Guideline for the Prevention and Control of Norovirus Gastroenteritis Outbreaks in Healthcare Settings, 2011

Evidence Table Q1 - Person characteristics / Virus Characteristics

Author, Yr (Ref)	Study Design Quality	Study Objective	Population and Setting N	Results	Comments	Ref ID_Data extracted by
Tu ET, 2008 108	Descriptive study   3, 4	To describe the emergence of new GII.4 variants during the early 2006 epidemic period in Australia and New Zealand.	Fecal samples from gastroenteritis outbreaks in Australia and New Zealand in early 2006.   231 fecal samples were obtained from patients with acute gastroenteritis from Australia and New Zealand through the surveillance network between December 2005 through August 2006. 87 outbreaks.   N=186 sequenced samples.	Norovirus genotype (%) in outbreaks GII.2 (0.5%) GII.3 (9%) GII.4 (86%) GII.5 (0.5%) GII.12 (2%) GII.16 (2%)   Genotype (%) by Location New South Wales, Australia (n=119 sequenced strains) GII.4 2006a (57.1%) GII.4 2006b (17.6%) GII.4 US95/96 (13.4%) GII.4 Hunter (2.5%) GII.b/GII.3 (4.2%) GII.3 (1.7%) GII.4/GII.12 (2.5%) GII.2 (08%) Queensland, Australia (n=11) GII.b/GII.3 (45.5%) GII.3 (36.3%) GII.4 2006a (18.2%) Victoria, Australia (n=14) GII.4 2006a (100%) New Zealand (n=42) GII.4 2006a (73.8%) GII.4 Hunter (11.9%) GII.16 (7.1%) GII.b/GII.3 (2.4%) GII.5 (2.4%) GII.4/GII.12 (2.4%)   Two GII.4 variants identified: 2006a (61.8%) and 2006b (11.3%).	Fecal samples tested using RT-PCR.   Power and sample size not reported.	5120_IL
Mattner, F; 2006 57	Prospective controlled study   1,3,4,6,7	To characterize risk factors for the clinical complications of norovirus infections (e.g. vomiting, diarrhea, potassium decrease, creatinine increase, C-reactive protein increase)	All individuals working in or admitted to five wards (psychiatry, nephrology, gastroenterology, cardiology and trauma) at a university hospital in Germany in the period from the onset of clinical symptoms of the first patient until 2 days after the last patient became symptom free.   All patients and staff members who were affected with a sudden onset of diarrhea and/or vomiting were included as cases. Patients admitted with clinical signs were regarded as index cases, and patients admitted ≥48 hrs before developing clinical signs were regarded as nosocomial cases   84 patients (72 acquired infection nosocomially) and 79 staff members (60 nurses). 3 norovirus positive patients were excluded from risk factor analysis. N for risk factor analyses was 53 for all outcomes except C reactive protein increase (N=52)	Clinical features in patients (study duration 3 months) Diarrhea – 79/84; 95% Vomiting – 57/84; 68% Somnolence – 2/84; 2% Serum creatinine increase > 10% – 22/84; 26% Serum potassium decrease > 20% – 7/84; 8%   Comparisons of attack rates in patients and nurses (study duration 3 months) All results are attack rate (%) in patients vs. nurses; P value Psychaitry ward – 78 vs. 88; <0.01 Nephrology ward – 32% in the first period and 33% in the second period in patients. Data for nurses not given Gastroenterology – 27 vs. 90; <0.01 Cardiology – 42 vs. 44; 0.87 Trauma – 35 vs. 83; <0.01 Total – 38 vs. 76; <0.01   Risk factors for complications of norovirus (study duration 3 months)   VOMITING>1 DAY: Univariate analysis: All results OR; P value Age > 65 years – 1.84; 0.30 Male gender – 0.91; 1.00 Underlying cardiovascular disorders – 2.7; 0.13 Underlying gastrointestinal disorders – 0.34; 0.31 Underlying autoimmune disease – 0.81; 1.00 Underlying renal disorders – 0.95; 1.00 Renal transplant – 1.31; 0.75 Underlying malignancy – P value 0.18; OR not reported Underlying trauma – 1.14; 1.00 Immunosuppressive therapy – 0.92; 1.00 Community acquired norovirus – 2.36; 0.19   Multivariate analysis: All results OR (95% CI) Underlying cardiovascular disorders – 7.17(1.59-51.2) Community acquired norovirus – 5.54(1.04-42.8)   DIARRHEA>2 DAYS: Univariate analysis: All results OR; P value Age > 