Rabies post-exposure prophylaxis of international travellers - Results from two major German travel clinics

Rabies exposure in international travellers: Experience from a single travel clinic in Paris, France, 2018-2022

BACKGROUND

Rabies is a vaccine-preventable zoonotic disease which causes thousands of deaths every year, mainly in Asia and Africa, and dogs are the main source of human cases. Although rabies is rare in international travellers, rabies exposure is relatively frequent and the number of travellers seeking post-exposure treatment may rise as international travel continues to increase. We aimed to better understand the characteristics of travellers exposed to rabies abroad, in order to deliver targeted advice and rabies vaccination during pre-travel clinics.

METHODS

During 2018-2022, we studied all returning travellers who attended a single travel clinic in Paris, France, for animal exposures abroad and requiring rabies post-exposure prophylaxis (n = 2916).

RESULTS

During the study period, 2916 returning travellers were included, and 59.7 % of exposures occurred in Southeast Asia (mainly Thailand and Indonesia) and North-Africa. Dogs were predominantly responsible for exposures, but the animals involved varied significantly according to the region visited and the age of the traveller. Monkey exposures were more frequently reported in Asia, and cat exposures in North Africa and among children. Exposures were reported as unprovoked in 22.9 % of cases, and 91 % of travellers had not received anti-rabies vaccines before travelling.

CONCLUSIONS

Travellers to rabies endemic countries should benefit from more targeted information based on the region visited, the animals they are likely to encounter, and the age of the travellers. Critically, they should be counselled on the importance of avoiding contact with animals, the long-lasting benefit of pre-travel rabies vaccination, and the need for adequate post-exposure prophylaxis.

The Deadly Details: How Clear and Complete Are Publicly Available Sources of Human Rabies Information?

Human rabies is preventable but almost always fatal once symptoms appear, causing 59,000 global deaths each year. Limited awareness and inconsistent access to post-exposure prophylaxis hinder prevention efforts. To identify gaps and opportunities for improvement in online rabies information, we assessed the readability, understandability, actionability, and completeness of online public rabies resources from government and health agencies in Australia and similar countries, with the aim of identifying gaps and opportunities for improvement. We identified materials via Google and public health agency websites, assessing readability using the Simple Measure of Gobbledygook (SMOG) index and understandability and actionability with the Patient Education Materials Tool for Print materials (PEMAT-P). Completeness was assessed using a framework focused on general and vaccine-specific rabies information. An analysis of 22 resources found a median readability of grade 13 (range: 10-15), with a mean understandability of 66% and mean actionability of 60%; both below recommended thresholds. Mean completeness was 79% for general rabies information and 36% for vaccine-specific information. Visual aids were under-utilised, and critical vaccine-specific information was often lacking. These findings highlight significant barriers in rabies information for the public, with most resources requiring a high literacy level and lacking adequate understandability and actionability. Improving readability, adding visual aids, and enhancing vaccine-related content could improve accessibility and support wider prevention efforts.

Rabies post-exposure prophylaxis: A retrospective analysis of timing of initiation and antibody responses in a Belgian cohort

BACKGROUND

We aimed to determine the timeliness of rabies post-exposure prophylaxis (PEP) and the proportion of individuals with an adequate antibody response post-PEP among those attending the Belgian national reference center.

METHODS

Retrospective analysis of patient records who attended our center from 2018 to 2023. Delay was defined as rabies immunoglobulin (RIG) and vaccine initiation beyond 2 calendar days after exposure. Antibodies were measured by rapid fluorescent focus inhibition test (RFFIT) after PEP in high-risk exposures. A titer ≥0.5 IU/ml was considered adequate.

RESULTS

We reviewed 317 patient records. Among individuals with inland exposure (n = 103), 85 % timely received PEP. Among travelers exposed abroad (n = 214), administration of RIG and vaccine initiation were timely in 30 % and 50 % of cases, respectively. An adequate antibody response was detected in 99.5 % (195/196) individuals.

CONCLUSION

Substantial PEP delays among travelers were observed. The robust antibody responses suggest that routine serological follow-up is not necessary for all patients.

Rabies post-exposure prophylaxis in the emergency department: A monocentric retrospective observational study

BACKGROUND

Emergency departments (ED) are frequently visited after suspected rabies exposure (SRE) and the potential need for rabies post-exposure prophylaxis (R-PEP). However, data on the number of visits, patients' demographics, travel history and the medical treatment is still rare. Therefore, the aim of this study was to assess the number of R-PEP and the appropriateness of medical management including wound treatment, vaccination regime and immunoglobulin application following SRE in a university hospital ED.

METHOD

We conducted a monocentric retrospective observational study on emergency patients treated in the ED of the LMU University Hospital, Ludwig-Maximilians-University Munich, Germany, between June 1st, 2023 and January 31st, 2024. Patients requiring post-exposure prophylaxis due to SRE abroad or in Germany were included. Demographic data, travel history, clinical findings, wound treatment, and R-PEP vaccination regimen were recorded.

