Human enteric coronaviruses: antigenic relatedness to human coronavirus OC43 and possible etiologic role in viral gastroenteritis.

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 less than .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.