H5N8 is a subtype of the Influenza A virus. Although H5N8 is considered one of the less pathogenic subtypes for humans, it is beginning to become more pathogenic. H5N8 has previously been used in place of the highly pathogenic H1N1 in studies.
Symptoms
For the most part, symptoms of the H5N8 virus are respiratory. The common symptoms are "flu-like": fever, chills, headache, coughing, and weakness. Conjunctivitis reportedly has been associated with the virus, as well. When farmed poultry are confirmed as having the virus, the farm will cull the birds. This way, the virus will hopefully not be passed along to the public. However, neighboring farms and area wildlife must be tested, also.
Outbreaks
1983
Perhaps the most known outbreak of H5N8 occurred in Ireland in 1983. Poultry on two farms showed the usual symptoms, plus diarrhea, nervousness, and depression. Poultry farms within close proximity soon began to show signs of infection, as well, but no contact between the farms could be established. In the end, 8,000 turkeys, 28,020 chickens, and 270,000 ducks were culled. When investigated in the lab, clinical findings demonstrated that turkeys were the most susceptible to infection. The virus could not be clinically reproduced in ducks.
2016–17
In the second half of 2016 H5N8 outbreak was first reported in Europe, spreading to Asia by the end of the year.
October 2016
On 27 October 2016, a H5N8 case was first reported in a wild swan in Hungary. Further reports were subsequently made from seven additional European countries. There were outbreaks in poultry and wild birds in Austria, Hungary and Germany. There were reports of infection in wild birds only in Croatia, Denmark, Poland and Switzerland.
November 2016
In the Netherlands, H5N8 was found in wild birds and birds in a zoo and on 26 November, 190,000 ducks were destroyed at six farms. Outbreaks have also been reported in India, Israel, South Korea, Taiwan and Russia.
December 2016
On 16 December 2016, it was confirmed that there was an outbreak of the H5N8 virus at a farm near Tetney, Louth — the first outbreak in the United Kingdom. This outbreak has caused the combined death and culling of 5,000 turkey birds. At the time of writing, a 3 km protection zone and a 10 km surveillance zone were enforced by the Department for Environment, Food and Rural Affairs. In the second week of December official delegations from Japan, South Korea and China gathered in Beijing for a symposium on preventing and controlling bird flu and other diseases in East Asia, according to the website of China's ministry of agriculture. By the end of December the outbreak had spread to South Korea, Japan, Germany, and the United Kingdom. Thousands of birds and animals were being culled in Germany to stop the spread. In the United Kingdom the flu was found in a wild duck at a turkey farm in Lincolnshire. In South Korea, a total of record 18.4 million birds had been killed by December since the first outbreak of avian flu was reported at a farm on Nov. 18. Japan has reported five outbreaks since the end of November with 800,000 chickens having been culled in one month.
A case of the virus was detected in Harare, Zimbabwe at one of the major poultry producers, Irvine's Private Limited. The virus saw over 7,000 birds succumbing to the virus. As a result, the company, culled over 140,000 birds to prevent the spread of the virus. Even though a ban on all avian products from Zimbabwe was issued, on 22 June an outbreak was reported at a commercial broiler poultry farm outside Villiers, South Africa after 5,000 chickens died. A few days later, just over 60 km away from the first outbreak, a separate outbreak was reported in Standerton, Mpumalanga, where over 25,000 birds were culled to prevent the virus spreading. The South African Poultry Association reported that wild ducks migrating from Europe are spreading the virus.
December 2017
On 20 December 2017, the Ministry of Environment, Water and Agriculture in Saudi Arabia announces the detection of the highly pathogenic H5N8 virus among birds at a poultry market in Riyadh. A few days later, the virus was detected in other farms in other cities including Al-Ahsa, Al-Kharj, Al-Quaiyat, Dharma, and Mazahmiya. This outbreak in the country has led cull more than 100,000 birds at 12 locations across the country to prevent the spread of the virus.
February 2020
On 4 February 2020, Saudi Arabia has reported an outbreak of the highly pathogenic H5N8 bird flu virus on a poultry farm. The outbreak, which occurred in the central Sudair region, killed 22,700 birds.
