Almost seven centuries after the Black Death struck Europe, the plague is still lurking. This summer, there have been eleven confirmed infections by Yersinia pestis, the scientific name for the bacteria responsible for bubonic plague, and three of these infections have been fatal. Although it may seem strange, plague is a naturally occurring phenomenon that is particularly centered in the American West, and though reports are rare, it is normal to have a few cases every year. This year, there have been 11 cases since April, which is an increase over the typical number, prompting the CDC to issue a statement asking people to be aware.
Half of the American plague cases in 2015 have occurred in Colorado. This localization of plague is not unusual, since plague is common in prairie dogs, native to the Western United States, and is spread to humans through their fleas. When plague becomes particularly successful in infecting and killing a population of rodents, the fleas are deprived of their typical host’s blood. These fleas then seek out humans, spreading plague wherever they find food.
The spread of plague is strongest during cool summers which follow particularly wet winters. Cats are more likely than dogs to become infected by plague and may infect humans by coughing out the bacteria into the air. If caught quickly, plague is fairly easily treated with antibiotics. Annually, there is a median of seven plague cases in the United States, and researchers aren’t sure why we are seeing more cases than average, but the CDC cautions that it isn’t unusual to have fluctuations in the number of cases.
Nearly all cases since 1970 have occurred in the Western United States because the rural areas with an abundance of the animals that can carry the disease allow it to spread more readily than in the Eastern US. If you live in this region, there are a few things you can do to protect from plague. First, minimize your contact with rodents and treat pets to remove fleas. Like ticks, fleas can be dissuaded by insect repellant, long clothing, and a cautious approach to wild animals, dead or alive.
Though dangerous, plague is a relatively benign killer when it comes to wildlife-borne illnesses. Lyme disease, for example, is particularly widespread and vicious and impacts far more people every year. Although three people have died from plague this year, it is not a threat to most Americans. If plague happens to befall your household and you catch it in its early stages, it can be stopped relatively easy and you won’t ever have to call this Doctor.