SARS: Overview and Healthcare Preparedness: SARS: Overview and Healthcare Preparedness Arjun Srinivasan, MD
Division of Healthcare Quality Promotion
asrinivasan@cdc.gov
SARS: A brief history: SARS: A brief history February 14, 2003-
Report of 305 cases of unexplained pneumonia in Guangdong Province, China.
February 21, 2003-
A 65 year old doctor from Guangdong checks into room 911 of the Metropole hotel in Hong Kong
Slide3: Hotel M Hong Kong Guangdong Province, China A A Spread from the Hotel M in Hong Kong
SARS: A brief history: SARS: A brief history February 28th- March 15, 2003-
Reports of unexplained pneumonia in Vietnam, Singapore and Canada.
More than 50 healthcare workers in the Prince of Wales hospital in Hong Kong come down with an unexplained respiratory illness.
The syndrome is named “severe acute respiratory syndrome”
SARS: A brief history: SARS: A brief history March 17, 2003
WHO asks 11 labs in 9 countries to form a network to discover the etiology of SARS.
All samples are shared between the labs and any information discovered is posted immediately on a secure site and instantly available to all the others.
SARS: A brief history: SARS: A brief history March 24, 2003-
Investigators in Hong Kong and at CDC announce novel coronavirus is possible cause of SARS.
April 8-12, 2003-
Coronavirus etiology is confirmed by other researchers and the sequence of the virus is published.
SARS: A brief history: SARS: A brief history April 16, 2003-
Investigators in the Netherlands fulfill Koch’s postulates to prove definitively that SARS coronavirus (SARS Co-V) is the cause of SARS.
Slide8:
A Major Outbreak of Severe Acute Respiratory Syndrome in Hong Kong Identification of a Novel Coronavirus in Patients with Severe Acute Respiratory Syndrome
SARS: A brief history: SARS: A brief history May 31, 2003-
Outbreak controlled in Singapore.
June, 2003
Outbreaks controlled in Taiwan, Hong Kong, Canada and China.
July 5, 2003
WHO declares outbreak contained worldwide.
Global SARS Outbreak*: Global SARS Outbreak* *Reported to WHO, November 1, 2002- July 11, 2003
Other outcomes: Other outcomes Tens of thousands of people quarantined.
Impact of hospital closures and delays of elective procedures.
More than $60 billion dollars lost in Asia alone.
Massive fear and panic.
Slide12: Empty jewelry showcases from Hong Kong and Singapore
Zurich Trade Fair
Caronaviruses: Caronaviruses Cause severe disease and death in animals.
In humans, caronaviruses were mostly associated with mild respiratory illness, with very rare reports of more serious infections.
Slide14: SARS HCoV-OC43 BCoV HEV Rat-SDAV MHV HCoV-229E PEDV TGEV CCoV FIPV IBV-Avian TCoV 10 nt I III II 100 100 68 100 Caronaviruses
Epidemiology and Transmission: Epidemiology and Transmission
Person to Person Spread: Probable cases of SARS by reported source of infection,
Singapore, Feb 25 – Apr 30 Person to Person Spread
Slide17: Toronto, Canada, April 2003
9 HCWs infected following difficult intubation of a critically ill SARS patient.
All HCWs reported wearing recommended protective equipment. Transmission during aerosol-generating procedures
Transmission characteristics: Transmission characteristics On average, each SARS patient infected 3 other people.
This rate of infectivity (R0) is most consistent with a disease spread by direct contact or large droplets, not light, airborne particles (WHO consensus report).
BUT . . . : BUT . . . Aerosol generating medical procedures and other acts that generate aerosols (e.g. surface cleaning) may increase risk of transmission.
Risk from stool and fomites remains unclear.
