Advanced

Incidence of Hospital Norovirus Outbreaks and Infections Using 2 Surveillance Methods in Sweden

Fraenkel, Carl Johan LU ; Inghammar, Malin LU ; Johansson, Hugo LU and Böttiger, Blenda LU (2017) In Infection Control & Hospital Epidemiology 38(1). p.96-102
Abstract

OBJECTIVE To evaluate 2 different methods of surveillance and to estimate the incidence of norovirus (NoV) outbreaks in hospitals. DESIGN Prospective observational study. SETTING All 194 hospital wards in southern Sweden during 2 winter seasons (2010-2012). METHODS Clinical surveillance based on outbreak reports of 2 or more clinical cases, with symptom onset within 5 days, was compared with laboratory surveillance based on positive NoV results among inpatients. At least 2 NoV positive patients sampled within 5 days at a ward defined a cluster. Outbreak reports including at least 1 NoV positive case and clusters including at least 1 NoV positive patient with 5 or more days from ward admission to sampling were defined as NoV outbreaks.... (More)

OBJECTIVE To evaluate 2 different methods of surveillance and to estimate the incidence of norovirus (NoV) outbreaks in hospitals. DESIGN Prospective observational study. SETTING All 194 hospital wards in southern Sweden during 2 winter seasons (2010-2012). METHODS Clinical surveillance based on outbreak reports of 2 or more clinical cases, with symptom onset within 5 days, was compared with laboratory surveillance based on positive NoV results among inpatients. At least 2 NoV positive patients sampled within 5 days at a ward defined a cluster. Outbreak reports including at least 1 NoV positive case and clusters including at least 1 NoV positive patient with 5 or more days from ward admission to sampling were defined as NoV outbreaks. RESULTS During the study periods 135 NoV outbreaks were identified; 74 were identified by both clinical and laboratory surveillance, 18 were identified only by outbreak reports, and 43 were identified only by laboratory surveillance. The outbreak incidence was 1.0 (95% CI, 0.8-1.2) and 0.5 (95% CI, 0.3-0.6) per 1,000 admissions for the 2 different seasons, respectively. To correctly identify NoV outbreaks, the sensitivity and positive predictive value of the clinical surveillance were 68% and 88% and of the laboratory surveillance were 86% and 81%, respectively. CONCLUSION The addition of laboratory surveillance significantly improves outbreak surveillance and provides a more complete estimate of NoV outbreaks in hospitals. Laboratory surveillance can be recommended for evaluation of clinical surveillance.

(Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Infection Control & Hospital Epidemiology
volume
38
issue
1
pages
7 pages
publisher
University of Chicago Press
external identifiers
  • scopus:85008707901
  • wos:000391243000015
ISSN
0899-823X
DOI
10.1017/ice.2016.237
language
English
LU publication?
yes
id
9b72d65e-9b2a-4d23-af18-759a0f5f6d91
date added to LUP
2017-02-01 15:00:37
date last changed
2018-01-07 11:47:38
@article{9b72d65e-9b2a-4d23-af18-759a0f5f6d91,
  abstract     = {<p>OBJECTIVE To evaluate 2 different methods of surveillance and to estimate the incidence of norovirus (NoV) outbreaks in hospitals. DESIGN Prospective observational study. SETTING All 194 hospital wards in southern Sweden during 2 winter seasons (2010-2012). METHODS Clinical surveillance based on outbreak reports of 2 or more clinical cases, with symptom onset within 5 days, was compared with laboratory surveillance based on positive NoV results among inpatients. At least 2 NoV positive patients sampled within 5 days at a ward defined a cluster. Outbreak reports including at least 1 NoV positive case and clusters including at least 1 NoV positive patient with 5 or more days from ward admission to sampling were defined as NoV outbreaks. RESULTS During the study periods 135 NoV outbreaks were identified; 74 were identified by both clinical and laboratory surveillance, 18 were identified only by outbreak reports, and 43 were identified only by laboratory surveillance. The outbreak incidence was 1.0 (95% CI, 0.8-1.2) and 0.5 (95% CI, 0.3-0.6) per 1,000 admissions for the 2 different seasons, respectively. To correctly identify NoV outbreaks, the sensitivity and positive predictive value of the clinical surveillance were 68% and 88% and of the laboratory surveillance were 86% and 81%, respectively. CONCLUSION The addition of laboratory surveillance significantly improves outbreak surveillance and provides a more complete estimate of NoV outbreaks in hospitals. Laboratory surveillance can be recommended for evaluation of clinical surveillance.</p>},
  author       = {Fraenkel, Carl Johan and Inghammar, Malin and Johansson, Hugo and Böttiger, Blenda},
  issn         = {0899-823X},
  language     = {eng},
  month        = {01},
  number       = {1},
  pages        = {96--102},
  publisher    = {University of Chicago Press},
  series       = {Infection Control & Hospital Epidemiology},
  title        = {Incidence of Hospital Norovirus Outbreaks and Infections Using 2 Surveillance Methods in Sweden},
  url          = {http://dx.doi.org/10.1017/ice.2016.237},
  volume       = {38},
  year         = {2017},
}