In addition to bat rabies cases, international travel-related rabies cases occur because of a lack of awareness about the ongoing global risk of rabies in dogs.
Efforts to control rabies in wildlife and maintain canine rabies elimination in the United States require ongoing, high-quality rabies surveillance and timely response capabilities. Rabies continues to be a priority zoonotic disease for One Health collaboration 17 , requiring multi-agency cooperation to ensure continued success of the U. Currently, U. Whereas canine rabies vaccination is required throughout the United States, animal registration and rabies vaccination laws vary by county, making it difficult to estimate the current rabies vaccination coverage rates among dogs in the United States.
In addition, recent antivaccination sentiments have been documented in owners reluctant to vaccinate their dogs against diseases Failure to vaccinate dogs against rabies could constitute a considerable public health threat to both humans and animals. The findings in this report are subject to three limitations. First, although rabies is a notifiable disease for both humans and animals, data on PEP use among persons seeking care for a potential exposure are limited and rely on emergency department data, some of which may be incomplete.
Finally, rabies prevention and control costs have a high degree of variability. For example, costs for public health emergency responses can vary considerably between states depending on the number and type of animals and humans involved. As the human urban environment encroaches into wildlife settings, human rabies exposures continue to occur. Although human rabies is now a rare disease in the United States, it remains one with extremely high consequences.
A critical component of rabies prevention in the United States is to avoid contact with wildlife, especially bats. Contact with a bat includes bites and scratches, which are often small and can be overlooked. Contact might also occur unknowingly if a bat is present in a room with a young child or mentally impaired person, including a child or person under the influence of medication, drugs, or alcohol or a person who is asleep.
In those cases where unrecognized contact might have occurred, persons should assume they have a potential exposure to rabies if the bat is not available for testing and urgently seek care from their medical provider. If the bat can be safely collected and tested, this can inform the need for PEP. Although the risk of travel-associated rabies infection is generally low, travelers should know the risk, avoid contact with animals, have a plan to get care if they are scratched or bitten, and have travel health insurance to pay for treatment should they need it.
Travelers at higher risk i. Corresponding author: Emily G. Pieracci, EPieracci cdc. Department of Agriculture, Washington, D. All authors have completed and submitted the ICMJE form for disclosure of potential conflicts of interest.
No potential conflicts of interest were disclosed. Cases in survivors were never laboratory-confirmed; three cases are included in bat rabies virus variants because of epidemiologic links to bats and two are included in other one unknown and one lab-acquired.
Cost includes immunoglobulin and rabies vaccine; does not include costs for hospital treatment or wound care. Department of Health and Human Services. Use of trade names and commercial sources is for identification only and does not imply endorsement by the U. CDC is not responsible for the content of pages found at these sites. This conversion might result in character translation or format errors in the HTML version. Skip directly to site content Skip directly to page options Skip directly to A-Z link.
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What are the implications for public health practice? Article Metrics. Metric Details. Related Materials. Abstract Introduction: Each year, rabies causes approximately 59, deaths worldwide, including approximately two deaths in the United States.
Introduction Rabies virus, a Lyssavirus that infects mammals, is transmitted through saliva, most commonly from the bite or scratch of an infected animal. Methods U. Results During —, cases of human rabies were reported in the United States.
Street, T. Leslie, K. Abstract The basic reproduction number R 0 , also called the basic reproduction ratio or rate or the basic reproductive rate, is an epidemiologic metric used to describe the contagiousness or transmissibility of infectious agents.
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Nonbite exposures contamination of an open wound or a mucous membrane via scratches, licks, and inhalation of aerosol rarely cause rabies in humans. Of these five human cases, four were apparently attributable via exposure to aerosols containing highly concentrated live rabies virus: two in spelunkers cave explorers and two in rabies research laboratory workers.
The fifth case occurred in the recipient of a cornea transplanted from a patient dying of unsuspected rabies encephalitis. This may be attributable either to an inability of the patient to recognize actual rabies exposure at the time, or a failure to properly question the patient concerning potential animal contact. Although it is now a rare human disease in the United States, its actual incidence may be higher than generally believed. The initial suspicion of rabies only occurred at postmortem examination in five reported human cases in the United States since The diagnosis of human rabies is usually suggested by epidemiologic and clinical findings and confirmed in the laboratory.
The diagnosis is not difficult if there is a history of animal bite exposure and if a full spectrum of symptoms and signs has appeared.
Otherwise, careful but rapid assessment of the epidemiologic and clinical features of less typical cases is essential before special laboratory tests are performed.
Every patient with neurologic signs or symptoms or unexplained encephalitis should be questioned about the possibility of animal exposure in a rabies-endemic area inside or outside the country of residence. The failure to suspect rabies in several of the recent human deaths in the United States may have occurred because no thorough exposure history had been sought. Early in the course of illness, rabies can mimic numerous infectious and noninfectious diseases.
Many other encephalitides, such as those caused by herpesviruses and arboviruses, resemble rabies. Other infectious diseases also may resemble rabies, such as tetanus, cerebral malaria, rickettsial diseases, and typhoid. Paralytic infectious illnesses that may be confused with rabies include poliomyelitis, botulism, and simian herpes type B encephalitis. Noninfectious diseases that may be confused with rabies encompass a number of neurologic syndromes, especially acute inflammatory polyneuropathy Guillain-Barre syndrome , as well as allergic postvaccinal encephalomyelitis secondary to vaccination with nervous-tissue rabies vaccines, intoxication with poisons or drugs, withdrawal from alcohol, acute porphyria, and rabies hysteria.
