Smallpox: Isolation and Quarantine

1
Smallpox Isolation and Quarantine

• Terri Rebmann, RN, MSN, CIC
• Infectious Disease Specialist
• Centers for the Study of Bioterrorism and
  Emerging Infections
• Saint Louis University, School of Public Health

2
Smallpox

• Infection Control Precautions are critical
  Smallpox is a communicable disease
• Can be spread
• Droplet
• Aerosol
• Hand-to-hand contact

3
Infection Control

• Lesions and scabs contain viral particles
• Remain viable for decades, but infection threat
  unknown
• Secondary transmission possible
• Housekeepers highly susceptible
• Contaminated clothing and linens

4
Infection Control

• Not as infectious as other diseases
• Chickenpox and measles
• 25 40 risk of transmission
• Typically 1 primary case caused 3-4 secondary
  cases
• ? 20 in non-immune population
• Transmission more likely in non-immune population

5
Isolation

• Airborne and Contact Precautions
• Negative pressure room
• HEPA-filtered room PLUS physical isolation
• N-95 respirator
• Surgical mask not sufficient
• Gowns and gloves

6
Isolation

• Continue isolation until all scabs separate
• Approximately 3 weeks

7
Housekeeping Infection Control

• Exact mechanism of transmission uncertain
• Physical contact with linens
• Possible re-aerosolization of viral particles
• Handle linens carefully
• Minimize risk of aerosolization

8
Laundry

• Current recommendations
• Incinerate OR
• Autoclave then wash in hot water with bleach
  added
• Another option Use disposable linens

9
Laundry

• Recommendations based on information from
  smallpox outbreaks (over 30 years ago)
• Infection Control practices have changed
  significantly
• Standard Precautions may be sufficient to prevent
  secondary transmission

10
Laundry

• Recommendations are under review
• Suspect low risk of secondary transmission when
  using Standard Precautions and high cost of
  incineration or autoclaving
• Preliminary recommendation
• Minimize disruption of laundry
• Wash in hot water with 1 cup of bleach added

11
Infection Control

• Cremation is preferred
• Prevent secondary transmission to mortuary
  employees

12
Contacts

• Monitor for 17 days past date of exposure OR
• 14 past date of vaccination
• Best if not self-monitored
• May be necessary in large outbreak setting

13
Monitoring Contacts

• Take and record temperature twice daily
• Morning and evening
• If self-monitoring, communicate results to health
  department

14
Contacts

• If asymptomatic, may continue routine activities
• Isolate immediately if symptoms occur
• Fever gt 1010 F or 38.30 C
• Two successive readings taken 12 hours apart

15
Identification of Contacts

• Epidemiological investigation
• Patient history
• Starting day of fever onset
• 1-2 days before appearance of first lesion

16
Identification of Contacts

• Make list of all potential contacts during
  communicable period
• Fever onset to date of isolation for index case
• 1-10 days

17
Definition of Contact

• All household members and anyone who has had
  face-to-face contact (within 6 feet) with patient
  since onset of fever
• May include every department within hospital,
  other patients, and visitors

18
Identification of Contacts

• High-risk
• Prolonged face-to-face contact
• Household members and HCWs involved with direct
  patient care of smallpox case

19
Identification of Contacts

• Low-risk
• Indirect contact with patient
• Did not provide patient care to case

20
Contact Follow-up

• High risk contacts
• Vaccinate AND
• Monitor
• Use method described previously
• Low risk contacts
• Vaccinate
• May not require monitoring, especially in large
  outbreak with staff shortages

21
Monitoring Contacts

• To decrease confusion, many facilities may choose
  to vaccinate and monitor all contacts, regardless
  of level of risk
• Establish approach before an event occurs
• Case definitions
• Include in facility disaster/bioterrorism plan

22
Home Isolation

• An option when
• Patient has mild disease
• Extensive medical care not needed
• May be preferred in large outbreak
• Prevent nosocomial transmission

23
Alternative Isolation Option

• Designated smallpox center or hospital
• Warehouse
• School gymnasium
• Outside tented areas
• Determine alternative sites during disaster
  planning
• Must be a community-wide decision

24
Quarantine

• Enforced isolation
• Detainment of known or suspected cases
• Exclusion of healthy individuals from
  contaminated area(s)

25
Quarantine Laws

• Existing laws must be evaluated
• May require creation of new law or revising
  existing law