Emerg Infect DiseidEmerging Infectious Diseases1080-60401080-6059Centers for Disease Control106535672627973Research ArticleNorwalk-like calicivirus genes in farm animals.van Der PoelW. H.Wim.van.der.Poel@rivm.nlVinjéJ.van Der HeideR.HerreraM. I.VivoA.KoopmansM. P.National Institute of Public Health, Bilthoven, The Netherlands.Jan-Feb2000613641

Viruses closely related to Norwalk-like viruses (NLVs) were recently found in stored stool samples from two calves (United Kingdom and Germany) and four pigs (Japan), sparking discussions about the potential for zoonotic transmission. To investigate if NLVs are commonly present in farm animals, pooled stool samples from 100 pig farms, 48 chicken farms, 43 dairy cow herds, and 75 veal calf farms from the Netherlands were assayed by reverse transcription- polymerase chain reaction amplification, using primers specific for the detection of NLVs from humans. NLV RNA was detected in 33 (44%) of the specimens from veal calf farms and two (2%) specimens from pig farms. Our data show that NLV infections until recently thought to be restricted to humans occur often in calves and sometimes in pigs. While zoonotic transmission has not been proven, these findings suggest that calves and pigs may be reservoir hosts of NLVs.