Average number of secondary cases from un-isolated patients: Average number of secondary cases from un-isolated patients
Total SARS Cases and % Healthcare Workers by Location: Total SARS Cases and % Healthcare Workers by Location Total No. SARS cases % HCW % HCW
Percentages who acquired SARS in healthcare facilities: Percentages who acquired SARS in healthcare facilities
Clinical Features: Clinical Features
Initial clinical features: Initial clinical features Incubation period 1-10 days
Median 4-7
Rarely up to 14 days
Initial symptoms: fever, chills/rigors, headache, myalgias, malaise
Diarrhea has been a prominent feature of early illness in some
Initial respiratory symptoms: Initial respiratory symptoms Respiratory symptoms often begin 3-7 days after symptom onset, peak in second week
Fever may resolve prior to respiratory symptoms
30% have respiratory symptoms at onset
Symptoms Commonly Reported: Symptoms Commonly Reported
Clinical Findings: Clinical Findings
Chest radiographs: Chest radiographs Chest X-ray infiltrates develop in nearly 100% of laboratory confirmed cases:
66% abnormal by day 3
97% abnormal by day 7
100% abnormal by day 10
Wong. Radiology 2003;228:401-6.
Wang. Proceedings of International Science Symposium on SARS. Beijing, China, 2003
Xue. Chin Med J 2003;116:819-822
Zhao. J Med Microbiol 2003;52:715-20.
Rainer. BMJ 2003;326:1354-8.
Radiographic Features of SARS: Radiographic Features of SARS Infiltrates
initially focal, often peripheral lower lobes
interstitial
75% progress to involve multiple lobes or both lungs
High resolution computed tomography more sensitive
Ground glass opacification
Peripheral lower lobes
Case fatality rate by age group- Hong Kong: Case fatality rate by age group- Hong Kong
Patients requiring mechanical ventilation: Patients requiring mechanical ventilation 1. Unpublished data, CDC. 2. Booth CM SM, et al. JAMA 5/6/03. 3. Tsang KW, et al. NEJM. 3/31/03 4. Peiris JSM, et al. Lancet 4/8/03 5. Lee N. et al NEJM 4/7/03
SARS Laboratory Diagnostics: SARS Laboratory Diagnostics
Available tests for SARS: Available tests for SARS Polymerase chain reaction (PCR)
Most rapid test
Have been problems with false positive and false negative results.
Serology (antibody assay)
Appears quite reliable
Results may take up to 28 days
Beware of lab tests!: Beware of lab tests! A test is limited by the quality of the specimen- especially an issue with respiratory specimens.
The predictive value of any test is ultimately determined by the prevalence of the disease.
Effect of disease prevalence on Positive Predictive Value (PPV): Effect of disease prevalence on Positive Predictive Value (PPV) Prevalence of SARS among persons tested PPV Sensitivity of test = 50%
Specificity of test = 95% Prevalence = 1%
PPV = 9% Prevalence = 50%
PPV = 95%
SARS PCR: SARS PCR Reasons for false negative results
low titer virus in respiratory secretions in first few days after onset of illness
Reasons for false positive results
contamination from previously amplified DNA
cross-contamination between specimens
SARS PCR- confirmation of results: SARS PCR- confirmation of results Given challenges with testing, positive results must be confirmed, preferably in another lab using the original sample.
Preferable to also test specimens from at least 2 sites OR from the same site on different days.
SARS Serology: SARS Serology Current enzyme immunoassay appears to be highly specific
No cross reactions with other CoV
No false positives in normal blood donors
Can be positive in as few as 8 to 10 days.
Not definitively negative until day 28.
What to test: What to test Respiratory specimens:
sputum > aspirates > NP/OP washes > NP/OP swabs
Blood
Stool
Multiple samples and larger quantities are better!
Slide40: When to test
Slide41: Peiris et al: Lancet, May 24, 2003
Slide42: Peiris: personal communication
The future of SARS: An enigma shrouded in mystery: The future of SARS: An enigma shrouded in mystery
Will SARS be back?: Will SARS be back? Un-known, but there are potential reservoirs for re-emergence:
From original animal reservoir
Unrecognized transmission in humans
Persistent infection in humans
Labs
Most likely to re-emerge outside the US.
Future treatment options: Future treatment options Potential therapies requiring further investigation
Cystine proteinase inhibitors
Interferons
Immunomodulatory agents
Corticosteriods
SARS-CoV specific immune globolin
Others?
