Objective: In order to find out a more convenient, rapid and efficient way in detecting human Norovirus infections in specimens collected from hospitalized patients with acute non-bacterial diarrhea in Beijing.
Methods: Two kits for enzyme immunoassay (EIA) were used to detect human Noroviruses in stool specimens collected from 69 infants and young children as well as 15 adults who were all diagnosed as acute non-bacterial diarrhea in 4 different hospitals. Reverse transcription-polymerase chain reaction(RT-PCR) was performed to evaluate the data from two kits in this study. Data were statistically analyzed by SPSS 11.5 software. chi2 test was used to test categorical variables.
Results: Out of 84 stool specimens collected from infants and young children or adults with acute non-bacterial diarrhea, 17 (20.2%) were Norovirus positive determined by EIA kit A and 31 (36.9%) were Norovirus positive determined by EIA kit B. chi2 test used to test categorical variables showed significant differences (P < 0.01), suggesting that the EIA kit B was superior to the EIA kit A. Among these 84 stool specimens, 20 were tested by RT-PCR simultaneously. Out of those 20 specimens, 11 (55.0%) were Norovirus positive as determined by RT-PCR, which was higher than that from 2 EIA kits.
Results: from 10 (50.0%) samples detected by EIA kit A were consistent with those detected by RT-PCR. Through chi2 test, the categorical variables showed significant differences with P < 0.05, suggesting that RT-PCR was superior to the EIA kit A. Results from 14 (70.0%) samples detected by EIA kit B were consistent with those detected by RT-PCR while chi2 test showed that the differences were not significant (P > 0.05), among categorical variables suggesting that EIA kit B was as sensitive as RT-PCR in detecting Norovirus. The were hospital acquired diarrhea outbreaks in these three hospitals since at least 2 Norovirus positive specimens were detected in each of the hospitals.
Conclusion: To detect human Noroviruses infection, EIA seemed to be more convenient and time saving than RT-PCR which had been used worldwide. The EIA kit B in this study was comparable to RT-PCR for detecting Norovirus in stool specimens. Norovirus was a pathogen causing hospital acquired diarrhea outbreaks in these three hospitals.