INCIDENCE OF HUMAN CALICIVIRUS AND ROTAVIRUS INFECTION IN PATIENTS WITH GASTROENTERITIS IN SOUTH-AFRICA

Human caliciviruses (HuCVs) are reportedly responsible for 2.5-4% of n onbacterial sporadic gastroenteritis. The incidence of HuCV infection in South Africa is unknown. Stool specimens from 1,296 South African p atients with sporadic gastroenteritis were screened for the presence o f HuCVs using electron microscopy, recombinant enzyme immunoassays for Norwalk (NV) and Mexican (MX) viruses, and the reverse transcriptase- polymerase chain reaction (RT-PCR). RT-PCR products were sequenced to ascertain which HuCV genogroups were present. HuCVs were detected in 4 3/1,296 (3.3%) specimens examined, with RT-PCR proving to be the most sensitive detection method. Genetic analysis of the isolates indicated that 81% were Snow Mountain Agent, or MX-like; 8% were NV-like; and 1 1% were HuCV/Sapporo-like. This study indicates that a combination of assays is needed for the accurate detection of HuCVs. Comparative data on hospitalised patients showed that the incidence of rotavirus infec tion was approximately ten times greater than that of HuCV infection. (C) 1997 Wiley-Liss, Inc.