Bubonic Plague - Causes, Symptoms, Diagnosis, and Treatment

Introduction

Bubonic plague is considered the cause of the black death that swept two-thirds of the population in Europe in the 14th century. It killed almost 50 million people, and many who died had blackened tissue due to gangrene formation; hence, it got the name black death. There have been other episodes in the world history of bubonic plague; it still occurs in the United States, Asia, and Africa.

What Is a Bubonic Plague?

Bubonic plague is a common form of plague and is an infectious disease caused by the bacteria Yersinia pestis. The bacteria can affect animals and humans and is transmitted through fleas. It gets its name because of the swollen lymph nodes, also called buboes, caused by the disease. It is also known as the black death because of the gangrene formation in people who died from the disease. Bubonic plague can be a very serious condition in humans, with a case-fatality ratio of 30 percent to 60 percent.

What Causes Bubonic Plague?

Bubonic plague is a zoonotic disease; it spreads from animals to humans. It is caused by the bacterium Yersinia pestis which is spread by fleas that travel on rodents and other animals. The fleas bite and transmit the bacteria to humans. The bacteria is harmless to fleas, and hence, they act as disease carriers. The fleas live on the house and field rats; however, the rat blood can withstand a major concentration of plague. When the infected rodent dies, the fleas that have bitten these animals may bite humans and other animals. Pet cats are also vulnerable to plague and get infected by eating infected rodents. The cats can then pass the infection to humans through droplets.

What Are the Risk Factors for Bubonic Plague?

Risk factors for bubonic plague include:

• Location - In rural and semirural settings, rat populations and associated fleas are the primary hosts of the disease. It has also happened in cities with high rodent populations, inadequate sanitation, or overpopulation.

• Profession - Working outside in places where plague-infected animals are abundant puts people at risk of contracting the disease. Pet cats and dogs with the disease pose a risk for individuals performing duties at animal clinics in these areas.

• Interests - The chance of contracting the plague from an infected flea can rise when camping, hunting, or hiking in locations where animals that carry the plague are present.

• Scratch or Bite - Scratches or bites from infected domestic animals can increase the risk of contracting the disease.

What Are the Symptoms of Bubonic Plague?

Once the bacteria enter the body, they become localized in the lymph nodes, where they colonize and multiply. Yersinia pestis bacteria are resistant to phagocytes and can reproduce within phagocytes and kill them. The infected lymph nodes develop hemorrhages and become swollen, which may later result in cell death or necrosis. The bubonic plague can also spread to other organs and cause pneumonic and septicemic plague. Symptoms of bubonic plague appear two to seven days after exposure to the bacteria.

The symptoms include:

• Malaise.

• Weakness.

• High fever (more than 102 degrees Fahrenheit).

• Seizures.

• Muscle cramps.

• Chills.

• Headache.

• Bubo formation is most often in the groin, armpit, and neck and usually near the initial bite site.

• Pain in the abdomen, arms, and legs.

• Gangrene of the nose's toes, finger, lips, and tip.

The characteristic symptom of bubonic plague is the formation of buboes. Buboes are swollen lymph glands filled with pus, commonly found in the armpit, groin, upper femoral, and neck region. Symptoms include hematemesis (vomiting blood), difficulty breathing, cough, and extreme pain due to the decay of the skin while the person is alive. Other symptoms include gastrointestinal problems, extreme fatigue, spleen inflammation, black dots throughout the body, coma, organ failure, and death.

How Is Bubonic Plague Diagnosed?

The bubonic plague can be diagnosed by testing a pus sample from the bubo, blood, or sputum. The pus samples will then be sent to a lab to test for the presence of Yersinia pestis. Another method is a laboratory-validated rapid dipstick test done with the support of WHO (World Health Organization).

How Is Bubonic Plague Treated?

Bubonic plague is treated with antibiotics; several antibiotics are effective against Yersinia pestis. One might require hospitalization and sometimes an isolation unit if diagnosed with bubonic plague. Antibiotics that are effective against bubonic plague include Ciprofloxacin, Levofloxacin, Moxifloxacin, Gentamicin, and Doxycycline. Plague-infected people may also require additional support, including respiratory support and medications to maintain blood pressure.

What Are the Complications of Bubonic Plague?

• Death: Bubonic plague can cause the patient’s disease if not treated. The infection may sometimes spread throughout the body and cause organ failure, septicemic plague, and mnemonic plague. Without treatment, the plague can be fatal.

• Meningitis: Plague may also cause an inflammation of the membrane around the brain and spinal cord rarely.

• Gangrene: Hemorrhages in the blood vessels of fingers and toes can disrupt the blood flow and cause tissue death. These portions of the body may need to be amputated.

How Can Bubonic Plague Be Prevented?

The following actions can help stop the spread of the bubonic plague:

• Prevent rodents (squirrels, rats, and mice) and other wild creatures from entering the home and yard. Refrain from providing them with food or hiding spots. This entails taking care when feeding animals and clearing away debris, brush, and other objects.

• If the pets are permitted to roam freely, make sure they are treated against fleas using specific products. Take sick animals to the vet right away.

• Pets that are allowed to roam around should not sleep on the bed.

• In particular, gloves should be worn if handling dead animals.

• If individuals walk into woodland areas or other areas where they can be exposed to fleas, wear insect repellent. Seek for repellents that contain DEET (diethyltoluamide) or permethrin.

When to Consult a Healthcare Provider Regarding Bubonic Plague?

Contact a healthcare provider if one develops symptoms of a plague, such as high fever, pain, and swollen lymph nodes, following a flea bite. Early diagnosis and treatment are effective against bubonic plague, especially if treated within 24 hours of developing symptoms.

Conclusion

Bubonic plague or the black death may seem like a disease of the past, but it still exists in many parts of the world. The infection is caused by Yersinia pestis, a bacteria in fleas that live on rodents. Bubonic plague, if untreated, is fatal, and the symptoms include swollen lymph nodes, fever, and extreme pain. However, antibiotics are effective against bubonic plague. So, contact a healthcare provider immediately if one develops symptoms of plague.