Upload
dominicdr
View
1.142
Download
3
Tags:
Embed Size (px)
Citation preview
SmallpoxSmallpox
D. GOLDBERGD. GOLDBERGPED ID SVCEPED ID SVCE
WRAMCWRAMC
SMALLPOXSMALLPOX• Genus Orthopoxvirus
Smallpox, monkeypox, cowpox,vaccinia
• DNA Virus
• 200 nm brick
shaped
• Smallpox-person to person spread via respiratory secretions/direct contact
• Spread best in low humidity/temperature
SMALLPOXSMALLPOX
SMALLPOXSMALLPOX
• 2 principle forms-
variola major-Europe/Asia
variola minor-19th century USA
• 2 minor forms-malignant & hemorrhagic
• Spread via respiratory droplets/direct contact at time of rash
• Historically spreads slower than chicken pox, measles
SMALLPOX-PathogenesisSMALLPOX-Pathogenesis
• Incubation period (7-17 days):
Virus infects respiratory/pharyngeal mucosa--> regional lymph nodes--> viremia-->spleen, bone marrow, lymph nodes-->second viremia--> fever,
toxemia--> rash and infectivity
SMALLPOX-PathogenesisSMALLPOX-Pathogenesis
• Clinical Stage-
Onset fever (1030), HA, prostation, bachache, malaise, +/- abd pain, delerium, rash by day 3
Rash-macularpapular on oropharynx, face
forearms-->trunk, legs
-turns vesicular 24-48 hrs
- turns tense round pustules
SMALLPOXSMALLPOX
SMALLPOXSMALLPOX
SMALLPOXSMALLPOX
SMALLPOXSMALLPOX
• Secondary infection is rareSecondary infection is rare
• Death in second week due to toxemiaDeath in second week due to toxemia
• Variola minor-less severe symptoms, Variola minor-less severe symptoms, rashrash
• Vaccinated -milder formVaccinated -milder form
• HIV-? (Disseminated vaccina in HIV+ HIV-? (Disseminated vaccina in HIV+ soldier in 1986) soldier in 1986)
SMALLPOX- Laboratory DiagnosisSMALLPOX- Laboratory Diagnosis
• Level BL-4 onlyLevel BL-4 only
EM of fluid/scabsEM of fluid/scabs
Culture/PCRCulture/PCR
Oropharyn swabs-day 7/8 of Oropharyn swabs-day 7/8 of infectioninfection
AB titers (day 6 of rash)AB titers (day 6 of rash)
SMALLPOX- Clinical DiagnosisSMALLPOX- Clinical Diagnosis
SmallpoxSmallpox VaricellaVaricella
Prodrome: 2-4 days 1-2 days
Rash: 1-2 days several days
Lesions: deep/tense superficial
Distribution: centrpetal centrifugal
(truncal) (face/extremeties)
Stage: same new crops
SMALLPOXSMALLPOX
ChickenpoxChickenpox ShinglesShingles
SMALLPOX-TherapySMALLPOX-Therapy
• Cidofovir ?
• ?
SMALLPOXSMALLPOX
• Postexposure Control-Postexposure Control-
Home care vs hospital care (neg pressure)
Mass “contact” vaccination (up to 4 days post exposure may ameliorate/prevent)
Vaccinated individuals serve as caretakers
Cremation of bodies
Smallpox-VaccinationSmallpox-Vaccination
SMALLPOX
• Vaccination-Vaccination-
limited stock (6 million/ ? dilution)
untrained administrators
Special risk groups immuno- suppressed/ pregnant
women/eczema
limited Vaccina IG (VIG)
side effects
SMALLPOX-Vaccine complicationsSMALLPOX-Vaccine complications
* 70% children with fever > 39C day 4-14
SMALLPOX-AutoinoculationSMALLPOX-Autoinoculation