2007.9.14. EM R3 김현진

PATHOLOGY-Virology- Neurotropic virus of genus Lyssavirus. The classic rabies virus, two European bat lyssaviruses, an Australian bat lyssavirus, African Duvenhage virus Produce fatal encephalomyelitis in humans

Transmission Infection initially of wild and then domestic animals-> humans by bites, aerosol inhalation in bat caves Most infections (90%) are transmitted via domestic animals (cats and dogs) Scratches infected with saliva

Transmission Human to human transmission has not been recorded, Exception of six cases resulting from corneal graft Breast milk may be shed Transplacental infection Occurs in animals but has not been reported in humans.

Pathophysiology Virus replicates in muscle cells(bite site) Ascends to central nervous system via the peripheral nerves. Central nervous system, Massive viral replication on membranes within neurones Transmitted directly across synapses into efferent nerves Deposited in almost every body tissue Incubation period from bite to disease Usually between 30 and 90 days. Bites on the head and neck have a shorter Sometimes even as short as 15 days

Pathology Brain, spinal cord, and peripheral nerves Inflammation Ganglion cell degeneration Perineural and perivascular mononuclear cell infiltration Inflammation Midbrain and medulla in furious rabies spinal cord in paralytic rabies Vascular lesions Thrombosis and haemorrhage Brainstem, hypothalamus, limbic system Focal degeneration Salivary, lachrymal glands, pancreas, adrenal medullae

SYMPTOMS AND SIGNS First symptom Prodromal symptoms Itching, pain, or paraesthesia at site of healed bite wound Prodromal symptoms Fevers, myalgia, headache, irritability, depression, and upper airway or gastrointestinal symptoms

Furious rabies More common Irritability, agitation, and hyperaesthesia. Autonomic disturbances (disorders of blood pressure, hypersalivation, and sweating). Symptom of hydrophobia Inspiratory muscle spasm Painful laryngospasm Terror (fear of swallowing) Fatal within months Very few reported cases of survival

Paralytic rabies Under 20% of human cases Bites from vampire bats Bites in people who have received pre-exposure vaccination. Flaccid paralysis Bitten limb Ascends (symmetrically or asymmetrically) with pain and fasciculation in the affected muscles. Mild sensory disturbance Fatal paralysis of respiratory muscles Hydrophobia is rare A few spasms of the laryngeal muscles Survive for up to 30 days without ITU support

DIAGNOSIS-Laboratory diagnosis- Animal Brain biopsy Rabies antigen by direct immunofluorescence or PCR Observed for a period of 10 days Not overtly ‘‘rabid’’ Any sign of infection or deterioration, brain tested Patient suspected rabies Viral RNA by PCR or viral antigen in skin biopsies Earliest diagnosis Rabies antibodies in CSF or serum Not usually detectable until the eighth day Most cases died before an antibody response is detectable.

RISK ASSESSMENT Circumstances of the bite Biting animal’s behaviour Provoked or unprovoked Wild or pet animal, Site of bite Initial treatment of wound Previous vaccination of the patient and animal Country in which the bite

RISK ASSESSMENT Type of exposure Bites pose a high risk Scratches and non-bite exposure of open wound or mucous membrane assumed to risk. Contact with animal’s coat or faeces Not risk Position of the wound Face and neck should be treated as more serious

TREATMENT Prevent development of rabies Once rabies symptoms have developed, treatment itself is manily supportive. Cleaning of the wound and use of post-exposure prophylaxis Most important steps Reduce risk from a known rabid animal bite from 37–60% to near zero. Supportive care Control their pain and terror. Paralysis, sedation, and ventilation. Antiserum, antiviral agents, interferon, corticosteroids Useless

Pre-exposure vaccination Not aim to provide full immunity Deltoid on days 0, 3, and 28 Seroconversion rate 98.2%. Boosters Between 6 and 24 months

Wound treatment Easily killed by sunlight, soap, and drying Almost completely prevented by local wound treatment given within the first 3 hours after exposure Iodine solution, 40–70% alcohol, or quaternary ammonium compounds

Post-exposure prophylaxis

Passive immunisation Human rabies immunoglobulin (HRIG) Neutralizing the rabies virus Enhance patient’s T cell response to the vaccine Dose 20 IU/kg body weight Infiltrated around wound site as much as is anatomically Hypersensitivity reactions 1 - 6%.

Vaccination Protocol Complication Vaccinated patients booster vaccine on days 0 and 3 Unvaccinated patients 0, 3, 7, 14 and 28 days Complication Pain, swelling, erythema, and itching around the injection site 30–74% Anaphylaxis rates 0.1%.

Vaccination Pregnancy not a contraindication vaccine or immunoglobulin,

광견병,대한의사협회지 제42권 제7호

캄랍주(공수병 사람 면역글로불린 )

캄랍주(공수병 사람 면역글로불린 )