Plague in California: What Tourists and Expats Need to Know

Introduction

When news broke in August 2025 that a California resident tested positive for the plague near Lake Tahoe, many travelers and expats were understandably alarmed. For most people, “the plague” sounds like something from medieval history books — the Black Death that once swept through Europe. But the reality is that plague cases still appear in the United States every few years, especially in the south regions of California and neighboring states.

According to recent reports from The New York Times, Los Angeles Times, and NBC News, health officials confirmed that the person was likely bitten by an infected flea while spending time outdoors.

For tourists planning a trip to Lake Tahoe or new residents settling in northern California, understanding what plague is, its symptoms, and how to stay safe can make the difference between panic and preparedness.

What Happened at Lake Tahoe?

The confirmed case occurred in South Lake Tahoe, a popular vacation area on the border of California and Nevada. Local health officials reported that a resident tested positive for plague after likely being exposed during outdoor activities. Investigators believe the person was bitten by a flea carrying the bacterium Yersinia pestis — the same bacterium that historically caused the bubonic plague.

This is not the first time plague has been detected around Lake Tahoe. Wildlife in the Sierra Nevada region — especially squirrels and chipmunks — can carry infected fleas. When people camp, hike, or spend time in wooded areas, they may come into contact with these animals or the fleas they host.

Authorities emphasized that the risk for the general public remains very low, but they issued safety reminders for anyone planning trips, camping, or relocating to the south Tahoe area.

Understanding the Plague

The word plague may sound terrifying, but in modern medicine it’s a well-understood and treatable disease. It is caused by the bacterium Yersinia pestis, which lives in small mammals and the fleas that bite them. Humans usually become infected when bitten by those fleas, or — more rarely — by handling sick animals.

There are three main forms of plague, and the most common is the bubonic plague. This form affects the lymph nodes, causing them to swell and become painful. In history, this swelling was called a “bubo,” which is where the name comes from. Other, less common forms include septicemic plague (affecting the blood) and pneumonic plague (affecting the lungs).

While the plague once caused mass death in medieval Europe — known as the Black Death — today it is rare and almost always treatable with antibiotics. The key is early recognition of symptoms and quick medical attention.

Common Plague Symptoms to Watch For

Recognizing plague symptoms early can save lives. The illness usually begins within a few days after being bitten by an infected flea, though the timeline may vary.

The most common symptoms include:

• Sudden high fever and chills
• Severe headache and body aches
• Painful, swollen lymph nodes (often in the groin, armpit, or neck)
• Extreme fatigue and weakness

In cases of bubonic plague, the swollen lymph nodes — called “buboes” — are the clearest warning sign. If untreated, the disease can progress into the blood (septicemic plague) or the lungs (pneumonic plague), which greatly increases the risk of death.

Because these signs can look similar to the flu or other illnesses, travelers and residents in affected areas should seek health care immediately if they notice sudden fever and swollen lymph nodes, especially after camping or outdoor activities around Lake Tahoe or other parts of California.

How the Disease Spreads

Plague does not spread easily from person to person. In most cases, it is caused by the bite of an infected flea that has fed on a rodent carrying Yersinia pestis. These fleas are found in rural and wilderness areas, including parts of California’s south Sierra Nevada and around Lake Tahoe.

The cycle usually looks like this:

• Wild animals such as squirrels, chipmunks, and mice carry the bacteria.
• Fleas feed on these animals and become infected.
• A human is bitten, usually while camping, hiking, or spending time outdoors.

On rare occasions, the plague can spread directly from one person to another through droplets, but this typically happens only with pneumonic plague, which affects the lungs. Health officials emphasize that such cases are extremely uncommon in the United States.

For most travelers and new residents, the risk is tied to outdoor activities, especially when close contact with wild animals or their fleas is possible.

Recent Plague Cases in California and the U.S.

While the latest diagnosis in South Lake Tahoe drew international attention, it is not the only recent case of plague in the United States. According to the CDC, an average of seven cases are reported nationwide each year.

Recent examples include:

• 2025 – South Lake Tahoe, California: a local resident tested positive after likely being bitten by an infected flea. Several rodents in the area also tested positive for plague, according to NBC News.
• 2020 – South Lake Tahoe, California: the last confirmed case in the same region before 2025, successfully treated.
• 2015 – Yosemite National Park, California: two visitors were diagnosed during a plague outbreak linked to infected fleas, both recovered with antibiotics.
• 2025 – Arizona: a rare case of pneumonic plague led to one death, underscoring the importance of early treatment.
  
