1. Clinical, Epidemiologic and Genotypic Characteristics of Norovirus Gastroenteritis in Lebanon
Nada M. Melhem, PhD
American University of Beirut
Faculty of Health Sciences
Center for Infectious Diseases Research
Faculty of Medicine
December 7, 2015
Melhem, 2015

2. Introduction
Norovirus (NoV) is responsible for at least 50% of all gastroenteritis outbreaks worldwide (Lamata et al., 2013).
Data from the Centers for Disease Control and prevention (CDC) suggest that NoV is the leading cause of acute gastroenteritis across all age groups seeking medical care in emergency departments, outpatient clinics and the community (Hall et al., 2011).
NoV-gastroenteritis accounts for % of severe cases in children less than 5 years old (Patel et al., 2009).
9-15 % of mild-to-moderate diarrhea are due to NoV among individuals of all ages (Patel et al., 2008).
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3. NoV: Transmission, Pathogenesis and Management
Primary mode of transmission is through the fecal-oral route.
The incubation period is hours.
The symptoms include: vomiting, diarrhea, nausea, abdominal cramps, malaise and low grade fever.
The illness resolves in hours.
Treatment involves reversal of dehydration and electrolyte deficiency.
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4. Genome Organization & Capsid Structure
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5. Classification of Noroviruses and Viral Diversity
(Vinjé et al. 2015)
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6. Aim of the Study
To our knowledge, there are no studies in Lebanon on NoV and its association with gastroenteritis.
The aim our study is to determine the prevalence of Norovirus gastroenteritis as well as the genotypic characterization of the virus among hospitalized children less than 5 years old.
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7. Methods Study Period: January 2011 to June 2013
Age group: ≤5 years old
Sample size: 739 stool samples from hospitalized children presenting with diarrhea
Collection sites and number of samples:
American University of Beirut Medical Center (Capital Beirut): n=81
Hariri Governmental Hospital (Capital Beirut): n=47
Makassed Hospital (Capital Beirut): n=89
Nini Hospital (North Lebanon): n=316
Hammoud Hospital (South Lebanon): n=116
Nabatiyeh Hospital (South Lebanon): n=90
Melhem, 2015

8. Methods
QIAamp Viral RNA Mini Kit (Qiagen, Germany) was used for viral RNA extraction.
For reverse transcription polymerase chain reaction (RT-PCR) QIAGEN OneStep RT-PCR Kit was used, using genogroup-specific primers.
PCR products were analyzed by gel electrophoresis and nucleotide sequencing of NoV positive samples was performed.
Multiple sequence alignments were carried out using CLUSTALL or BioEdit.
Phylogenetic trees were constructed using the MEGA 6 software.
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9. Table 1. Demographic Characteristics of Study Participants
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10. Table 2. Clinical Characteristics of NoV-associated Gastroenteritis
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11. Incidence of Norovirus by Region
Positives
Total Number of Samples
Incidence
South 28
206
13.59%
North 35
316
11.08%
Beirut 20
217
9.22%
Total 83
739
11.23%
11.08
9.22
13.59
