06 May 2015
HPAI viruses: Canada and the United States of AmericaNovel highly pathogenic avian influenza (HPAI) viruses: Canada and the United States of America
Highly pathogenic avian influenza viruses are circulating in wild and domestic birds in many parts of the world. Since December 2014, United States of America (USA) and Canada have reported several outbreaks of highly pathogenic avian influenza HPAI due to the novel H5 influenza viruses A (H5N2) and A(H5N8). A number of states in USA have reported outbreaks which resulted in millions of turkeys and chickens being slaughtered as commercial farms try to control the spread of the virus. In Canada, HPAI H5 influenza viruses have been reported in two unrelated outbreaks among commercial birds in the province of British Columbia and the province of Ontario [1,2]. These are the first outbreaks due to HPAI H5 influenza reassortants of Eurasian origin to be registered in North America.
A novel reassortant of HPAI A( H5N1) viruses has also been identified in wild birds in USA, but has not been found in commercial poultry [3, 4]. This novel, mixed origin H5N1 virus is different from the strain that has been known to cause illness in humans .
Human cases of avian influenza virusesHuman infections of avian influenza viruses are rare and when they have occurred, these viruses have not spread easily from person to person. So far there have been no reported human cases of infection with the avian influenza A(H5N8), A(H5N2)or A(H5N1) reassortant viruses in the Americas, or globally.
Advice for travellers
Although there have been no reported cases of human infection with these novel HPAI H5 viruses, you are advised to follow special precautions to minimise potential exposure if you are planning to visit a country currently affected by avian influenza. In particular you should:
- Avoid close contact with live poultry
- Avoid visiting live bird and animal markets (including ‘wet’ markets) and poultry farms
- Avoid contact with surfaces contaminated with animal faeces
- Avoid untreated bird feathers and other animal and bird waste
- Do not eat or handle undercooked or raw poultry, egg or duck dishes
- Do not pick up or touch dead or dying birds
- Do not attempt to bring any poultry products back to the UK
- Exercise good personal hygiene with regular hand washing with soap and use of alcohol-based hand rubs.
Anyone engaging in hunting activities whilst travelling to the USA or Canada should follow the CDC advice for hunters.
Seasonal influenza vaccine does not protect against avian influenza viruses.
You are advised to seek medical advice promptly if you become ill with respiratory symptoms following a recent trip to countries affected by avian influenza outbreaks, by telephone from your GP or NHS 111, clearly stating your recent travel.
Advice for health professionals
Whenever avian influenza viruses are circulating in poultry, sporadic infections and small clusters of human cases are possible in people exposed to infected poultry or contaminated environments .
Healthcare professionals should be alert to the possibility of avian influenza in travellers presenting with a severe respiratory illness following recent travel from countries affected by outbreaks of avian influenza. Public Health England (PHE) has published avian influenza algorithms which provide guidance for physicians on the recognition, investigation and initial management of possible human cases of avian influenza, in travellers returning to the UK.
- PHE: Avian influenza A(H5N2) and A(H5N8): risk assessment
- Public Health England: Avian influenza
- World Health Organization: Monthly Risk Assessment Summary
1. Pan American Health Organization (PAHO)/World Health Organization. Epidemiological Update – Outbreaks of Avian Influenza due to reassortant viruses, public health implications for the Americas. 21 April 2015. [Accessed 6 May 2015]