Descriptive study of an imported case linked to an international ferry travel

e202607042

Abstract

BACKGROUND // Spain lost its measles elimination status in January 2026, entering a phase of reemergent transmission. Although overall vaccination coverage remains high, pockets of susceptibility persist and international mobility continues to play a key role in virus introduction and spread. This study described the management of an imported measles case detected on an international ferry and the associated contact tracing in Algeciras.

METHODS // We conducted a descriptive study following national and regional epidemiological surveillance and alert protocols. The index case was an unvaccinated
7-month-old infant from Morocco, confirmed by PCR. Contacts were defined as individuals exposed at home, in the paediatric emergency department, or during the sea voyage. A descriptive analysis was performed. As part of routine public health surveillance, the study did not require ethics committee approval or individual informed consent.

RESULTS // A total of twenty-three close contacts were identified. Six individuals received post-exposure prophylaxis, and two children had their second dose advanced. Delayed access to ferry passenger data hindered the identification of two close contacts; as an alternative, the shipping company issued a public health advisory. No secondary cases were reported after two incubation periods.

CONCLUSIONS // Rapid response, timely access to vaccination records, and interinstitutional coordination are critical to preventing onward transmission. This case highlights the importance of maintaining 24/7 epidemiological surveillance capacity, improving access to passenger data, and strengthening collaboration with international transport operators, particularly in the context of measles re-emergence in Spain and Europe.