New TB test on
isle horizon

A state official says a new blood
exam is more accurate and
more sensitive

Hawaii's tuberculosis rate was nearly double the national rate last year, but World TB Day will be observed Thursday on a hopeful note, says Dr. Jessie Wing, chief of the state Health Department's TB Control Program.

"The big story this year is about a new blood test, QuantiFERON-TB Gold, developed by Cellestis, an Australian company," she said.

"Hopefully, it will replace the skin test," which has been used to screen for active TB infection "perhaps over 100 years," she said.

State TB clinics did 53,000 skin tests last year, including 20,000 at the new clinic at Lanakila Health Center, and 19.2 percent were positive, she said. An unknown number of tests also were done by private doctors.

The new blood test is more accurate and more sensitive and "could really help us revolutionize how we do our screening," she said.

Cellestis and U.S. Centers for Disease Control and Prevention officials are joining state health officials at events this week to educate doctors and laboratories about the new diagnostic tool, Wing said.

"It's the first significant change in many, many years. It's imperative that we move on with better technology."

Tuberculosis is an ancient disease caused by mycobacterium, an airborne bacteria spread from one person to another by sneezing or coughing.

Hawaii has the highest case rate in the nation, largely because of its foreign-born population.

Wing said the state's TB rate remained about even last year with 116 cases (compared with 117 in 2003), or 9.2 for every 100,000 residents. But this was almost twice the national rate of 14,511 cases or 4.9 per 100,000, she said.

The national rate dropped 3.3 percent from 2003 last year, but it was one of the smallest declines in more than 10 years, CDC reported. Cases increased in 17 states and the District of Columbia.

The TB rate among U.S.-born people declined 64.6 percent in the past 12 years while the rate among foreign-born residents dropped only 33.9 percent, according to the CDC.

In 2003, 1.9 percent of Hawaii's TB cases were U.S.-born, and 46.2 percent were foreign-born, Wing said.

One of her biggest concerns has been the number of drug-resistant TB cases. Data is not complete for 2004, but she is hoping for an improvement over 2003 when there were 11 drug-resistant cases. All were foreign-born and four were multidrug-resistant, she said.

"That's bad," she said, noting 3.4 percent of Hawaii's TB cases in 2003 were multidrug-resistant while the national rate was 1.2 percent.

In 2002, Hawaii had 22 drug-resistant cases -15 percent of cases overall - and 20 involved foreign-born residents.

Most TB cases are curable, but multidrug-resistant strains are much more difficult and expensive to treat, taking longer and requiring additional antibiotics, Wing said.

She said the new blood test is the second version of a first-generation QuantiFERON test that San Francisco has used for a year.

She was tracking it, and the improved second-generation test, approved by the U.S. Food and Drug Administration in December, "seems to be what we want to use here," she said.

"We're in the process of trying to get labs interested and trained, and we have to amend our Hawaii state administrative rules to allow us to use QuantiFERON for TB clearance. We're in an educational stage now."

Wing said she is looking for grants and hoping for more support for the state's TB laboratory, a regional facility that is running at a deficit. The new test will do a better job of diagnosing infections, but it is more expensive, she said.

Until a vaccine is available that works, Wing said the best that can be done is to try to eliminate tuberculosis.

"Here, we have a long way to go. Our rates are high. We're patching folks who come from overseas. All we can do is offer them antibiotics."