sars: a view from a public health department

“SARS in the City”: Infection control lessons

Bonnie Henry MD MPH FRCP(C), CSTE

Buffalo, 10 June 2009

City of Toronto

Severe Acute Respiratory Syndrome Symptoms include:

◦ a fever of more than 38 degrees C ( 100.4 degrees F)

◦ muscle aches, severe fatigue, severe headache

◦ dry cough, shortness of breath◦ positive chest x-ray

What is SARS?

Where it began..

21 February, 2003 a Chinese Doctor from Guandong checks into room 911 at the Metropole hotel….

Christian et al. Submitted to CID October

2003

Phase 1: Mar 13 - Apr 20 Phase 2: May 20 - Jun 24 438 cases across Canada (225 in

Toronto)◦ 44 deaths (38 in Toronto)◦ 222 hospitalized, 50 in Intensive Care Units◦ 50% in health care workers (4 deaths)◦ cluster of 31 cases associated with a religious

group◦ no significant community spread

A Brief Chronology

Figure 2. Cases investigated for SARS and contacts identified as requiring quarantine

0

10

20

30

40

50

60

15-Mar-0

3

25-Mar-0

3

4-Apr-03

14-Apr-03

24-Apr-03

4-May-03

14-May-03

24-May-03

3-Jun-03

13-Jun-03

Date of report to Toronto Public Health

Num

ber o

f inv

esti

gate

d ca

ses

0

1000

2000

3000

4000

5000

6000

7000

8000

Num

ber o

f con

tact

s re

quir

ing

quar

anti

ne did not meetcase definition

met SARS casedefinition

contactsrequiringquarantine

*Cases are graphed as stacked bars comprised of persons investigated that met and did not meet SARS case definition.

† Contact numbers do not include healthcare workers who were placed in work quarantine (n=5743). The maximum number of persons requiring quarantine at any one time was 6995.

Average incubation period 4.7 days (range 1-12)

66% of cases were female, Average age was 49 years (5mos-99years)

Average age of those who died 71 (38-99) Only 3 deaths in persons less than 50 Mean time from onset of symptoms to death

19 days (1-78)

Epidemiology

Index Case Case A

Mr. D

(Mother) (Son)

Mr. P

Mr. P’swife

Mr. R?

24 persons

9 persons

21 persons

15 persons

7 persons

Infection Control Directives Screening, recognition of cases Administrative controls: screening of staff,

limiting visitors etc. PPE: initial recommendations based on

uncertainty BUT not able to lower level when more known

Issue of Fit Testing of N95 Respirators Dealing with changes: occurred frequently,

communications was difficult, led to mistrust

How do you stop an outbreak when: Agent is unknown Incubation period uncertain Mode of transmission not entirely clear No diagnostic test No prophylaxis No vaccine No treatment

R0 = population density x infectivity x time

Outbreak Control

Quarantine◦ not used > 50 years in Canada◦ “invented” work quarantine

Used combination of◦ quarantine/work quarantine with daily or

twice daily assessment◦ active surveillance with daily assessment◦ self-monitoring with periodic follow-up◦ day 10 follow-up and counselling

Isolation/Quarantine

Isolation/Quarantine Linking ill with

assessment centres Provision of needed

supplies for monitoring and infection control (thermometers, masks etc)

Very difficult physically, emotionally, mentally

Linkage of symptomatic contacts to assessment centres

“Voluntary” quarantine -

issues

Issued 27 Section 22 orders

under HPPA Challenges of determining if

someone is at home by phone e.g. cell phones, internet, lack of phone

Government financial support

Very difficult mentally, physically, emotionally and financially

Infection Control Continuum Public Health in the

community (schools, daycares, restaurants, gatherings etc)

Public Health and sometimes hospital based ICPs manage outbreaks in Long Term Care

Hospital epidemiologists, ICPs and infection control programs in Acute Care Facilities

What role does OHS have or should have in IPC?

What about the regulators (Ministry of Labour)

Where do private physician offices fit in? What about prehospital and home care, who

provides them with IPC guidance? What about other community based

providers? (radiology clinics, OT, Physio, dialysis centres etc)

Beyond the Continuum

Key role in communication with the public Can be liaison or link between healthcare

facilities, first responders and the community

Limited expertise in hospital infection prevention and control issues

Have legal authority for many restrictive actions

Public Health Role

Need to invest in infection control Need to invest in occupational health

resources Need to define roles and responsibilities of

federal, provincial and local public health authorities

Far more stakeholders need to be connected than we used to think (schools, business, shelters, jails, transit etc.)

Lessons Learned

Lessons from SARS

It is easier to control disease than fear

CoordinationCollaborationCommunication

Clarity

=Confidence

Influenza: Why have we worried?

Novel virus in avian/animal population

Susceptible human population

Infectious to humans Highly pathogenic

BUT no efficient human to human spread

Will this lead to a pandemic…

F/P/T communication much improved but still needs work

IC guidance developed for H5N1 avian flu Still having issues with communications to

community providers

Influenza A H1N1(Swine)

NEJM (Trifonov V et al. Geographic dependence, surveillance, and origins of the 2009 influenza A (H1N1) virus. N Engl J Med 2009 May 27 [Epub ahead of print].

IPC guidance developed rapidly BUT delayed at the federal government for translation

Approval process still not worked out completely

Facilities, HCWs filled the void with CDC and others (Web 2.0)

Led to difficulty when guidance differed (especially around N95 respirator use)

Fit testing became an impediment to safety

H1N1 and IPC

Things to Think About for the Fall SARS was about containment

◦ Mostly spread in hospitals

Influenza is about capacity◦ Mostly spread in the community◦ HCWs will get sick whether they use N95s or not!

Need to reinforce this is INFLUENZA not SARS

IPC guidance needs to reflect the evolving situation

Thank you