PCR DETECTION OF ROTAVIRUSES, CALICIVIRUSES, ADENOVIRUSES IN CHILDREN WITH ACUTE DIARRHEA IN MOSCOW, RUSSIA

Bokovoi A.G.1, Shipulin G.A.2, Mukhina A.A.2

1-Central Clinical Hospital, Moscow; 2-Central Research Institute of Epidemiology, Moscow

Objective: Gastroenteritis due to viral infection of the gastrointestinal tract is common illness in children, with high morbidity reported worldwide. Severeal etiological agents such as rotavirus (RV), calicivirus (CV) and adenovirus (AV) group F are considered to be the main viral causes of gastroenteritis. By the last classification, family Caliciviridae is divided into 2 genus Norwalk-like virus, genotypes 1, 2 (NLV1 and NLV2), and Sapporo-like virus (SLV). The aim of the present study was to investigate the role of RV, CV and AV in structure of acute gastroenteritis in Russia using in-house RT-PCR method for detection of these viruses in stool samples.

Methods: RT-PCR with primer pair to the NSP4 gene of Rotavirus; RT-PCR with primer pair to the capsid gene of NLV1, NLV2 and SLV, PCR with primer pair to the hexon region of Adenovirus. Routine tests for detection of bacteriological agents (Salmonella, Shigella, E.coli and Yersinea) were made for all children.

Results: 123 children were admitted to the Central Clinical Hospital (Moscow) with acute diarrhea during winter-spring period in 1998-2000 years. Clinical manifestations included fever, vomiting, diarrhea, anorexia and abdominal pain. The age of the kids was from 6 months to 14 years old. 33 of them were younger then 1 year old, 54 were younger then 3 years and 36 were older then 3 years. All kids were examined by PCR and routine methods for the presence of bacterial and viral pathogens. 7 (5.7%) episodes of acute diarrhea were caused by bacteriological pathogens (3 & #8211, Salmonella ent. D.1- Shigella Sonne, 2-Yersinea enterocolitica, 1 & #8211, E.coli). Rotavirus was detected in feces of 80 children (68.9%). In stool samples of 7 (6%) infants we found Norwalk-like virus genotype 2. There were no samples containing Norwalk-like virus genotype 1 and Sapporo-like virus. Adenovirus was identified in feces of 3 (2.5%) kids with nonrotaviral diarrhea. In one case we detected mixed infection of Salmonella enteritidis and rotavirus. There were no cases with 2 or more viral pathogens. 26 (21%) cases of nonbacterial diarrhea remained etiologically unresolved. Rotaviruses caused predominantly moderately severe and severe cases. The overall severity of acute gastroenteritis caused by Norwalk-like virus genotype 2 was mild in 5 of 7 cases, even though it occurred in children younger then 3 years old. Children with adenoviral infection were of all age groups, and the severity of the illness was estimated as mild. Control group included 51 stool samples from 17 healthy children and 34 kids with noninfectious pathology of gastrointestinal tract. All children from the control group were of the same age as children with acute diarrhea. All stool samples from the control group were negative for the presence of RV, CV and AV.

Conclusion: We developed in-house PCR assays for detection of enteric viruses and by using this method we demonstrated prevalence (68.9%) of RV infection in children with acute gastroenteritis and showed that CV and AV are not very frequent – 6% and 2%, respectively. Application of these techniques for detection of viral pathogens could reduce the number of cases of acute gastroenteritis with unclear etiology. But, nevertheless 21% of nonbacterial diarrhea remained etiologically unknown.

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