Systematic literature review and meta-analysis on preventing and controlling norovirus outbreaks on cruise ships, 1990 to 2020: calling for behaviour change strategies of travellers

Background Outbreaks of norovirus gastroenteritis aboard cruise ships may affect a large number of people, debilitate vulnerable travellers, disrupt vacations and cause economic losses to the cruise ship industry. Aim We aimed to identify risk factors for norovirus outbreaks on cruise ships and assess the effectiveness of prevention and control measures. Methods We conducted a systematic literature review searching PubMed and Scopus databases as well as grey literature for articles and reports describing norovirus outbreaks on cruise ships between 1990 and 2020. We also performed a meta-analysis of norovirus prevalence in passengers and crew members. Results Data from 45 outbreaks on 26 cruise ships from 1990 to 2020 were identified in 13 articles and five reports, with a weighted average of prevalence (attack rate) for passengers of 7% (95% confidence interval (CI): 5.00–9.00) and for crew of 2% (95% CI: 0.00–3.00). Person-to-person was the most frequent mode of transmission in 35 of the 45 outbreaks (in 14 the only mode and in 21 as part of multiple transmission routes). Having an ill cabin mate (OR = 38.70; 95% CI: 13.51–110.86) was the most common risk factor. Six outbreak investigations reported poor hygiene, while four reported satisfactory hygiene in the cruise setting. Behavioural risk factors among travellers were investigated in three of the 13 studies. Conclusions The findings indicate a need for behavioural interventions to improve personal hygiene, symptom reporting and compliance with isolation measures, and for reconsidering current isolation policies where symptomatic and healthy individuals are isolated in the same cabin.

This supplementary material is hosted by Eurosurveillance as supporting information alongside the article [A systematic literature review and meta-analysis on preventing and controlling norovirus outbreaks on cruise ships: calling for behaviour change strategies of travellers, 1990-2020], on behalf of the authors, who remain responsible for the accuracy and appropriateness of the content.The same standards for ethics, copyright, attributions and permissions as for the article apply.Supplements are not edited by Eurosurveillance and the journal is not responsible for the maintenance of any links or email addresses provided therein This supplementary material is hosted by Eurosurveillance as supporting information alongside the article [A systematic literature review and meta-analysis on preventing and controlling norovirus outbreaks on cruise ships: calling for behaviour change strategies of travellers, 1990-2020], on behalf of the authors, who remain responsible for the accuracy and appropriateness of the content.The same standards for ethics, copyright, attributions and permissions as for the article apply.Supplements are not edited by Eurosurveillance and the journal is not responsible for the maintenance of any links or email addresses provided therein Supplementary Figure S2: Funnel plot: Crew attack rates -6 -5 -4 -3 -2 1.0 0.8 0.6 0.4 0.2 0.0

Error
This supplementary material is hosted by Eurosurveillance as supporting information alongside the article [A systematic literature review and meta-analysis on preventing and controlling norovirus outbreaks on cruise ships: calling for behaviour change strategies of travellers, 1990-2020], on behalf of the authors, who remain responsible for the accuracy and appropriateness of the content.The same standards for ethics, copyright, attributions and permissions as for the article apply.Supplements are not edited by Eurosurveillance and the journal is not responsible for the maintenance of any links or email addresses provided therein This supplementary material is hosted by Eurosurveillance as supporting information alongside the article [A systematic literature review and meta-analysis on preventing and controlling norovirus outbreaks on cruise ships: calling for behaviour change strategies of travellers, 1990-2020], on behalf of the authors, who remain responsible for the accuracy and appropriateness of the content.The same standards for ethics, copyright, attributions and permissions as for the article apply.Supplements are not edited by Eurosurveillance and the journal is not responsible for the maintenance of any links or email addresses provided therein This supplementary material is hosted by Eurosurveillance as supporting information alongside the article [A systematic literature review and meta-analysis on preventing and controlling norovirus outbreaks on cruise ships: calling for behaviour change strategies of travellers, 1990-2020], on behalf of the authors, who remain responsible for the accuracy and appropriateness of the content.The same standards for ethics, copyright, attributions and permissions as for the article apply.Supplements are not edited by Eurosurveillance and the journal is not responsible for the maintenance of any links or email addresses provided therein

