On August 19, 2025, a California resident in South Lake Tahoe tested positive for the bubonic plague. It is believed that while camping in the South Lake Tahoe area, the victim was bitten by an infected flea carrying the bacterium Yersinia pestis. This type of bacterium was also responsible for other major plague outbreaks in the past. Health experts remain uncertain about the causes of the plague’s reappearance, but it is important to determine them as soon as possible.
Symptoms of the plague include nausea, fever, and weakness. These symptoms usually appear within two weeks. If diagnosed early, the sickness can be treated with antibiotics, but if not, it can get very serious.
Yersinia pestis is often transmitted by fleas, but it can also spread through rodents such as chipmunks or squirrels, and even dogs or cats. Between 2021 and 2025, in the Lake Tahoe Basin, an area near South Lake Tahoe, a total of 45 rodents tested positive for the plague bacterium. Because it can be transmitted by animals ranging from fleas to dogs, Yersinia pestis appears to be nearly impossible to eliminate.
Contrary to popular belief, this is not the first time the plague has reappeared in recent years. Another case of the plague occurred in South Lake Tahoe in 2020, and two additional cases were reported in 2015 near Yosemite National Park. However, these are only a few recent cases. According to CDC Maps and Statistics, “An average of seven human plague cases are reported each year in the United States.”
Some general precautions recommended by professionals to help prevent the spread of the plague include avoiding contact with rodents and wearing long pants to reduce exposure. Another tip is to protect pets by keeping them on a short leash or by choosing not to bring them at all. Although the plague is no longer as deadly as it was in medieval times, it remains important to remain protected against this recurring disease.
In the mid-14th century, the Black Death, a plague, was among the most devastating pandemics in history. From 1347 to 1352, the plague killed more than 20 million people in Europe, representing nearly a third of the continent’s population. Although the Black Death occurred approximately 675 to 680 years ago, its symptoms remain the same. These symptoms include fever, chills, lymph node swelling, and death (rare today due to modern medicine).
In medieval times, people had virtually no idea how to treat the plague. However, that didn’t stop people from trying. One method used in medieval times was piercing the plague boils, which was not only ineffective but also unsanitary. Another method was simply letting blood exit the victim’s body, which was essentially just pouring salt on a wound. Another ineffective remedy was bathing in vinegar or burning odorous plants and herbs. Fortunately, modern medicine, including antibiotics, enables the treatment of plague cases today.
Medieval Europeans were clueless about what was causing the plague. Many believed that it was a divine punishment by God for committing sins. At the time, there were no other widely accepted theories about what had caused the plague, so many people believed it was a punishment. As a result, the public murdered the people whom they considered to be “bad.” This did nothing except cause further chaos during the stressful period of the plague. Today, we know that the plague is caused by the bacterium Yersinia Pestis, and that it is not, in fact, a punishment from God.
Although the plague remains a deadly and unsettling disease, experts are working to identify its cause to eradicate the causative bacterium. Until then, the public should remain safe by taking every necessary precaution. The good news is that another outbreak of the same magnitude as the medieval plague is highly unlikely. Just in case, people and their pets should avoid rodents – especially their fleas!
