Infections in travellers returning to the UK: a retrospective analysis (2015–2020)

• Published in: Journal of travel medicine Vol. 30; no. 2
• Main Authors: Warner, Jennifer C, Hatziioanou, Diane, Osborne, Jane C, Bailey, Daniel J, Brooks, Timothy J G, Semper, Amanda E
• Format: Journal Article
• Language: English
• Published: England Oxford University Press 05-04-2023
• Subjects: Adult; Chikungunya Fever - diagnosis; Data base management systems; Demographics; Demography; Dengue fever; Dengue virus; Fever; Health promotion; Humans; Infections; Laboratory information management systems; Leptospirosis; Medical diagnosis; Myalgia; Public health; Retrospective Studies; Risk factors; Travel; Travellers; United Kingdom; Vector-borne diseases; Zika Virus; Zika Virus Infection; United Kingdom; United Kingdom > UK; Infections; diagnostic; travellers; returning
• ISSN: 1195-1982; 1708-8305
• DOI: 10.1093/jtm/taad003

Abstract
Background
Every year, many thousands of travellers return to the United Kingdom (UK) from visits to other countries and some will become unwell due to infections acquired abroad. Many imported infections have similar clinical presentations, such as fever and myalgia, so diagnostic testing is an important tool to improve patient management and outcomes. The aim of this study was to examine the demographics, travel history, presenting symptoms and diagnostic outcomes of referrals to the UK’s specialist diagnostic Rare & Imported Pathogens Laboratory (RIPL) for the period 2015–2020.
Methods
Anonymised clinical and laboratory data were extracted from RIPL’s Laboratory Information Management System and cleaned prior to descriptive analysis of the data. Travel history data were mapped to one of eight world regions, whereas symptom data were categorised into presenting syndromes. Diagnostic data were categorised as either positive, equivocal or negative.
Results
During the period 2015–2020, RIPL received 73 951 samples from 53 432 patients suspected of having infections that are rare in the UK. The most common age group for unwell returning travellers was 30–39 years and the most commonly reported travel destination was Southern and SE Asia. Dengue virus was the most diagnosed infection overall, followed by chikungunya, Zika, leptospirosis and spotted fever group Rickettsia. Dengue virus was among the top three most frequent diagnoses for all world regions except Europe and represented 62.5% of all confirmed/probable diagnoses.
Conclusions
None of the top five infections diagnosed by RIPL in travellers are vaccine-preventable, therefore understanding traveller demographics, destination-specific risk factors and encouraging preventative behaviours is the best available strategy to reduce the number of returning travellers who become infected. Prompt referral of acute samples with a detailed travel history, including purpose of travel and activities undertaken as well as dates and destinations can be a valuable tool in designing public health interventions and diagnostic algorithms.