The World Organisation for Animal Health (OIE) received an immediate notification on 22 April, stating that the morbidity and mortality rates are 5 on a scale of 0 to 5. The causal agent has been identified as a novel swine enteric coronavirus. However, the serotype has not yet been identified.

The affected states are Ohio, Indiana, Iowa, Colorado, Minnesota, Pennsylvania, Oklahoma, Missouri, Michigan, Illinois, South Dakota, Kansas, New York, North Carolina, Tennessee, Texas, Wisconsin, Kentucky, Maryland, Nebraska, California, Wyoming, South Carolina, Arizona, Idaho, Montana, North Dakota, Vermont and Mississippi.

A total of 5,978 pigs have been reportedly affected by the outbreaks.

According to the OIE, Novel Swine Enteric Coronavirus Disease(s) (SECoV) is a disease in swine caused by emerging porcine coronaviruses, including Porcine Epidemic Diarrhoea virus (PEDv) and Porcine Delta Coronavirus (PDCoV). SECoV affects swine causing diarrhoea, vomiting and 50-100 per cent mortality of infected piglets.

The clinical presentation of SECoV infections in growing pigs can be variable in its severity and not readily distinguishable from many other causes of diarrhoea in growing pigs. While adult pigs can become infected, mortality is low.

SECoV is clinically indistinguishable from transmissible gastroenteritis (TGE), another swine disease caused by a coronavirus that is endemic in the United States.

Chronological occurrence of the SECoV event

May 2013: USDA APHIS National Veterinary Services Laboratory (NVSL), in close collaboration with Iowa State University-Veterinary Diagnostic Laboratory (ISU-VDL) confirmed the presence of PEDv in the United States.

Iowa State University Veterinary Diagnostic Laboratory (ISU-VDL) managed case reporting of PEDv through the American Association of Swine Veterinarians (AASV), https://www.aasv.org/. Retrospective testing identified PEDv-positive cases from April 2013.

June 2013: The USDA National Animal Health Laboratory Network (NAHLN) began management of SECoV case reporting. - November 2013: The United States provided the OIE with information related to the PEDv situation affecting swine herds. - March 2014: Confirmation of the presence of porcine delta coronavirus (PDCoV); NAHLN began management of PDCoV case reporting.

2013–2014 (ongoing): USDA APHIS Collaborative Efforts with Stakeholders: Development of a PEDv case definition and testing protocols; Sequenced the PED virus and deposited the information in GenBank; Banked paired specimens for use in future diagnostic test development; Diagnostic test evaluations and pathway assessments in progress; Completed and ongoing epidemiological studies; Development of a ‘Monitoring and Management Program for Novel Swine Enteric Coronavirus Diseases’.

As of 16 April 2014: Since its confirmation in the United States, SECoV PCR-positive laboratory accessions have been reported from 29 States. This data only includes voluntarily submitted biological samples. It does not include testing conducted at private laboratories, at the NVSL, or for research purposes.

The source of all the outbreaks remains inconclusive.