Stevan Cordas DO MPH
Clinical Assistant Professor UNTHSC
Smallpox - Stevan Cordas DO MPH 1
First indicated in Egypt 1500 BC.
Rameses V died of smallpox in 1154 BC.
China first recorded 4th century AD.
622 AD Ahrun of Alexandria first
India 7th century AD.
Smallpox - Stevan Cordas DO MPH 2
Early 16th century – smallpox epidemics
1507 –introduced into the Caribbean.
1520 to 1555 – introduced into Mexico
and south America.
1617 severe outbreak in Massachusetts.
1763 used against Indians by Amherst.
Smallpox - Stevan Cordas DO MPH 3
1721 Boston cotton Mather obtained services
of Zabeil Boylston. 285 patients inoculated. 6
died. (2%) of 5579 cases not inoculated 844
died (about 15%). Smallpox lesions were
1774 Benjamin Jesty, a farmer, introduced
cowpox vaccination. Never given credit.
1794 Edward Jenner legitimized and refined
cowpox vaccination for smallpox
immunization. Vacca means cow in Latin.
Smallpox - Stevan Cordas DO MPH 4
1777 Washington orders variolation of
Early 19th century pandemics among
1870 last great epidemic in Europe.
1947 last case in US.
1977 last case in the world -Somalia.
Smallpox - Stevan Cordas DO MPH 5
Last known case of smallpox
Smallpox - Stevan Cordas DO MPH 6
U.S. Smallpox Hospital
Minton House, Cape Girardeau, Missouri
Smallpox - Stevan Cordas DO MPH 7
Smallpox - Stevan Cordas DO MPH 8
Orthopoxvirus include smallpox, monkeypox,
rabbitpox, camelpox, cowpox, and other
animal pox viruses, all of which cross react
serologically. Large DNA virus.
Pox viruses enter the respiratory tree mucosa
and produce a brief viremia followed by a
latent period of 4 to 14 days. The incubation
period of smallpox is 7 to 17 days with 10-12
days the mean.
Smallpox - Stevan Cordas DO MPH 9
Smallpox prodrome occurs abruptly and
lasts 2 to 3 days. It produces
headaches, fever often 102º or more,
prostration, and backache. Infection
and enanthema of the pharynx and
tongue occur initially. This precedes the
appearance of dermal rash by one day.
Smallpox - Stevan Cordas DO MPH 10
The epithelial capillary bed is invaded
and a characteristic rash appears. The
kidney, spleen, lymph nodes, liver bone
marrow and other organs become
The rash at first is macular then in one
or two days, 2 to 3 mm papules form.
Smallpox - Stevan Cordas DO MPH 11
In another 2 or 3 days 3 to 5 mm vesicles
form. They first occur on the face and
extremities and affect the palm and soles
(centrifugal distribution). Lesions in a region
appear the same age.
Between 4 and 7 days after the rash appears,
pustules are present which last 5 to 8 days.
Umbilication and crusting then occur.
Smallpox - Stevan Cordas DO MPH 12
Smallpox - Stevan Cordas DO MPH 13
Types of smallpox
Ordinary (Variola major) three
subtypes. About 30 % mortality.
Confluent – confluent rash on the face and
Semiconfluent – Confluency only on face,
Discrete – areas of normal skin between
the lesions, even on the face.
• Rao 1972
Smallpox - Stevan Cordas DO MPH 14
Smallpox - Stevan Cordas DO MPH 15
Types of smallpox
Variola sine eruptione – fever without
rash – must be confirmed serologically.
Flat type – lesions remain flat and
confluent. Usually fatal. 3-5% of cases
Hemorrhagic type – early –with
purpuric rash –always fatal. Late
bleeding into the pustules – usually
fatal. 5-7% of cases
Smallpox - Stevan Cordas DO MPH 16
Smallpox - Stevan Cordas DO MPH 17
Differential Diagnosis -Varicella
Varicella – usually in children less than 10.
