Rabies antibody seroprotection rates among travelers in Nepal: "rabies seroprotection in travelers"

Guidelines for the prevention of travel-associated illness in older adults

International travel to the developing world is becoming more common in elderly patients (defined here as individuals greater than 65 years old). When providing pre-travel counseling, providers must appreciate the changing physiology, comorbidities, immunity and pharmacokinetics associated with the aging process to prepare elderly patients for the stressors of international travel. These guidelines present an evidence-based approach to pre-travel counseling, immunization, and pharmacology concerns unique to elderly patients seeking care in a travel clinic setting.

Epidemiology, Impact and Control of Rabies in Nepal: A Systematic Review

Background

Rabies is a vaccine-preventable viral zoonosis belonging to the group of neglected tropical diseases. Exposure to a rabid animal may result in a fatal acute encephalitis if effective post-exposure prophylaxis is not provided. Rabies occurs worldwide, but its burden is disproportionately high in developing countries, including Nepal. We aimed to summarize current knowledge on the epidemiology, impact and control of rabies in Nepal.

Methods

We performed a systematic review of international and national scientific literature and searched grey literature through the World Health Organization Digital Library and the library of the National Zoonoses and Food Hygiene Research Centre, Nepal, and through searching Google and Google Scholar. Further data on animal and human rabies were obtained from the relevant Nepalese government agencies. Finally, we surveyed the archives of a Nepalese daily to obtain qualitative information on rabies in Nepal.

Findings

So far, only little original research has been conducted on the epidemiology and impact of rabies in Nepal. Per year, rabies is reported to kill about 100 livestock and 10–100 humans, while about 1,000 livestock and 35,000 humans are reported to receive rabies post-exposure prophylaxis. However, these estimates are very likely to be serious underestimations of the true rabies burden. Significant progress has been made in the production of cell culture-based anti-rabies vaccine and rabies immunoglobulin, but availability and supply remain a matter of concern, especially in remote areas. Different state and non-state actors have initiated rabies control activities over the years, but efforts typically remained focalized, of short duration and not harmonized. Communication and coordination between veterinary and human health authorities is limited at present, further complicating rabies control in Nepal. Important research gaps include the reporting biases for both human and animal rabies, the ecology of stray dog populations and the true contribution of the sylvatic cycle.

Interpretation

Better data are needed to unravel the true burden of animal and human rabies. More collaboration, both within the country and within the region, is needed to control rabies. To achieve these goals, high level political commitment is essential. We therefore propose to make rabies the model zoonosis for successful control in Nepal.

Rabies has been known as a deadly disease in Nepal for decades, but information on epidemiology, impact and control remains scattered. We collected and summarized information from a variety of sources, including scientific literature and government agencies. Only little original research has been conducted on the epidemiology and impact of rabies in Nepal, leaving many questions unanswered. Official reports show that each year 100 livestock and 10–100 humans die of rabies, but these numbers very likely underestimate the true rabies burden. Availability and supply of anti-rabies vaccines have remained suboptimal and rabies control activities have been hampered by a lack of collaboration and comprehensiveness. High level political commitment is essential to overcome these problems and to reduce the burden of rabies. We therefore propose to make rabies the model zoonosis for successful control in Nepal.

Immunogenicity and feasibility of intradermal vaccination against rabies in Quebec

OBJECTIVES

Preexposure vaccination against rabies is recommended for some travellers and individuals exposed to the virus through their work. At a cost of at least $150 per intramuscular (IM) dose, few follow this recommendation. In Canada, provided certain conditions are met, the National Advisory Committee on Immunization (NACI) and the Comité d'immunisation du Québec allow a more economical alternative, intradermal vaccine administration (ID) which uses 1/10 the IM dose. The purpose of this study is to assess the feasibility and immunogenicity of intradermal preexposure vaccination.

METHODS

Students and employees at the Faculty of Veterinary Medicine received three doses of ImovaxRage™ (Sanofi Pasteur) inactivated, human diploid cell rabies vaccine at days 0, 7 and 21 or 28. An IM or ID booster dose was administered after two years when indicated.

OUTCOMES

Among the 159 participants who received three doses, 139 underwent serological testing in the year following vaccination and all achieved protective antibody levels. The antibody level was higher when measured within five weeks of the third dose. When the serological control was performed two years later, 65% of participants had a <0.5 IU/ml titre. Of the 22/30 participants who chose an ID booster, 100% responded and the average antibody titres were multiplied by 11, indicating a strong anamnestic response.

DISCUSSION

ID rabies vaccination is immunogenic, economic and could be considered for the booster dose. Protective antibodies decline rapidly after primary immunization by ID, so it would seem prudent to perform a serological control one year later on individuals at high risk of occult occupational exposure. An alternative would be to give these individuals a routine ID booster dose one year after primary vaccination, which would simplify initial treatment and reduce related costs (follow-up, blood sampling, serological tests, etc.). The persistence of protective antibodies after this booster dose should be assessed to determine the need for subsequent serological tests and the ideal interval between tests.

Knowledge, attitudes, and practices of French travelers from Marseille regarding rabies risk and prevention

OBJECTIVE

To assess the awareness of the mode of rabies transmission, travel-associated rabies risk, and adequate preventive measures among French travelers.

METHODS

Three hundred travelers were administered a detailed questionnaire prior to pretravel advice, addressing their knowledge, attitudes, and practices (KAP) with respect to animal-related injuries and rabies risk. Two hundred and nine were administered a post-travel questionnaire by telephone, addressing the occurrence of contacts with animals during travel.

RESULTS

Countries visited were at risk for rabies in 84.7% of the cases. Only 6.7% of travelers knew that the risk of rabies was important, while 40.1% considered it moderate or low. Dog bites appeared to be a well-known mode of transmission of rabies. By contrast, licks on broken skin or contamination of the mucous membrane with saliva (10%) and scratches (0.7%) were rarely known. Cats (23.7%), foxes (28.3%), monkeys (10.3%), and bats (5.0%) were rarely mentioned as possible rabies vectors. Only 50.7% of travelers were aware of the preventive vaccination. Approximately 57.6% of individuals traveling to rabies-endemic countries presented to the clinic less than 21 days before departing, rendering a complete preventive vaccination against rabies unfeasible. Immediate washing of the injury with water and soap was mentioned by only 3.0% of individuals and self-disinfection with antiseptics by 21.3%. Of those who traveled in a rabies-risk country, 3.8% declared that they had been attacked by animals; however, none was injured. Animal encounters were frequent with dogs (53.8%), monkeys (39.5%), bats (17.9%), and cats (15.4%).

CONCLUSIONS

The KAP of French travelers with regard to travel-associated rabies risk need to be improved, particularly regarding the prevention of animal bites, postbite measures, and their urgency.

Travel Recommendations for Older Adults

Older age is an important factor in preparing travelers owing not only to physiologic changes and the increased probability of underlying medical conditions and prescription medications but also to immune status with regard to naturally acquired immunity versus immunization for vaccine-preventable diseases. Cardiovascular events (including myocardial infarctions and cerebrovascular accidents) account for most deaths abroad, followed by injuries. To plan for healthy travel, international travelers should be advised to seek care at least 4 to 6 weeks before departure. Travel medicine is a dynamic field because conditions worldwide are subject to rapid change. Clinicians must maintain a current base of knowledge if they will be regularly advising travelers or must set a threshold for referral to a travel medicine specialist.