RESULTS

During the observation period of 245 days 43 patients presented to our ED for R-PEP. There was a total of 51 presentation appointments, as 5 patients returned for further treatment. Most patients (27, 52.9 %) presented at the ED on a Saturday, Sunday, or a public holiday. 17 (39.5 %) patients had a category II exposure, and 26 (60.5 %) had a category III exposure. In our ED, there were 28 (55.0 %) active vaccinations and 23 (45.0 %) both active and passive vaccinations.

CONCLUSIONS

Our data show that patients frequently present for R-PEP in ED. Therefore, there is a high need for education on indication for R-PEP and for implementation of precise R-PEP treatment guidelines in daily clinical practice.

Influencing factors and prediction of neutralizing antibodies in post-exposure rabies vaccine recipients

To assess the factors that influencing the persistence of virus neutralizing antibody (VNA), and to establish prediction models to provide the appropriate timing for booster administration, a cohort of post-exposure rabies vaccine recipients was investigated. The VNA determined records from 2019 to 2023 and interrelated factors were analyzed, including gender, age, rabies immunoglobulin (RIG) administration, vaccine products, vaccination schedule, and vaccination intervals etc. The geometric mean of VNA titre within 1 month after primary vaccination with 2-1-1 schedule was statistically higher than that with 5-dose course (P = 0.031). The interaction between exposure and vaccination schedule was observed on primary vaccination, which showed that a decrease of 19.74 % (95 % CI: 5.99%-64.95 %, P = 0.008) of VNA titre among vaccinee with 5-dose and exposure III. Individuals with RIG administration produced lower VNA titres than those without RIG administration (P = 0.001). Vaccine products (Chengda, P = 0.015; human diploid cell, P = 0.026) and re-exposed time (P = 0.000) exhibited independent effects following booster vaccination. Based on the prediction model, the 99 % individual prediction intervals (IPI) of VNA titres were established at 3, 6, 12 and 18 months for the 12 characteristic populations respectively. The cases of VNA below 0.5 IU/ml first appeared at 6 months in group D of primary vaccinations and at 10 years in group F of boosters. We conclude that for primary vaccination 2-1-1 schedule is more efficient than 5-dose; the use of residual rabies immunoglobulin for distal intramuscular injection isn't recommended. The 99 % IPI of VNA titres could provide the appropriate timing for booster vaccination.

Rabies knowledge gaps and risk behaviour in Dutch travellers: An observational cohort study

BACKGROUND

Travellers visiting rabies-endemic countries are at risk of rabies infection. Assessing travellers' knowledge and risk perception of rabies and risk behaviour during travel can help identify knowledge gaps and improve pre-travel risk education.

METHODS

Cohort study in Dutch adult travellers, using two surveys: one before travel to assess knowledge and perception of rabies, and one after return to identify risk behaviour during travel.

RESULTS

The pre-travel and post-travel survey were completed by 301 and 276 participants, respectively. 222 participants had travelled to a high-risk rabies-endemic country. 21.6 % of the participants scored their rabies knowledge as poor. Some participants were unaware cats or bats can transmit rabies (26.6 % and 13.6 %, respectively), or that post-exposure prophylaxis (PEP) is required for certain exposures such as skin abrasions without bleeding or licks on damaged skin (35.5 % and 18.9 %, respectively), while 27.9 % of participants did not know PEP needs to be administered within one day. 115 participants (51.8 %) reported any form of contact with any animal during travel. Two participants reported animal exposure, of which one took adequate PEP measures. Risk factors for animal contact abroad were regularly touching cats or dogs at home or abroad, longer travel duration, having pets during childhood and being an animal lover.

CONCLUSIONS

Pre-travel rabies risk education currently does not meet travellers' needs, which is reflected in knowledge gaps and engagement in risk behaviour during travel. During pre-travel health advice, avoiding animal contact abroad should be emphasized, and additional education is required about indications for PEP.

Real-world evidence of rabies post-exposure prophylaxis in Serbia: Nation-wide observational study (2017-2019)

BACKGROUND

Rabies remains a deadly zoonotic disease, primarily prevalent in Eastern European countries, with a significant global burden in Asia and Africa. Post-exposure prophylaxis (PEP) is critical to prevent clinical rabies. Serbia, a country with a relatively low animal rabies incidence, has been implementing a 4-dose Essen PEP regimen for 13 years. This real-world study aimed to assess the effectiveness of the 4-dose Essen regimen, considering demographic and clinical factors, after WHO Category III exposure.

METHOD

The study included 601 patients who received the 4-dose Essen PEP and 79 who received an additional 5th dose.

RESULTS

Age emerged as a critical factor influencing seroconversion rates after the 4-dose regimen, with older individuals exhibiting lower RVNA titers. Logistic regression indicated a 3.18% decrease in seroconversion odds for each added year of age. The Cox proportional hazards mixed model highlighted age-related risks, with age groups 45-60 and 75-92 at the highest risk of non-seroconversion. Human Rabies Immune Globulin (HRIG) administration was associated with lower RVNA values after the 4-dose regimen, suggesting interference with vaccine immunogenicity among people who received larger doses of HRIG.

CONCLUSIONS

This study provides valuable real-world evidence for rabies PEP in a non-homogeneous population with potential comorbidities. The results underscore the importance of optimizing PEP strategies, particularly in older individuals, and reconsidering HRIG dosing to improve seroconversion rates.