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12. Figure 1. Norovirus and Seasonal Distribution
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13. Figure 2. Phylogenetic Analysis of NoV VP1 Capsid Gene
LBM073/2011 GII
LBH065/2011 GII
LBM123/2011 GII
LBM122/2011 GII
LBM104/2011 GII
LBN159/2011 GII
LBH048/2011 GII
LBH075/2011 GII
LBH062/2011 GII
LBH077/2011 GII
LBN120/2011 GII
LBN111/2011 GII
LBH009/2011 GII
LBN047/2011 GII
LBN086/2011 GII
LBH089/2011 GII
LBH049/2011 GII
LBN131/2011 GII
JB-15/KOR/2008 GII.4 Apeldoorn 2008
LBR034/2011 GII
LBN095/2011 GII
LBN142/2011 GII
LBN185/2011 GII
LBM097/2011 GII
LBH066/2011 GII
LBN154/2011 GII
LBM109/2011 GII
Orange/NSW001P/2008/AUS GII.4 New Orleans 2009
Farmington Hills/2002/USA GII
Guangzhou/NVgz01/CHN GII.4 Asia 2003
Hunter504D/04O/AU GII.4 Hunter 2004
Kenepuru/NZ327/2006/NZL GII a
Osaka1/2007/JP GII.4 Osaka 2007
Yerseke38/2006/NL GII.4
Shellharbour-NSW696T/2006/AUS GII b
LBA147/2012 GII
Sydney/NSW0514/2012/AUS GII.4 Sydney 2012
LBA163/2013 GII
LBN516/2013 GII
LBNG112/2012 GII
LBR040/2011 GII
LBN365/2012 GII
LBN330/2012 GII
LBN323/2012 GII
2012/FRA GII.4 variant Sydney
LBA113/2012 GII
LBN384/2012 GII
LBN478/2012 GII
LBN382/2012 GII
LBN393/2012 GII
LBN328/2012 GII
LBH208/2012 GII
LBNG175/2013 GII
LBN458/2012 GII
LBH054/2011 GII
LBH068/2011 GII
LBH185/2012 GII
LBH203/2012 GII
LBN259/2011 GII
LBR081/2012 GII
LBN339/2012 GII
LBN374/2012 GII
LBA126/2012 GII
LBH186/2012 GII
Sutherland/NSW505G/2007/AUS GII.4 Cairo 2007
Maizuru8915/2008/JPN GII.6
LBA057/2011 GII
LBN360/2012 GII
CBNU1/2006/KOR GII.3
LBNG107/2012 GII
LBA125/2012 GII
LBNG098/2012 GII
NSW743L/2008/AUS GII.7
HCMC-VNM30241/2009/VNM GII.9
LBN480/2012 GII
LBN052/2011 GII
LBH046/2011 GII
LBR082/2012 GII
LBM093/2011 GII
LBA038/2011 GII
LBH028/2011 GII
LBNG147/2012 GII
Ascension208/2010/USA GII.1
LBM101/2011 GII
HS207/2010/USA GII.12
Vaals87/2005/NL GII.2
LBN329/2012 GII
LBN358/2012 GII
LBM102/2011 GII
10N4555/2010/NP GII.13
LBH091/2011 GII
Salisbury150/2011/USA GII.21
LBH221/2012 GII
LBNG129/2012 GII
LBN387/2012 GII
LBN373/2012 GII
LBN366/2012 GII
LBH098/ GI
LBH112/2011 GI
LBN187/2011 GI
LBN040/2011 GI
141/2009/BFA GI.3
JKPG 881/SWE/2007 GI.3
/2008/US GI.8
1643/2008/US GI.4
LBN343/2012 GI
Leuven/2003/BEL GI.2
CS-841/2001/USA GI
StromstadP7-587/2007/Sweden GI.1 74 70 88 92 98 97 91 96 75 94 99 93
100
0.2
GII.4 68% (52/76)
GII.3 (5/76, 6.6%)
GII.9 (1/76, 1.3%)
GII.6 (7/76, 9.2%)
GII.13 (3/76, 3.95)
GII.1 (1/76, 1.3%)
GII.2 (1/76, 1.3%)
GII.21 (5/76, 6.6%)
GII.3
GII.9
GII.6
GII.1
GII.2
GII.13
GII.21
GI.3 80% (4/5)
GI.4
Melhem, 2015

14. Figure 3. Phylogenetic Analysis of NoV VP1: GII.4
LBM073/2011 GII
LBH065/2011 GII
LBM123/2011 GII
LBM122/2011 GII
LBM104/2011 GII
LBN159/2011 GII
LBH048/2011 GII
LBH075/2011 GII
LBH062/2011 GII
LBH077/2011 GII
LBN120/2011 GII
LBN111/2011 GII
LBH009/2011 GII
LBN047/2011 GII
LBN086/2011 GII
LBH089/2011 GII
LBH049/2011 GII
LBN131/2011 GII
JB-15/KOR/2008 GII.4 Apeldoorn 2008
LBR034/2011 GII
LBN095/2011 GII
LBN142/2011 GII
LBN185/2011 GII
LBM097/2011 GII
LBH066/2011 GII
LBN154/2011 GII
LBM109/2011 GII
Orange/NSW001P/2008/AUS GII.4 New Orleans 2009
Farmington Hills/2002/USA GII
Guangzhou/NVgz01/CHN GII.4 Asia 2003
Hunter504D/04O/AU GII.4 Hunter 2004
Kenepuru/NZ327/2006/NZL GII a
Osaka1/2007/JP GII.4 Osaka 2007
Yerseke38/2006/NL GII.4
Shellharbour-NSW696T/2006/AUS GII b
LBA147/2012 GII
