Smallpox Flashcards
What is the causative organism for smallpox?
Causative agent: Variola virus
What family of viruses does smallpox belong?
Family: Poxvirus
What is the genome of this virus?
Genome: DNA Double stranded
Does this virus always have an envelope?
Envelope: May or May not be Present
What is the shape of the variola (smallpox) virus?
Smallpox viral particle: Brick shape
What is the organization known as WHO?
World Health Organization
How was smallpox eliminated as a naturally occurring infection?
WHO (World Health Organization) worked with governments to eliminate Small Pox threat
Successful vaccine program
When was the last naturally occurring case of smallpox reported in the world?
Last reported case: 1977; Somalia, Africa
What 2 labs are authorized to handle the smallpox virus?
Authorized storage in labs: United States (CDC) and Russia
What are some possible modes of transmission for smallpox?
Main mode: contaminated air droplets person-to-person
coughing, breathing
Contact with skin sores
6 ½ feet from infected person for transmission
Contaminated clothing or bedding
1 person: infects 5 individuals
Is smallpox contagious?
YES
Is smallpox always fatal?
No
Death Rate of Smallpox Infection
Variola minor = 1% of victims
Variola major = 30% of victims (1 in 3)
What are the clinical symptoms for smallpox?
Initial: high fever (1010F ), fatigue, headache, backache
2 – 3 days later:
Macular rash or pox
pink spots begin in mouth
spread to: face and arms then to trunk and legs
What is the duration of a typical smallpox case until recovery?
1
What is the difference between the macular, vesicular and pustular rash?
Macular Rash: Flat, Pink Spots
Vesicular Rash: Fluid-filled Pimples w/ Dip in Center
Pustular Rash: Hard, Round, Painful, Pus-Filled Blisters
Is there a vaccine for smallpox?
Yes: Made of Vaccinia Virus (Today)
Made of Cowpox (Historically)
What is the difference between variolation and vaccination?
Variolation: thread saturated with fluid from smallpox lesions introduced into a scratch of nonimmune person
Vaccination:
Who was Lady Montagu and what is her significance in history?
Wife of British Ambassador to Turkey (1700’s)
Introduced Variolation to England
Variolation became popular in Europe
Is cowpox in the same family of viruses as smallpox?
1
Who was Edward Jenner and what was his contribution to the smallpox vaccine?
Improved Smallpox immunization
Cowpox (disease of cows) causes few – no symptoms in humans
Discovered Cowpox exposure immunized against Smallpox
Vaccination: vacca (cow)
What is the component of the vaccine for smallpox?
Vaccinia virus (not cowpox!)
Possibly a hybrid between Cowpox and Smallpox virus
Horsepox?
Not clear where virus originated
What is an attenuated vaccine?
An attenuated vaccine is a vaccine created by reducing the virulence of a pathogen, but still keeping it viable (or “live”). Attenuation takes an infectious agent and alters it so that it becomes harmless or less virulent.
How long does immunity last after smallpox vaccine?
Protective for 3 – 5 years, no more than 10 years
What is a bifurcated needle?
“Double prong” Needle designed for one time use
Needle designed to hold a tiny drop of vaccine
Are there side effects from the smallpox vaccine? Is there any segment of the population that should not receive this vaccine because of high risk?
Encephalitis (Brain inflammation): 12.3 cases/1 million vaccinations (1/4 died)
Progressive vaccinia : 1.5 cases/million vaccinations (lesions fail to heal/immunocompromised)
Eczema vaccinatum( vaccine virus spreads with allergic rash): 38.5 cases/million vaccinations; spread of eczema with lesions
Generalized vaccinia(vaccine blister spreads all over the body): 241 cases/million vaccines; lesions erupt 6 – 9 days after vaccine
People at risk
Cancer patients
Immune deficiency (AIDs)
Skin condititions (eczema)
Pregnancy
Is anyone vaccinated for smallpox today?
Scientists that handle smallpox or related viruses
Military personnel
Select Health care workers
Select Emergency personnel
Is there treatment for smallpox?
No Drug Treatment; Vaccination immediately after exposure may prevent onset of disease
Is smallpox always fatal?
No
Is there immunity after recovery of a natural infection with smallpox?
Lifelong immunity after recovery of natural infection
What is the availability of smallpox virus to a terrorist?
Availability: very low
What is an N95 respirator?
N95 Respirator: Recommended that all family members have one
Filters at least 95% of particles
Reduces exposure doesn’t eliminate risk entirely
Cost: $1 -2
What would be the danger of reintroducing smallpox in today’s world?
Catastrophic
Younger generations have never been vaccinated
Older generations vaccine is probably no longer protective
Very lethal disease
