A Porcine Epidemic Diarrhea Virus Outbreak in One Geographic Region of the United States: Descriptive Epidemiology and Investigation of the Possibility of Airborne Virus Spread

Beam, Andrea; Goede, Dane; Fox, Andrew; McCool, Mary Jane; Wall, Goldlin; Haley, Charles; Morrison, Robert

Although our findings are not a definitive assessment of airborne spread of PEDv, we believe they justify additional research on the possibility of airborne spread. A similar analysis of wind direction could be conducted on data from outbreaks in other geographic regions in the United States. Additional studies should include information on the movements of trucks and pigs, as well as other movements that could cause virus spread, if possible. In addition, testing of more air samples with PCR and bioassay are recommended. Sequencing of isolates could more accurately track movement of specific virus in future research and was another limitation of this study. Studies have shown that infectious virus can persist in fecal slurry for at least 28 days at 4°C and for at least 14 days but less than 28 days at room temperature [14] , and it could be important to determine if slurry could be aerosolized or carried aloft by the wind as small fecal clumps that could protect the virus. Additionally, although it has been shown that infectious virus survives for less than 2 weeks on dry feed mixture at room temperature [14] , it would be helpful to determine how long the virus can survive on dry matter, which could be easily borne on the wind. Flies and other insects may also play a role in disease transmission, and insects may be affected by wind patterns. Therefore, research is also needed to evaluate whether PEDv on or in flies can infect pigs and, if so, whether the flies are biological or mechanical vectors.