Animal health and human health are closely linked and constitute a fundamental aspect in our ecosystem. Transboundary animal diseases can spread rapidly, cross borders and cause serious consequences for the health of animals and humans, as well as society as a whole.
One such transboundary animal disease is avian influenza, which normally spreads among birds but can also affect mammals, including humans. The Middle East and North Africa (MENA) region, in particular, plays a key role in this dynamic, as these countries are on key migratory routes for birds.
Biosecurity is essential to prevent avian influenza outbreaks. In areas where it is insufficient, sustainable and reliable poultry production systems are seriously threatened.
We are pleased to welcome Dr Xavier today, who will talk to us about avian influenza and the implications of its prevention for our ecosystem.
— Can you define avian influenza and specify which species are mainly affected by this disease? Furthermore, what is its impact on animal health and production systems?
— Avian influenza, commonly called avian flu, is caused by type A viruses belonging to the influenza family. These viruses are transmitted primarily among wild aquatic birds and can infect domestic poultry. Waterfowl, such as ducks, geese and swans, are most likely to be infected with avian influenza.
Over the past 20 years, we have seen an increased frequency of avian flu outbreaks. Since 2005, more than 500 million birds have been lost, with around 40,000 cases officially reported. For more than ten years, highly pathogenic avian influenza (HPAI) has remained endemic (that is, it appears frequently) in Egypt.
— What are the main factors contributing to the increase in outbreaks and losses associated with avian influenza?
— Since 2019, the increase in the number of avian influenza cases is mainly attributed to the high circulation of the H5 virus. This predominant clade has acquired, on the one hand, an increased capacity to infect birds more easily and more quickly, and on the other hand, it is now capable of infecting a greater number of avian species. For example, seabirds, which were previously little affected by the H5 virus, are now largely affected by this new clade. As a result, massive losses have been recorded in seabird populations, and the spread of the H5 virus has extended to new regions, notably South America, due to migratory flows of birds.
Another major factor to note is the contamination of mammals, particularly cattle herds in the United States, which demonstrates the ability of these viruses to infect non-avian species.
According to the 2022 report from the World Organization for Animal Health (WHOA), 67 countries across five continents have recorded outbreaks of highly pathogenic avian influenza H5N1 in poultry and wild animals. In 2023, 14 additional countries reported outbreaks, mainly in America, with 2,238 cases recorded since October 2023, indicating the continued spread of the disease.
— Can you describe the symptoms of avian influenza?
— It is crucial to quickly detect highly pathogenic avian influenza (HPAI) in birds to prevent its spread. Infected poultry, as well as domestic birds, may exhibit various symptoms, such as loss of appetite, purplish discoloration or swelling of the wattles, reduced egg production with altered shell quality, discharge. nasal passages, respiratory signs such as coughing and sneezing, loss of coordination, diarrhea, and sometimes sudden death without warning signs. It is essential to identify these symptoms quickly to effectively limit the spread of the infection.
— What measures should be taken to avoid avian influenza?
— There are three main measures to adopt to combat avian influenza:
1. Strengthening biological security practices: This approach aims to minimize the risks of spreading the virus. Key measures include: keeping poultry away from wild and migratory birds, reducing entry to farms, rigorous cleaning and disinfection of equipment, as well as the application of the poultry management system based on the “all-in-all-out” principle, where all animals enter and leave the farm simultaneously.
2. Active surveillance and early detection: It is crucial to maintain regular surveillance to quickly detect the presence of avian influenza. This includes capturing or hunting wild birds in habitats or regions with a history of outbreaks. Samples must be collected within 24 hours of detection. Environmental samples, such as those from water and soil, as well as blood and feather samples are also essential for testing and assessing the presence of the virus.
3. Vaccination of poultry: Vaccination is an effective preventive measure to reduce the risk of infection. It helps prevent epidemics in domestic birds, reduce economic losses, reduce post-infection viral shedding (thus limiting human exposure to the virus) and minimize environmental impact. In addition, it allows the collection of essential data on the effectiveness of vaccines, thus contributing to the continued research and improvement of strategies to combat the disease.
— What role does vaccination play in reducing the transmission of avian influenza and in minimizing its health and economic impact?
— Vaccines induce specific immunity in birds against certain viruses, thereby helping to reduce mortality and alleviate symptoms. In addition, they reduce viral shedding after infection, thus limiting the spread of the virus in avian populations and reducing the risk of transmission to humans. An effective vaccination program can prevent epidemics, limit economic losses and minimize the environmental impact of the disease. In Egypt, the majority of funds allocated to the fight against avian influenza were invested in vaccination.
As a global leader in preventing and combating cross-border diseases, Boehringer Ingelheim supports the use of vaccines to prevent and combat emerging diseases and zoonoses. Our broad portfolio of prevention products, intended for farm and domestic animals, aims to protect the health of humans and animals. We remain firmly committed to research and innovation to address the challenges posed by emerging diseases and zoonoses, particularly avian influenza.
— Regarding food safety, is the consumption of meat and eggs from birds infected with avian influenza considered safe?
— Consumption of meat and eggs from infected birds can be safe if these products are properly prepared and cooked. It is imperative that consumers follow the four fundamental rules of food safety: clean, separate, cook and keep cool. In addition to proper preparation, proper handling and cooking methods help reduce the risk of contamination by bacteria and viruses, such as avian influenza.
— What are the ecological and economic consequences associated with avian influenza epidemics?
— Avian influenza can have dramatic consequences on wild and domestic wildlife. With high mortality rates, it seriously affects domestic and wild bird populations, which can lead to devastating impacts on ecosystem biodiversity. Economically, this disease can devastate entire sectors, particularly poultry farming, with losses reaching several billion dollars. For example, avian influenza outbreaks are estimated to have caused the loss of 40 million birds, with economic costs estimated at between $2.5 billion and $3 billion. In Egypt, since 2006, avian flu epidemics have caused significant economic losses for the poultry sector, affecting the incomes of 1.5 million people. During the first wave of the disease in 2006, Egyptian veterinary authorities culled 40 million birds to contain the spread of infection on farms.
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