Aging Begins at 30

Tuberculosis Returns to Plague the Elderly

Tuberculosis in 1900 was the number two cause of death in the U.S. (after pneumonia-influenza) causing 11% of all deaths. In the 1940's almost 10% of my medicine class developed active tuberculosis and two of them died. Now it is not even in the top 20 causes of death but it hits the elderly harder than the rest of the population. Tuberculosis used to called phthisis, the Greek for decay. In the very old this kind of wasting may seem to be many things not connected with tuberculosis.

A positive tuberculin skin test indicates tuberculosis infection. Tuberculosis infection can come in two varieties, latent and active. In the latent variety the disease heals and the bacteria remain walled off by the body's immune system. In the majority of TB infected individuals the infection remains latent throughout life. People with latent infection are symptomless and not infectious.

Two percent of elderly with latent infections develop active tuberculosis. People who have active infection have persistent cough, fevers, and weight loss (consumption). Active tuberculosis infection can cause cavities or holes in the lungs which are teeming with tubercle bacilli that can be dispersed in the air by coughing or speaking. Therefore people with active tuberculosis can spread the infection to others particularly when living in close quarters such as nursing homes.

The tuberculosis rate in the U.S. is 11/cases/100,000 population, but twice this rate in persons age 65 or older and over 200 in nursing homes. Nursing homes are storehouses of the disease and all residents need to be screened for tuberculosis at entry and regularly afterwards. Some elderly with tuberculosis don't get a positive skin test. Therefore all nursing home residents with a positive skin test or an unexplained chronic cough need chest x-rays. More sophisticated tests may be needed to diagnose the rare forms of tuberculosis outside the lung.

In the 1940's there were no drugs to treat tuberculosis. Now there are more than 20. Tuberculosis in elderly patients is a treatable and curable disease. Treatment lasts 6 to 9 months, but after two weeks of treatment you are no longer infectious. In a growth of tubercle bacilli, one in a million organisms is spontaneously resistant. Further drug resistance is caused by improper, inadequate, and interrupted treatment. If the organisms are present in small numbers (latent infection), one drug, Isoniazid, is adequate. Because many organisms are present in patients with active disease three anti-tuberculosis drugs are necessary to suppress the resistant ones. Ususally Isoniazide, Rifampin, and Pyrazinamide are used. A fourth drug, Ethambutol, is usually added if drug resistance may be present, for example in recent immigrants from Asia or in AIDS patients where the tubercle organisms have a high incidence of resistance.

Tuberculosis in the elderly is a disease to be feared only if it is undiagnosed and untreated.

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See related Patient Topics Infections, Lungs and Breathing or Tuberculosis.

See related Provider Topics Infections, Lungs and Breathing or Tuberculosis.

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