Ottawa-There is a risk that avian influenza could mutate into a danger to more wildlife species as well as humans, says the Auditor General of Canada (AGC).

In a report on the federal response to the disease since it began in Canada in 2021, the AGC said Environment Canada, the Canadian Food Inspection Agency and the Public Health Agency need to improve planning, documentation and the management of vaccines to better prepare for future threats to public health and vulnerable wildlife.

An outbreak of avian influenza began in Canada in December 2021 and there are concerns that the virus could mutate, leading to human-to-human transmission and potentially a pandemic, AGC said.

While the departments took action to prevent and manage avian influenza outbreaks, there remain challenges in assessing the impact of the disease on species at risk.

Also needed is consistent documenting of activities intended to eliminate the virus from infected premises and effective management of of human vaccines.

Avian influenza is caused by a highly contagious virus that mainly infects wild birds but can spread to domestic animals - such as chickens, dairy cattle and pets - and then to humans.

The Public Health Agency secured vaccines for people at higher risk of exposure, such as farmers and veterinarians, but purchasing decisions were not supported by sufficient analysis.

This led to an oversupply and more than 95 per cent of the purchased vaccine doses expired before they could be used.

While the agency obtained the financial approval to purchase more doses, it had not yet decided whether updating the vaccine inventory was needed.

Since the outbreak, Environment Canada has strengthened its surveillance of migratory birds by redirecting existing funding. However, without dedicated funding, future efforts may be difficult to sustain.

Also, despite recognizing the need to understand the impact of avian influenza on species that are or could become threatened, endangered or extinct, the department did not conduct routine and targeted surveillance for species at risk.

There now are 43 bird species at risk of contracting the disease, the AGC said. Environment Canada expanded its avian influenza surveillance program for migratory birds by increasing the numbers of samples tested and by including antibody testing in blood samples from wild birds and wild bird eggs.

About 17.3 million commercial birds either died or were culled due to the virus, costing about $360 million in compensation paid by the Canadian Food Inspection Agency.

Avian influenza is a major conservation threat for wild birds due to the current outbreak’s unprecedented large-scale mortality and broad distribution among migratory bird populations.

The World Health Organization and the Public Health Agency warn that further mutations of the highly pathogenic avian influenza virus could lead to sustained human-to-human transmission, AGC said.

Environment Canada should improve its surveillance methods for detecting avian influenza in species at risk to understand which are most vulnerable and susceptible to the impacts of the virus and to inform the management and conservation of these species.