65 years – 3.58; 0.01 Male gender – 2.15; 0.12 Underlying cardiovascular disorders – 2.80; 0.15 Underlying gastrointestinal disorders – 0.22; 0.03 Underlying autoimmune disease – 4.67; 0.24 Underlying renal disorders – 1.77; 0.39 Renal transplant – 1.71; 0.54 Underlying malignancy – 0.07; 0.01 Underlying trauma – 0.27; 0.053 Immunosuppressive therapy – 1.29; 0.79 Community acquired norovirus – 3.09; 0.06   Multivariate analysis: All results OR (95% CI) Age > 65 years – 11.56(1.89-224.00) Underlying malignancy – 0.02(0.00-0.19) Underlying trauma – 0.05(0.00-0.55)   POTASSIUM DECREASE >20%: Univariate analysis: All results OR; P value Age > 65 years – 0.94; 1.00 Male gender – 0.90; 1.00 Underlying cardiovascular disorders – 5.17; 0.06 Underlying gastrointestinal disorders – 0.46; 0.67 Underlying autoimmune disease – 0.98; 1.00 Underlying renal disorders – 1.74; 0.71 Renal transplant – 3.91; 0.09 Underlying malignancy – P value 0.58; OR not reported Underlying trauma – P value 0.19; OR not reported Immunosuppressive therapy – 2.83; 0.25 Community acquired norovirus – 0.48; 0.68   Multivariate analysis: All results OR (95% CI) Underlying cardiovascular disorders – 17.10(2.17-403.00) Renal transplant – 13.02(1.63-281.00)   CREATININE INCREASE >10%: Univariate analysis: All results OR; P value Age > 65 years – 1.04; 1.00 Male gender – 1.79; 0.24 Underlying cardiovascular disorders – 0.60; 0.42 Underlying gastrointestinal disorders – 1.93; 0.36 Underlying autoimmune disease – 4.50; 0.12 Underlying renal disorders – 1.44; 0.59 Renal transplant – 3.53; 0.07 Underlying malignancy – 0.93; 1.00 Underlying trauma – 0.07; <0.01 Immunosuppressive therapy – 5.74; <0.01 Community acquired norovirus – 5.07; 0.01   Multivariate analysis: All results OR (95% CI) Immunosuppressive therapy – 5.67(1.78-20.1)   C REACTIVE PROTEIN >58 MG: Univariate analysis: All results OR; P value Age > 65 years – 0.81; 0.79 Male gender – 2.63; 0.11 Underlying cardiovascular disorders – 0.32; 0.06 Underlying gastrointestinal disorders – 1.54; 0.55 Underlying autoimmune disease – 3.71; 0.14 Underlying renal disorders – 2.13; 0.19 Renal transplant – 1.33; 0.76 Underlying malignancy – 2.96; 0.25 Underlying trauma – 0.23; 0.35 Immunosuppressive therapy – 3.38; 0.06 Community acquired norovirus – 2.30; 0.23   Multivariate analysis: All results OR (95% CI) Underlying malignancy – 9.07(1.17-193.00) Immunosuppressive therapy – 5.37(1.62-19.9)	Diarrhea was defined as three or more episodes of loose stools in a 24 hr period.   Cases were considered to be norovirus-positive if samples from at least two patients from the same ward were positive by norovirus-specific RTPCR.   Power and sample size not reported	358_RA
Adamson, WE; 2007 109	Descriptive study   3,4	To determine if the increased number of norovirus cases in Scotland during early 2006 was due to the emergence of a new norovirus variant	A representative number of norovirus cases from outbreaks in Scotland were analyzed at the West of Scotland Specialist Virology Centre laboratory   149 samples were GII genotype 4	Norovirus GII genotype 4 variants (study duration 19 months) 1/2005-2/2006 vs 3/2006-8/2006: 69/84 (82%) GII-4 v3 vs 61/77 (79%) GII-4 v4		011_IL
Gallimore, CI; 2004 110	Descriptive study   3,4	To determine if norovirus was present during a 2002 outbreak in a pediatric tertiary hospital and determine the strains in symptomatic vs. asymptomatic patients.	Staff and patients in a pediatric tertiary hospital during a norovirus outbreak in June-July 2002. 9 symptomatic (6 patients and 3 staff members).   9 asymptomatic (12 patients and 87 staff members). Point prevalence survey.	Norovirus strains Symptomatic vs. asymptomatic patients and staff– 9/9 (100%) GII-3a vs 27/99 (27%) GII-4.	Asymptomatic excretion of norovirus can occur. However, in this case, the strain did not cause nosocomial infection and may suggest either low level excretion or commensal carriage	673_IL

Next Table