Chinese avian influenza is ready to go global again with a newly identified strain, H10N8. Previous strains, such as H7N9, and H5N1 have been cause for multi-national concern, and the spending of billions of dollars on preparation for a major outbreak. However, the continuous emergence of new forms of flu are keeping global health organisations busy.
This latest version, H10N8, was found as a possible cause of death of an elderly chinese woman who had shown signs of the illness four days after visiting a poultry market. Nine days after that the 73-year-old died of multiple organ failure, and only then was it discovered that she was carrying a novel strain of flu. The case, which occurred in November last year, has just been reported in the Lancet, a prestigious medical publication. In the Lancet the new strain, which has already been reported in birds in China, was identified as a mutation of an earlier version of the flu virus H9N2, and its genes were described as “avian” in origin.
Now a second case of H10N8 has been reported in China, dating from Jan 26th. This case is being closely monitored as previous strains, such as H7N9 have proven to be significantly more deadly than initially hoped. Indeed, of 139 confirmed cases 47 deaths have occurred. However there is no evidence yet that H10N8 can be spread between humans. The global threat from these Chinese avian influenza strains mainly comes from their potential to spread among other animals, birds, who then infect humans afterwards. However, this process makes the virus potentially more deadly, as it encounters a human immune system as something that has never been experienced before, giving the human body less time to respond and adapt to the invasive virus.
In the Chinese cases of H7N9, nearly half of patients who were admitted to hospital went straight into intensive care, because their condition deteriorated so rapidly. The majority of patients were over fifty, and there was no sustained human to human transmission of this type of avian influenza. However, other family members in close proximity to the initial carrier have caught the virus as well.
There is growing pressure on the Chinese authorities to significantly, and nationally, deal with food safety issues that dog the country. The Chinese consume vast quantities of chicken, and for the key ingredient in a nation’s staple diet to be constantly a source of infection and death, is publicly considered unacceptable.
Many Chinese consumers get their food from “wet markets,” where animals are stored in often appalling battery farming conditions, and are slaughtered in the same place. These conditions are ripe for flu pandemics among the birds in the markets, and can consequently be the cause of potentially significant threats to human health as a result. The latest news on H10N8 lead to tens of thousands of birds being destroyed.
One of the challenges China faces is that the cases of H7N9 are occurring close to the border with Vietnam, and coordinating a response between the two countries will be difficult. If an avian influenza strain; that is pandemic among animals, and transmitted by humans does appear, then there will be massive global implications.
By Andrew Willig