Avian influenza

Avian influenza

Avian Influenza (AI) or "Bird Flu" is a highly contagious viral infection which can affect all species of birds and can manifest itself in different ways depending mainly on the ability of the virus to cause disease (pathogenicity) and on the species affected.

Influenza infections in birds are divided in two groups on the basis of their pathogenicity:

  • Highly Pathogenic Avian Influenza (HPAI): spreads rapidly causing serious disease with high mortality (up to 100% within 48 hours) in most poultry species (except domestic waterfowl)

  • Low Pathogenic Avian Influenza (LPAI): causing generally a mild disease, may easily go undetected

Highly pathogenic avian influenza (HPAI) - Latest developments 2021

The HPAI epidemic season which started in October 2020 will continue in 2021. Outbreaks and cases in wild birds continued to be confirmed by several EU countries. This map represents the distribution of the HPAI detections.

A detailed overview on the situation in Member States since the start of the current HPAI epidemic season and the adopted measures is given in the Chronology of events.

HPAI in 2020

During 2020, two distinct epidemic seasons of highly pathogenic avian influenza (HPAI) were observed in the European Union. The first HPAI epidemic season started on 31 December 2019, with the first outbreak in poultry confirmed in Poland. A new HPAI virus of subtype H5N8 (2020) was involved in the outbreak. By March, the disease was confirmed in Poland, Czechia, Germany, Hungary, Slovakia and Romania. The H5N8 (2020) subtype of the HPAI virus was responsible for all of these outbreaks. The most affected Member State was Hungary, after the virus entered in the area with with a high density of duck and geese holdings. Outbreaks of HPAI were also detected in Bulgaria between March and June 2020, but the virus involved was of subtype H5N8 which also circulated in Bulgaria in 2018-2019. The last outbreak in poultry related to the first epidemic season of HPAI was confirmed on 5 June 2020.

Only three wild birds were found infected with HPAI during the first half of 2020 (in Germany and Poland). The virus involved was the same as the one detected in the poultry farms.

The second HPAI epidemic season started at the end of October 2020 when the first cases were reported in wild birds in the Netherlands. Again, the first HPAI virus detected was of H5N8 subtype, different from the one that circulated in the first half of the year. Since then and until the end of 2020, a high number of dead and sick wild birds, mostly of migratory species, were found to be infected with HPAI viruses of subtypes H5N8, H5N5, H5N1 and H5N3 being detected by several EU countries and the United Kingdom. The largest number of cases in wild birds were reported in the Northern part of Germany, in Denmark and in the Netherlands. Between October and end of December 2020, the disease was also confirmed in poultry in Croatia, Denmark, France, Ireland, Germany, the Netherlands, Poland, Sweden and the United Kingdom.

See the map with the distribution of the HPAI detected during 2020, separated by epidemic season.

A detailed overview on the situation in EU countries and the adopted measures is given in the Chronology of events.

HPAI in 2019

During 2019, the HPAI H5N6 subtype was confirmed in wild birds and closely related to other viruses detected during 2017/2018 in wild birds. There were few HPAI outbreaks in poultry during the course of the year. The outbreaks were confirmed in Bulgaria in March-April.

HPAI in 2018

In wild birds only, the HPAI H5N6 subtype was confirmed mainly in the first half of 2018 in Finland, Sweden, the Netherlands, Germany, Ireland, Slovak Republic, the United Kingdom and Denmark. Infection persisted at a low level throughout the summer period with a last reported case in mid-September in Denmark. During the second half of 2018, outbreaks of HPAI of subtype H5N8 continued to be confirmed in poultry in Bulgaria, last in mid-December (see map).

HPAI Epidemic 2016/2017

In October 2016, HPAI of subtype H5N8 virus was first detected in a wild bird found dead in Hungary. The virus was then identified in wild birds, poultry farms and/or captive bird holdings (e.g. in zoos) in 19 Member States. Member States with a high density of duck and geese holdings were most affected. By end April 2017 the outbreaks sharply declined, while infection was still detected from July to December 2017 in poultry in Italy and Bulgaria. To a very limited extent, HPAI of subtype H5N6 was detected end 2017 in a poultry holding and in a few captive bird holdings. Based on the genetic analysis of H5N6 viruses detected in Europe and Asia, the EU Reference Laboratory for avian influenza concluded that the European strains can be differentiated from those associated with zoonotic infection in Asia. Furthermore, they do not carry any virulence markers strongly associated with human infection risk. There have been no reported human infections with this particular genetic sub-lineage of H5N6.

The veterinary authorities of affected Member States immediately took EU control measures (Council Directive 2005/94/EC) to possibly prevent virus spread to other poultry holdings and established protection and surveillance zones around the infected holdings. The Commission continues to call for maintaining extreme vigilance and strict biosecurity on farms to prevent contacts between wild birds and poultry. It has adopted urgent protective measures in relation to these outbreaks. The disease situation and the measures adopted by the Commission are regularly reviewed during the periodical meetings of EU Member State experts at the Standing Committee on Plants, Animals, Food and Feed.

The Commission has published updated rules on biosecurity and risk mitigation measures on poultry farms which obtained unanimous support by Member States. These measures follow EFSA's advice and are in particular directed at preventing contact with wild birds, as well as early detection systems. The implementation of these measures by the farmers is crucial to prevent future HPAI outbreaks on farms.

A detailed overview on the situation in Member States and the adopted measures is given in the Chronology of events and in the ADNS overview reports.

The European Food Safety Authority (EFSA) published a scientific opinion on avian influenza and since then, quarterly reports on the development of the avian influenza situation in the EU and worldwide.

The European Centre for Disease Prevention and Control collaborates with EFSA on these reports. ECDC also publishes reports and risk assessments in relation to the relevance of avian influenza for humans: risk assessment on public health.

Influenza Preparedness

A Joint meeting of Member States' Chief Veterinary and Chief Medical Officers on Influenza Preparedness in the context of One Health took place on 23 and 24 October in Brussels.

Member States' responsible authorities for animal and human health, the EU agencies EFSA and ECDC and international organisations - the World Health Organisation (WHO), the World Organisation for Animal Health (OIE), and the United Nations Food and Agriculture Organisation (FAO) - met to address the EU's enhanced preparedness and intersectoral co-operation for the next epidemic waves of animal and human influenza using an One Health approach.

The EU works closely with international partners in the fight against avian influenza. Regular contacts and information exchange occur between the European Commission, the World Organisation for Animal Health (OIE), the World Health Organisation (WHO) and the Food and Agriculture Organisation (FAO)

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EU legislation

Surveillance for Avian Influenza


Emergency and control measures

Chief Veterinary Officers and EU-RLs

Human Health Implications

Highly Pathogenic Avian Influenza