Investigation of norovirus presence in stool of diarrheal patients

The main aims of these study to investigate the frequency of norovirus in patients with diarrhea and the determination of the sensitivity and specificity of the other diagnostic methods by the reference molecular method which is accepted currently as the gold standard in the diagnosis of norovirus. We evaluated the 184 stool samples of patients with diarrhea who applied to I.U Istanbul Faculty of Medicine Medical Microbiology Laboratory and whose bacterial agent investigation of stool samples resulted as negative. All of the samples which were included in the study were evaluated with RT-PCR, EIA and IKG methods. In addition to the demographic information of the patients, the information about symptoms of the norovirus positive patients were collected and the results were evaluated with this information. Norovirus was detected 14 out of 184 (7,6%) patients with the gold standard RT-PCR method. Sensitivity of the EIA and ICG methods are calculated as 50% and 57% respectively and the specificity of both methods is calculated as 100%. Factors as age groups, gender, stool macroscopy were not found to be statistically significant in terms of norovirus positivity. The sensitivity performance of EIA and ICG methods were higher in patients with short-term symptoms beside that the requirement of RT-PCR method was noticed in the patients with long-term symptoms who were immunosuppressed in general. As a result, it was found that norovirus which is not routinely investigated in our country has substantial positivity in diarrheal patients. Antigen detection methods which are found to have limited sensitivity can be used in specific patient groups beside that the use of molecular methods was considered as advantageous in the patients who is under the risk of long-term infection.