Norovirus acute gastroenteritis among US and European travellers to areas of moderate to high risk of travellers' diarrhoea: a prospective cohort study

Martin Alberer; Christine L Moe; Christoph Hatz; Kerstin Kling; Amy E Kirby; Lisa Lindsay; Hans Dieter Nothdurft; Margarita Riera-Montes; Robert Steffen; Thomas Verstraeten; Henry M Wu; Herbert L DuPont

doi:10.1093/jtm/taad051

Norovirus acute gastroenteritis among US and European travellers to areas of moderate to high risk of travellers' diarrhoea: a prospective cohort study

J Travel Med. 2023 Apr 19:taad051. doi: 10.1093/jtm/taad051. Online ahead of print.

Authors

Affiliations

¹ Division of Infectious Diseases and Tropical Medicine, University Hospital, LMU Munich, Munich, Germany.
² Hubert Department of Global Health, Rollins School of Public Health, Emory University, Atlanta, GA, USA.
³ Epidemiology, Biostatistics and Prevention Institute, WHO Collaborating Center for Travellers' Health, University of Zurich, Zurich, Switzerland.
⁴ Immunization Unit, Department of Infectious Disease Epidemiology, Robert Koch Institute, Berlin, Germany.
⁵ P95 Pharmacovigilance and Epidemiology Services, Leuven, Belgium.
⁶ Division of Epidemiology, Human Genetics & Environmental Sciences, University of Texas School of Public Health, Houston, TX, USA.
⁷ Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, GA, USA.
⁸ Kelsey Research Foundation, Houston, TX, USA.
⁹ University of Texas-Houston Health Science Center, School of Public Health, Center for Infectious Diseases, and McGovern Medical School, Department of Internal Medicine, Houston, TX, USA.

PMID: 37074164
DOI: 10.1093/jtm/taad051

Abstract

Background: Acute gastroenteritis (AGE) is a major medical condition for travellers worldwide, particularly travellers to low- and middle-income countries. Norovirus (NoV) is the most common cause of viral AGE in older children and adults, but data on prevalence and impact among travellers is limited.

Methods: Prospective, multi-site, observational cohort study conducted 2015-2017, among adult international travellers from the US and Europe to areas of moderate to high risk of travel-acquired AGE. Participants provided self-collected pre-travel stool samples and self-reported AGE symptoms while travelling. Post-travel stool samples were requested from symptomatic subjects and a sample of asymptomatic travellers within 14days of return. Samples were tested for NoV by RT-qPCR, genotyped if positive, and tested for other common enteric pathogens by Luminex xTAG GPP.

Results: Of the 1109 participants included, 437 (39.4%) developed AGE symptoms resulting in an overall AGE incidence of 24.7 per 100 person-weeks (95% CI: 22.4; 27.1). Twenty NoV-positive AGE cases (5.2% of those tested) were identified at an incidence of 1.1 per 100 person-weeks (95% CI: 0.7; 1.7). NoV-positive samples belonged mostly to genogroup GII (18, 85.7%); None of the 13 samples sequenced belonged to genotype GII.4. Clinical severity of AGE was higher for NoV-positive than for NoV-negative cases (mean modified Vesikari Score 6.8 vs 4.9) with more cases classified as severe or moderate (25% vs 6.8%). Eighty percent of NoV-positive participants (vs. 38.9% in NoV-negative) reported at least moderate impact on travel plans.

Conclusions: AGE is a prevalent disease among travellers with a small proportion associated with NoV. Post-travel stool sample collection timing might have influenced the low number of NoV cases detected; however, NoV infections resulted in high clinical severity and impact on travel plans. These results may contribute to targeted vaccine development and the design of future studies on NoV epidemiology.

Keywords: Epidemiology; e; genotype; impact; incidence; symptoms; travel plans; viral gastroenteritis; vomiting.