FRIDAY, Jan. 17, 2003 (HealthDayNews) -- When a Texas Tech University professor reported 30 vials of bubonic plague missing this week, state and federal officials snapped to attention at what was seen as a possible move by terrorists.
Thomas Butler, an infectious diseases expert at Tech, is now in custody, having allegedly reported the vials missing after destroying them himself. But the episode points up how seriously officials are taking this particular bio-threat to national security and health.
Appropriately enough, French scientists report in the Jan. 18 issue of The Lancet that they have developed a simple and quick bedside test to diagnose bubonic and pneumonic plague in its earliest stages. The test will find immediate use in the various remote regions of the world where the plague still occurs and, experts say, will be invaluable in the event of a real bioterrorist attack.
Although relatively rare, some 3,000 to 4,000 cases of the plague still occur around the world each year, say the study's authors. Most of these cases are in Africa but, according to the U.S. Centers for Disease Control and Prevention (CDC), up to 40 cases occur in the United States annually, most of them in Western states.
The plague is caused by the bacterium Yersinia pestis and is usually transmitted via fleas. It can take one of three forms: bubonic plague, which manifests in sores on the skin; septicemic plague, when the bubonic form spreads to the central bloodstream; and pneumonic plague, which infects the lungs and which can pass from person to person.
Pneumonic plague is by far the deadliest form and is thought to be the most likely candidate for a terrorist attack -- probably via an aerosol release of the organism that can be inhaled, says Dr. David Dennis, an epidemiologist and guest researcher at the CDC's National Center for Infectious Diseases in Fort Collins, Colo., who wrote an accompanying commentary in the same issue of the journal.
Scientists worry about the use of plague because it has been used as a weapon since the 14th century, when invading Mongols launched a huge outbreak by catapulting infected corpses over the wall of a town in the Crimea.
Today, early diagnosis leading to early treatment is key in all cases, but particularly when dealing with pneumonic plague. "If you don't treat it [with antibiotics] within 24 hours of the onset of symptoms, there's very high mortality," Dennis says.
The problem lies with diagnosis. "Usually there are no routine special tests done in laboratories in hospitals. They're usually expensive and are done in outside laboratories," says Dr. Tareg Bey, associate clinical professor at the University of California, Irvine, Medical Center in Orange, Calif., and one of only about 200 board-certified medical toxicologists in the United States.
Also, the fact that plague is so seldom seen in the United States can also be a problem.
"If something is rare, the doctors are not likely to include the disease early on in their differential diagnosis," Bey adds. "Unless you practiced medicine in India before, you are less likely to recognize the disease right away."
The current study was conducted by Dr. Suzanne Chanteau in Madagascar, the island nation off the southeastern coast of Africa, which has a disproportionately high number of plague cases.
The test zeroed in on more than one section of the F1 antigen, Dennis says, which is specific to Y. pestis and which has been used in other plague tests. The test kits were distributed to 26 sites in Madagascar, most of them remote and rural, to health-care workers who had only routine training. The tests were able to detect antigens within 15 minutes of infection, were reliable 100 percent of the time, and produced no false diagnoses. The field tests results concurred with tests done at a central laboratory almost 90 percent of the time.
The conditions present in a remote island village and in a bioterrorist threat in North America are not necessarily very different, giving the test a potentially much wider applicability.
"There's not that much difference between remote rural areas and on-site requirements in case of attack," says Marc Gillespie, assistant professor of pharmaceutical sciences at St. John's University in New York. "You can't assume you have a laboratory right next to you when you have first responders trying to figure out exactly what infectious materials are present. The government is very interested in having tests that are power-independent [do not require electricity], that are very specific, and that respond only to what they're supposed to."
"There are two principal rules for a test -- to treat plague patients where it usually occurs in remote, rural areas, and then in a bioterrorist situation." Dennis adds. In both cases, you need a quick diagnosis, you need to be able to rule out other causes, and you need to be able to establish that an outbreak has occurred, he says.
The test does need more real-time and real-situation evaluation, Dennis says. It is already being distributed throughout Madagascar, with plans to make it available in other countries with endemic plague.
More information
For more on the plague, visit the CDC. Learn about defending against bioterrorism at the Center for Civilian Biodefense Studies at Johns Hopkins University.
