Basic Study
Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Dec 28, 2016; 22(48): 10557-10565
Published online Dec 28, 2016. doi: 10.3748/wjg.v22.i48.10557
Clinical and epidemiological characteristics of norovirus gastroenteritis among hospitalized children in Lebanon
Nada M Melhem, Hassan Zaraket, Khalil Kreidieh, Zeinab Ali, Moza Hammadi, Soha Ghanem, Farah Hajar, Amjad Haidar, Adlette Inati, Mariam Rajab, Hassan Fakhouri, Bassam Ghanem, Ghassan Baasiri, Ghassan Dbaibo
Nada M Melhem, Hassan Zaraket, Zeinab Ali, Moza Hammadi, Soha Ghanem, Farah Hajar, Amjad Haidar, Ghassan Dbaibo, Center for Infectious Diseases Research, Faculty of Medicine, American University of Beirut, Beirut 1107-2020, Lebanon
Nada M Melhem, Khalil Kreidieh, Medical Laboratory Sciences Program, Faculty of Health Sciences, American University of Beirut, Beirut 1107-2020, Lebanon
Hassan Zaraket, Department of Experimental Pathology, Immunology and Microbiology, American University of Beirut, Faculty of Medicine, Beirut 1107-2020, Lebanon
Zeinab Ali, Moza Hammadi, Soha Ghanem, Farah Hajar, Ghassan Dbaibo, Department of Pediatrics and Adolescent Medicine, Faculty of Medicine, American University of Beirut Medical Center, Beirut 1107-2020, Lebanon
Adlette Inati, Department of Pediatrics, Nini Hospital, Tripoli 1300, Lebanon
Mariam Rajab, Department of Pediatrics, Makassed General Hospital, Beirut 1107-2020, Lebanon
Hassan Fakhouri, Department of Pediatrics, Rafic Hariri University Hospital, Beirut 1107-2020, Lebanon
Bassam Ghanem, Department of Pediatrics, Nabatieh Governmental Hospital, Nabatieh 1700, Lebanon
Ghassan Baasiri, Department of Pediatrics, Hammoud Hospital, Saida 1600, Lebanon
Author contributions: Melhem NM designed the study, supervised the experimental work, performed the analysis and wrote the paper; Zaraket H contributed to the analysis; Kreidieh K performed the experiments and contributed to the analysis; Ali Z, Hammadi M, Ghanem S, Hajar F, Haidar A, Inati A, Rajab M, Fakhouri H, Ghanem B and Baasiri G helped in the recruitment of participants and approval of the final version of the article to be published; Dbaibo G critically read and revised the manuscript; Melhem NM and Dbaibo G are co-corresponding authors of this manuscript.
Supported by an investigator-initiated research grant from Merck Sharpe and Dohme (MSD); and University Review Board Grant, American University of Beirut.
Institutional review board statement: The study was reviewed and approved by the Institutional Review Board of the American University of Beirut.
Conflict-of-interest statement: The authors declare no conflict of interest.
Data sharing statement: Not applicable.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Nada M Melhem, PhD, Associate Professor, Medical Laboratory Sciences Program, Faculty of Health Sciences, American University of Beirut, PO Box 11-0236 Riad El Solh, 325 Van Dyck Hall, Beirut 1107-2020, Lebanon. melhemn@aub.edu.lb
Telephone: +961-1-3500004699 Fax: +961-1-744470
Received: June 28, 2016
Peer-review started: June 29, 2016
First decision: October 11, 2016
Revised: October 20, 2016
Accepted: October 27, 2016
Article in press: October 27, 2016
Published online: December 28, 2016
Abstract
AIM

To assess the burden of norovirus (NoV) and to determine the diversity of circulating strains among hospitalized children in Lebanon.

METHODS

Stool samples were collected from children presenting with acute gastroenteritis to six major hospitals in Lebanon. A total of 739 eligible stool samples, testing negative for diarrhea caused by rotavirus as a possible viral pathogen, were collected between January 2011 and June 2013. A standardized questionnaire including demographic, epidemiological and clinical observations was used at the time of hospitalization of children presenting with diarrhea. Viral RNA was extracted from stool samples followed by reverse transcription polymerase chain reaction and nucleotide sequencing of a fragment of the viral protein 1 capsid gene. Multiple sequence alignments were carried out and phylogenetic trees were constructed using the MEGA 6 software.

RESULTS

Overall, 11.2% of stool samples collected from children aged < 5 years tested positive for NoV genogroups I (GI) and II (GII). GII accounted for 10.6% of the gastroenteritis cases with only five samples being positive for GI (0.7%). The majority of hospitalized children showed symptoms of diarrhea, dehydration, vomiting and fever. Upon sequencing of positive samples and based on their clustering in the phylogenetic tree, 4/5 of GI gastroenteritis cases were designated GI.3 and one case as GI.4. GII.4 was predominantly detected in stool of our study participants (68%). We report a JB-15/KOR/2008 GII.4 Apeldoorn 2008-like variant strain circulating in 2011; this strain was replaced between 2012 and 2013 by a variant sharing homology with the Sydney/NSW0514/2012/AUS GII.4 Sydney 2012 and Sydney 2012/FRA GII.4 strains. We also report the co-circulation of non-GII.4 genotypes among hospitalized children. Our data show that NoV gastroenteritis can occur throughout the year with the highest number of cases detected during the hot months.

CONCLUSION

The majority of NoV-associated viral gastroenteritis cases among our participants are attributable to GII.4, which is compatible with results reported worldwide.

Keywords: Norovirus, Reverse transcription polymerase chain reaction, Sequencing, Norovirus genogroup I, Norovirus genogroup II, Lebanon

Core tip: We report the results of a large study of norovirus (NoV)-associated gastroenteritis among children aged < 5 years in Lebanon. The majority of viral gastroenteritis cases were attributable to NoV GII.4, which is compatible with results reported worldwide. Our data support a peak incidence in July, while reports from other countries show peaks during the cold months. We report NoV A JB-15/KOR/2008 GII.4 Apeldoorn 2008-like variant strain circulating in 2011. This strain was replaced between 2012 and 2013 by a variant sharing homology with the Sydney/NSW0514/2012/AUS GII.4 Sydney 2012 and Sydney 2012/FRA GII.4 strains.