Why Does It Take so Long to Cure Tuberculosis?

It takes so long to cure tuberculosis because the organism that causes it, Mycobacterium tuberculosis, can enter a dormant state where it does not reproduce, explains National Institutes of Health. Almost all types of antibiotics rely on interference with reproduction to eliminate bacteria, so for antibiotics to be effective, they must be present in the body long enough for all the bacteria to become active and begin reproducing.

Treatment for active tuberculosis often takes between six and nine months, as stated by Mayo Clinic. The primary treatment for tuberculosis is the use of several antibiotic drugs at once. The most common medications include ethambutol, rifampin, isoniazid and pyrazinamide. With drug-resistant tuberculosis, treament takes even longer -- between 20 and 30 months. Drug-resistant tuberculosis also requires different medications, often including fluoroquinolones and injected medications, such as capreomycin or amikacin.

Latent tuberculosis occurs when all the tuberculosis bacteria are inactive, and in this state, they cause no symptoms and are not contagious, says Mayo Clinic. Latent tuberculosis can become active tuberculosis at any time, years after the initial infection. Treatment of latent tuberculosis usually requires only one of the standard tuberculosis medications, and it may require less time to treat than active tuberculosis.