From Dr. Richard Loyd. Astroviruses are a type of virus that was first discovered in 1975 using electron microscopes following an outbreak of diarrhea in humans. In addition to humans, astroviruses have now been isolated from numerous mammalian animal species and from avian species such as ducks, chickens, and turkey poults.Encyclopedia Entry for Astrovirus :Astrovirus infection. Source of disease: Astroviridae family