4.4.6 Porcine Corona virus infections in older pigs

A porcine enteric corona virus infection, either TGE or the Epidemic virus diarrhoea (EVD) with the European prototype CV777 infection may, under special circumstances, affect the large intestine and result in a catarrhal to fibrinous typhlocolitis in addition to small intestinal lesions. Fattening pigs and sows may develop sudden onset of severe diarrhoea. This condition will generally be associated with loss of piglets in the nursery and will be accompanied with other clinical symptoms. For the histopathologist, the complete loss of small intestinal villi in most of the small intestine is the most significant finding, along with the demonstration of virus antigen in mucosal enterocytes by IHC.

Diagnostic methods for the detection of TGEV and EVDV:

For the diagnosis of a TGEV infection, different diagnostic tools such as the detection of viral antigen and viral genome, microscopic investigation, isolation and the detection of specific antibodies are available and widely used.

The electron microscopic investigation of faecal samples enables the investigator to detect Corona virus like particles but it does not offer the possibility to differentiate between TGEV and EVDV. The latter can easily be detected using ELISA methods for EVDV antigen from faeces or demonstrating EVDV specific anti-bodies in serum.