Antibodies to VP1 of swine pasivirus in humans without evidence of transmission from a pig source

Abstract Background Swine pasivirus (SPaV1) is a recently described enteric virus close to human parechoviruses and highly prevalent in pigs. Antibodies to Escherichia coli -expressed VP1 of SpaV1 have been found in a majority of humans in China. Objectives The objectives were to estimate the antibody prevalence in a European country, to test if exposure to the virus was linked to pig products and if this exposure was a risk factor for the development of diabetes type 1. Study design An ELISA test was developed and used to screen 842 healthy subjects with known exposure to pig products, 39 patients with diabetes type 1 and 20 controls. Results We identified a high seroprevalence (15.6%) reacting to VP1 of SPaV1 among healthy human subjects. Analysis of risk factors argues against cross-species transmission from pigs as the source of infection. Data also indicate that the presence of SPaV1 VP1-binding antibodies is not associated with diabetes type 1 in humans. Conclusion Our results suggest that the seroreactivity frequently found in humans against SpaV1 is due to cross-reactivity with related antigen, perhaps a picornavirus, and that SpaV1 is not a zoonotic virus.