CDC) put him into strict isolation for being infected with a deadly and dangerous contagion - tuberculosis (TB)! Wait - is TB dangerous? Isn't TB easily treatable and curable?

What is Extensively Drug Resistant-TB (XDR-TB)? TB is caused by the micro-organism Mycobacterium tuberculosis (MTb). XDR-TB is a strain of MTb resistant not only to the first-line anti-TB drugs (rifampicin and isoniazid), but also to the best second-line drugs, fluoroquinolones, and at least one of the injectable drugs (i.e., amikacin, kanamycin, or capreomycin). This leaves very few treatment options for the patient diagnosed with XDR-TB. According to the aid agency, Doctors Without Borders, treatment for XDR-TB is non-existent in many countries. Health officials think Andrew Speaker may have been infected when he visited Asia as a hospital fundraiser.

Each year, around the world, an estimated 450,000 patients are diagnosed with multiple drug resistant TB, and only two-thirds of them are cured. The World Health Organization (WHO) has confirmed 269 cases of XDR-TB in 35 countries, including the United States. About 85% of these patients are expected to die as a result of this disease. The worst health ramifications come to those who are infected with HIV/AIDS - approximately 90% die within months of contracting TB. According to the CDC, there have been 49 XDR-TB cases in the US since 1993. In March 2007 Italy reported the first case of a patient with TB resistant to "all known drugs." Generally speaking, resistant TB resulted when people self-prescribed or otherwise did not take their antibiotics as directed.

What are the symptoms of XDR-TB? Symptoms of TB disease can vary depending on what part of the body is affected. However, the disease is only contagious when it is located in the lungs or throat. General symptoms include feelings of sickness or weakness, weight loss, fever, and night sweats. Active pulmonary TB disease symptoms may also include coughing, chest pain, and hemoptysis (coughing up blood).

How do I protect myself when I travel? Singing, coughing, sneezing, or speaking can aerosolize MTb into the air where it can "float" for several hours, depending on the environment. Persons who breathe in the air containing MTb can become infected. Airline travel carries a relatively low risk of infection to TB, as TB transmission requires prolonged close contact with someone who is highly infected. However, travelers should avoid high-risk settings where few or no infection control measures are in place, such as crowded hospitals, prisons, homeless shelters, and other settings where susceptible persons come in contact with persons with active TB disease. A TB skin test or the QuantiFERON®-TB Gold blood test can help determine if a person has been exposed to MTb. Final diagnosis for TB, and especially for XDR TB, may take from 6 to 16 weeks.