Weight
This supplementary material is hosted by Eurosurveillance as supporting information alongside the article [A systematic literature review and meta-analysis on preventing and controlling norovirus outbreaks on cruise ships: calling for behaviour change strategies of travellers, 1990-2020], on behalf of the authors, who remain responsible for the accuracy and appropriateness of the content.The same standards for ethics, copyright, attributions and permissions as for the article apply.Supplements are not edited by Eurosurveillance and the journal is not responsible for the maintenance of any links or email addresses provided therein

Random effects model
Heterogeneity:

Weight
This supplementary material is hosted by Eurosurveillance as supporting information alongside the article [A systematic literature review and meta-analysis on preventing and controlling norovirus outbreaks on cruise ships: calling for behaviour change strategies of travellers, 1990-2020], on behalf of the authors, who remain responsible for the accuracy and appropriateness of the content.The same standards for ethics, copyright, attributions and permissions as for the article apply.Supplements are not edited by Eurosurveillance and the journal is not responsible for the maintenance of any links or email addresses provided therein

Weight
This supplementary material is hosted by Eurosurveillance as supporting information alongside the article [A systematic literature review and meta-analysis on preventing and controlling norovirus outbreaks on cruise ships: calling for behaviour change strategies of travellers, 1990-2020], on behalf of the authors, who remain responsible for the accuracy and appropriateness of the content.The same standards for ethics, copyright, attributions and permissions as for the article apply.Supplements are not edited by Eurosurveillance and the journal is not responsible for the maintenance of any links or email addresses provided therein This supplementary material is hosted by Eurosurveillance as supporting information alongside the article [A systematic literature review and meta-analysis on preventing and controlling norovirus outbreaks on cruise ships: calling for behaviour change strategies of travellers, 1990-2020], on behalf of the authors, who remain responsible for the accuracy and appropriateness of the content.The same standards for ethics, copyright, attributions and permissions as for the article apply.Supplements are not edited by Eurosurveillance and the journal is not responsible for the maintenance of any links or email addresses provided therein This supplementary material is hosted by Eurosurveillance as supporting information alongside the article [A systematic literature review and meta-analysis on preventing and controlling norovirus outbreaks on cruise ships: calling for behaviour change strategies of travellers, 1990-2020], on behalf of the authors, who remain responsible for the accuracy and appropriateness of the content.The same standards for ethics, copyright, attributions and permissions as for the article apply.Supplements are not edited by Eurosurveillance and the journal is not responsible for the maintenance of any links or email addresses provided therein

Weight
This supplementary material is hosted by Eurosurveillance as supporting information alongside the article [A systematic literature review and meta-analysis on preventing and controlling norovirus outbreaks on cruise ships: calling for behaviour change strategies of travellers, 1990-2020], on behalf of the authors, who remain responsible for the accuracy and appropriateness of the content.The same standards for ethics, copyright, attributions and permissions as for the article apply.Supplements are not edited by Eurosurveillance and the journal is not responsible for the maintenance of any links or email addresses provided therein

Figure S3 :
Figure S3: Forest plot: Passenger attack rates with 95% confidence intervals, according to the cruise itinerary

Figure S4 :
Figure S4: Crew attack rates with 95% confidence intervals, according to the cruise itinerary

Figure S5 :
Figure S5: Forest plot: Subgroup analysis for passengers' risk factors, proportions with their corresponding 95% confidence intervals, associated with Norovirus gastroenteritis on cruise ships

Figure S6 :
Figure S6: Forest plot: Subgroup analysis for passengers' risk factors, proportions with their corresponding 95% confidence intervals, associated with Norovirus gastroenteritis on cruise ships

Figure S7 :
Figure S7: Forest plot: Subgroup analysis for crew members' risk factors, proportions with their corresponding 95% confidence intervals, associated with Norovirus gastroenteritis on cruise ships

Table S2
Results of subgroup analysis per cruise itineraries of proportion meta-analysis of passengers

Table S4
Results of subgroup analysis per risk factors of proportion meta-analysis of passengers

Table S5
Results of subgroup analysis per risk factors of proportion meta-analysis of crew members