Plague Today

      The mortality and morbidity from plague has been significantly reduced in the 21st century. The disease, however, has not been eradicated. On November 2, 2007, Eric York, age 37, a wildlife biologist, was found dead in his home on the South Rim of the Grand Canyon. He died from plague after performing an autopsy on a dead cougar on October 27. This was the first case reported in Arizona since 2000. A year earlier a woman in Los Angeles was reported in the Los Angeles Times Online to have caught the Black Death. She had been taken to the hospital on April 13 suffering with characteristic swollen inguinal lymph nodes (buboes), fever, and other telltale symptoms of plague. It was suspected (but not proven) that the woman caught the disease after being bitten by infected fleas in her home.

      Time magazine reported on October 30, 2015, that a 16-year-old girl from Oregon who had been on a hiking trip was in intensive care after being hospitalized a week earlier with bubonic plague. It was the 16th reported case that year, and so far, according to the Centers for Disease Control and Prevention, there already had been 4 deaths. In 2015 most of the bubonic plague cases were from Arizona, California, Colorado, Georgia, New Mexico, Utah, as well as Oregon. Two cases were linked to exposure in or near Yosemite National Park.

      Between 1900 and 2012, 1,006 confirmed or probable human plague cases occurred in the United States. More than 80% of U.S. plague cases have been the bubonic form. In recent decades an average of 7 human plague cases have been reported each year (range, 1 to 17 cases per year). Plague has occurred in people of all ages (infants up to age 96), though 50% of cases occur in people ages 12 to 45. It occurs in both men and women, though historically is slightly more common among men, probably because of increased outdoor activities that put them at higher risk.

      Worldwide between 2010 and 2015 there were 3,248 cases of plague reported and 584 deaths. Following the reappearance of plague in the 1990s in India, the World Health Organization considered plague as a reemerging disease. Over the years there has been a major shift of cases from Asia to Africa, with >90% of all cases occurring in Madagascar, Tanzania, Mozambique, Malawi, Uganda, and the Democratic Republic of the Congo (DRC). Most cases are of the bubonic variety; cases of pneumonic plague, however, were reported from the DRC in 2006 and Uganda in 2007. Madagascar is the most seriously affected country, with an overall fatality rate of 23% associated with pneumonic plague. In the United States plague has been encountered when houses have encroached on rural areas that harbor plague-infected rodents (sylvatic plague), such as prairie dogs, ground squirrels, mice, and rats. Infection may also be acquired from domestic pets (cats and dogs) that have come in contact with prairie dogs and can transmit disease to humans via fleas or in the pneumonic form. In the United States there has been an increase in the number of human cases of pneumonic plague, especially among veterinarians who have been exposed to infected cats.

      Control of plague can be effected by surveying wild populations for infections, monitoring die-offs in the rodent population, making plague-infested areas known to the public, reducing the appeal of residential areas to rodents, and treating rodent burrows with cabaryl dust or bait stations to kill fleas. In some cases, rodenticides have been used.

      Because of sylvatic plague and enzootic infections (i.e., outbreaks of a disease in animals other than humans), total eradication cannot be achieved.

      Though human disease is rare, a feverish patient who has been exposed to rodents or flea bites in an area where plague is endemic should be considered a possible plague victim. The potential for the spread of pneumonic plague has been increased by air travel. Passengers who have fever, cough, or chills and come from areas where plague is endemic should be placed in isolation and, if necessary, treated. The diagnosis of plague has remained virtually unchanged since the days of Yersin: Gram staining and culture of bubo aspirates or sputum. The bacteria can also be grown in the laboratory on blood agar.

      Unless specific treatment is given, the condition of a plague-infected individual deteriorates rapidly, and death can follow in 3 to 5 days. Untreated plague has a mortality rate of >50%. Streptomycin, tetracyclines, and sulfonamides are the standard treatments, and gentamicin and fluoroquinolones are alternatives when these other antibiotics are unavailable. In May of 2015 the U.S. Food and Drug Administration approved moxifloxacin (Avelox) to treat patients with plague. Earlier treatment was effected by using a serum Yersin had prepared in horses after injecting them with the plague bacilli he had isolated in Hong Kong in 1894.