Poult enteritis complex.

Poult enteritis complex (PEC) is a general term that encompasses the infectious intestinal diseases of young turkeys. Some diseases, such as coronaviral enteritis and stunting syndrome, are relatively well characterised, while others, such as transmissible viral enteritis, poult growth depression and poult enteritis mortality syndrome, remain ill-defined. All forms of PEC are multifactorial, transmissible and infectious. Salient clinical features include stunting and poor feed utilisation that result from enteritis. In the more severe forms, runting, immune dysfunction and mortality are reported. Gross and microscopic lesions of enteritis are present in all forms but tend to be non-specific. Other lesions may be present, depending on the agents involved. The basic pathogenesis involves the following: a) alteration of the intestinal mucosa, generally by one or more viruses infecting enterocytes; b) inflammation; c) proliferation of secondary agents, usually bacteria. Non-infectious factors interplay with infectious agents to modulate the course and severity of disease. Diarrhoea is believed to be primarily osmotic because of maldigestion and malabsorption, but may also have a secretory component. Transmission is primarily faecal-oral. No public health significance is recognised or suspected. Prevention is based on eliminating the infectious agents from contaminated premises and preventing introduction into flocks. This is accomplished by an effective cleaning, disinfection and biosecurity programme. All-in/all-out production or separate brooding and finishing units are helpful. Control may require regional co-ordination among all companies producing turkeys, especially if the production is highly concentrated, and a quarantine programme for more severe forms of PEC. No vaccines or specific measures for controlling the organisms involved in PEC are available. Treatment is supportive for the viral component, while antibiotics, especially those with efficacy against Gram positive bacteria, may help to reduce the impact to bacterial infections. Evidence suggests that PEC occurs wherever turkeys are raised commercially, but this is not well documented and distribution of the various organisms that have been associated with PEC is largely unknown. The disease causes enormous economic loss, mostly from failure of the turkey to reach its genetic potential.