Epidemiological investigation of an outbreak of acute gastroenteritis caused by human calicivirus in Lulong County / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To survey an outbreak of acute gastroenteritis in Lulong County and analyze the cause of the disease.</p><p><b>METHODS</b>Epidemiological methods were applied to investigate an outbreak of acute gastroenteritis occurred in June 2000 in Lulong County. Stool specimens were collected from diarrhea patients and were tested for human calicivirus by ELISA and RT-PCR. The products of RT-PCR were cloned and sequenced, then phylogenetic analysis was carried out.</p><p><b>RESULTS</b>In total, 736 farmers were surveyed, among them 134 had acute gastroenteritis, the attack rate was 18.20%, and one elderly patient died. The age of patients was from 1 to 77 years and the incidence of the disease among young people was higher with a peak in June 25 through 30. Six stool specimens were tested for caliciviruses by ELISA and 3 were positives, one of them was confirmed by RT-PCR and belonged to norovirus genotype GI/2. No other pathogens were detected.</p><p><b>CONCLUSION</b>Human calicivirus was confirmed to be the cause of the outbreak of acute gastroenteritis.</p>

Epidemiological study of human caliciviruses among children with acute diarrhea in Lulong county, 1999 - 2001 / 中华流行病学杂志

<p><b>OBJECTIVE</b>To investigate the epidemiological characteristus of human caliciviruses (HuCVs) among children under 5 years of age with acute diarrhea and to estimate the disease burden in Lulong county.</p><p><b>METHODS</b>HuCVs were detected by enzyme linked immunosorbent assay (ELISA) and reverse transcription-polymerase chain reaction (RT-PCR). Some PCR amplicons were cloned and sequenced. Phylogenetic tree was constructed for strain characterization. The rate of HuCVs-attributed hospitalization was estimated according to the positive rate of HuCVs detection in fecal specimens collected from hospitalized diarrhea patients.</p><p><b>RESULTS</b>Between July 1999 and June 2001, 708 fecal specimens were collected, of which 393 rotavirus-negative and 5 rotavirus-positive specimens were detected for HuCVs. Thirty-one point six percentage of fecal specimens from patients with diarrhea was HuCVs positive. Among inpatients, HuCVs positive rate was 17.5%. HuCVs detection was mainly distributed in 3 - 17 mouth-old children, in winter. All 11 strains belonged to NLV GII in which 6 strains GII-3, 2 strains GII-4 and 3 strains GII-7, and they shared 55.1% - 100% nucleotide identity. NLV GII-4 and GII-7 were identified in 2000, while NLV GII-3 and GII-7 in 2001. The preliminary estimate of HuCVs-attributed hospitalization rate was 3.6 per thousand.</p><p><b>CONCLUSION</b>Human caliciviruses with different genotypes circulated among children in Lulong county with GII NLVs were the prevalent strains. The disease burden of HuCVs was second to rotavirus.</p>