Training Kit for

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Training Kit for Pandemic Influenza
Unit 5 - Clinical Management
Prepared by Infectious Disease Control Training
Centre, Hospital Authority Infection Control
Branch, Centre for Health Protection, Department
of Health


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By the end of this unit, you will be familiar
with
Objectives

• the clinical features of H5 influenza
• the various laboratory diagnostic methods of H5
  influenza
• the radiological findings of H5 influenza
• the principles of patient management
• the management flow in out-patient and in-patient
  settings

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Transmission (H5 Influenza)
Clinical Features
Virus detected 24 hrs before onset of illness and
peaks in 24-72 hrs in human cases

• Droplet transmission
• Direct contact and fomite

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Clinical Features
Signs Symptoms (H5 influenza)

• Median incubation period
• 3 days (2 4 days)
• Up to 8 days has been reported
• Typical Flu-Like Symptoms
• fever gt 38 oC
• Cough
• Other constitutional symptoms Myalgia, lethargy
• Special Clinical Features
• GI Symptoms (diahorrea, abdominal pain, and
  vomiting)
• Dyspnoea
• Encephalitis
• Conjunctivitis (in H7N7)
• Rapid progression to primary viral pneumonia
• Associated with lymphopenia, impaired LFT, RFT
  and prolonged clotting time

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Case Identification
Clinical Features

• Always think about TOCC in Febrile ILI patients
• In recent 7 days
• Travel History to environments contaminated by
  faeces of poultry or wild birds in a country /
  area with H5N1 infections in the last month.
• Occupation handling samples suspected of
  containing influenza A (H5, H7 or H9) virus in a
  laboratory
• Contact infected human case and animals
  poultry/wild birds/their remains consumption of
  raw or undercooked poultry products in a country
  / area with H5N1 infections in the last month
• Clustering clustering of persons with fever and
  pneumonia
• HIGH vigilance is needed

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WHO Case Definition
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HKSAR CENO Case Definition of Influenza
A(H5N1) Last updated on 14 Sep 2006
Source https//ceno.chp.gov.hk/casedef/casedef.js
p
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HKSAR CENO Case Definition of Influenza
A(H5N1) Last updated on 14 Sep 2006
Source https//ceno.chp.gov.hk/casedef/casedef.js
p
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HKSAR CENO Case Definition of Influenza
A(H7)/(H9) Last updated on 14 Sep 2006
Source https//ceno.chp.gov.hk/casedef/casedef.js
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Specimen Collection
Diagnosis

• Test
• Viral Culture direct detection
• Time
• Acute phase preferably within 3 days of illness
  onset
• Type
• Oropharyngeal swab and lower respiratory tract
  specimens (e.g. bronchoalveolar lavage or
  tracheal aspirates) are the preferred specimens
• Nasal or Nasopharyngeal swab are acceptable
• Stool rectal swab as clinically indicated
• Transport medium
• viral transport

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Diagnosis
Rapid Antigen Detection of Influenza A
DirectigenTM
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Type (H5)-Specific Laboratory Diagnosis
Diagnosis

• NPA
• RT-PCR (H5 specific)
• Direct IF (H5-specific)

• Serology
• Micro-neutralization (H5 specific)
• horse red blood cell agglutination inhibition
  titer
• Western blot (H5 specific)

• Culture

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Confirmed Influenza A/H5N1 Case
Diagnosis (WHO/CENO)

• A clinically compatible individual tested (one or
  more)
• Isolation of an H5N1 virus
• Positive H5 PCR results from tests using 2
  different PCR targets
• A four-fold rise in neutralization antibody titer
  for H5N1
• A single microneutralization antibody titer for
  H5N1 of 180 or greater at day 14 or later after
  symptom onset and a positive result using a
  different serological assay.

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Confirmed Influenza A (H7)/(H9) Case
Diagnosis (CENO)

• An individual tested (one or more)
• Positive viral culture
• Positive PCR
• ?4 fold rise in specific antibody titre in paired
  serum samples

Source https//ceno.chp.gov.hk/casedef/casedef.js
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Diagnosis
CXR taken from H5N1 patients
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Principles
Management

• Proper isolation
• Supportive treatment
• Use of neuraminidase inhibitor
• please refer to unit 8 vaccines anti-virals
• No aspirin for pediatric patients under 18 years
  of age
• risk of Reye syndrome
• No routine use of corticosteroids,
  immunoglobulin, interferon and ribavirin outside
  the context of a randomized trial.
• Ribavirin particularly should not be used in
  pregnant women (WHO strong recommendation).

Reference WHO interim guidelines on clinical
management of humans infected by influenza A
(H5N1) 2 Mar 2004 WHO Rapid
Advice Guidelines on pharmacological management
of humans infected with avian influenza A
(H5N1) virus May 2006
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Approach to influenza like illness at out-patient
(designated FM clinics, AE Depts.)
Influenza like illness
History of epidemiological link to Avian flu ?
Yes
No
At risk group
Admit isolate (see next chart)
Advise personal hygiene
Admit, manage and investigate according to
current clinical protocol
Please refer to Management Approach of ILI and
CAP suspected of Avian Influenza (18 September
2006) at http//ha.home
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Approach to Influenza like illness with
pneumonia/ hospitalised CAP for patient admitted
into hospitals

ILI with pneumonia / All hospitalised CAP






History of epidemiological link to Avian flu?



No
Yes






Isolation and investigation according to risk
stratification of admitted fever/CAP
Isolation







Clinically ill

• Report to CHP
• Oseltamivir
• Lab test

Yes

No







Oseltamivir not immediately indicated
Oseltamivir indicated









Notify CHP, Oseltamivir and manage according to
current clinical protocol



Positive for H5

Negative for H5



Please refer to Management Approach of ILI and
CAP suspected of Avian Influenza (H5) (18
September 2006) at http//ha.home
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End of Unit 5