Travel-related respiratory symptoms and infections in travellers (2000–22): a systematic review and meta-analysis

Abstract

Background: Respiratory tract infections (RTIs) are common in travellers due to the year-round or seasonal presence of respiratory pathogen and exposure to crowded environments during the itinerary. No study has systematically examined the burden of RTI infections among travellers. The aim of this systematic review and meta-analysis is to evaluate the prevalence of RTIs and symptoms suggestive of RTIs among travellers according to risk groups and/or geographic region, and to describe the spectrum of RTIs. Methods: The systematic review and meta-analysis was registered in PROSPERO (CRD42022311261). We searched Medline, Embase, Scopus, Cochrane Central, Web of Science, Science Direct, and preprint servers MedRxiv, BioRxiv, SSRN, and IEEE Xplore on February 1, 2022. Studies reporting RTIs or symptoms suggestive of RTIs in international travellers after January 1, 2000, were eligible. Data appraisal and extraction were performed by 2 authors, and proportional meta-analyses were used to obtain estimates of the prevalence of respiratory symptoms and RTIs in travellers and predefined risk groups. Findings: A total of 429 articles on travellers’ illness were included. Included studies reported 86 841 symptoms suggestive of RTIs and 807 632 confirmed RTIs. 78% of reported respiratory symptoms and 60% of RTIs with available location data were acquired at mass gatherings events. Cough was the most common symptom suggestive of respiratory infections, and the upper respiratory tract was the most common site for RTIs in travellers. The prevalence of RTIs and respiratory symptoms suggestive of RTIs were 10% [8%; 14%] and 37% [27%; 48%], respectively, among travellers. Reporting of RTIs in travellers denoted by publication output was found to correlate with global waves of new respiratory infections. Interpretation: This study demonstrates a high burden of RTIs among travellers and indicates that travellers RTIs reflect respiratory infection outbreaks. These findings have important implications for understanding and managing RTIs among travellers.

Pulmonary infections in the returning traveler

“…In the cited study, SARS-CoV detected during the 2002--2003 outbreak accounted for 2% of all confirmed respiratory viral infections in travelers [9 ▪▪ ]. In this outbreak, more than 8000 individuals in 29 countries were affected, with a fatality rate of around 10%.…”

“…The cause of respiratory infections in travelers appears to be similar to that of the local population [11]; in the previous review, in cases wherein a diagnosis was established based on molecular methods, the most common cause was viral (94%), followed by bacterial infections (6%), whereas fungal infections represented less than 1% [9 ▪▪ ].…”

“…Orthomyxoviridae were second in frequency (35%), with H1N1 (A/H1N1) being the most common influenza virus detected (22%; 8% of all detected viruses). Rhinovirus was the third most common virus detected accounting for nearly 4% of all detected viruses [9 ▪▪ ]. Other common vaccine preventable viruses such as measles have also been reported in travelers [12,13].…”

“…A study on travel-related infections in Europe from 1998 to 2018 showed that acute respiratory infections were the most common infectious diseases reported by travelers from the USA and Europe [8]. A systematic review of respiratory symptoms and confirmed chest infections in travelers conducted between 2000 and 2022 estimated a prevalence of respiratory symptoms in travelers of 37% (27–48%) [9 ▪▪ ] and this prevalence raised to 64% (51–75%) in the event of mass gatherings. Confirmed respiratory illness prevalence among travelers was estimated to be 10% (8–14%) [9 ▪▪ ] and the importance of seasonality in these infectious has been highlighted in previous studies [10].…”

“…In the recent systematic review of respiratory infections among travelers, Coronaviridae accounted for 54% of all detected viruses, and as data included the COVID-19 pandemic period, SARS-CoV-2 represented 95% of these [9 ▪▪ ]. Orthomyxoviridae were second in frequency (35%), with H1N1 (A/H1N1) being the most common influenza virus detected (22%; 8% of all detected viruses).…”