By Larry Sater, MS BT/CT Coordinator, Colorado Department of Public Health & Environment Laboratory Services Division
When the Laboratory Response Network (LRN) was established in 1999, the goal was to establish accurate, rapid testing methods to confirm or rule out dangerous bacteria, viruses and toxins that bioterrorists might unleash on the American public. However, those same laboratory tools and trained staff do not sit idle waiting for a bioterrorist threat. A great success of the LRN is the day-to-day use of these resources in detecting the presence of select agents in people, pets, livestock and food during everyday life. If you do not believe me, speak with a seven-year-old Colorado girl and her parents.
Each year, and especially during the summer, the Colorado Department of Public Health & Environment Laboratory Services Division (CDPHE) laboratory is busy testing for West Nile Virus, rabies, plague and other diseases in both clinical and environmental samples. On August 27, 2012, the lab received another one of these calls, but this one was very different. A seven-year-old girl was critically ill and determination of the cause of her illness was critical to quickly proceed with appropriate treatment. A courier from Presbyterian/St. Luke’s Rocky Mountain Hospital for Children delivered the specimens to the state laboratory just before noon on that day.
This was the story: While at a Colorado campground, the little girl found a dead squirrel and insisted on giving it a proper burial. In the process, it is suspected that fleas containing the plague bacteria left the squirrel carcass and contacted the girl, inflicting several bites. The child soon became ill with a fever of 107 and required airlifting to St. Luke’s. There, an alert physician checked both symptoms and the literature, concluding bubonic plague was a possible culprit.
The hospital collected specimens for culture and could not rule out the presence of Yersinia pestis, the bacteria causing plague. At this point, the Laboratory Services Division was contacted and specimens collected from the girl were sent to us for confirmation testing.
Before the LRN, bacteria had to be grown in a culture for at least 1-2 days before the organism could be detected and colonies sampled for testing. However, thanks to rapid technologies adopted by LRN laboratories, the DNA for the plague bacteria was detected and identified within 2 hours of receipt of the specimens using a method called polymerase chain reaction (PCR). A second rapid test, direct fluoroimmunoassay (DFA) which uses the antibody to the suspected bacteria, confirmed the presence of Yersinia pestis.
Thus within hours, the cause of the girl’s life-threatening illness had been identified as a presumptive positive and a confirmation test conducted that supported the physician’s suspicions. Samples of the specimens were cultured overnight with microscopic observation of the organisms. Other tests confirmed the presence of the agent and the fact that it was still alive.
Earlier that month, two human cases of brucellosis were confirmed by the CDPHE laboratory, as well as several cases of plague in rabbits discovered in communities across Colorado.
Such specimens come in routinely to the CDPHE laboratory—all part of a day’s work for the staff. While the LRN Network was established to rapidly confirm the presence of biological and chemical agents that could be employed in a terrorist attack, it has offered a bonus to the American public, protecting them from naturally-occurring health threats every day of the year.