DECK 2 — THE PLAGUE

What organism causes the plague?

Yersinia pestis

What type of bacterium is Yersinia pestis?

Gram-negative bacterium

Where is Yersinia pestis commonly found?

Rodents

How is plague usually transmitted in nature?

By fleas between rodents

What is the plague also known as?

The Black Death

Why was it called the Black Death?

It causes black scabs on the skin

What are the three main forms of plague?

Bubonic septicemic and pneumonic

Which form is most common?

Bubonic plague

What percentage of cases are bubonic?

Over 80 percent

What are buboes?

Painful swollen lymph nodes

Where do buboes usually appear?

Near the flea bite such as groin underarm or neck

How long after a flea bite do symptoms appear?

About 2 to 6 days

What are early symptoms of bubonic plague?

Fever chills muscle aches headache weakness

What happens if bubonic plague is untreated?

It can become septicemic plague

What is septicemic plague?

Bloodstream infection with Yersinia pestis

How can septicemic plague begin?

Spread from buboes lungs or infected animal contact

What are symptoms of septicemic plague?

Nausea vomiting diarrhea bleeding shock kidney failure

What is survival rate with treatment for septicemic plague?

About 75 to 80 percent

What is pneumonic plague?

Plague infection of the lungs

How is pneumonic plague transmitted?

By inhaling infected droplets

Why is pneumonic plague dangerous?

It can quickly lead to death

What is the most common mode of plague transmission?

Flea bites

How else can plague be transmitted?

Contact with infected blood or tissues

How can pneumonic plague spread person to person?

Through coughing droplets

What new research suggests about medieval plague spread?

Fleas spread it directly between people not rats

What is the take-home message from plague transmission?

Hygiene counts

How is plague diagnosed?

Phenotypic methods and lab tests

What samples are used for plague diagnosis?

Lymph node aspirates blood sputum bronchial washings

What does Yersinia pestis look like on gram stain?

Safety pin appearance

How can serology help diagnose plague?

Detects antibodies to Yersinia pestis

How can plague be prevented?

Reduce rodent habitats and avoid flea exposure

What should you wear when handling animals?

Gloves

What repellent helps prevent flea bites?

DEET on skin permethrin on clothing

How can pets increase plague risk?

They bring infected fleas into homes

What is the treatment for plague?

Antibiotics

What is the drug of choice for plague?

Streptomycin

What other antibiotics treat plague?

Tetracycline and chloramphenicol

Where do most US plague cases occur?

Southwest US and California region

Which states have the highest plague incidence?

New Mexico Arizona Colorado California Oregon Nevada

What percentage of US cases are bubonic?

Over 80 percent

How many plague cases occur yearly in the US?

About seven per year

What age group is most affected?

Ages 12 to 45

Is plague found worldwide today?

Yes

The bacterium that causes plague is _.

Yersinia pestis

Yersinia pestis is a _ bacterium.

gram-negative

Plague is usually transmitted by _.

fleas

The three forms of plague are , , and _.

bubonic; septicemic; pneumonic

The most common form of plague is _.

bubonic

Swollen lymph nodes in plague are called _.

buboes

Untreated bubonic plague can progress to _.

septicemic plague

Septicemic plague is an infection of the _.

bloodstream

Pneumonic plague affects the _.

lungs

The most common way plague spreads to humans is through _.

flea bites

Yersinia pestis appears as a _ on gram stain.

safety pin

Serological testing looks for _ against Yersinia pestis.

antibodies

The drug of choice for plague treatment is _.

streptomycin

Most US plague cases occur in the _ United States.

southwestern

The key prevention message for plague is that _ matters.

hygiene