Poult Enteritis and Mortality Syndrome in Turkey Poults: Causes, Diagnosis and Preventive Measures

Abstract

Poult enteritis and mortality syndrome (PEMS) is one of the most significant problem affecting turkeys and continues to cause severe economic losses worldwide. Although the specific causes of PEMS remains unknown, this syndrome might involve an interaction between several causative agents such as enteropathogenic viruses (coronaviruses, rotavirus, astroviruses and adenoviruses) and bacteria and protozoa. Non-infectious causes such as feed and management are also interconnected factors. However, it is difficult to determine the specific cause of enteric disorders under field conditions. Additionally, similarities of clinical signs and lesions hamper the accurate diagnosis. The purpose of the present review is to discuss in detail the main viral possible causative agents of PEMS and challenges in diagnosis and control.

Keywords: PEMS; astroviruses; coronaviruses; phytogenic substances; prebiotics; probiotics; rotaviruses; turkeys.

Figure 1

Corona-like particles (100–150 nm) in fecal samples of turkeys. Negative staining with phosphotungstic acid revealed that TCoVs are enveloped particles, roughly spherical, with diameters ranging from 100 to 200 nm (scale bar: 50 nm).

Figure 2

Astrovirus particles using electron microscopy (CVUA-Stuttgart 2010), showing five or six-rayed star-shaped particles (white arrow) using negative contrast EM (scale bar: 200 nm).

Figure 3

Adenovirus particles using electron microscopy (scale bar: 100 nm, CVUA-Stuttgart 2010).

Figure 4

Rotavirus particles using electron microscopy. (A) intact virus particles; (B) Virus particles without an outer protein layer (scale bar: 100 nm, image, CVUA-Stuttgart).