Aging Begins at 30

Immigrant Tuberculosis Must Be Controlled

As a foreign immigrant exposed to lots of tuberculosis myself, "Prevention and Control of Tuberculosis Among Foreign Born Persons" caught my eye. It was a report of a Centers For Disease Control conference on U.S. immigrant tuberculosis.

TB cases annually among immigrants increased from 4,925 (22% of the U.S. total) to 7,702 (39% of the total) from 1986 to 1997. In Canada, immigrants account for over half the TB. In 1996, 915,900 persons were granted residence in the United States and an estimated 275,000 illegal aliens arrived. U.S. foreign born are 9% of the population. Twenty million nonimmigrants and students visit the United States each year.

Immigration from Asia and Latin America, where TB rates are 20 times higher than in the United States, has increased. Mexico (22%), the Philippines (14%), and Vietnam (11%) lead the list of immigrants with TB. China, Haiti, and Korea each account for 5% of TB immigrants. Controlling for tuberculosis in the country of origin before admission is very cost-effective.

Tuberculous immigrants live in California (34%) and New York (9%), and Florida, Texas, New Jersey, and Illinois each have 6% of the immigrants with tuberculosis. Control depends on completing treatment, which can take six or more months. Most immigrant tuberculosis results from reactivation of latent previously acquired infection. Transmission occurs from adults to children, but the active disease is most prevalent in the elderly. Active disease risk is highest in the first years after U.S. arrival. Preventive treatment is needed when contact with TB is proved by a newly positive skin test. Too many doctors attribute positive tests to previous anti tuberculosis BCG vaccination. About 7 million immigrants have latent TB (are skin test positive). Of these, 3% will develop active disease again unless they complete treatment with isoniazid.

Immigrants are screened overseas by local physicians chosen by the U.S. consuls. X-rays suggest tuberculosis and sputum is examined for microscopically visible tubercle bacilli. Those with positive smears are most infectious. Normal chest x-rays can be bought, officials can be bribed, or medicine can be taken to suppress a positive smear. Those with TB on sputum smear are treated before departure for the United States but information often does not accompany them. Smear-negative patients with questionable x-rays are referred after immigration to public health departments but can get lost. If already in the United States, immigrants are skin tested and if positive are x-rayed and referred to local authorities, but again some are lost. Targeted programs are used for immigrant farm laborers, english-as-a-second-language students, and school entrants. Tuberculosis is a social stigma so many are reluctant to begin or complete preventive treatment.

Drug resistance is common in immigrant tuberculosis: 18% from Vietnam, 15% from the Philippines, and 10% from Mexico compared to 6% from the United States. Multiresistant TB is immensely more difficult and expensive to treat.

Without treatment, about 55% of active tuberculosis patients will die; with treatment only 15% or less will die. The big decline in tuberculosis in the United States was reversed in the late 1980s in large part due to immigrant TB. Complete information with immigration service and public health department treatment record cooperation is needed. Immigrants from certain countries require special attention. Programs must be evaluated and made relevant to the immigrants. Educational materials and outreach workers must be of the same cultural and linguistic background. Tuberculosis is the leading fatal infectious disease globally and must be controlled.

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

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

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http://www.vh.org/adult/patient/internalmedicine/aba30/1998/immigranttb.html