Human enteric Coronaviruses: Antigenic Relatedness to Human Coronavirus OC43 and Possible Etiologic Role in Viral Gastroenteritis

Gerna, Giuseppe; Passarani, Nilda; Battaglia, Massimo; Rondanelli, Elio G.

In a group of infants with acute nonbacterial gastroenteritis, examination of paired sera for antibody to human coronavirus (HCV) OC43 and neonatal calf diarrhea coronavirus showed a peculiar pattern of serological response, restricted only to HCV OC43 surface antigens, in a significantly higher proportion than among age-matched controls. In another group of infants and young children with acute nonbacterial gastroenteritis, fecal excretion of coronavirus-like particles was detected by electron microscopy in 34 (16.3%) of 208 patients as compared with three (1.6%) of 182 controls (P < .01). Two strains of human enteric coronavirus (HECV) were purified from stools of two patients, and immune sera were raised in mice and guinea pigs. Immune electron microscopy showed a two-way cross-reactivity between HECV and HCV OC43 when tested with immune sera and convalescent-phase sera from patients with infection due to HECV or HCV OC43.