II. Epidemiology

  1. Worldwide: Responsible for 59,000 deaths worldwide per year (95% in Asia and Africa)
    1. Children under age 15 years account for 40% of cases
  2. U.S.
    1. Typically 1-3 Rabies (up to 8 in some years) cases in U.S. per year
    2. Most cases of Rabies are from exposure to wild animals in U.S. (90%)
    3. Up to 8000/year in U.S. of documented cases of Rabies in animals
      1. The most common reported domestic Rabies cases are in cats
      2. Although rodents and rabbits can carry Rabies, no human cases have been attributed to these animals

III. Pathophysiology

  1. Lyssavirus Infection
    1. Rhabdoviridae Family (RNA Viruses)
  2. Transmitted by bite of infected mammals
    1. Saliva, brain and other nerve tissue are infectious
    2. Blood, urine, and stool are not infectious
  3. Highest risk animals
    1. Bats
      1. See Bat Bite
      2. Responsible for most U.S. cases of Rabies (87% of cases 1980-2015)
    2. Dogs
      1. See Dog Bite
      2. Worldwide, these are main vector for infection
      3. However, in U.S. Rabies is less common in dogs (70 cases/year in U.S.)
        1. Responsible for 11 of 31 U.S. human Rabies cases 2003-2016
    3. Cats
      1. See Cat Bite
      2. Most common domesticated animal with Rabies in U.S. (257 cases of cats with Rabies in 2012)
    4. Raccoons
    5. Skunks
    6. Foxes
    7. Coyotes
    8. Bobcats
    9. Woodchucks
    10. Ferrets

IV. Symptoms

  1. Incubation Period: Days to months
  2. Early (Prodromal)
    1. Local radiating Paresthesia from bite site
    2. Malaise
    3. Nausea
    4. Pharyngitis
  3. Late (Neurologic)
    1. Restlessness
    2. Significant Agitation
    3. Hallucinations
    4. Bizarre behavior
    5. Seizures
    6. Aerophobia and Hydrophobia are pathognomonic

V. Signs

  1. Early
    1. Wound Inflammation
    2. Hyperesthesia at wound site
  2. Late
    1. Dysarthria
    2. Hoarseness
    3. Aphonia
    4. Dysphagia for fluids
    5. Shallow or irregular breathing
    6. Seizure
    7. Delirium
    8. Opisthotonos stimulated by lights or noises
    9. Hyperactive Deep Tendon Reflexes
    10. Nuchal Rigidity
    11. Abnormal Babinski Reflex (Up-going toes)
  3. Terminal signs
    1. Flaccid Paralysis
    2. Hospitalization <1 week after symptom onset
    3. Coma within one week of encephalopathy signs
    4. Death

VI. Labs

  1. Live Observation of suspected infected mammal
  2. Rabies Virus Antigen Testing
    1. Saliva contains virus
    2. Brain and spinal cord of suspected infected animal

VII. Management

VIII. Prognosis

  1. Uniformly fatal once patient is symptomatic
  2. Early Postexposure Prophylaxis after Animal Bite is critical

IX. Prevention

  1. Rabies Vaccine
    1. For Rabies Postexposure Prophylaxis and preexposure prophylaxis
  2. Rabies Immunoglobulin
    1. Rabies Postexposure Prophylaxis
  3. Avoid bat exposure
    1. Remove bat roosts from home
    2. Bats trapped within a home living space are more likely to be sick (disabled navigation)
  4. Pets should be vaccinated against Rabies
    1. In U.S., of pets causing a bite evaluated in ER, only 45% of dogs and 8% of cats were vaccinated against Rabies
  5. Test for Rabies in pets who succumb to illness quickly

X. References

Images: Related links to external sites (from Bing)

Related Studies

Ontology: Rabies (disorder) (C0034494)

Definition (MSHFRE) Maladie infectieuse aiguë du système nerveux central, retrouvée chez presque tous les mammifères dont l'homme. Elle est due à un rhabdovirus. La contamination par la salive infectée lors de morsures par des animaux contaminés est le mode principal de diffusion. Les principaux vecteurs sont le chien, le chat, la chauve-souris vampire, la mangouste, le skunk, le loup, le raton laveur, et le renard. (Extr. Dorland, 27ème éd. )
Definition (MSH) Acute VIRAL CNS INFECTION affecting mammals, including humans. It is caused by RABIES VIRUS and usually spread by contamination with virus-laden saliva of bites inflicted by rabid animals. Important animal vectors include the dog, cat, bat, fox, raccoon, skunk, and wolf.
Definition (MEDLINEPLUS)

Rabies is a deadly animal disease caused by a virus. It can happen in wild animals, including raccoons, skunks, bats and foxes, or in dogs, cats or farm animals. People get it from the bite of an infected animal.

