Friday, 7 October 2016

Meet the new virus named influenza D

A virus, relatively newly detected, that affects cattle has been given a new name: influenza D. The reason for the new naming is because of the virus is distinct from other influenza types — A, B and C.
The naming of the virus was decided at a meeting of the International Committee of Taxonomy of Virus. The committee declared that the virus forms part of a new genus called Orthomyxovirdae. Currently a single species sits within the genus — the Influenza D virus.
Influenza ("the flu") is an infectious disease caused by an influenza virus. The disease symptoms vary from the mild to severe, with common symptoms including a high fever, runny nose, sore throat, muscle pains, headache, coughing. Influenza affects many types of mammals.
Three types of influenza viruses affect people, called Type A, Type B and Type C. The new fourth type has, so far, only been shown to affect cattle.
The new virus was isolated in 2011. Although the virus was isolated from a pig, the reservoir for infection was traced back to a cow. This made influenza Type D the first known influenza virus to affect cattle. The discovery was made by Professor Feng Li and one of his doctoral students, Ben Hause. Noting that the virus was atypical, the U.S. National Institutes of Health provided a grant to allow for further examination.
The examination showed that the Type D virus was sufficiently different to other influenza viruses, with the closet match being the Type C virus, although even her the difference was 50 percent.
The virus is spread through direct contact, normally from one cow to another (in laboratory studies guinea pigs were used to study viral transmission). Subsequently to cows and pigs, the virus has been detected in sheep and goats. Studies with poultry have shown the virus cannot be transmitted to chickens.
The virus is not pathogenic to humans and does not pose any (immediate) future risk. However, a risk of mutation exists and further studies are taking place into the likelihood of the virus forming a new genetic strain that could pose a risk to people.
The original research paper was published in mBio and it is titled “Characterization of a Novel Influenza Virus in Cattle and Swine: Proposal for a New Genus in the Orthomyxoviridae Family.”

Posted by Dr. Tim Sandle