Future prevention options: Future prevention options Research is under way to develop a vaccine.
Availability of animal coronavirus vaccines is encouraging.
Unclear how applicable that experience will be to SARS vaccine development.
SARS preparedness and response planning: An ounce of prevention: SARS preparedness and response planning: An ounce of prevention
SARS preparedness planning: SARS preparedness planning We must take advantage of what was learned to prepare for future outbreaks.
SARS preparedness and response planning can both build on and enhance planning for bioterrorism and other emerging infections.
CDC approach to SARS planning: CDC approach to SARS planning SARS task force assembled to address several aspects of preparedness and response planning.
CDC approach to SARS planning: CDC approach to SARS planning Draft plans developed and input solicited from members of over 20 partner societies representing public health, healthcare workers and healthcare administration.
Conference calls.
Face-to-face meetings.
Key objectives: Key objectives Rapid identification of SARS cases.
Early implementation of control measures.
Efficient communication and co-operation between healthcare, the public and public health.
SARS plan- Core document/summary and supplements: SARS plan- Core document/summary and supplements A: Command and control issues
B: Surveillance
C: Healthcare facilities
D: Community containment
E: International travel
F: Laboratory diagnosis
G: Communication
The devil is in the details!: The devil is in the details! The supplements provide specific guidance in the various areas.
Suggestions are divided into basic and enhanced measures to allow for escalation as an outbreak progresses.
Preparedness and Response in Healthcare Facilities: Preparedness and Response in Healthcare Facilities
Lessons learned for healthcare: Lessons learned for healthcare Healthcare facilities were critical areas in the 2003 outbreak.
They were essential in controlling the outbreak, despite being among the hardest hit by it.
Lessons learned for healthcare: Lessons learned for healthcare SARS stretched healthcare resources to their limits.
Preparedness planning will be essential to limiting the impact of any future outbreaks.
Key objectives for healthcare facilities: Key objectives for healthcare facilities Multi-disciplinary plan to address a potential outbreak.
Early identification of cases.
Rapid and effective isolation of cases.
Implementation of effective infection control measures.
Key objectives for healthcare facilities: Key objectives for healthcare facilities Ability to manage a small number of SARS patients without disrupting delivery of care.
Good communication with HCWs, community and public health.
Development of a SARS plan: Development of a SARS plan Given the range of issues involved, and the speed and complexity of the required response, facilities should consider developing a formal SARS preparedness and response plan.
This plan may simply be an addition to existing bio-terrorism or emergency response plans.
SARS planning committee: SARS planning committee Designated person to co-ordinate an outbreak response and chair a planning committee.
Multi-disciplinary planning committee with representation from all groups potentially affected by SARS, e.g.:
Medical, nursing, laboratory and support staff.
Administration.
Infection control
SARS planning committee: SARS planning committee Other groups may need to be adjunct members to consider certain issues, e.g.
Labor and unions
Mental health
Directors of training/teaching programs
Key issues to consider: Key issues to consider Surveillance
Clinical evaluation
Infection control measures
Patient isolation
Engineering controls
Exposure evaluation
Staffing needs and personnel policies
Access controls
Supplies and equipment
Communication
SARS surveillance- The backbone of response: SARS surveillance- The backbone of response Early diagnosis and detection can prevent further transmission, while missed cases can lead to large outbreaks.
Healthcare facilities will play a crucial role in surveillance.
Surveillance activities must expand as SARS activity escalates.
Surveillance in the absence of SARS: Surveillance in the absence of SARS Challenges-
How to catch early cases given that SARS is extremely unlikely and the presentation is non-specific.
How to screen with no epidemiologic links.
Less of an issue in the US since SARS will probably re-emerge elsewhere.
Surveillance in the absence of SARS: Surveillance in the absence of SARS Will need to rely on known risk factors for SARS:
Travel to previously affected areas
Contact with healthcare facilities
Contact with other patients with unexplained pneumonia.
