Avian influenza case definition for doctors        

Doctors who suspect that a patient may be suffering from avian influenza as per recommended case definition from ECDC as outlined below are to contact urgently the Disease Surveillance Unit on 21332235 or 21324086 from 8.00 to 15.00 hours and the on call Public Health physicians via SLH operator on 21241251 during week ends or after office hours.

Purpose

The following definitions are developed from the WHO guidelines for global surveillance of influenza A/H5 and are intended for European counties. They should be used, in the current situation for the purpose of undertaking surveillance for cases of influenza A/H5N1 infections in humans in EU. The definitions are not intended to be used for diagnosis or management of cases.

Clinical description    

Any individual with:

(1) Acute onset of fever (temperature >38ºC) with signs and symptoms of an acute respiratory infection

OR

(2) Conjunctivitis (red eye, eyelid/conjunctiva inflammation, tearful eye, itching eye, painful eye, burning eye, discharge from eye or sensitivity to light)

OR

(3) Death from an unexplained acute respiratory illness AND one or more of the following :         

(a) Residing or having stayed during the 7 days prior to onset of symptoms in area where avian influenza A/H5N1 is suspected or confirmed;  

(b) Having worked in a laboratory during the 7 days prior to onset of symptoms in area where there is processing of samples from persons or animals that are suspected of having influenza A/H5N1 infection;                                     

(c) Having been in close contact (within 1m) during the 7 days prior to the onset of symptoms with a confirmed case of Influenza A/H5N1

Epidemiological link

At least one of the following exposures (a, b, c) within 7 days prior to onset of symptoms:

1. Human Contact : Having been in close contact  (within one metre) of a person reported as probable or confirmed case of influenza A/H5N1;

2. Laboratory Contact : Having worked in a laboratory where there is potential exposure to influenza A/H5N1;

3. Contact with poultry or wild birds : Reside in or have visited an area of a country where influenza A/H5N1 is currently suspected or confirmed as reported in the DSU web-site (See Travel Advice)

AND

• Having been in close contact with sick or dead poultry or wild birds in affected area;

OR

• Having been in a home or farm where sick or dead domestic poultry have been reported in the previous six weeks in the affected area;

Known source of avian influenza

Known source of avian influenza virus include

• Infected poultry and uncooked poultry products

• Infected wild or pet birds

• Other infected animals ex pigs

• Manure and litter containing high concentrations of virus

• Contaminated surfaces

• Contaminated vehicles, clothing and footwear at involved sites

• Contaminated air space (eg barn when movement of birds or manure may have resulted in aerosolization of the virus

• Individuals known to be infected with an avian influenza virus

Laboratory criteria for diagnosis

Influenza A/H5 or A/H5N1 will be demonstrated by at least one of the following lab tests :

1. Positive RT-PCR for influenza A/H5 or A/H5N1;

2. Positive viral culture for Influenza A/H5N1;

3. Immunofluorescence antibody (IFA) test positive using Influenza A/H5 monoclonal antibodies;

4. 4-fold rise in Influenza H5-specific antibody titre in paired serum samples.
   

Case definition for influenza A/H5N1

Possible case :

Any individual meeting the clinical description and with an epidemiological link.

Probable case :

A possible case with one positive laboratory test for influenza A/H5 performed in a laboratory which is not a National Reference Laboratory participating in the EU Community Network of Reference Laboratories for Human Influenza (CNRL)

National confirmed case :

An individual with a positive test for influenza A/H5 or A/H5N1 performed by a National Reference Laboratory participating in the EU Community Network of Reference Laboratories for Human Influenza (CNRL).