No significant prodrome.
Starts on trunk and doesn’t affect palms or
Different appearances of lesions in a given
region of the body.
Rapid progression to vesicles in 24 hours.
Not morbidly ill.
Lesions not hard, fragile.
Smallpox - Stevan Cordas DO MPH 18
Smallpox - Stevan Cordas DO MPH 19
Other diseases in differential
Herpes Zoster disseminated
Stevens Johnson syndrome
Disseminated herpes simplex
Foot and mouth disease
Smallpox - Stevan Cordas DO MPH 20
Smallpox - Stevan Cordas DO MPH 21
Direct fluorescent antibody
Indirect fluorescent antibody
Polymerase chain reaction
3 specimens from each person
Smallpox - Stevan Cordas DO MPH 22
Treatment of febrile vesicular
Isolate immediately – Airborn and contact
Divide into high risk, moderate risk and low
risk of having Variola. Check CDC site.
Contact health department and infectious
Supportive care and testing per support
Vaccinia immune globulin and cidofovir.
Smallpox - Stevan Cordas DO MPH 23
Effective up to 72 hours after the
prodrome symptoms start. Not after the
It is a live virus of vaccinia (similar to
cowpox) so site must be covered and
taken care of until scab falls off.
Smallpox - Stevan Cordas DO MPH 24
Vaccine is 95% effective.
Lasts for 3 to 5 years then wanes.
Revaccination lasts longer.
Vaccine is given on upper arm with bifucated
If vaccine successful – red itchy bump forms
in about 3 days. In first week a large blister
appears. Then scab forms and falls off the
Smallpox - Stevan Cordas DO MPH 25
Smallpox - Stevan Cordas DO MPH 26
Complications of vaccine
If exposed to smallpox the risks of
smallpox out way the risks of the
vaccine. About 14 to 52 per million
vaccinated will get serious side effects
and about 1 to 2 out of a million will die
as a result of the vaccine.
Most suffer from low grade fever, flu-
like symptoms and sore arm.
Smallpox - Stevan Cordas DO MPH 27
Complications of vaccine
About a thousand out of a million will
get more serious problems such as
spreading the vaccinia from the local
site to a distant site. It can cause
blindness if it gets in the eye.
Bloodborn (generalized vaccinia)
Erythema multiforme at site of lesion
Smallpox - Stevan Cordas DO MPH 28
Eczema Vaccinatum CDC
Smallpox - Stevan Cordas DO MPH 29
Smallpox - Stevan Cordas DO MPH 30
Fatal Vaccinia Necrosum CDC
Smallpox - Stevan Cordas DO MPH 31
Do not give vaccine to the
Children under 12 months.
Do not give to children under age 18 except
under emergency conditions. - Advisory
Committee on Immunization Practices.
Immune depressed individuals.(HIV etc.)
Those with eczema or certain skin conditions.
If you are living with such patients except
under emergency conditions.
Smallpox - Stevan Cordas DO MPH 32
Major criteria of Smallpox
Febrile prodrome 1 to 4 days before
rash occurs with fever (they all have a
fever), fatigue, headache, backache,
perhaps vomiting, abdominal pain.
Rash follows which is firm, hard, deep.
May be confluent or umbilicated
Lesions all in the same stage of
Smallpox - Stevan Cordas DO MPH 33
Centrifugal distribution with greatest
concentration on face and extremities.
Patient appears morbid
First lesions in mouth, face and
Lesions on soles and palms
Slow development of lesions.
Smallpox - Stevan Cordas DO MPH 34
Local Public Health Departments
Tarrant county - 1800 university drive.
Fort worth Texas 817–871-8828
Dallas county – 2377 north Stemmons
freeway Dallas Texas 214-819-2004
Smallpox - Stevan Cordas DO MPH 35
Smallpox - Stevan Cordas DO MPH 36