Studies on Cytopathogenic Avian Enteroviruses II. Influence of Age on Virus Excretion and Incidence of Certain Serotypes in a Colony of Chicks

Abstract

Enteroviruses producing cytopathogenic changes in chicken kidney tissue have been isolated by a number of workers from the feces or rectal swabs of chickens and found to occur in up to 15 distinct serological groups on the basis of serum neutralization tests (1,2,3,7,9). It was further observed in examination of birds of various ages that percentage of isolation was definitely correlated with age but not with season (2,3,7,9). Similar results have been reported for bovine enteroviruses (4). Burke et al. (3) examined fecal samples from 10 chickens weekly between 4 weeks and 8 weeks of age and isolated at least two types of enteric viruses. The incidence of infection with different serotypes in different flocks of chickens has been very variable (7). In routine examination of fecal samples from apparently healthy offspring, different strains of ECHO viruses have been isolated (5,8). A study was undertaken to establish the correlation of age with virus excretion by examining the monthly fecal samples from 34 chickens from one month of age up to eleven months and to classify the isolates serologically on the basis of serum neutralization tests.