Influenza Viruses Type D, also known as influenza D virus (IDV), is a classification of the influenza virus that primarily affects livestock, particularly cattle. It is one of four types of influenza viruses, the others being types A, B, and C. IDV was first identified in 2011 and classified as a distinct type due to its genetic and molecular differences from the other types.
Influenza D viruses belong to the Orthomyxoviridae family and possess a single-stranded RNA genome. They are enveloped viruses with a helical nucleocapsid and can cause respiratory illness in livestock, including cattle, swine, and small ruminants.
Although influenza D viruses have not been known to cause significant outbreaks in humans, studies have shown that they have the potential to infect and replicate in human cells. However, human-to-human transmission of IDV has not been reported.
In terms of symptoms and clinical presentation, little is known about the illness caused by IDV in humans. However, in livestock, it can cause mild to severe respiratory disease, decrease in milk production, and occasionally lead to pneumonia or other secondary bacterial infections.
Influenza D viruses are distinct from types A, B, and C, both genetically and antigenically, which implies that they have a unique evolutionary lineage. Continuous surveillance, research, and understanding of IDV are necessary to provide insights into its potential as a human pathogen and to develop appropriate preventative and control measures.
