Human caliciviruses in acute gastroenteritis of young children in the community

Episodes of acute gastroenteritis in prospectively followed children betwee n 2 months and 2 gears of age were examined for rotaviruses, enteric adenov iruses, astroviruses, and human caliciviruses, including both Norwalk-like viruses (NLVs) and Sapporo-like viruses (SLVs), using PCR and reverse trans cription (RT)-PCR assays. A virus was identified in 60% (502/ 832) of all e pisodes and in 85% of the moderately severe or severe episodes. Human calic iviruses were as common as rotaviruses, both being detected in 29% of the c ases. NLVs accounted for a 20% etiologic share of all cases; the clinical p icture was a moderately severe disease with vomiting as a predominant sympt om. SLVs were detected in 9% of the cases, the clinical picture being a mil d diarrheal disease. Astroviruses were found in 10% and enteric adenoviruse s in 6% of the cases. Diagnosis with PCR and RT-PCR methods increases the d etection of all gastroenteritis viruses, particularly human caliciviruses. As a group, human caliciviruses are common causative agents of gastroenteri tis in children a years of age in Finland, and, of these, NLVs cause more s evere disease than SLVs.