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 > 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 HCW’s 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