'Negligible risk' in contracting bird flu from eating contaminated raw eggs

The EFSA concluded that the probability of infection was 'negligible' for both raw table eggs and raw poultry meat
The EFSA concluded that the probability of infection was 'negligible' for both raw table eggs and raw poultry meat

The chances of catching low pathogenic avian influenza from eating contaminated raw egg is negligible, according to a European Union report.

The European Food Safety Authority (EFSA), which was asked to produce the report, did so at the request of the European Commission.

The Commission asked EFSA to assess the risk for transmission of low-pathogenicity avian influenza viruses (LPAIV) of subtypes H5 and H7 via raw poultry meat and table eggs leading to infection and onward virus transmission to animals and humans.

And EFSA concluded that the probability of infection was negligible for both raw table eggs and raw poultry meat.

“The combined probability of exposure and subsequent LPAIV infection via raw table eggs containing LPAIV is negligible for commercial poultry and humans and extremely unlikely to negligible for non-commercial poultry and wild birds,” said the authors of the report in their findings.

They went on to say that the probability of LPAIV transmission from an individual infected via raw table eggs containing LPAIV was “negligible for commercial poultry and humans and very unlikely to negligible for non-commercial poultry and wild birds.”

Those conducting the assessment said that they had carried out a rapid qualitative assessment by performing a theoretical analysis on the transmission of low pathogenic avian influenza via fresh meat from poultry reared or kept in captivity for the production of meat or raw table eggs.

A predetermined transmission pathway followed a number of steps from a commercial or non-commercial poultry establishment.

The EFSA report said that avian influenza viruses could affect all species of birds and that infection of birds manifested itself depending mainly on the ability of the virus to cause disease (pathogenicity).

Low pathogenic avian influenza viruses (LPAIV) generally caused mild disease in susceptible birds, affecting the respiratory and enteric tracts. The HA subtypes H5 and H7 could mutate to highly pathogenic avian influenza viruses.

Highly pathogenic avian influenza viruses (HPAIV) spread rapidly, causing serious disease with high mortality up to 100 per cent within 48 hours in most galliformes poultry species, said the report.

However, it said that avian influenza virus transmission through ingestion of raw fresh poultry meat and table eggs sourced from infected poultry may only occur if there was “sufficient and viable virus in the commodity able to infect the target susceptible host, which must be exposed to the source of infection.”

The report's authors said that fresh poultry meat sourced from HPAI infected birds was very likely to contain virus due to the systemic distribution of the HPAI viruses throughout the bird's body, including blood and muscle tissue. HPAI virus could also be found in table eggs laid by infected hens before they died from the disease.

But they said no human case had ever been reported in the EU due to avian influenza viruses of the subtypes A(H5N1), A(H5N6), A(H7N9) or A(H9N2). Just one single human fatality due to infection with influenza virus A(H7N7) occurred during a large ongoing outbreak in poultry, they said.

As far as LPAI was concerned, several experiments and risk assessments had determined that the probability of transmitting LPAI virus of H5 or H7 subtypes through raw chicken meat and eggs from infected poultry to produce infection in naïve bird populations ranged from insignificant to negligible.

But there were some experiments, said the report, that suggested LPAI virus distribution “outside the respiratory and intestinal tracts in birds could be wider than currently assumed, which might change the level of risk for a possible virus transmission related to movements and ingestion of fresh meat and table eggs derived from LPAI infected poultry.”

The European Commission had decided that an evaluation and re-assessment of existing and new scientific information was necessary in order to “ensure that the most appropriate measures are in place for animal disease control to protect animal and public health and for safeguarding movements of these commodities within and between member states as well as when trading with non-EU countries.”

This evaluation was conducted by EFSA, which found that the risk of infection was negligible.