In people, symptoms of rabies include fever, headache and fatigue, then confusion, hallucinations and paralysis. Once the symptoms begin, the disease is usually fatal. A series of shots can prevent rabies in people exposed to the virus. You need to get them right away. If an animal bites you, wash the wound well; then get medical care.

To help prevent rabies

  • Vaccinate your pet. Rabies vaccines are available for dogs, cats and farm animals
  • Don't let pets roam
  • Don't approach stray animals. Animals with rabies might be aggressive and vicious, or tired and weak

Centers for Disease Control and Prevention

Definition (NCI) A life-threatening viral infection caused by the neurotropic Rabies virus. It is transmitted to humans usually from a bite by an infected dog. The initial signs and symptoms include malaise, fever, and headache, followed by the central nervous system manifestations which include abrupt behavioral changes. Paralysis, lethargy, and coma follow the behavioral changes.
Definition (NCI_NCI-GLOSS) A disease of the nervous system caused by the rabies virus. Rabies is marked by an increase in saliva production, abnormal behavior, and eventual paralysis and death.
Definition (CSP) acute infectious disease of the central nervous system affecting almost all mammals, including humans; it is caused by a rhabdovirus and usually spread by contamination with virus-laden saliva of bites inflicted by rabid animals; important animal vectors include the dog, cat, vampire bat, mongoose, skunk, wolf, raccoon, and fox.
Concepts Disease or Syndrome (T047)
MSH D011818
ICD9 071
ICD10 A82 , A82.9
SnomedCT 186644005, 275370001, 187393002, 14168008
English Hydrophobia, Rabies, Lyssa - rabies, Rabies, unspecified, [X]Rabies, unspecified, hydrophobia, lyssa, rabies (diagnosis), rabies, Rabies viral infections, Rabies virus infection, Rabies (disorder), Rabies [Disease/Finding], Lyssa, Lyssas, Rabies (& hydrophobia) (disorder), Rabies (& hydrophobia), Hydrophobia (finding), [X]Rabies, unspecified (disorder), Rabies - hydrophobia, Infection due to Rabies virus, Rabies encephalitis, St Hubert's disease, Rabies, NOS
Italian Infezioni da virus della rabbia, Infezione da virus della rabbia, Idrofobia, Rabbia
Dutch rabies-virusinfectie, Rabies, niet gespecificeerd, hondsdolheid, rabies-virusinfecties, Rabies [hondsdolheid], Hondsdolheid, Hydrofobie, Rabiës
French Infection par le virus de la rage, Infections par le virus de la Rage, Rage (maladie), Infection rabique
German Tollwutvirus-Infektion, Tollwut [Rabies], Tollwut, nicht naeher bezeichnet, Tollwutvirus-Infektionen, Rabies, Tollwut, Hydrophobie (bei Tollwut)
Portuguese Infecção pelo vírus da raiva, Infecções a vírus da raiva, Hidrofobia, Raiva
Spanish Infección por el virus de la rabia, [X]rabia, no especificada, [X]rabia, no especificada (trastorno), hidrofobia (hallazgo), hidrofobia, lisa, rabia (trastorno), rabia, Infecciones por el virus de la rabia, Hidrofobia, Rabia
Japanese 狂犬病ウイルス感染, キョウケンビョウウイルスカンセン, キョウケンビョウ, 狂犬病, 恐水病, 恐水症
Swedish Rabies
Czech rabies, vzteklina, Rabies, Vzteklina, Infekce způsobené virem vztekliny
Finnish Vesikauhu
Russian BESHENSTVO, GIDROFOBIIA, БЕШЕНСТВО, ГИДРОФОБИЯ
Korean 상세불명의 광견병, 광견병
Croatian BJESNOĆA
Polish Wodowstręt, Wścieklizna
Hungarian Veszettség vírusos fertőzések, Rabies vírus fertőzés, veszettség
Norwegian Hundegalskap, Rabies