Serologic evidence of exposure to influenza D virus among persons with occupational contact with cattle

J Clin Virol. 2016 Aug:81:31-3. doi: 10.1016/j.jcv.2016.05.017. Epub 2016 May 31.


Background: Influenza D virus (IDV), a novel influenza virus with proposed classification: family Orthomyxoviridae, genus Influenzavirus D, species Influenza D virus, has been associated with influenza-like illness in cattle and swine. More recently, anti-IDV antibodies have also been detected in small ruminants. A seroprevalence of approximately 1.3% has been estimated for the general human population.

Objectives: To gain insights on the zoonotic potential of IDV to human adults with occupational exposure to cattle in north central Florida.

Study: A cross-sectional serological study was performed on human serum samples from 35 cattle-exposed and 11 non-cattle-exposed adults to screen for IDV antibodies using hemagglutination inhibition (HI) and microneutralization (MN) assays.

Results: A seroprevalence of 91% was detected via HI assay, and 97% by MN assay among individuals working with cattle in Florida. Among non-cattle-exposed individuals, seropositivity determined via MN assay (only) was lower (18%).

Conclusions: IDV poses a zoonotic risk to cattle-exposed workers, based on detection of high seroprevalence (94-97%). Whereas it is still unknown whether IDV causes disease in humans, our studies indicate that the virus may be an emerging pathogen among cattle-workers.

Keywords: Influenza; Influenza D virus; Occupational health; Zoonoses.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Agriculture
  • Animals
  • Antibodies, Viral / blood
  • Cattle
  • Female
  • Florida / epidemiology
  • Hemagglutination Inhibition Tests
  • Humans
  • Influenza, Human* / epidemiology
  • Influenza, Human* / immunology
  • Influenza, Human* / transmission
  • Influenza, Human* / virology
  • Male
  • Middle Aged
  • Occupational Exposure
  • Orthomyxoviridae Infections
  • Thogotovirus / immunology*
  • Young Adult
  • Zoonoses*


  • Antibodies, Viral