Influenza D Virus (Worryingly) Mutates Further

Since the discovery of the novel Influenza D Virus in 2014, we've seen that this virus also has the capacity to mutate. See here.

Cattle were found to serve as its primary reservoir. Although there is an increasing number of strains, their origin remain unclear.

Phylogenetic analyses, published in 2021, suggest that there existed three major Influenza D Virus lineages designated as D/Yama2016, D/OK and D/660 as well as some intermediate lineages. Influenza D viruses show strong association with geographical location indicating a high level of local transmission, which suggests that this new family of viruses tend to establish a local lineage of in situ evolution[1].

However, the research mentioned above failed to include another Influenza D Virus lineage that was isolated from cattle in Japan with respiratory disease[2]. It was designated D/Yama2019.

Thus, then there were four distinct Influenza D Virus lineages.

But it didn't take long before another novel Influenza D Virus group was identified with broad antigenicity in American bovine herds, which is genetically different from previously known lineages of Influenza D Virus. Since these herds were grazing in the US state of California, this newly discovered lineage was given the designation D/CA2019[3].

Now there are five.

Are humans still safe, you might ask. The answer is that people are 'relatively safe' for now. Individuals working with cattle can become infected with Influenza D Virus, though they show (or have shown) no symptoms of disease.

Until Influenza D Virus mutates again. And again.

My advice: don't hug or kiss your cows anymore.

[1] He et al: Emergence and adaptive evolution of influenza D virus in Microbial Pathogenesis – 2021
[2] Murakami et al: Influenza D Virus of New Phylogenetic Lineage, Japan in Emerging Infectious Diseases – 2020. See here
[3] Huang et al: Emergence of new phylogenetic lineage of Influenza D virus with broad antigenicity in California, United States in Emerging Microbes and Infections – 2021. See here.