Risk factors for delayed post-exposure prophylaxis among Japanese travelers with animal bite exposure: A multicenter retrospective study

Abstract

Introduction: Rabies is a fatal zoonotic disease; however, no comprehensive studies have been conducted on rabies prevention among Japanese travelers with animal exposure providing detailed information on pre-travel consultation, pre-exposure prophylaxis (PrEP), rabies immunoglobulin administration, and post-exposure prophylaxis (PEP). Therefore, this study aimed to assess the risk factors of delayed PEP among Japanese travelers exposed to animal bites.

Materials and methods: This multicenter retrospective study evaluated patients who underwent PEP in Japan between January 2018 and December 2024.

Results: Among 508 patients, 303 (60%) received PEP within 24 h. Delayed PEP was associated with female sex, age 20-59 years, destination in Europe, Category II exposure, prior PrEP, and pre-travel consultation. Subsequent analyses revealed that female sex, category II exposure, and prior PrEP use were independent predictors of delayed PEP. Sensitivity analyses using delayed PEP thresholds of >24 h, >48 h, and >72 h showed highly stable patterns across demographic, travel, and exposure factors. Female sex, category II exposure, and PrEP consistently predicted delays, while backpacking was associated with delays >48 h. Other variables showed minimal fluctuations.

Conclusions: A considerable proportion of patients received delayed PEP. Additionally, female sex, category II exposure, and prior PrEP were identified as the key determinants of delayed PEP. These findings underscore the need for targeted strategies to enhance compliance with rabies prophylaxis among Japanese travelers.

Keywords: Delayed PEP; Rabies post-exposure prophylaxis; Rabies pre-exposure prophylaxis.