Rabies post-exposure prophylaxis of overseas travelers in the international travel clinic of the national medical center from 2006 to 2012, Korea

Evaluation of potential rabies exposure among Japanese international travelers: A retrospective descriptive study

BACKGROUND

Although Japan has been a rabies-free country for >50 years, a few cases have been reported among people traveling abroad. This study aimed to investigate animal exposure among Japanese travelers using the Japanese Registry for Infectious Diseases from Abroad (J-RIDA).

METHOD

In this retrospective analysis, we examined Japanese overseas travelers with animal exposure, as included the J-RIDA database, reported from October 1, 2017, to October 31, 2019, with a focus on pre-exposure prophylaxis (PrEP) administration and the animals to which the patients were exposed.

RESULTS

Among the 322 cases included in the analysis, 19 (5.9%) patients received PrEP and 303 did not. The most common purpose of travel was a non-package tour (n = 175, 54.3%). Most trips (n = 213, 66.1%) were to a single country for <2 weeks. Most patients (n = 286, 87.9%) traveled to countries with a rabies risk. The majority of patients with and without PrEP were injured in rabies-risk countries [n = 270 (89.1%) for non-PrEP and n = 16 (84.2%) for PrEP]. Animals associated with injuries included dogs (55.0%), cats (25.5%), and monkeys (15.5%). Most patients were classified as World Health Organization Category II/III for contact with suspected rabid animals (39.5% and 44.1% for categories II and III, respectively) and had exposure within 5 days of travel. Southeast Asia (n = 180, 55.9%) was the most common region in which travelers were exposed to animals.

CONCLUSIONS

Japanese overseas travelers had contact with animals that could possibly transmit the rabies virus, even on short trips. Promoting pre-travel consultation and increasing awareness of the potential for rabies exposure are important for prevention of rabies among Japanese international travelers.

A broad-spectrum and highly potent human monoclonal antibody cocktail for rabies prophylaxis

Post-exposure prophylaxis (PEP) is highly effective in preventing disease progression of rabies when used in timely and appropriate manner. The key treatment for PEP is infiltration of rabies immune globulin (RIG) into lesion site after bite exposure, besides wound care and vaccination. Unfortunately, however, RIG is expensive and its supply is limited. Currently, several anti-rabies virus monoclonal antibody (mAb) products are under development as alternatives to RIG, and two recently received regulatory approval in India. In this study, fully human mAbs that recognize different rabies virus glycoprotein conformational antigenic site (II and III) were created from peripheral blood mononuclear cells of heathy vaccinated subjects. These mAbs neutralized a diverse range of lyssavirus types. As at least two anti-rabies virus mAbs are recommended for use in human PEP to ensure broad coverage against diverse lyssaviruses and to minimize possible escape variants, two most potent mAbs, NP-19-9 and 11B6, were selected to be used as cocktail treatment. These two mAbs were broadly reactive to different types of lyssaviruses isolates, and were shown to have no interference with each other. These results suggest that NP-19-9 and 11B6 are potent candidates to be used for PEP, suggesting further studies involving clinical studies in human.

Rabies exposure in travellers to Asia, the Middle East, Africa, South and Central America-a German Airport study

BACKGROUND

Rabies causes thousands of deaths worldwide and trips to rabies endemic countries are popular. Travellers are often uncertain whether pre-exposure prophylaxis (PrEP) is advisable since they find it difficult to estimate the exposure risk during travel and the availability of post-exposure prophylaxis in endemic regions. The aim of this study was to determine the potential rabies exposures in travellers and to assess their knowledge on rabies. Secondly, we explored the access to appropriate post-exposure medical care in respective countries.

METHODS

We conducted a cross-sectional study at Frankfurt Airport. Returning adult travellers arriving from Asia, the Middle East, Africa, South and Central America were invited to participate in this questionnaire-based study while waiting in the baggage claim area.

RESULTS

Over a one-month recruitment phase in March 2019, we enrolled 3066 travellers; 2929 were included in the analysis. The gender ratio was balanced; the median age was 42 years (range 18-83 years). Participants arrived from Asia (46%), Africa (29%), Central/South America (13%), the Middle East (8%) and the Caribbean (8%). Forty-five per cent sought pretravel advice and 22% received ≥2 injections of rabies PrEP. Travellers with pretravel advice from tropical medicine specialists reached significantly higher knowledge scores than others. We found that potential rabies exposure occurred in 2.0% (57/2915) of travellers with 31% (13/42) of the contacts being unprovoked; 19% (8/42) of the exposed sought medical care and 3/8 were adequately treated before returning to Germany. Risk factors for animal exposure were: male sex, young age, trips to Asia and a long stay abroad (>4 weeks).

CONCLUSIONS

A total of 2% of returning travellers (n = 2915) experienced a potential rabies exposure during their journey. A majority of the exposed individuals did not seek medical care; those seeking medical care were often treated inadequately. Rabies information must be emphasised during pretravel counselling and PrEP should be offered generously, especially to travellers with high exposure risks.

Rabies post-exposure prophylactic vaccination for returning travelers to Japan

BACKGROUND

Rabies post-exposure prophylaxis (PEP) in Japan is administered using 6 subcutaneous doses (on days 0, 3, 7, 14, 30, and 90), which is not in line with international recommendations of 4 or 5 intramuscular doses. For reducing dose frequency, we evaluate the immunogenicity of PEP with a regimen of 6 subcutaneous doses.

