Case definition for avian influenza - H5N1
|a) Suspected case of avian
- Clinical presentation
- Fever ( › or = 38°C) OR history of fever AND respiratory
symptoms (cough or shortness of breath) requiring
- Death from unexplained respiratory illness
- History of travel in the 7 days prior to onset of symptoms to
any affected area AND close contact (within 1 metre) with live
or dead domestic fowl, wild birds, or swine in any setting,
including bird markets.
- OR one of the following
• Close contact ( touching/speaking distance) with other case(s)
of severe respiratory illness or unexplained death from above
• Part of a Health Care Worker cluster of severe unexplained
• A Laboratory worker with potential exposure to influenza A
Fever ( 38°C) OR history of fever AND respiratory symptoms
(cough or shortness of breath) requiring hospitalization.
b) Probable case of influenza A (H5N1)
Limited laboratory evidence of influenza A (H5N1).
c) Confirmed case definition for influenza H5N1
A confirmed case of influenza H5N1 infection is an individual
for whom laboratory testing demonstrates one or more of the
- Positive viral culture for influenza A/H5.
- Positive polymerase chain reaction (PCR) for influenza A/H5.
- Positive immunofluorescence antibody (IFA) test to H5 antigen using H5 monoclonal antibodies.
- 4-fold rise in H5 specific antibody titre in paired serum samples.
The laboratory tests for the diagnosis of influenza A/H5
infection included in the case definition are considered the
standard for the identification of these viruses.