
Extensively Drug-Resistant Tuberculosis (XDR TB)
What is
XDR TB?
Extensively drug-resistant tuberculosis (XDR TB) is a relatively rare
type of multidrug-resistant tuberculosis (MDR TB). It is resistant to almost all
drugs used to treat TB, including the two best first-line drugs: isoniazid and
rifampin. XDR TB is also resistant to the best second-line medications:
fluoroquinolones and at least one of three injectable drugs (i.e., amikacin,
kanamycin, or capreomycin).
How is XDR TB spread?
Drug-susceptible (regular) TB and XDR TB are spread the
same way. TB germs are put into the air when a person with TB disease of the
lungs or throat coughs, sneezes, speaks, or sings. These germs can float in the
air for several hours, depending on the environment. Persons who breathe in the
air containing these TB germs can become infected.
TB is not spread by
- shaking someone's hand
- sharing food or drink touching bed linens or toilet
seats
- sharing toothbrushes
- kissing smoking or sharing cigarettes
Why is XDR TB
so serious?
Because XDR TB is resistant to the most powerful first-line and
second-line drugs, patients are left with treatment options that are much less
effective and often have worse treatment outcomes. XDR TB is of special concern
for persons with HIV infection or other conditions that can weaken the immune
system. These persons are more likely to develop TB disease once they are
infected, and also have a higher risk of death once they develop TB disease.
Who is at risk for getting XDR TB?
Drug-resistant TB (MDR or XDR) is more
common in people who:
- Do not take their TB medicine regularly
- Do not take all of their TB medicines
as told by their doctor or nurse
- Develop active TB disease again, after having
taken TB medicine in the past
- Come from areas of the world where drug-resistant
TB is common
- Have spent time with someone known to have drug-resistant TB
disease
Source:
MedicineNet.com
http://www.medicinenet.com/extensively_drug-resistant_tuberculosis_xdr_tb/article.htm