Rotavirus replication in the villous enterocytes
results in cell lysis and villous blunting and atrophy.
The degree of villous atrophy and the distribution of
atrophic villi in the small intestine depend on the age
of the pig (Shaw et al. 1989), rotavirus strain (Collins
et al. 1989), and serogroup (Saif 1999). Younger pigs
have more severe and extensive villous atrophy, and
porcine A and C rotaviruses tend to produce more
severe villous atrophy and diarrhea than groups B and
E rotaviruses in pigs (Saif 1999). Group B rotavirus
produces scattered foci of infection in the villous tips
of the distal small intestine and mild diarrhea (Saif and
Jiang 1994).