The government’s Environment department is conducting regular monitoring on migratory bird aggregation sites in light of the reported large-scale outbreaks of the highly pathogenic avian influenza (HPAI) in wild birds in several countries.
Department of Environment and Natural Resources (DENR) Regional Offices and its Biodiversity Management Bureau (BMB) are conducting regular monitoring on migratory bird sites, including on the annual waterbird count, and on the abnormal wild bird mortalities.
This came as the Philippines reported last week confirmed its first outbreaks of HPAI type A subtype H5N1 that killed over 42,000 quails and ducks in four Central Luzon farms.
Meanwhile, in the United states avian influenza has been detected in a sixth commercial poultry flock in southern Indiana, state officials said on March 1, the Associated Press reported.
Three previous cases were found in Dubois County and two in Greene County. Cases have also been detected in Michigan, in a backyard flock and in a zoo.
Officials have begun euthanizing the 16,500 birds at the latest farm to prevent the spread of the disease.
Avian flu was also detected in New York and Iowa in February.
Influx of migratory birds cannot be prevented
The Philippines’ DENR-BMB Veterinarian Rizza Araceli F. Salinas said the influx of migratory birds cannot be prevented since their long journeys to escape the winter season are necessary for their survival.
As such, the BMB and some selected regional and field offices have been conducting disease surveillance among wild birds in aggregation sites.
“Thus far, all samples collected are negative of the avian influenza virus,” Salinas said.
According to Salinas, the Bureau of Animal Industry (BAI) of the Department of Agriculture (DA) has published the Avian Influenza Protection Program Manual of Procedures, which serves as a reference for the conduct of active and passive surveillance on avian influenza.
“Though not directly related to avian influenza, [the] BMB issued a Technical Bulletin on Birding Guidelines to reduce negative impacts of recreational photography to wild birds and their habitats,” she said.
Moreover, she said that as a preventive measure, the DENR-BMB issues a public advisory at the onset of migration season and during outbreaks as notified by the DA-BAI. The advisory is then disseminated to concerned offices.
On the other hand, the local government units, she said, are enjoined to support Republic Act 9147, or the Wildlife Act, by protecting wild birds. It includes the prevention of hunting of wild and migratory birds.
International scientific task force convened
To recall, in response to recent large-scale outbreaks of HPAI in wild birds, the Secretariat of the Convention on the Conservation of Migratory Species of Wild Animals (CMS) and the Food and Agriculture Organization of the United Nations (FAO) convened the Scientific Task Force on Avian Influenza and Wild Birds.
The highly pathogenic avian influenza H5N1 HPAI virus, plus other subtypes, including H5N8, have caused multiple avian influenza outbreaks in the UK, the Netherlands, Israel and India, the task force said. It added that outbreaks of H5N1 have seriously affected migratory wild birds.
The task force provided recommendations and guidance for authorities and managers of countries affected or at risk of avian influenza.
Wild birds, including globally threatened species, are victims of HPAI viruses causing avian influenza.
Affected sites also include areas of international relevance for conservation, such as protected wetlands.
The scientific group said authorities with responsibility for animal health should apply the “One Health” approaches for communicating and addressing avian influenza, the task force said. This means recognizing that the health of humans, domestic and wild animals, plants and the wider environment are interlinked and acting with a coordinated and unified approach.
It is recommended that surveillance and biosecurity measures be reinforced to reduce spillover risk between poultry and wild birds.
Authorities need to fulfill their international obligations to avoid the culling of wild birds and damage to natural ecosystems, especially wetlands.
Dr. Ruth Cromie, coordinator of the scientific task force said: “Avian influenza represents a One Health issue threatening health across the board. The highly pathogenic viruses are still relatively new in wild birds and this winter’s high levels of mortality remind us of their vulnerability and that working to promote healthy wildlife benefits us all.”
H5N1 is currently the avian influenza lineage most found in Africa and Eurasia in both poultry and wild birds. It affects wildfowl, waders, gulls, cranes, grebes, herons, pelicans, game birds, corvids and raptors, and occasionally mammals, such as red fox, Eurasian otter, harbour and grey seal.
In terms of human health, the currently circulating H5N1 HPAI viruses do not seem to pose the same zoonotic risk—infectious disease that jump from animals to humans—as to the “original” Asian lineage H5N1 (clade 2.2 and their derivatives plus clade 2.3.4.4b H5N6 viruses currently in China), the task force said.
Considering people working on poultry culling operations, the risk can be considered moderate, it added.
Recommendations from scientific task force
General recommendations concerning different categories of animals affected include the following.
On wild birds: The task fore said there is no benefit in attempting to control the virus in wild birds through culling or habitat destruction.
All those with responsibilities for animal health are reminded of the advice of FAO and Office International des Epizooties, or the World Organisation for Animal Health, and international obligations under CMS, the Ramsar Convention, and the Agreement on the Conservation of African-Eurasian Migratory Waterbirds to ensure that there is no consideration of killing of wild birds, spraying toxic products or negatively affecting wetland and other habitats as disease control measures.
On poultry: Responses to HPAI in poultry must follow OIE international standards, guidelines and recommendations on notifications, surveillance, diagnosis, trade, and control measures.
It added that biosecurity should include efforts to prevent the spread of infection from infected poultry holdings to wild birds.
It said that there is a need for reorganization of poultry production systems highly susceptible to avian influenza exposure in order to minimize the risk of virus introduction and further spread
On captive birds: There is no justification for any pre-emptive culling of zoological collections, it pointed out.
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