Detection of viruses in avian faeces by direct electron microscopy

A total of 151 specimens of turkey and chicken faeces and intestinal contents were examined for the presence of viruses by electron microscopy. Viruses were detected in 48 of these specimens (32%). The most frequently observed viruses were rotaviruses and enterovirus-like particles. Rotavirus infection was associated with outbreaks of diarrhoea in turkeys, but symptomless rotavirus infection was seen in broiler chickens. Adeno-viruses and infectious bursal disease virus were also observed in turkey faeces. The best method for preparing faecal material for examination employed initial purification by extraction with a fluorocarbon, followed by concentration in the ultracentrifuge. Examination of the pooled contents of the caeca and large intestine gave better results than examination of small intestinal contents. It is concluded that direct electron microscopic examination of faeces has considerable potential as a diagnostic technique in avian virology.