Microbiology and Immunology

Tuberculosis WORLD OF MICROBIOLOGY AND IMMUNOLOGY

556

•

one still in use although some scientists question its effective-

ness. Despite doubts about the vaccine, it is still widely used,

especially in TB endemic countries where other preventive

measures are lacking. The U.S. Public Health Service’s policy

recommends testing and drug therapy for those infected

instead of vaccination. The two factors responsible for this

policy are the low incidence of TB in the United States and the

doubts raised about BCG. The Centers for Disease Controland

Prevention, (CDC), however, in its concern over the rising

incidence of TB in the United States and the appearance of

multidrug-resistant tuberculosis (MDR TB) which is difficult

to treat, reexamined the TB vaccination issue, and released

recommendations for its use in limited situations.

The CDC still recommends the use of skin tests and

drug therapy as the most important measures in controlling the

incidence of TB in the United States. Drug therapy is 90%

effective in halting the infection. Since those vaccinated test

positive with the skin test, a vaccination program would inter-

fere with skin testing. Mass vaccination would risk giving up

a simple test that provides an early warning. Relying on the

drug treatment program to stop TB epidemics, however, has

one major drawback. The drug therapy takes six months to a

year before halting the infection. People infected are often

among the homeless, poor, drug addicted, or criminal soci-

eties. Unless these people are carefully supervised to make

sure they complete a regimen of drug therapy, it is difficult to

effect a cure for the disease.

Throughout the nineteenth century and up until the

1960s, physicians sent their TB patients to sanatoriums which

were rest homes located in mountains or semi-arid regions

such as the American southwest. These locations were sup-

posed to help the breathing process by providing clean and dry

air. Physicians assumed that deeper, easier breathing in a

work-free environment would help overcome the disease.

Prior to the advent of antibiotics, these retreats were the only

recourse for chronically ill tubercular patients. Although treat-

ment in sanatoriums did help many, they were phased out

before the 1960s, and replaced by antibiotic drug chemother-

Hospital for tuberculosis patients in Turkey.

womi_T 5/7/03 11:03 AM Page 556