Sydney/NSW0514/2012/AUS GII.4 Sydney 2012
LBA163/2013 GII
LBN516/2013 GII
LBNG112/2012 GII
LBR040/2011 GII
LBN365/2012 GII
LBN330/2012 GII
LBN323/2012 GII
2012/FRA GII.4 variant Sydney
LBA113/2012 GII
LBN384/2012 GII
LBN478/2012 GII
LBN382/2012 GII
LBN393/2012 GII
LBN328/2012 GII
LBH208/2012 GII
LBNG175/2013 GII
LBN458/2012 GII
LBH054/2011 GII
LBH068/2011 GII
LBH185/2012 GII
LBH203/2012 GII
LBN259/2011 GII
LBR081/2012 GII
LBN339/2012 GII
LBN374/2012 GII
LBA126/2012 GII
LBH186/2012 GII
0.005
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15. Conclusions: NoV in Lebanon
This is the first study assessing NoV infections in Lebanon.
Our results are compatible with globally reported ones where GII.4 contributes to the majority of viral gastroenteritis outbreaks ( Bull and White, 2011; Guo et al., 2009; Siebenga et al., 2007).
We report JB-15/KOR/2008 GII.4 Apeldoorn 2008-like variant strain circulating in 2011 among children less than 5 years.
Between 2012 and 2013, the Apeldoorn variant was replaced by a variant sharing homology with Sydney/ NSW0514/2012/AUS GII.4 Sydney 2012 and the Sydney 2012/FRA GII.4.
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16. Conclusions: NoV in Lebanon
NoV GII.6 incidence was the second predominant cause of gastroenteritis among hospitalized children in Lebanon, similar to what has been reported in several countries including Brazil, Japan, South Africa and Finland (Ferreira et al., 2012).
NoV GII.3 ranked third along with NoV GII.21 among our study participants; after GII.4 and GII.6, while it ranked second in other countries.
Reports show that NoV cases peak during the cold months in parts of Europe and North America with sporadic cases detected all year round as well as outbreaks during the summer time (Mounts et al., 2000; Rohayem, 2009; Thongprachum et al., 2015; Verhoef et al., 2008; Ahmed et al. 2013) .
Our data support a peak incidence in July; the seasonal pattern of NoV in Lebanon should be further investigated.
our data supports a peak incidence in July
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17. NoV in the Middle East and North Africa (MENA) Region
In the MENA region, NoV was detected in stool samples of 6-30% of hospitalized children under 5 years.
Only few studies further reported on the geno-subgroups.
3 reported GII.3 being more prevalent (Romani et al., 2012; Leshem et al., 2015; Muhsen et al., 2013; Kaplan et al., 2011).
Clear lack of data on the genetic relatedness and subtyping in the MENA .
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18. Conclusions
Variants of the NoV GII.4 lineage have been associated with 62 to 80% of NoV outbreaks worldwide (Donaldson et al., 2010; Siebenga et al., 2009).
NoV remains an understudied causative agent of acute gastroenteritis and not included in the Global Burden of Diseases (GBD) among the infectious agents causing gastroenteritis and diarrhea.
Thus there’s a lack of clinical diagnosis and reporting of NoV as an important cause of disease and further studies are needed to support intervention strategies.
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19. Acknowledgments Faculty of Health Sciences
Khalil Kreidieh
Rana Charide
Nour Rahal
Center for Infectious Diseases Research, Faculty of Medicine
Ghassan Dbaibo and team (Amjad Haidar)
Hassan Zaraket
Melhem, 2015