Bird Flu Epidemic in Europe Extended

Influenza viruses circulating in animal species such as pigs or birds can sporadically infect humans, causing mild to very severe diseases, reported the European Centre for Disease Prevention and Control (ECDC).

These viruses have the potential to severely affect public health, such as during the epidemics of avian influenza H5N1 in Egypt or H7N9 in China, or the 2009 H1N1 influenza pandemic caused by a virus initially spreading from pigs to humans.

As of October 3, 2022, the ECDC says the current highly pathogenic avian influenza (HPAI) epidemic season has been the largest observed in Europe.

The latest laboratory report for 2021-2022 shows a total of 2,467 outbreaks in poultry, 48 million birds culled in the affected establishments, 187 detections in captive birds, and 3,573 HPAI events in wild birds.

Additionally, the geographical extent of the outbreak is unprecedented, affecting 37 European countries.

"Thankfully, there have been no human infections during the recent outbreaks of avian influenza in the EU/EEA," commented Andrea Ammon, ECDC Director, in a media statement.

"However, several groups of people, mainly those working in the animal sector, are at increased risk of exposure to infected animals."

"It is vital that clinicians, laboratory experts, and health experts, both on the animal and human sectors, collaborate and maintain a coordinated approach."

"Vigilance is needed to identify infections with influenza viruses as early as possible and to inform risk assessments and public health action," she added.

New guidance released by ECDC stresses the importance of safety and health measures to be taken where animal contact cannot be avoided and enhanced in those where zoonotic influenza in animals has been identified. 

Public health professionals and clinicians must be aware of the need to test for infections in patients with respiratory illnesses and recent exposure to potentially infected animals.

Testing for zoonotic influenza should also be considered in patients with severe acute respiratory disease of unknown origin and severely ill patients with prior animal exposure.

It is of utmost importance to identify transmission events early, says the ECDC.

Serological testing methods include simple and inexpensive techniques utilizing standard laboratory equipment to identify zoonotic influenza virus subtypes and measure HA-specific antibodies to the virus to answer questions related to previous exposure or prevalence in specific populations.

Nevertheless, serological tests have several limitations that need to be considered, such as the fact that cross-reactions can occur between different lineages within one subtype or even among different subtypes.

Moreover, the results only provide information on historical exposure to zoonotic influenza viruses. They do not offer viral genetic information, which is vital for evaluating the potential pandemic threat of strains.

Due to the broad diversity of zoonotic influenza viruses, surveillance by genomic evaluation has become indispensable.

The nucleotide-level resolution of in-depth whole genome sequencing permits phylogenetic analysis and molecular epidemiological studies for a detailed understanding of an outbreak. 

To prepare the USA for a potential bird-flu pandemic, the U.S. CDC issued Health Alert Network Health Advisory CDCHAN-00473 on August 30, 2022, which includes updates on recent variant influenza virus infections.

And this Alert summarizes the CDC's recommendations for identification, treatment, and prevention of variant influenza virus infection for the fall of 2022.

As many as 20 shorebird species that visit North America in summer have migratory routes through Asia that overlap with past outbreak areas of highly pathogenic avian influenza. 

The Eurasian H5N1 strain first appeared in North America in January 2022 and has affected 40 states and led to the loss of about 47 million birds.

In 2022, over 2,500 people in the U.S. had been monitored for symptoms following exposure to infected birds.

On April 28, 2022, Montrose County, Colorado, reported the first human detection of any influenza A(H5) virus in the U.S.

As of October 5, 2022, the U.S. CDC says annual 'flu shots' do not prevent human zoonotic influenza infections.

However, the government has stockpiled Zoonotic influenza vaccines to prepare for pandemics.

On February 25, 2022, the U.S. government requested that CSL Seqirus Inc. provide influenza vaccines (AUDENZ™) and adjuvants for pre-pandemic stockpiling or manufacturing to support rapid response to an influenza pandemic or other public health emergencies.

Other Zoonotic influenza news is posted at PrecisionVaccinations.com/Zoonotic.

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