Plague is a potentially severe disease caused by a bacterium, Yersinia pestis. It caused the 'Black Death' in Europe during the Middle Ages, when approximately one-third of the European population died. Rats on ships brought plague from China to San Francisco in 1900. Today, it continues to cause disease in wild rodents (for example, ground squirrels and prairie dogs) and in cats and dogs in the southwestern United States, California and southern Oregon. Plague also exists in eastern and southern Africa, Southeast Asia, China, Russia and parts of South America.

What are the symptoms of plague?

Initial symptoms include high fever, chills, muscle aches, headache, nausea, vomiting, diarrhea, abdominal pain and extreme exhaustion. Swollen and tender lymph nodes near the spot where the plague bacteria entered the skin are typical of bubonic plague. Pneumonic plague usually presents with fever, cough, bloody sputum and difficulty breathing.

What are the different types of plague?

Bubonic (lymph gland) plague occurs when the plague bacteria enter the skin, usually through a flea bite. If a flea feeds on an animal that has plague bacteria in its bloodstream, it will carry the bacteria and then transmit the infection if it bites a person. The bacteria travel to the lymph glands in the groin, neck or armpit where they multiply and cause tender swellings called buboes. The disease also can occur if a person is scratched or bitten by an infected animal, or if an infected animal carcass is handled without gloves and the bacteria enter through a break in the skin. Bubonic plague can be effectively treated with a variety of widely-available antibiotics. As with all plague infections, bubonic plague is a severe illness. If untreated, it can be fatal in approximately 50-60% of cases.

Pneumonic (lung) plague is the only type of plague that can be spread from person to person. It can occur if someone breathes in plague bacteria from another person with the infection or from the cough of an infected animal (e.g., a cat). After entering the lungs, the bacteria multiply and cause life-threatening pneumonia. Pneumonic plague also can develop from bubonic plague if the bacteria enter the bloodstream and are then transported to the lungs. If not treated with antibiotics soon after symptoms appear, the illness is almost always fatal.

Septicemia (bloodstream) plague occurs when plague bacteria enter the bloodstream either through the skin or from the lungs. Once in the bloodstream, plague bacteria can spread to the brain and cause meningitis. If not treated with antibiotics soon after symptoms appear, the illness is usually fatal.

Meningeal plague (brain) occurs if bubonic, pneumonic or pharyngeal plague spread to the bloodstream and the plague bacteria are carried to the brain.

Pharyngeal (throat) plague occurs when a person swallows food or beverage that contains live plague bacteria, leading to a severe throat infection that can spread to the lungs and bloodstream if not treated.

How common is plague and how is it usually caused?

In the United States, plague is rare. Between 10 and 15 cases are typically reported any year, with most of them occurring in rural locales in the Southwest. Two persons were diagnosed in New York City with bubonic plague in 2002 but they had been exposed in New Mexico shortly before traveling to New York. Plague occurs naturally in certain parts of Africa, Asia and South America.

What is bioterrorism?

Bioterrorism is the intentional use of biological agents or germs to cause illness. Bioterrorism has occurred in NYC only in 2001, when several media outlets received letters that were intentionally contaminated with anthrax bacteria.

How soon after infection do symptoms appear?

Bubonic plague occurs one to seven days after the bacteria enter through the skin. Pneumonic, pharyngeal and septicemia plagues begin one to four days after exposure to the plague bacteria.

I am concerned that I have or someone who I know has plague symptoms. What should I do?

Anyone with the symptoms of plague should contact their medical provider immediately. If there is bloody cough, breathing difficulty, severe sore throat, severe headache or confusion, call 911.

Who usually gets plague when the disease occurs naturally?

Human plague infections occur when people come into contact with a plague-infected animal and either breathe in bacteria that the animal has coughed, touch an infected animal carcass or skin or are bitten by a flea that fed on an animal with plague. In 2002, two travelers from New Mexico were diagnosed in NYC with bubonic (lymph gland) plague; however, their infections occurred at home before they flew here.

How is plague diagnosed?

Plague is diagnosed by growing the bacteria from samples of sputum, blood, spinal fluid or infected lymph nodes. Antibody testing also can diagnose plague in some circumstances.

What is the treatment for plague?

A number of widely available antibiotics are usually effective against plague bacteria. The recommended treatment regimen is 10 days.

Is there a plague vaccine, and if so, how can I get it?

There are plague vaccines under development but there currently is no vaccine that is approved for use in the United States.

What has New York City done to address the threat of plague?

Many federal, state, and city agencies, including the NYC Department of Health and Mental Hygiene (DOHMH), have been working together for several years to prepare for a bioterrorist event in New York City. In cooperation with other emergency response agencies, the Health Department has created systems to improve the detection of and response to public health emergencies caused by the intentional release of a biological agent.

How will I cope?

A plague outbreak in NYC can be very stressful, especially if it is large scale event. It can disrupt your everyday life and make you and those around you feel less safe. You may experience fear and uncertainty. Learning about stress and strategies to manage it can help you cope.

Prepare Today, Cope Better Tomorrow - Stress during Disasters provides basic information and practical advice on dealing with the stress and anxiety caused by disasters. It is available in seven languages.

If there is plague in the city and you feel overwhelmed and unable to cope, or if you are concerned about someone else, you can find help by calling 988. 988 is a free, confidential helpline for New York City residents, available 24/7, with trained staff ready to take your calls and offer advice.

For more information about plague, visit: Centers for Disease Control and Prevention (CDC)