Active TB cases reach 30-year high in King County

Cases of active tuberculosis in King County last year jumped 11 percent to a 30-year high, reflecting this area's global connections in a world where a third of the population is infected with the deadly disease, health experts said today.

In 2007, 76 percent of the 161 cases of active TB in King County were among those not born in the U.S., and a majority were men, according to statistics from Public Health — Seattle & King County. The most common countries of origin were Vietnam, Somalia, Ethiopia, India and the Marshall Islands.The TB rate for the state as a whole was also up 11 percent, the State Department of Health reported, although most counties had 10 or fewer cases. King County accounted for 55 percent of all cases reported in the state.

As many as 100,000 people in King County have latent, or dormant, TB, said Dr. Masa Narita, tuberculosis control officer for Public Health — Seattle & King County. Those people have no symptoms and are not contagious, he said, but about 10 percent of them will eventually develop active TB, which is contagious.

Only two cases in Washington last year, both in King County, were the type of TB most feared by health officials: TB that resists treatment by multiple types of antibiotics. Regular tuberculosis is curable, when active, and preventable, when latent, through a long course of antibiotics, but multi-drug-resistant TB is much harder and more expensive to treat, and may require a patient to take antibiotics for more than two years. Twelve percent of the King County cases were resistant to at least one TB medication.

Active tuberculosis is only spread through prolonged exposure in confined spaces, Narita said. "If you meet somebody in the cafeteria for four or five minutes, that's not the way you catch TB."

The numbers for King County are only slightly above 2002, when there were 158 cases.

Worldwide, about 2 million people a year die of TB.

Carol Ostrom: 206-464-2249 or costrom@seattletimes.com