Surveillance recommendations: Surveillance recommendations Ask all patients hospitalized with unexplained pneumonia about the known risks.
Report cases to the health department to aid recognition of clusters of unexplained pneumonia.
Consider SARS testing in consultation with public health representatives.
Surveillance in the presence of SARS: Surveillance in the presence of SARS If SARS comes back, surveillance must expand.
Screen all patients with fever or respiratory symptoms (not just those admitted) for known risks, especially travel to areas where SARS is active OR contact with a SARS patient.
Clinical evaluation: Clinical evaluation In the absence of SARS activity in the world, patients with pneumonia should be evaluated as usual, with addition of screening questions for SARS risks.
In the presence of SARS activity, the SARS clinical algorithm can help guide evaluation in patients who have SARS risk factors.
Slide69: Fever or Respiratory Illness1 in Adults Who May Have Been Exposed to SARS Begin SARS isolation precautions, initiate preliminary work up and notify Health Department2
No Radiographic Evidence of
Pneumonia
No Alternative Diagnosis Continue SARS isolation and re-evaluate
72 hours after initial evaluation Persistent fever or
unresolving respiratory symptoms Perform SARS test
Continue SARS isolation for additional
72 hours. At the end of the 72
hours, repeat clinical evaluation
including CXR No radiogrpahic evidence of
pneumonia Symptoms
improve
or resolve - CXR Draft-Algorithm to Work Up and Isolate Symptomatic Persons who may have been Exposed to SARS + CXR Radiographic Evidence
Of Pneumonia + CXR Perform SARS testing Laboratory evidence
of SARS-CoV or
No alternative diagnosis Alternative diagnosis
confirmed3 Continue SARS isolation until
10 days following resolution of
fever given respiratory
symptoms are absent or
resolving Consider D/C
SARS isolation
precautions5 Alternative diagnosis
confirmed3 Consider D/C
SARS isolation
precautions5 Consider D/C
SARS isolation
precautions5
Clinical evaluation: Clinical evaluation Ensure that staff who will evaluate potential SARS cases have access to and appropriate training with personal protective equipment.
Infection control measures: Infection control measures Make sure HCWs understand the importance of basic infection control practices like isolation and hand hygiene (whether there is SARS or not!).
Ensure that HCWs have access to and training with, personal protective equipment.
Infection control measures: Infection control measures Consider adopting a universal, “respiratory hygiene/cough etiquette” strategy.
Common and important pathogens are transmitted by respiratory secretions: influenza, pertussis, mycoplasma.
Controlling respiratory secretions can help reduce transmission.
Respiratory hygiene/ Cough etiquette: Respiratory hygiene/ Cough etiquette Encourage patients to alert staff if they are suffering febrile respiratory illness.
Give patients a surgical mask to wear or tissues to cover their noses and mouths.
Encourage patients to practice hand hygiene after touching their faces.
Respiratory hygiene/ Cough etiquette: Respiratory hygiene/ Cough etiquette Separate patients with febrile respiratory illness from other patients in the waiting area.
Manage patients using droplet precautions until it is determined the cause of the respiratory illness is a pathogen that does not require precautions.
Patient isolation: Patient isolation Though most transmission appears to occur from infectious droplets, there are infrequent episodes where airborne transmission cannot be excluded.
For now, CDC continues recommend that SARS patients be managed with airborne PLUS contact precautions.
Airborne isolation: Airborne isolation Potential SARS patients should be placed in airborne infection isolation or negative pressure rooms (AIIRs).
Healthcare workers should wear a fit-tested N95 (or higher) respirator or personal air purifying respirator (PAPR) in addition to gowns, gloves and eye protection.
Patient cohorting: Patient cohorting Some facilities have few (or no) negative pressure rooms.
Facilities will need to decide at what point they will choose to cohort patients onto a “SARS unit” in private, but non-negative pressure, rooms.
Advantages of a SARS unit: Advantages of a SARS unit Focuses SARS related resources in one area.
Physically separates SARS patients from others.
Was an effective strategy in parts Toronto and Taiwan.
