A new study of tuberculosis in Alaska shows a 10 percent increase of cases from 1998 to 1999.
But a public health physician says the increase is not as bad as it sounds.
``Just a couple of cases make for a change in the rate because of the size of our population,'' said Dr. Elizabeth Funk of Anchorage, a physician with the state's epidemiology office.
Tuberculosis, also know as TB, primarily affects the lungs, although the intestines, joints and other parts of the body may also become infected. It is spread mainly by inhalation. Alaska has one of the highest per-capita rates of active cases of the potentially deadly disease in the United States.
In 1998, 55 TB cases were reported in Alaska, a rate of nine cases per 100,000 population, according to a recent epidemiology bulletin. In 1999, 61 cases were reported. While this increased the rate per 100,000 to 9.8, it was in actual count only six more cases statewide.
The highest rates continue to occur in the Northern and Southwest regions, reflecting ongoing transmission in villages such as Elim, Kwethluk and White Mountain. Northern cases peaked at 31 (a rate of 136.2 per 100,000) in 1996, in contrast to the cases in Anchorage and the Matanuska/Susitna region (where half the state's population lives), where there were 19 cases in 1996 (a rate of 6.2).
The lowest rates are in Southeast, which had five cases (a rate of 6.8 per 100,000) in 1995, a peak of eight cases in 1997, one in 1998 and two in 1999.
Funk, author of the TB report, didn't know why Southeast Alaska has the lowest rate.
``I know there are plenty of people in Southeast who have positive skin tests and thus a risk for developing the disease, but I don't why they don't develop'' active tuberculosis, she said.
In the 1950s, a study was conducted that showed about 50 percent of Southeast Alaska's Native children had positive skin tests for tuberculosis before they reached the age of 10, Funk said.
``In other parts of the state it was closer to 90 percent,'' she said.
The 1950s study would indicate that, 40 or more years later, a good proportion of today's Southeast Native elders are at risk for developing the disease. Yet they don't, Funk said.
``I am sure the spread of tuberculosis is multi-factorial,'' said registered nurse Mary Therese Thompson, who has worked as an infection specialist at Mount Edgecumbe Hospital in Sitka for 20 years.
``We have a very diligent and effective public health network in Southeast, and that helps to prevent the spread, for one thing. Directly observed therapy (medication of patients over a year's course of treatment) has increased compliance. And we don't have a high immigrant population, a high rate of HIV infection or homelessness -- and those populations are especially at risk ...'' Thompson said.
But it would be dangerous to draw the conclusion that Southeast is relatively ``safe'' from TB, she said, ``Because you could have one person coughing away, and that one person could cause an outbreak. So people should not be complacent. There's always that potential,'' Thompson said.
Tuberculosis is an infectious disease of various tissues of the body caused by a rod-shaped bacteria. Symptoms of the disease are listlessness, fever and loss of appetite; in the pulmonary form, symptoms include spitting up blood and severe coughing. As the disease progresses, hard swellings -- growths called nodular lesions -- reduce or impair the function of tissues such as the lungs. A century ago, the disease was called by a variety of names, including ``consumption.''
Tuberculosis once affected millions, but its incidence has greatly decreased with improved sanitation, early detection through X-rays and skin tests and anti-tuberculosis drugs.