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

Area of Science:

• Infectious Diseases
• Travel Medicine
• Public Health

Background:

• Many travellers returning to the UK develop infections acquired abroad.
• Imported infections often present with non-specific symptoms like fever and myalgia.
• Diagnostic testing is crucial for managing and improving outcomes for these patients.

Purpose of the Study:

• To analyze the demographics, travel history, symptoms, and diagnostic outcomes of referrals to the Rare & Imported Pathogens Laboratory (RIPL) in the UK.
• To understand the patterns of rare and imported infections in returning travellers between 2015 and 2020.

Main Methods:

• Anonymised clinical and laboratory data were extracted from RIPL's Laboratory Information Management System.
• Descriptive analysis was performed on patient demographics, travel history (mapped to world regions), and presenting symptoms.
• Diagnostic outcomes were categorized as positive, equivocal, or negative.

Main Results:

• RIPL received 73,951 samples from 53,432 patients between 2015-2020.
• The most common age group was 30-39 years, and Southern and SE Asia was the most frequent travel destination.
• Dengue virus was the most diagnosed infection (62.5% of confirmed/probable cases), followed by chikungunya, Zika, leptospirosis, and spotted fever group Rickettsia.

Conclusions:

• The most frequent imported infections are not vaccine-preventable, emphasizing the importance of understanding travel-related risks and promoting preventative behaviors.
• Prompt referral with detailed travel history aids public health interventions and diagnostic strategies for imported infections.
• Enhanced diagnostic algorithms and public health messaging are needed to mitigate the burden of imported infections in travellers.