In 2020 a new type of coronavirus, SARS-CoV-2, spread rapidly across the planet and caused a pandemic in which we are still immersed. However, what many experts feared for years, and whose risk has not disappeared, was that the next great pandemic was going to be caused by an outbreak of bird flu.
Although most avian influenza viruses do not cause human disease, some of them are zoonotic and have been found in mammals, including man. One of the best-known flu subtypes is the H5N1 strain, first found in Hong Kong in 1997: the virus jumped from waterfowl to humans, killing six of its eighteen victims.
In an updated version in March 2021, the World Organization for Animal Health (OIE) answers the most classic questions about bird flu.
What is bird flu?
We are talking about a viral disease that affects birds, both domestic poultry and pets and wild birds. The numerous strains of this virus are usually classified into two categories based on the severity of the disease they cause in poultry (low pathogenicity and high pathogenicity)
What is the current bird flu situation?
Since August 2020 there has been a substantial increase in the number of bird flu outbreaks caused by various subtypes but in particular H5N8, and which have been reported in Europe, Asia and Africa. In February 2021, Russia notified the World Health Organization (WHO) of the first case of transmission to humans of this strain. The network of experts in animal influenza analyzed the preliminary information of the event and affirmed that, to date, there is no evidence to suggest that there have been serious human infections or transmission of this virus from person to person. This situation probably represents an isolated spillover event of the virus.
What are the causes of this rebound and why is it worse than other years?
The molecular characterization of the avian influenza virus subtypes that currently circulate in birds shows genetic variability with respect to previous years, a fact that could be explained by multiple rearrangements with low pathogenic viruses that circulate in wild birds. It is necessary to closely monitor the evolution of viruses to assess the risks they pose to animal and human health.
Has the COVID-19 pandemic hindered the implementation of preventive measures against bird flu?
Maintaining veterinary activities in the pandemic is essential to avoid the negative impacts of animal diseases, which may further worsen the current health and socioeconomic crisis.
According to the OIE, despite the difficult context, veterinary authorities in affected countries have responded to contain outbreaks of avian influenza in poultry with stamping out measures, increased surveillance and recommendations to poultry owners to increase biosecurity.
What is the impact of bird flu?
This disease poses a great threat to the health and welfare of animals and can have devastating consequences. Avian influenza severely affects the livelihoods of small- and large-scale poultry producers and other actors involved in the supply chain.
In addition, to contain outbreaks and control the disease, it is often necessary to eliminate contact and suspicious bird populations, threatening food security around the world. The presence of highly pathogenic avian influenza also restricts international trade in live birds and poultry meat, which has a strong impact on national economies.
What is the risk of bird flu to human health?
The epidemiology of avian influenza viruses is complex, as they can change and evolve through mutation and rearrangement, with the appearance of new subtypes that cause significant impacts on animal health and production. Some, but not all, subtypes may be zoonotic and therefore pose a threat to human health.
Transmission of avian influenza viruses to humans occurs when there is close contact with infected birds or heavily contaminated environments.
What are the food safety recommendations?
There is no evidence to suggest that eating poultry or eggs can transmit the avian flu virus to humans. However, as a general precautionary measure, animals that have been euthanized as a result of the implementation of control measures in response to an outbreak of avian influenza, including the H5N8 subtype, should not enter the human and animal food chain.
What are the key elements to prevent further spread of avian influenza?
Control of its animal origin is essential to reduce the risk and, consequently, the impact of the disease. In this context, continued surveillance for the avian influenza virus in wild birds and poultry combined with the timely dissemination of data is essential. This early warning system enables the international community to follow the evolution of the virus and rapidly detect changes in the properties of the virus, such as genetic introductions, rearrangements or mutations, that are relevant to public and animal health.
When cases are detected in animals, control measures should be implemented at the infected farm level and within a short radius around infected facilities, in an effort to quickly contain and eradicate the disease.
What prevention measures are recommended at the farm level?
It is essential that poultry farmers maintain biosecurity practices to prevent the introduction of the virus. Some of these measures include:
- Avoid contact between poultry and wild birds
- Minimize movement around poultry houses
- Maintain strict control over access to animals from vehicles, people and equipment
- Clean and disinfect animal housing and equipment
- Avoid the introduction of birds of unknown disease state
- Report any suspected cases (alive or dead) to the veterinary authorities
- Ensure proper disposal of manure, garbage, and dead animals
- Vaccinate animals, where appropriate
What is the OIE doing to combat bird flu?
The OIE works with its network of animal influenza experts, as well as its partners, in particular WHO and the Food and Agriculture Organization of the United Nations (FAO), to assess risks and provide guidance and recommendations. necessary.