Guillain-Barre syndrome may be mistaken for the paralytic form of rabies, and vice versa. The detection of rabies antigen, antibody, viral RNA, or the isolation of virus establishes a diagnosis of rabies. Because any individual test may not be positive in a patient with rabies, serial serum specimens for detection of rabies antibodies, saliva specimens for culture of virus, and skin biopsies for direct immunofluorescence testing for virus antigen are sometimes necessary, especially when rabies is strongly suspected.
One of the most rapid methods to diagnose rabies antemortem in humans is to perform a direct immunofluorescence test on a skin biopsy from the nape of the neck for evidence of rabies antigen. The direct immunofluorescence test is the most sensitive and specific method of detecting rabies antigen in skin and other fresh tissue e.
If fresh tissue is unavailable, enzyme digestion of fixed tissues may enhance the reactivity of the immunofluorescence test; however, sensitivity may be unacceptably low.
The diagnosis can also be established if virus is isolated from saliva after inoculation of neuroblastoma cells or laboratory rodents; this is generally most successful during the first 2 to 3 weeks of illness. The detection of rabies virus-neutralizing antibody, as typically performed by the rapid fluorescent focus inhibition test RFFIT , in the serum of unvaccinated individuals is also diagnostic.
The presence of antibody in the cerebrospinal fluid confirms the diagnosis, but it may appear 2 to 3 days later than serum antibody and may there fore be less useful early in the disease. Whereas the serological response after vaccination cannot be generally differentiated from that due to disease, vaccination does not typically produce cerebrospinal fluid antibody.
Although rabies virus was not isolated in any of the patients, the high rabies-neutralizing antibody titer in serum samples and the presence of neutralizing antibodies in cerebrospinal fluid strongly supported the diagnoses. Animal rabies is prevented by vaccinating susceptible species, particularly dogs and cats. Mass dog vaccination programs in the United States and Europe were largely responsible for a dramatic reduction in canine and human rabies during the 's and s.
In these countries, the number of reported cases in wildlife is currently about fold greater than that in domestic animals; wildlife therefore constitute the greatest risk to human beings. Oral vaccination of wildlife with attenuated and recombinant rabies vaccines by the use of vaccine-containing bait offers hope of controlling the disease in susceptible wild free-ranging animal populations. Human rabies is best prevented by avoiding exposures to the disease.
When an exposure is suspected, the patient's physician and local health department authorities should determine whether an exposure actually occurred and whether a risk of rabies exists in the geographic area Table If treatment postexposure prophylaxis is necessary, it should be initiated promptly. Postexposure prophylaxis consists of the combination of local wound cleansing, human rabies immune globulin HRIG and rabies vaccine.
Postexposure treatment will abort the infection Table , but there is no cure for clinical disease. Preexposure immunization may be offered to persons at high risk Table , such as veterinarians, animal handlers, certain laboratory workers, and persons spending time e. Persons, such as spelunkers, whose vocational or recreational pursuits bring them into frequent contact with potentially rabid animals should also be considered for preexposure prophylaxis.
The schedules for preexposure prophylaxis are given in Table Turn recording back on. National Center for Biotechnology Information , U.
Show details Baron S, editor. Search term. General Concepts Clinical Manifestations Rabies virus causes acute infection of the central nervous system. Structure Rabies virus is a rod- or bullet-shaped, single-stranded, negative-sense, unsegmented, enveloped RNA virus. Classification and Antigenic Types Placement within the family is based on the distinctive morphology of the virus particle.
Multiplication The viral RNA uncoats in the cytoplasm of infected cells. Pathogenesis After inoculation, rabies virus may enter the peripheral nervous system directly and migrates to the brain or may replicate in muscle tissue, remaining sequestered at or near the entry site during incubation, prior to central nervous system invasion and replication. Host Defenses Susceptibility to lethal infection is related to the animal species, viral variant, inoculum concentration, location and severity of exposure, and host immune status.
Epidemiology Rabies occurs in nearly all countries. Diagnosis Early diagnosis is difficult. Control Vaccination of susceptible animal species, particularly dogs and cats, will control this zoonotic disease. Introduction The family Rhabdoviridae consists of more than single-stranded, negative-sense, nonsegmented viruses that infect a wide variety of hosts, including vertebrates, invertebrates, and plants.
Clinical Manifestations Five general stages of rabies are recognized in humans: incubation, prodrome, acute neurologic period, coma, and death or, very rarely, recovery Fig. Figure Pathogenesis of rabies. Figure Virion structure of rabies virus. Figure Genome of rabies virus ERA strain. Classification and Antigenic Types The genus Lyssavirus includes rabies virus and the antigenically- and genetically-related rabies- like viruses: Lagos bat, Mokola, and Duvenhage viruses, and two suggested subtypes of European bat lyssaviruses.
Multiplication The replication of rabies virus is believed to be similar to that of other negative-stranded RNA viruses. Pathogenesis Rabies virus is most commonly transmitted through the bite of an infected mammal, all of which may be susceptible, but to greatly varying degrees.
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