Prevalence of antibody to human calicivirus in general population of northern Japan.

Serum specimens from children and adults living in Saporo, Japan, were tested for antibody against human calicivirus by immune electron microscopy (IEM), using virus-rich faecal extracts as the source of antigen. Of 83 serum specimens tested, 49 (59%) were positive for calicivirus antibody. Age-related prevalence of antibody to calicivirus was as follows: 23% (3/13) in the 0-5-month-old group, 30% (6/20) in the 6-23-month-old group, 65% (13/20) in the 2-5-year-old group, and 90% in school children (18/20) and adults (9/10). As for IEM antibody ratings scored from 0 to 4, almost all positive sera from older infants and preschool children scored 3 to 4. Antibody scores were rather more scattered in school children. The results indicated that caliciviral infection is prevalent in younger children in this part of Japan.