• A tropical disease that is caused by the yellow fever virus.

What is yellow fever?

How do you get yellow fever?

• The bite of an infected mosquito.

• The mosquito injects the yellow fever virus into the victim.

• Only female mosquitoes spread yellow fever.

• Yellow fever is diagnosed by a blood test.

The Enemy

“Aedes aegypti”

Signs & Symptoms

• High fever• Chills• Headache• Muscle aches

Stage One (3-6 days after exposure)

• Loss of appetite • Nausea • Jaundice

(yellowing of eyes and skin)

Signs & Symptoms

Stage Two: Remission• 3-4 days

• Recovery possible

Stage Three: Toxic period

– Vomiting

– Bleeding

– Hemorrhage

– Kidney and liver failure

– Delirium, seizures

– Heart damage

– Coma

– Shock

– Death

Brief History of Yellow Fever, 1793

• August, 1793 – prominent citizens and physicians gather in Philadelphia to discus increase in number of patients with nausea, black vomit, lethargy and yellow skin coloration.

• Dr. Rush, most prominent physician and signer of the Declaration of Independence, proclaimed the disease yellow fever and advised all “that can move, to quit the city.”

• Half the population of Philadelphia fled to the surrounding countryside.

• Congress adjourned; President Washington and Thomas Jefferson left town.

• 5,000 died in 3 months (10% of Philadelphia's population)

• Cause of fever unknown at the time.

Brief History of Yellow Fever, 1793

(con’t)

Wet spring, stagnant pools of H2O

Hot temperatures

Tons of mosquitoes

Refugees with yellow fever fleeing Revolution in Santo Domingo

Mosquitoes bit the refugees, got yellow fever, then bit the

citizens of Philadelphia.

Why did it happen?

+

Was what happened

in Philadelphia an

epidemic or a plague?

What is an epidemic?

An outbreak of a contagious disease that spreads rapidly and widely; affecting or tending to affect a disproportionately large number of individuals within a population, community, or region at the same time.

What is a plague?

A disastrous evil or affliction; an epidemic disease causing a high rate of mortality.

Yellow Fever Today

• Common in West and Central Africa and parts of South America; very rare in U.S.

• Preventable by immunization

• Treatment: rest and fluids

END