Severe Acute Respiratory Syndrome (SARS)

SARS Mid November 2002

• Guangdong Province, China• “ outbreak of atypical pneumonia”11 February 2003

• WHO informed• 305 cases (5 deaths)• 30% in health care workersJuly 2003

• 8,437 probable cases from 32 countries• major foci in China, SE Asia and Toronto• 4 in UK (none from NI)

Hasn’t SARS been eliminated?

• On 5 July WHO said outbreak was contained.

• BUT WHO have warned it might return and urged planning for it.

• Majority of experts think it might return.

• Planning for it remains a high government priority.

Why might it return?

• Other new and poorly understood viruses (e.g. Ebola and Marburg) periodically surface to cause outbreaks then disappear again.

• This is a respiratory illness – these are usually worse in winter and disappear in summer.

• We don’t know how it appeared or where from – so can’t be confident of stopping it from doing so again.

SARS coronavirus (SARS CoV)• New member of coronavirus family• found in wild animals in China• incubation period 2-7 (max 10) days• viral shedding peaks 6-10 days after onset

of symptoms• droplet spread• less infectious than influenza• no vaccine available

SARS CoV - infectivity

• Most transmission via close contact with a symptomatic person via large respiratory droplets. Transmission by fomites possible.

• Those severely ill more infectious (attack rate of >50% in some hospital staff)

• Infectivity increases during second week of illness• Transmission from an asymptomatic person

unlikely

• May remain infectious up to 10 days once afebrile

(MMWR 2003:52 (18): 405-11)

SARS CoV - infectivity

Clinical symptoms at presentation (in %)

99

28*

69

49

31

2

12

n.a

24

35

94

65*

50

51

64

25

23

31

27

50

100

74

62

54

50

24

20

20

10

20

100

73

57

61

n.a

23

23

n.a

20

56

Fever

Chills or rigors

Cough

Myalgia

Malaise

Runny Nose

Sore Throat

Shortness of breath

Diarrhoea

Headache

Booth et al. n=144

Donnelly et al. n>1250

Peiris et al.

n=50

Lee et al.

n=138

* chills

www.sarsreference.com

Clinical course - triphasic

Week 1• fever, myalgia, systemic symptoms that

improve after a few daysWeek 2• Fever returns, oxygen desaturation, CXR

worsensLater• 20% get ARDS needing ventilation

Peiris - Lancet 2003b; 361: 1767-72

SARS - morbidity

• Most cases are in healthcare workers caring for SARS patients and close family members of SARS patients

• overall mortality 15%

• mortality increases with age

(> 65 years - 50% mortality)

• children seem to develop mild illness

Clinical case definitionA respiratory illness severe enough for hospitalisation and

include a history of: • Fever (> 380C) and• one or more symptoms of respiratory tract illness (cough,

difficulty breathing, SOB) and• CXR of lung infiltrates consistent with pneumonia or RDS

or PM consistent with pneumonia or RDS without an identifiable cause

and• No alternative diagnosis to fully explain the illness

CDSC Colindale 15 Aug 03

SARS diagnosis

• Clinical findings of an atypical pneumonia not attributed to other causes

• exposure to suspect/probable SARS

• or exposure to their respiratory secretions or body

SARS laboratory diagnosis

• PCR positive for SARS CoV using validated methods on at least 2 different clinical specimens

• Seroconversion (gold standard) (negative antibody test on acute specimen

followed by positive test on convalescent sera or > 4 rise in antibody titre between acute and convalescent sera)

SARS - treatment

• Supportive

• avoid aerosol inducing interventions

• evidence base for anti-viral drugs lacking

• steroids may be helpful

NI SARS contingency plan:levels of response

0: initial preparedness (no active cases in UK/Ireland)

1: (A) sporadic imported case(s) to GB/Ireland

1: (B) sporadic imported case(s) to NI

2: intra hospital transmission and/or limited community transmission within definable groups

3: extensive community transmission

4: post outbreak and de-escalation of outbreak response

SARS preparedness NI Taskforce and subgroups

Clinical Training Port Health Training

Primary &Community Care

Human Resources

Acute

Infectioncontrol

Key points in control of any communicable disease

• early case detection• swift isolation• thorough control of infection measures• vigorous identification and management of

close contacts by home confinement• public information for those at risk of

infection• education of health care professionals

Personal protective equipment

• Masks

• Waterproof long sleeved gowns

• Gloves

• Goggles

• Centrally sourced and distributed

Masks and Respirators.

