Exposure to Multiple Infectious Agents and the Development of Colibacillosis in Turkeys

Abstract

This investigation sought to determine which primary infectious agents, either alone or in combination, may be associated with the development of secondary Escherichia coli infections in 6- to 12-wk-old turkeys. In a preliminary assessment, 20 turkey flocks experiencing clinical signs and mortality consistent with colibacillosis were sampled to ascertain whether, in addition to E. coli, evidence of previous or concurrent infection with hemorrhagic enteritis virus, Newcastle disease virus, and/or Bordetella avium was present. Results suggested that all three agents, either individually or collectively, were associated with the development of colibacillosis in turkeys.Using the above information, we designed a case-control study that used serological evidence to evaluate the association of these and several other infectious agents with the occurrence of colibacillosis. Ten turkey flocks experiencing a peak in mortality between 6 and 12 wk of age were compared with 10 healthy flocks of the same age and sex distribution. Statistical analysis of the data suggested a strong association between the occurrence of colibacillosis and the appearance of antibodies to hemorrhagic enteritis virus, Newcastle disease virus, Bordetella avium, and Mycoplasma meleagridis in the flock serological profiles.