Monday, September 25, 2023

Increase in reported avian influenza outbreaks worldwide from 2013 to 2022

This is shown by a study by the Centers for Disease Control and Prevention (CDC). The number of reported outbreaks of avian influenza in animals and infections in humans is increasing worldwide. Between 2013 and 2022, the number of avian influenza outbreaks in animals and infections in humans not only increased, but was also detected over a larger geographical area and in increasingly diverse categories of animals. These findings are particularly relevant in the context of ongoing outbreaks of H5 avian influenza worldwide and in the United States in livestock and domestic poultry and wild birds, and sporadically in some mammals, with one human case reported in the United States and others in the rest of the world .

The study authors analyzed avian influenza outbreaks in animals around the world between 2013 and 2022, reported to the World Organization for Animal Health (WHO) and other animal health authorities, as well as avian influenza virus infections in humans reported to the World Health Organization. They compared these findings with reports from the period 2005-2012.


The The number of reported bird flu outbreaks has increased. Categories of animals with avian influenza outbreaks included wild birds, captive birds, birds in live bird markets, livestock and livestock poultry, and non-human mammals such as mink.

Likewise, from January 2013 to June 2022, 34 subtypes of avian influenza viruses were reported in more than 21,000 outbreaks of avian influenza in animals 2,000 human infections with bird flu viruses worldwide.

On average, 42 Member States reported outbreaks of avian influenza in animals each year, and four Member States reported avian influenza virus infections each year.

A total of 16 subtypes of the avian influenza virus have been detected; Of these, 10 were highly pathogenic avian influenza virus (HPAI) subtypes identified in animals, including birds (nearly twice as many subtypes identified in the last eight years).

On the other hand, six subtypes of avian influenza viruses (LPAI) with low pathogenic incidence in animals, including birds, were reported for the first time in 2013–2022. Four subtypes of HPAI-H5 virus were responsible for almost 90% of reported outbreaks in animals: H5N1 (47%), H5N8 (32%), H5N2 (6%), H5N6 (4%).

He H5N8 was the virus subtype that caused the most outbreaks in animals worldwide each year since 2017, except in 2019 and 2022.

From 2013 to 2022, 26 Member States reported their first outbreak of avian influenza in animals. Avian influenza viruses also spread to other categories of animals.

Between 2016 and 2022, an average of 14% of outbreaks reported each month involved another category of animal, with wild birds accounting for the highest proportion (37%).

The increase in geographical extent and animal category in terms of spread could, they explain in the report, be due to greater production and trade in poultry, greater exposure to wild birds due to repeated annual movements of infected birds and due to changes in the Migration patterns can be attributed to climate change and the conversion of land for agricultural production. These increases could also better reflect avian influenza surveillance and reporting systems.

The spread of avian influenza viruses among birds, animals and people “can serious consequences for public health“. Additionally, as outbreaks in animals increase, the spread to humans may also increase Reassortment options for bird flu viruses“which may increase its transmissibility.”


The most effective surveillance of avian influenza is that which includes comprehensive monitoringwhich, in addition to the timely reporting of cases in domestic and wild birds, humans and ideally also non-human mammals, especially pigs, includes all subtypes of the virus, “since Pigs could play a key role in reassorting new influenza viruses“. Efficient and sustained transmission between people could lead to a flu pandemic.

While recent detections of H5N1 avian influenza in poultry and wild birds in the United States are not currently considered to pose a high risk to the public’s health, “Yes, human infections are possible”, they clarify. As of August 9, 2023, more than 58.7 million poultry and more than 7,100 wild birds have been affected by bird flu in the United States. While a single human case of H5N1 has been detected in the United States, helps The CDC continues to monitor the situation for other infections in people who have had contact with infected birds.

To date, more than 6,500 people exposed to H5N1-infected birds/poultry in the United States have been or are being monitored for symptoms.

In summary, the trends highlighted in the report point to and underline concerns about avian influenza Importance of constant monitoring and timely reporting of bird flu cases in animals and humans in the United States and the rest of the world.

World Nation News Desk
World Nation News Desk
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