Bird flu is hitting Australian poultry farms, and the primary human case has been reported in Victoria. Here’s what we know

The first human case of avian influenza (bird flu) in Australia was reported yesterday in Victoria. A baby acquired the H5N1 strain of the virus in India and have become ailing upon returning home to Australia in March this 12 months.

Based on information made available yesterday on the Global Initiative on Sharing All Influenza Data (GISAID), we are able to ascertain the kid is a two-year-old girl. She tested positive in early March and was reportedly very unwell but has since fully recovered.

According to the Victorian Department of Healthcontact tracing revealed no additional cases, and the chance to others could be very low.

Humans who acquire H5N1 generally have close contact with infected poultry; H5N1 doesn’t spread easily between people. But the fatality rate in human cases is about 50%.

So what should we make of this latest development, as bird flu makes news locally and world wide?

H5N1

There’s no publicly available information on how this child became infected in India, and even where in India this case got here from. However, the country is currently facing significant avian flu outbreaks within the states of Kerala, Andhra Pradesh and Maharashtra.

H5N1 is a strain of influenza A, which is further divided into variants called clades. GISAID data shows the virus the kid was infected with belongs to the H5N1 clade 2.3.2.1a. The South Asian clade 2.3.2.1a was first identified in 2009 and remains to be circulating in birds in Bangladesh and India.

This is different from the clade behind outbreaks in dairy cattle making headlines within the United States (H5N1 clade 2.3.4.4b). A second human case within the US related to this outbreak has just been reported – a dairy employee in Michigan. Globally, a complete of 14 human cases have been linked to this clade.

What in regards to the poultry farms?

On the identical day we heard in regards to the child with H5N1, a bird flu outbreak was reported at an Australian egg farm in Meredith, Victoria.

This was a distinct straininfluenza A H7N3. H7 outbreaks aren’t latest to Australia. The earliest H7 outbreak in Australia was an H7N7 outbreak in Melbourne, Victoria in 1976. The three most up-to-date outbreaks occurred in free-range farms in Lethbridge, Victoria, in 2020.

While some strains of avian flu are likely to produce mild or no visible disease (called low pathogenic), H5N1 and H7N3 are each highly pathogenic viruses. This means they cause severe illness in poultry and wild birds.

Wild birds are the source, and may infect farmed or domestic poultry. They may infect animals reminiscent of pigs and horses.

Free range farms are liable to avian flu, as they’re outdoors and should be exposed to infected wild birds. But overall there have been only a few highly pathogenic avian influenza outbreaks in Australian poultry, summarised within the table below.

The strain dominating Europe and the Americas, H5N1 clade 2.3.4.4b, began in 2020 and spread globally to contaminate greater than 300 avian and 40 mammalian species.

This is the most worrying cladebecause it has spread further and more widely than every other avian flu virus. In mammals and birds it causes severe respiratory disease but in addition affects the brain.

Some excellent news

To date, H5N1 has not been detected in birds in Australia. It’s positive news that the egg farm outbreak is H7N3 fairly than H5N1. The unrelated H5N1 infection within the child showed no evidence of spread, and the kid recovered.

Australia has historically been protected against highly pathogenic avian flu since it’s spread by migrating geese, geese and swans (often known as waterfowl) from Asia. Their flyways bypass Australia.

However, with a spread of various wild birds now infected by H5N1 clade 2.3.4.4bincluding in Antarctica, there could also be latest bird migration routes by which the virus could enter Australia.

The egg farm outbreak must be controlled quickly by culling infected birds. There are vaccines for poultry, but they’re only partially effective and may mask outbreaks, so tend not for use. France, which has had widespread outbreaks of H5N1 in its farms, began vaccinating poultry recently, but has experienced continued outbreaks.

What must occur now?

Past H7 outbreaks have been controlled rapidly in Australia, but we must remain vigilant. Meanwhile, an outbreak of low-pathogenic avian influenza virus H9N2 has been reported in a poultry farm in Western Australia today. The situation is being closely monitored.

There are sometimes delays in reporting and sharing of avian flu data. Information on the child in Victoria was reported almost three months after the eventwhich shouldn’t be ideal for preparedness.

Open source surveillance using publicly available data and intelligencereminiscent of our Epiwatch platform, can provide more rapid information where there could also be delays in updates to international reporting databases.

Avian influenza is a worldwide concern, so heightened and timely surveillance in animals, birds and humans is crucial, as is global data sharing. The impact of avian flu on farming and the economy is substantial, but we also worry a few human pandemic arising.

H5N1 is so widespread globally now that the prospect of it mutating to a degree where it’s in a position to spread between humans is higher than ever.