Tuberculosis testing at Public Health Laboratories in Shoreline

By Allison Cook, Communications Office

Washington State Department of Health

When you hear the word tuberculosis, you probably think of a disease that was cured nearly 70 years ago. Yes, a breakthrough drug to treat this highly-contagious infection was discovered in the 1940s, but that doesn’t mean the disease is a thing of the past.

Tuberculosis, usually called TB, is a worldwide pandemic — a disease that is present across the globe. About one third of the world’s population has been infected with the disease.

Tuberculosis is a bacterial infection that usually affects the lungs, but can attack other parts of the body. In Washington, TB rates are higher than many other states.

In the early 20th century, tuberculosis was such a major public health concern that the need for a facility to do TB testing in Washington was fairly urgent. The Washington State Public Health Laboratories were created to respond to the need to test for TB, among other diseases. The facility has been around since the 1940s, and has been located in Shoreline for the last 25 years. Previously these labs were in downtown Seattle.

In the Public Health Laboratories TB lab, more than 2,000 tuberculosis tests are performed each year. Of those, about 250 are positive for the bacterial infection, on average. TB testing can be a very long and expensive process. Specimens come in from health care providers, hospitals, and local health agencies across the state.

The initial TB test is done with a microscope, looking at samples for Mycobacterium, the bacteria that cause the illness. Next, a culture test on the sample determines the exact type. All of this can take a couple weeks or more because TB bacteria grow slowly. When tuberculosis is confirmed, lab scientists do a drug test to see which medications will best treat the infection. Testing each sample — from start to finish — can cost from $250 to $300 each. Once a positive result is confirmed, lab staff work with other Department of Health employees who ensure treatment occurs quickly. Tuberculosis can be very hard to treat for many reasons, but time — the months or years it can take to clear an infection — is among the most difficult.

All tuberculosis testing at the lab is done by skilled microbiologists. TB testing is done in a special containment area, with staff wearing masks (respirators) and other personal protective equipment because the bacteria that cause TB can be spread through the air. To keep themselves and others safe, scientists who work with the TB bacteria have been trained to carefully use specific microbiology techniques in a laboratory facility specially designed for this work.

In April, the state Public Health Laboratories officially broke ground on a construction project to expand lab capacity. The project will provide more space for disease and environmental testing, ensure safety for staff and the community, and improve efficiency. The facility provides testing for public and private health organizations across the state. Testing is performed by nationally recognized scientists. More than five million tests are performed at the facility every year.

The need for TB testing may have been one of the reasons the state public health labs was put on the map, but the lab’s ability to do shellfish testing, newborn screening, environmental monitoring, and communicable disease testing helps ensure Washington is a safe, healthy place to live. The Washington State Public Health Laboratories is part of the Shoreline community that serves as a vital link in the public health system.

Photo credit, top to bottom: DOH, Wikimedia, DOH, Steven H. Robinson