• Masks– Main purpose – help prevent particles (droplets) being

expelled into environment by wearer

– Resistant to fluids – help protect wearer from splashes of blood or other potentially infected substances

– Not necessarily designed for filtration efficiency, or to seal tightly to the face

– Protection to wearer is therefore limited.

Masks and Respirators.

• Respirators– Intended to help reduce wearer’s exposure to

airborne particles– Made to defined standards– When worn correctly – seal firmly to face –

reducing risk of leakage– Some have one way valves – would be useless

for putting on infected person

What is the correct way to use a mask?

First – How not to do it!

Could result in serious injury.

Could result in suffocation.

Could result in serious injury and suffocation!

What is the correct way to use a mask?

• Should fit snugly over mouth, nose and chin• Coloured side out• Metal strip at top – mould to bridge of nose• If in healthcare setting dispose of as clinical waste• In home – patients should place in plastic bag then

in domestic waste• Hands must always be washed following removal.

(Remove handling straps only – avoid contact with face part)

What is the correct way to use a respirator?

• Each type may differ - So always read the accompanying instructions.

• Do a fit check or user seal check every time a respirator is put on – Fit is critically important.

• It must seal tightly to the face – needs clean-shaven skin – beards, long moustaches and stubble may cause leaks.

• Go to a safe area to change it if: breathing becomes difficult; it becomes damage, distorted, or splashed by body fluids; or a proper face fit cannot be maintained.

When should masks or respirators be used?

• Healthcare workers should use respirators for any contact with suspected or probable cases of SARS

• A mask should be used only if a respirator is not available – better than no protection

• Patients should use a mask while symptomatic whether in hospital, at home or in transit.

• But wearing a mask or respirator is not a guarantee of protection against SARS.

Other aspects of infection control

• Hand hygiene – essential

• Gloves

• Fluid resistant long sleeve gown

• Eye protection (visor best)

• Environmental & equipment decontamination.

Putting on PPE

• Put on in following order:– Respirator– Eyewear– Gown– Gloves – ensuring wrists of gloves are pulled

up over sleeves of gown.

Removal of PPE

• Crucial that PPE is removed without accidental contamination of facial skin or mucous membranes.

• Remove PPE in following order:– Gown– Gloves– Wash hands– Eye protection– Mask– Wash hands

Importance of Infection Control Procedures

• Detailed aspects of infection control are very important e.g. exactly how to remove a gown, correct hand washing technique etc.

• A video describing all this will be produced and widely distributed – Please make sure you and all relevant colleagues watch it.

• Correct use of all infection control procedures will provide very good protection against SARS.

Likely pathway

Sporadic cases

• GP - A&E - designated SARS facility

Extensive community transmission

• Home versus hospital management

THIS WILL EVOLVE OVER TIME

Scenario 1:Unannounced presentation

• Isolate patient• Mask on patient• Assessment – wear your PPE

– Case definition/ clinical status– Refer to A&E

• Register of staff contacts• Report to public health• Decontamination

Scenario 2:Announced (patient at home)

• Triage by telephone

• Home visit or refer direct to hospital

• Refer to A&E

• Report to public health

• Advise family

Implications for primary care

Get prepared now!

– Develop a practice protocol – Develop a patient pathway (receptionist GP)– Train all staff – Know PPE procedures*– Plan decontamination systems (include nebulisers)*– Identify a dedicated room.

Situation has potential to change rapidly!

What resources are/ will be available?

• Advice on decontamination• Referral algorithms (?designated hospitals)• Training materials• CCDC/ on-call public health• Updated DHSSPS communications

• Websites:– www.dhsspsni.gov.uk – www.hpa.org.uk– www.who.int