There is a season for everything, even the bubonic plague. The Centers for Disease Control and Prevention states the plague has already infected 15 people in 2015 in the United States. Four of those cases were fatal.
Doctor Natalie Kwit, a veterinarian with the division of vector borne diseases at the CDC, says that plague season is generally late spring to early fall, but cases have been seen at any time of the year. The 15 cases this year–two in Arizona, four in Colorado, four in New Mexico, one in Oregon, one in California, one in Utah, one in Georgia, and one in Michigan–is eight more cases than the yearly average. Georgia and Michigan may seem like outliers compared to the western states, but the patients had picked up the disease in California and Colorado and brought it back to their home states.
Two to six days after exposure to Yersinia pestis, the bacteria that causes the plague, an infected person will experience sudden fever, abdominal pain, swollen lymph nodes, nausea, and vomiting. The death rate for patients that aren’t treated ranges from 66 percent to 93 percent, although with quick treatment that rate falls to 16 percent. Cases are usually picked up and spread the same way that aging history books teach grade school students the plague was picked up and spread in 14th century Europe: from fleas that feasted on infected rodents.
The Black Death (as the plague was called when it swept Europe, killing nearly 50 million people, during the Middle Ages) isn’t generally thought of as a first world or United States problem, but it has been striking the U.S. intermittently since 1900. It likely came to the mainland via Hawaii and then made landfall at the port of San Francisco. In the span of four years, 121 cases and 113 deaths were documented in the city. Another burst of infections spanned from 1906 to 1908. Cases were generally confined to San Francisco, but an organized rodent extermination plan never materialized and the plague made its way to other Western cities. To this day, the epicenter of plague infections still lies in the West.
The CDC suggests the plague should be considered when diagnosing any patient living or even traveling from the western United States. The window for eliminating the plague in the United States had a rock thrown through it when a seemingly countless number of rodents left San Francisco and populated other regions, effectively ensuring the spread of the disease. There are, however, a few preventative measures the CDC suggests. Wear long pants and use insect repellent, use flea medication on pets and remove trash that can be a food source and gathering place for rats and other rodents.
Modern medicine won’t let the country fall into the disarray of 14th century Europe, but it’s the simple things that can keep people from becoming another statistic on the unusually large number of cases this year.