Engineering controls: Engineering controls Determine capacity for airborne isolation in both the ICU and non-ICU settings.
Determine how a SARS unit might be created:
Can any nursing unit be made negative pressure to surroundings?
Can rooms on any unit be converted to negative pressure?
Engineering controls: Engineering controls Identify a space that might serve as a SARS evaluation center in the event of a larger outbreak.
Determine how best to get patients to and from the evaluation center.
Exposure reporting and evaluation: Exposure reporting and evaluation Surveillance of exposures may help with early case identification.
Develop a mechanism for reporting and follow-up of exposed HCWs.
Exposure reporting and evaluation: Exposure reporting and evaluation Perform symptom surveillance for fever or respiratory symptoms in HCWs with unprotected exposures.
Consider furlough of HCWs with unprotected high-risk exposures (i.e. during respiratory procedures).
Evaluate symptomatic HCWs with the SARS clinical algorithm.
Staffing needs : Staffing needs SARS posed a unique challenge for staffing needs with increased demands but diminished availability of HCWs due to illness and furlough.
Staffing issues: Staffing issues Determine staffing needs for varying numbers of SARS patients.
Consider designating teams to provide initial care in an outbreak:
General, multi-disciplinary care team
Emergency care/ ICU team
Respiratory procedures team
Consider how teams could be expanded.
Staffing issues: Staffing issues Caring for SARS patients is emotionally and physically draining for HCWs, especially with prolonged respirator wear.
Staffing may have to be increased to allow HCWs to have “PPE free” time.
Home/work quarantine: Home/work quarantine To ensure adequate staff in facilities in Toronto, some exposed HCWs were placed on home/work quarantine.
They were only allowed to travel back and forth to work, but were otherwise required to stay home.
This might be needed if an outbreak become large.
Personnel policies: Personnel policies A variety of issues to consider:
What will be the criteria for furlough?
Will furlough be paid or unpaid?
How will exposure evaluations and follow-up be done?
What assistance can the facility provide to HCWs on home/work quarantine?
What mental health assistance can be provided to help HCWs deal with the stress of an outbreak?
Facility Access Controls: Facility Access Controls During an outbreak, careful screening of entrants, combined with access controls to the facility can help keep unrecognized cases from entering.
Access controls: Access controls Facilities will also need to establish criteria to limit visitors, especially to SARS patients.
Criteria for limiting elective procedures and even new admissions may be needed in a large outbreak.
Supplies and Equipment: Supplies and Equipment Determine the current availability of and anticipated need for supplies that might be needed in an outbreak:
Personal protective equipment and hand hygiene supplies.
Ventilators
Consider what back up plans are in place if supplies are limited.
Communication: Communication Clear and quick communication with the health department, facility staff and public will be crucial to manage the outbreak and control panic.
Health Departments: Health Departments Establish a mechanism to share information with the health department:
SARS activity in the community
SARS activity in the facility
Exposures, for contact tracing
Information on SARS patients about to be discharged for community isolation
Staff and Public: Staff and Public Determine ways to update people on SARS activity in the hospital, what control measures are being taken and what they may be asked to do (e.g. entry screening etc).
Co-ordinate information release with health department so messages are consistent.
Broader Healthcare System Issues: Broader Healthcare System Issues A large SARS outbreak will generate resource needs that must be addressed at a larger level than one facility:
Funding for furlough, lost revenue
Supply shortages
Staff shortages
Regulatory issues
Conclusions: Conclusions SARS poses a major challenge to healthcare facilities and staff.
Healthcare workers around the world demonstrated enormous courage to meet that challenge last year.
Conclusions: Conclusions Facilities can help by developing plans to manage SARS (and other infectious emergencies) in advance.
Facilities should be prepared to move “swiftly and boldly” to implement aggressive control measures.
CDC SARS Preparedness Plan http://www.cdc.gov/ ncidod/sars/sarsprepplan.htm: CDC SARS Preparedness Plan http://www.cdc.gov/ ncidod/sars/sarsprepplan.htm Thank you!