Plague – Symptoms and Causes
Overview
Plague is a rare but serious disease caused by the bacteria Yersinia pestis. This illness primarily exists in small rodent populations and their fleas, with humans typically becoming infected through flea bites.
Though uncommon, plague appears in specific regions globally, including rural and semi-rural parts of western United States, affecting a small number of people yearly.
When identified promptly, plague can be effectively treated with antibiotics. However, without proper treatment, this disease often proves fatal.
Due to its potential as a biological weapon, the U.S. government has developed emergency protocols and stockpiled treatments in case of such an event.
Signs of the Disease
Swollen Lymph Node Plague
Swollen lymph node plague causes enlarged lymph nodes called buboes. These swellings appear in the neck, armpit, or groin areas. They can be painful and range from smaller than 1 centimeter to about 10 centimeters in size.
Other symptoms include:
- Sudden high fever with chills
- Headaches
- Extreme tiredness
- General unwell feeling
- Weakness
- Muscle pain
- Skin sores (rare)
Blood Infection Plague
Blood infection plague happens when plague bacteria multiply throughout the bloodstream. Patients may not develop buboes with this form.
Early warning signs:
- Sudden fever with chills
- Severe weakness
- Stomach discomfort with diarrhea and vomiting
As the disease worsens, more serious symptoms may appear:
- Bleeding from mouth, nose, rectum, or under the skin
- Seizures, rash, and low blood pressure (signs of shock)
- Black, dying tissue (gangrene) on fingers, toes, ears, or nose
Lung Plague
Lung plague affects the respiratory system. It can start in the lungs or spread there from infected lymph nodes. Symptoms begin quickly after exposure and rapidly worsen.
Common symptoms include:
| Symptom | Description |
|---|---|
| Fever | Sudden high temperature with chills |
| Cough | Often producing bloody mucus |
| Breathing | Difficult or irregular patterns |
| Chest pain | May be severe |
| Digestive issues | Upset stomach and vomiting |
| Head and body | Headaches and weakness |
Without treatment on the first day, lung plague quickly leads to respiratory failure, shock, and death.
When to Get Medical Help
Seek immediate medical attention if you develop a sudden high fever.
Get emergency care if you have a fever or other symptoms and live in or have visited areas with known plague cases. In the United States, Arizona, California, Colorado, and New Mexico report most cases.
Worldwide, countries with frequent cases include Madagascar, the Democratic Republic of Congo, and Peru across Africa, Asia, and Latin America.
What Causes Plague
Plague is caused by bacteria called Yersinia pestis. These bacteria live in small animals and their fleas. When infected fleas bite humans, they can pass along the bacteria.
Flea bites are the most common way people get plague. These fleas usually come from wild animals or pets that have been in contact with infected animals. This creates a path for the disease to spread from animals to humans.
Direct contact with infected animals can also cause plague. Hunters face risk when they handle or skin sick animals. The bacteria enter through cuts or breaks in the skin.
Pneumonic plague spreads through the air. When infected people or animals cough or sneeze, tiny droplets carrying the bacteria float in the air.
Others can breathe these droplets in and become sick. People can also get infected by touching mucus from an infected person’s cough.
Common animal carriers include:
- Rats, mice and voles
- Squirrels and prairie dogs
- Rabbits
- Ground squirrels and chipmunks
Animals that can get plague by eating infected animals or from fleas:
- Pet cats and dogs
- Coyotes
- Wild cats
Risk Factors
Plague appears in several regions around the world, with only a few thousand cases reported globally each year. The United States averages just seven cases annually.
Madagascar experiences yearly outbreaks, while the Democratic Republic of Congo and Peru also report significant numbers of cases. In the U.S., plague mainly affects western states like Arizona, California, Colorado, and New Mexico.
The disease primarily exists in rural and semi-rural rodent populations and their fleas. Urban areas with poor sanitation, overcrowding, or large rat populations can also harbor plague.
Occupational Risks
People working outdoors in regions where plague-infected animals live face higher exposure risks. This includes:
- Wildlife management professionals
- Forest rangers
- Agricultural workers
- Veterinary staff
Animal clinic workers in these areas also risk contact with infected pets, particularly cats and dogs that may have caught plague from wild animals.
Recreational Activities
Outdoor activities in plague-prone regions increase exposure risk. These include:
| Activity | Risk Factors |
|---|---|
| Camping | Contact with wildlife areas |
| Hiking | Exposure to rodent habitats |
| Hunting | Direct animal contact |
These activities raise the chances of flea bites from infected animals.
Biological Warfare Concerns
Plague is considered a potential biological weapon by the U.S. government. Historical evidence shows it has been developed or used as a weapon in the past. Government guidelines exist for treatment and prevention if plague were used in this manner.
Problems
When plague is not treated, problems may happen. These problems can change how sick you get and might even be deadly.
Blood clots may form in the small blood vessels of your fingers, toes, nose, and ears. This can make the tissue die, which doctors call gangrene. When this happens, the dead tissue must be removed.
In rare cases, plague can cause meningitis. This means the tissues around your brain and spinal cord become swollen and infected.
Another uncommon problem is pharyngeal plague. This happens when the disease affects the area behind your nose and mouth.
Risk of Dying
About 11% of people with any type of plague in the United States die from the disease.
Most people with bubonic plague live if they get the right treatment quickly. Septicemic plague is more deadly because it’s hard to spot and gets worse fast. This can delay treatment.
Pneumonic plague is very serious and quickly becomes worse. If treatment doesn’t start within 24 hours after symptoms begin, the risk of dying is very high.
Lowering Your Exposure Risk
While scientists work on developing a vaccine, antibiotics can prevent infection if you’ve been exposed to plague. People with pneumonic plague need isolation during treatment to stop disease spread. Healthcare providers must wear protective gear when treating plague patients.
If you live in areas where plague exists, take these steps to protect yourself:
-
Make your home rodent-free:
- Remove brush piles, rocks, and firewood where rodents nest
- Store pet food in sealed containers
- Take action quickly if you notice rodents in your home
-
Keep pets safe:
- Use effective flea control products
- Get quick veterinary care if your pet seems sick
- Don’t share your bed with pets that go outdoors in plague areas
-
Stay safe around animals:
- Always wear gloves when handling dead animals
- Contact local health authorities if you need help with animal removal
- Use proper insect repellents:
| Type of Repellent | Notes |
|---|---|
| DEET | Effective against fleas |
| Picaridin | Safe for most skin types |
| IR3535 | Good for clothing and skin |
| Oil of lemon eucalyptus | Not for children under 3 |
| Para-menthane-3,8-diol | Not for young children |
| 2-undecanone | Plant-based option |
Here are some tips for applying repellent:
- Never spray directly on your face
- Don’t use on infants under 2 months
- Follow product instructions carefully
