Tuberculosis: illegal immigrants bring serious new threats.

• Position: Your Life

Seventy-five percent of current illegal immigrants are coming from countries in Central America, South America, the Middle East, West Africa, China, India, Pakistan, and others far beyond Mexico where multi-drug resistant tuberculosis (MDR-TB) is common and extremely widespread in children and adults, warns Elizabeth Lee Vliet, former director of the Association of American Physicians and Surgeons, Tucson, Ariz.

Extensively drug resistant TB (XDR-TB), meanwhile, is an even more serious form, she points out, accounting for about 10% of cases in these countries, particularly Central and South America and India. Many illegal border crossers now flooding the U.S. are carrying an invisible, disease-causing co-traveler: the Mycobacterium tuberculosis bacterium.

MDR-TB does not respond well to treatment, even with complicated and expensive medications that must be taken over a two-year period and can cause severe adverse drug reactions. XDR-TB does not respond well even to second-line drugs and, therefore, is more likely to cause death, explains Vliet.

Tuberculosis, or "consumption" as it was once called, is a highly contagious disease that killed millions before essentially being eradicated in the U.S. In the 1920s, TB was the eighth-leading cause of death in children ages one to four. By the 1960s, with improved sanitation, medical care, and antibiotics, TB was reduced drastically. The last remaining TB hospital in the U.S. recently closed its doors, Vliet reports.

In Central and South America, where public health programs are limited and antibiotics are not widely available, TB is a widespread, debilitating, and deadly disease. Vliet references data from World Health Organization:

* TB is second only to HIV/AIDS as the greatest killer due to a single infectious agent.

* In 2012 alone, 15% of the reported 8,600,000 cases resulted in death.

* HIV/AIDS and TB are a lethal combination, each disease accelerating the progression of the other. People with HIV/AIDS who are exposed to TB are 30 times more likely to develop the disease, with a death rate of over 20%.

* TB is the third-leading cause of death for women (15-44) in low- and middle-income nations.

* All age groups are at risk, although TB primarily affects young adults. About 80% of those crossing our southern borders in this latest wave are in this age group.

* Hardest hit are those with compromised immune systems: HIV/AIDS, cancer, and elderly patients.

"TB is spread when infected...