Docstoc

smallpox

Document Sample
smallpox Powered By Docstoc
					Smallpox



     D. GOLDBERG
      PED ID SVCE
          WRAMC
SMALLPOX
• 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
SMALLPOX
SMALLPOX
• 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-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-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
SMALLPOX
SMALLPOX
SMALLPOX
SMALLPOX

•   Secondary infection is rare
•   Death in second week due to toxemia
•   Variola minor-less severe symptoms, rash
•   Vaccinated -milder form
•   HIV-? (Disseminated vaccina in HIV+
    soldier in 1986)
SMALLPOX- Laboratory Diagnosis

• Level BL-4 only
     EM of fluid/scabs
     Culture/PCR

     Oropharyn swabs-day 7/8 of infection
     AB titers (day 6 of rash)
 SMALLPOX- Clinical Diagnosis
                Smallpox           Varicella
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
SMALLPOX




Chickenpox   Shingles
SMALLPOX-Therapy

• Cidofovir ?
• ?
SMALLPOX

• 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-Vaccination
SMALLPOX
• Vaccination-
    limited stock (6 million/ ? dilution)
    untrained administrators
    Special risk groups immuno-
      suppressed/ pregnant women/eczema
    limited Vaccina IG (VIG)
    side effects
 SMALLPOX-Vaccine complications




* 70% children with fever > 39C day 4-14
SMALLPOX-Autoinoculation

				
DOCUMENT INFO