Search

Competing Interests: All authors have completed and submitted the International Committee of Medical Journal Editors form for disclosure of potential conflicts of interest. No potential conflicts of interest were disclosed.

Introduction: Each year, rabies causes approximately 59,000 deaths worldwide, including approximately two deaths in the United States. Before 1960, dogs were a common reservoir of rabies in the United States; however, increasingly, species of wildlife (e.g., bats, raccoons) are the main reservoirs. This report characterizes human rabies deaths, summarizes trends in rabies mortality, and highlights current rabies risks in the United States., Methods: Rabies trends in the United States during 1938-2018 were analyzed using national rabies surveillance data. Data from the Healthcare Cost and Utilization Project for 2006-2014 were used to estimate the number of postexposure prophylaxis (PEP) visits per 100,000 persons during 2017-2018. The Centers for Medicare & Medicaid Services' average sales price data were used to estimate PEP costs., Results: From 1960 to 2018, a total of 125 human rabies cases were reported in the United States; 36 (28%) were attributed to dog bites during international travel. Among the 89 infections acquired in the United States, 62 (70%) were attributed to bats. In 2018, approximately 55,000 persons sought PEP after contact with a potentially rabid animal., Conclusions and Comments: In the United States, wildlife rabies, especially in bats, continues to pose a risk to humans. Travelers also might be exposed to canine rabies in countries where the disease is still present; increased awareness of rabies while traveling abroad is needed. Vaccinating pets, avoiding contact with wildlife, and seeking medical care if one is bitten or scratched by an animal are the most effective ways to prevent rabies. Understanding the need for timely administration of PEP to prevent death is critical., Competing Interests: All authors have completed and submitted the ICMJE form for disclosure of potential conflicts of interest. No potential conflicts of interest were disclosed.

Overview: Rabies virus belongs to the genus Lyssavirus, together with European bat lyssaviruses 1 and 2. In clinical practice, rabies virus is easily inactivated by detergent-based disinfectants., Infection: Rabid animals are the only source of infection. Virus is shed in the saliva some days before the onset of clinical signs and transmitted through a bite or a scratch to the skin or mucous membranes. The average incubation period in cats is 2 months, but may vary from 2 weeks to several months, or even years., Disease Signs: Any unexplained aggressive behaviour or sudden behavioural change in cats must be considered suspicious. Two disease manifestations have been identified in cats: the furious and the dumb form. Death occurs after a clinical course of 1-10 days., Diagnosis: A definitive rabies diagnosis is obtained by post-mortem laboratory investigation. However, serological tests are used for post-vaccinal control, especially in the context of international movements., Disease Management: Post-exposure vaccination of cats depends on the national public health regulations, and is forbidden in many countries., Vaccination Recommendations: A single rabies vaccination induces a long-lasting immunity. Kittens should be vaccinated at 12-16 weeks of age to avoid interference from maternally derived antibodies and revaccinated 1 year later. Although some vaccines protect against virulent rabies virus challenge for 3 years or more, national or local legislation may call for annual boosters.

Human rabies is rare in the United States; however, an estimated 40,000 patients receive rabies postexposure prophylaxis each year. Misconceptions about the transmission of rabies are plentiful, particularly regarding bats. Most cases of human rabies caused by bat variants have no definitive history of animal bite. Three hypotheses are proposed and reviewed for the transmission of rabies from bats to human beings. They include nonbite transmission (including aerosol transmission), the alternate host hypothesis (an intermediate animal host that acquires rabies from a bat and then transmits rabies to human beings), and minimized or unrecognized bat bites. Nonbite transmission of rabies is very rare, and aerosol transmission has never been well documented in the natural environment. The known pathogenesis of rabies and available data suggest that all or nearly all cases of human rabies attributable to bats were transmitted by bat bites that were minimized or unrecognized by the patients.