Human rabies, a disease of the poor - also in travelers?

Delayed rabies post-exposure prophylaxis treatment among Dutch travellers during their stay abroad: a comprehensive analysis

BACKGROUND

After an animal-associated injury (AAI) in rabies-endemic regions, post-exposure prophylaxis (PEP) is needed to prevent infection.1,2 PEP consists of rabies vaccinations (RV) and in some cases also additional rabies immune globulins (RIG). Not always PEP medication, and RIG in particular, is accessible. Along with an increased number of exposure notifications among Dutch travellers, this might lead to treatment delay and thus to increased health risks. Until now, research mainly focused on factors associated with exposition, but none on which factors are associated with PEP delay. This study aimed to identify which general sample characteristics are associated with PEP delay while being abroad.

METHODS

A quantitative retrospective observational study was conducted. The study population consisted of insured Dutch international travellers who actively contacted their medical assistance company (2015-2019) because of an animal-associated injury (AAI) (N = 691). The association between general sample characteristics and delay of different PEP treatments was studied using survival analysis.

RESULTS

Travellers without pre-exposure prophylaxis (PrEP) had an increased hazard, and therefore a shorter delay, for receiving their first RV as compared to travellers with PrEP (HR:1.11, 95%CI:1.01-1.22). The travellers needing both RV and RIG had a decreased hazard, and therefore a longer delay, as compared to travellers only needing RV (HR:0.81, 95%CI:0.67-0.96). General sample characteristic associated with RIG administration delay was travel destination. Travellers to Central and South America, East Mediterranean and Europe had a decreased hazard, and therefore a longer delay, for receiving RIG treatments relative to travellers to South East Asia (HR:0.31, 95%CI:0.13-0.70; HR:0.34, 95%CI:0.19-0.61; HR:0.46, 95%CI:0.24-0.89; HR:0.48, 95%CI:0.12-0.81, respectively).

CONCLUSIONS

Our results suggest that the advice for PrEP should be given based on travel destination, as this was found to be the main factor for PEP delay, among travellers going to rabies-endemic countries.

Comparison of safety and immunogenicity of PVRV and PCECV immunized in patients with WHO category II animal exposure: a study based on different age groups

BACKGROUND

The aim of this study was to compare the safety and immunogenicity between purified vero cell rabies vaccine (PVRV) and purified chick embryo cell vaccine (PCECV) in patients with WHO category II animal exposure, especially in different age groups.

METHODOLOGY/PRINCIPAL FINDINGS

In one-year clinical observation after vaccination with PVRV or PCECV under Zagreb (2-1-1) or Essen (1-1-1-1-1) regimens, information collection for the demographic and adverse events (AEs) and rabies virus laboratory examination of neutralizing antibody (RVNA) titers were performed for all patients with WHO category II animal exposure in Wuhan city. The results showed no significant differences of safety and immunogenicity between PVRV and PCECV both in Zagreb and Essen regimens. However, when compared with other age groups, most systemic AEs (36/61) occurred in <5-year-old patients, and <5-year-old patients have significant lower RVNA titer and seroconversion rate (RVNA ≥0.5 IU/ml) at day 7 both in Zagreb and Essen regimens or PVRV and PCECV groups.

CONCLUSIONS

Our data showed that vaccination with PVRV is as safe and immunogenic as PCECV in patients of all age groups, but might be more popular for clinical use. When performing a vaccination with rabies vaccine in young children, the most optimal vaccine regimen should be selected.