  

These cases show that plague is still present in certain western U.S. areas, especially rural and mountain regions of California. However, thanks to modern health officials’ monitoring and antibiotics, the disease is quickly recognized and effectively treated.

Notable Plague Events Outside the U.S.

Plague outbreaks are not limited to the United States. In fact, some of the most severe modern epidemics happened abroad.

In Madagascar, there was a deadly outbreak in 2014 with over 260 confirmed cases and 71 deaths, followed by a much larger epidemic in 2017 that resulted in more than 2,000 cases and 200 deaths. Most of these were pneumonic plague, the most dangerous form of the disease.

In India, the 1994 Surat plague outbreak led to 693 suspected cases and 56 deaths. The event triggered mass panic, airport closures, and a large-scale migration of residents fleeing the city.

According to the World Health Organization, between 1,000 and 2,000 plague cases are still reported worldwide each year, mostly in Africa, including Madagascar and the Democratic Republic of Congo.

Risk for Tourists and Relocants

For most visitors, the risk of catching plague in California is very low — but it is not zero. People who spend time outdoors in south Lake Tahoe or other wilderness areas face a higher chance of exposure.

Tourists are more likely to encounter risk while:

• Camping in forests or meadows
• Hiking along trails where rodents live
• Feeding or approaching wildlife

Relocants and residents may face additional risks if they live in rural areas where rodents are common around homes or cabins. Pets can also bring infected fleas indoors after being outside.

While the plague is rare, health officials recommend that both short-term travelers and long-term residents learn to recognize symptoms, avoid direct contact with wildlife, and take preventive steps. The disease can be serious, but with awareness and early testing, it can usually be treated before it causes lasting harm.

Prevention and Safety Tips

Even though plague sounds frightening, there are simple steps that can reduce the risk while traveling or living near Lake Tahoe and other parts of California. Health officials recommend the following precautions:

• Use insect repellents that protect against fleas when camping or hiking.
• Keep food stored securely to avoid attracting rodents.
• Do not feed squirrels, chipmunks, or other wildlife.
• Check pets regularly for fleas, and use veterinarian-approved flea control products.
• Seek medical care quickly if you develop sudden fever or swollen lymph nodes.

According to the World Health Organization and the CDC, the best protection comes from avoiding contact with rodents, controlling fleas on pets, and acting fast if plague symptoms appear.

Treatment and Recovery

The good news is that while plague has a frightening reputation, modern medicine makes it highly treatable. If a person is diagnosed early, doctors usually prescribe antibiotics that kill the Yersinia pestis bacteria. With prompt treatment, recovery is the usual outcome, and the risk of death is very low.

Treatment typically involves:

• Strong antibiotics given orally or intravenously
• Hospital care in more serious cases
• Supportive measures to reduce fever and manage pain

Both the WHO and U.S. health experts stress that early antibiotic treatment is highly effective. The CDC confirms that most patients recover fully when treatment begins promptly.

Key Facts About the Plague in California (2025)

To make the situation clearer for travelers and new residents, here are the most important details about the recent case and general plague facts in California:

This summary shows why the recent case near Lake Tahoe gained attention: while the overall risk is low, knowing the basics helps tourists and expats stay safe.

Conclusion

Hearing about plague in California can sound alarming, especially for travelers and expats heading to Lake Tahoe. But health experts emphasize that the disease is rare, well understood, and usually treatable. The recent case in the south Tahoe area, likely caused by an infected flea, is a reminder that nature still carries risks — yet with basic precautions, the chances of getting sick are extremely small.

For tourists, the key is to stay informed: use repellents, avoid close contact with wildlife, and pay attention to unusual symptoms like sudden fever and swollen lymph nodes. For new residents, regular flea control for pets and awareness of local health guidance provide long-term protection.

The California Department of Public Health regularly monitors plague activity in the Sierra Nevada region, including Lake Tahoe, and issues yearly safety updates. The plague is no longer the unstoppable Black Death of the past. Today, with fast diagnosis, effective antibiotics, and guidance from trusted health officials, it is a manageable risk.