METHOD

This prospective single-center cross-sectional study was performed between September 2013 and December 2014. We included patients underwent rabies PEP by purified chick embryo-cultured rabies vaccine Kaketsuken (PCEC-K) at our clinic, and excluded patients with a history of pre-exposure prophylaxis or PEP using rabies immunoglobulin. The rabies virus-neutralizing antibody tests were performed at the first visit to our office (doses 1-4) and at the fifth and sixth doses.

RESULTS

Data were available for 43 of 59 enrolled patients. Thirty-two patients did not start PEP within 48 h after exposure to animals. The seroprotection rates (≥0.5 IU/mL) were 90.7% and 75.7%, at days 30 and 90, respectively. Despite receiving a fifth dose, 85.3% of the patients exhibited decreasing antibody titers during days 30-90 (p < 0.001).

CONCLUSIONS

The seroprotection rates of PCEC-K induced subcutaneously were insufficient to prevent rabies at day 30 and 90.

Rabies post-exposure prophylaxis started during or after travel: A GeoSentinel analysis

BACKGROUND

Recent studies demonstrate that rabies post-exposure prophylaxis (RPEP) in international travelers is suboptimal, with only 5-20% of travelers receiving rabies immune globulin (RIG) in the country of exposure when indicated. We hypothesized that travelers may not be receiving RIG appropriately, and practices may vary between countries. We aim to describe the characteristics of travelers who received RIG and/or RPEP during travel.

METHODOLOGY/PRINCIPAL FINDINGS

We conducted a multi-center review of international travelers exposed to potentially rabid animals, collecting information on RPEP administration. Travelers who started RPEP before (Group A) and at (Group B) presentation to a GeoSentinel clinic during September 2014-July 2017 were included. We included 920 travelers who started RPEP. About two-thirds of Group A travelers with an indication for rabies immunoglobulin (RIG) did not receive it. Travelers exposed in Indonesia were less likely to receive RIG in the country of exposure (relative risk: 0.30; 95% confidence interval: 0.12-0.73; P = 0.01). Travelers exposed in Thailand [Relative risk (RR) 1.38, 95% Confidence Interval (95% CI): 1.0-1.8; P = 0.02], Sri Lanka (RR 3.99, 95% CI: 3.99-11.9; P = 0.013), and the Philippines (RR 19.95, 95% CI: 2.5-157.2; P = 0.01), were more likely to receive RIG in the country of exposure.

CONCLUSIONS/SIGNIFICANCE

This analysis highlights gaps in early delivery of RIG to travelers and identifies specific countries where travelers may be more or less likely to receive RIG. More detailed country-level information helps inform risk education of international travelers regarding appropriate rabies prevention.

Application of recombinant adenoviruses expressing glycoprotein or nucleoprotein of rabies virus to Korean raccoon dogs

Purpose

A new rabies vaccine for animals, including raccoon dogs, in Korea is needed to eradicate rabies infection. In this study, we constructed two recombinant adenoviruses expressing the glycoprotein or nucleoprotein of the rabies virus (RABV). We then investigated the safety and immunogenicity of these strains in raccoon dogs, depending on inoculation route.

Materials and Methods

Recombinant adenoviruses expressing the glycoprotein (Ad-0910G) or nucleoprotein (Ad-0910N) of rabies were constructed in 293A cells using an adenoviral system. One-year-old raccoon dogs underwent intramuscular (IM) inoculation or oral administration of the recombinant Ad-0910G and Ad-0910N. Clinical symptoms were observed and virus-neutralizing antibodies (VNA) against RABV were measured at 0, 2, 4, and 6 weeks after the immunization. Raccoons were considered positive if VNA titers were ≥ 0.1 IU/mL.

Results

Raccoon dogs inoculated with the combined Ad-0910G and Ad-0910N virus via the IM route did not exhibit any clinical sign of rabies during the observation period. All raccoon dogs (n = 7) immunized IM had high VNA titers, ranging from 0.17 to 41.6 IU/mL at 2 weeks after inoculation, but 70% (7/10) of raccoon dogs administered viruses via the oral route responded by 6 weeks after administration against RABV.

Conclusion

Raccoon dogs inoculated with Ad-0910G and Ad-0910N viruses showed no adverse effects. Immunization with the combined Ad-0910G and Ad-0910N strains may play an important role in inducing VNA against RABV in raccoon dogs.

Prophylaxis of human hydrophobia in South Korea

Domestic human hydrophobia has not been reported since the one case of 2004 in South Korea, but still a few animal rabies occur persistently since the reemerging stage of rabies from 1993. The government has made efforts to control animal rabies in many aspects, but whether prophylactic strategy for human hydrophobia is performed adequately is in question. The rate of proper post-exposure prophylaxis for animal bite case in 'high-risk region' of rabies is very low with 20% between 2011 and 2013. The National Animal Bite Patient Surveillance targeting 'high-risk region' is missing out animal bite cases who visit directly to hospitals in 'suspect-risk region' of rabies. Little data seems to exist for pre-exposure prophylaxis of domestic hydrophobia. Danger of reoccurrence of human hydrophobia always remain in South Korea. The medical personnel needs to have greater interest on the matter and the government strengthen the management system.