The world’s largest northern gannet colony on the Bass Rock, an island off the coast of North Berwick, Scotland has been just lately decimated by avian influenza (H5N1) or chook flu. H5N1 has triggered unprecedented lack of tens of hundreds of birds within the U.Okay. The annual congregations on breeding grounds rapidly became a super-spreader occasion as extremely pathogenic H5N1 ripped by way of chook colonies, leaving many mendacity lifeless on the seashores or distant islands.

The affect of this illness may be very critical for chook conservationists. From epidemiological perspective, transmission from lifeless birds to scavenging animals reminiscent of sea lions, foxes, and gulls has posed critical dangers. Lately, intra-mammal transmission of H5N1 in captivity in mink farms was recorded, posing an even bigger concern in relation to zoonotic potential.

In India, the most recent main avian flu outbreak in 2020-2021 swept by way of many States inflicting mass mortality of untamed birds which introduced the issues on the dearth of energetic surveillance to the forefront, and the way wetland and waterfowl habitats on the interface of poultry should be monitored. India is a serious wintering floor for a lot of waterfowl that depend on the central Asian Flyway. 

Whereas the avian flu outbreaks coincide with the height migratory season resulting in post-outbreak surveillance and culling, there are additionally studies of outbreaks within the low season suggesting endemic transmission inside the poultry sector. India is the quickest rising egg producer on this planet, however in contrast to in Europe, poultry birds right here usually are not vaccinated in opposition to flu. Moreover, the farms with a variety of animals or within the neighborhood of close by wetlands will increase the potential for the viruses to bear reassortment that may doubtlessly generate extra virulent strains — H5N1 or H7N9 — which may then infect people. 

Regardless of this potential, there isn’t any energetic surveillance within the poultry sector. There could also be no environment friendly human-to-human transmission mechanism but, nevertheless, the danger can’t be dominated out because the virus continues to evolve. 

We want an energetic and passive year-round surveillance community underneath One Well being which connects monitoring of human and animals in a shared setting.

The significance 

Wastewater-based epidemiology or pathogen surveillance has change into an integral element of environmental surveillance offering close to real-time info on well being and neighborhood publicity to pathogens. Whereas environmental surveillance shouldn’t be a brand new idea and has been used broadly for monitoring a number of pathogens, it provides a wonderful instrument.

Birds contaminated with avian influenza virus shed massive portions of virus of their faeces, saliva and nasal secretions for a couple of week. Wild aquatic birds within the Orders  Anseriformes and  Charadriiformes are the primordial reservoir for the virus. The transmission of the virus inside these wild chook populations depends on faecal/oral transmission by way of contaminated water. 

Avian influenza viruses have been remoted from unconcentrated water in lakes within the U.S., Canada and China. Recurrent infections of animal hosts with the virus have posed a persistent risk. Having a large-scale influenza A virus surveillance community in place throughout a number of websites is essential for bettering our understanding on the range, seasonal and geographical distributions of the virus in environments related to poultry and wild birds. The surveillance must goal the areas the place spillover is most certainly. 

Avian influenza viruses can stay viable for prolonged intervals of time in floor water and carcasses, suggesting that lakes and wetlands can act as environmental reservoirs at variable temperatures for a number of months. In a research in Hong Kong, an H3N2 virus was remoted from faeces and pond water each month throughout a one-year interval, and the upkeep of this virus was proposed to be depending on environmental persistence and the continued introduction of prone ducklings.

Home geese are recognised as an essential reservoir for H5N1. Environmental surveillance is a vital space that may improve the data on prevalence variety of avian influenza viruses in free-ranging home flocks or underneath confinement situations the place faeces or different effluent are deposited into the setting.

Virus surveillance

Presently, virus surveillance is reactive and depends on sampling lifeless birds. Environmental surveillance can be a fantastic non-invasive instrument that may be performed with out disturbing the birds and can be utilized to acquire each host and viral genetic materials.

Most significantly, environmental surveillance needs to be complemented with efficient carcass assortment and testing, and higher biosecurity on poultry farms to enhance preparedness and response sooner or later. 

( Farah Ishtiaq is a scientist on the Tata Institute for Genetics and Society, Bengaluru)