Rabies and its Post-Exposure Management of Domestic Animals

Important Concepts

• Rabies: Acute, progressive encephalomyelitis caused by lyssaviruses, primarily affecting mammals.

• Transmission: Through saliva via bites, open wounds, or mucous membranes.

Infectious Agents

• Rabies Virus (RABV): Nonsegmented, single-stranded negative-sense RNA virus.

Clinical Changes

• Early Signs: Behavioral changes, anorexia, nervousness, irritability.

• Advanced Signs: Hyperexcitability, aggression, ataxia, paralysis, excessive salivation, and altered phonation.

Pathological Changes

• Pathogenesis:

  
  

  • Virus replicates at the entry site, travels via peripheral nerves to the CNS.

  • Replication in the CNS leads to neuronal dysfunction and neurological signs.

  • Virus spreads to salivary glands and is shed in saliva.

  
  

Diagnostic Procedures

• Tests: Immunofluorescence microscopy on brain tissue, RT-PCR for confirmation.

• Laboratory Testing: Conducted on fresh brain tissue including the brainstem and cerebellum.

Treatment and Management

• Post-Exposure Prophylaxis (PEP):

  
  

  • For unvaccinated animals: Euthanasia or strict quarantine with vaccination.

  • For vaccinated animals: Immediate booster vaccination and observation.

  
  

Prevention and Control

• Vaccination: Regular vaccination of domestic animals and oral vaccination for wildlife.

• Disinfection: Rabies virus is inactivated by disinfectants, heat, and UV light.

Zoonotic Risk

• High Fatality: Rabies has the highest case fatality of any infectious disease.

• Human Risk: Pre-exposure vaccination for high-risk individuals and immediate PEP for exposed individuals.

Important Concepts

• Rabies: A fatal viral disease affecting the CNS, caused by the rabies virus (RABV).

• Transmission: Mainly through bites from infected animals, but also via saliva on mucous membranes or open wounds.

Infectious Agents

• Rabies Virus (RABV): A member of the Lyssavirus genus, family Rhabdoviridae.

Clinical Changes

• Early Signs: Nonspecific signs like lethargy, fever, vomiting, anorexia.

• Advanced Signs: Behavioral changes (e.g., aggression, abnormal gait, ataxia), paralysis, seizures, excessive salivation, difficulty swallowing.

Pathological Changes

• Pathogenesis:

  
  

  • Virus enters through bites or saliva exposure.

  • Replicates in local muscle tissue before traveling via peripheral nerves to the CNS.

  • Causes neuronal dysfunction and severe neurological signs.

  • Virus then spreads to other organs, especially the salivary glands, leading to viral shedding.

  
  

Diagnostic Procedures

• Direct Fluorescent Antibody Test (FAT): Standard test for rabies detection.

• RT-PCR: Molecular technique for confirming the presence of rabies virus.

• Additional Tests: Include the Formalin Fixed Assay (FFA), Tissue Culture Inoculation Test (RTCIT), and virus variant typing.

Treatment and Management

• Post-Exposure Prophylaxis (PEP):

  
  

  • Non-Immunized Animals:

    
    

    • Immediate euthanasia is recommended.

    • Alternatively, a strict 4- to 6-month quarantine with vaccination upon entry.

    
    

  • Vaccinated Animals:

    
    

    • Immediate booster vaccination.

    • Observation period of 45 days under owner’s control.

    
    

  • Animals with Lapsed Vaccination:

    
    

    • Evaluation and potential booster vaccination, followed by an observation period.

    
    
  
  

• Wound Care: Immediate and thorough cleaning of any bite or scratch wounds.

Prevention and Control

• Vaccination:

  
  

  • Regular vaccination of domestic animals (dogs, cats, ferrets, and livestock in frequent contact with humans).

  • Booster vaccinations as per the vaccine manufacturer’s recommendations.

  
  

• Surveillance and Reporting:

  
  

  • Reporting rabies cases and exposures to local health authorities.

  • Laboratory-based surveillance and variant typing.

  
  

Additional Details

• Rabies in Wildlife: Control measures include vaccination programs and restriction of animal translocation.

• Legislation: Rabies is a reportable disease, and specific regulations govern the management and reporting of cases.

• Human Exposure: Requires immediate wound care, administration of HRIG, and a series of rabies vaccinations.