Introduction:
Vectors onboard passenger ships can impact travellers’ health, while ships can facilitate vector spread across borders. This systematic review aimed to understand risk factors, transmission dynamics and effectiveness of measures for vector-borne infection on passenger ships.

Methods:
Conducted according to PRISMA 2020, peer-reviewed articles reporting infectious disease events in human travellers linked to passenger ships and seaports worldwide were eligible. Vector-borne events were defined as: malaria/zika/other described as a case, cluster or outbreak. Articles had to describe infection frequency with at least one case laboratory-confirmed. PubMed, Scopus and Cochrane Library were searched from January 2000 – March 2023.

Results:
We identified a case report, cross-sectional study and randomized trial describing Israeli spotted fever (ISF), malaria and other tick-borne illnesses (TBIs) (Lyme disease, Babesiosis, Ehrlichiosis), respectively^1-3. Two publications related to ferry travel with African and North American itineraries^2,3, and one to Mediterranean cruise travel¹. The presumed risk factor in one study was time ashore during cruise excursions, with an ISF case likely infected spending time in Libya1. Another study reported spending time on mainland Equatorial Guinea as a risk factor for malaria, with prevalence higher among ferry passengers travelling from mainland to island². Strength of evidence was low for both studies. A TBI educational intervention among ferry passengers was reported as a somewhat successful prevention measure, with estimated TBI risk among longer-term visitors in the intervention group 43% that of the control group³.

Conclusions:
There was no published evidence that vector-borne infection may be acquired onboard passenger ships; however, there was evidence infection could be acquired during ashore activities before/during travel. Results indicate the role that ferry transport in particular can play in importation of vector-borne pathogens to geographic areas. Based on voyage profiles, risk communication and educational interventions promoting prevention behaviors could be delivered before embarkation or during the journey.