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Rabies

Introduction

Rabies is an acute viral infection. Rabies is present in animals in many countries worldwide. Most cases of human infection occur in developing countries.

Causative agent: The rabies virus, a rhabdovirus of the genus Lyssavirus

Transmission: Through the bite of an infected animal or any other contact involving penetration of the skin occurring in an area where rabies is present. The virus is present in the saliva.

Incubation period: usually 3-8 weeks, rarely as short as 9 days or as long as 7 years.

In rabies endemic areas, travelers may be at risk if there is contact with both wild and domestic animals including dogs and cats.

Sign & Symptoms

An acute viral encephalomyelitis

Initial signs include a sense of apprehension, headache, fever malaise and sensory changes around the site of the animal bite.

Excitability, hallucinations and aerophobia are common followed in some cases by fear of water (hydrophobia) due to spasms of the swallowing muscles, progressing to delirium, convulsions and death a few days after onset.

A less common form, paralytic rabies, is characterized by loss of sensation, weakness, pain and paralysis.

Complication

Respiratory paralysis leads to death.

Treatment

Post exposure treatment

To prevent the establishment of rabies infection

  • First aid treatment of the wound by immediate vigorous washing and flushing with soap or detergent and water or water alone. Following washing, apply either ethanol (70%) or tincture or aqueous solution of iodine or povidone iodine.

Specific treatment

Antirabies Immunoglobulin (RIG) is applied by instillation into the depth of the wound and by infiltration of the surrounding tissues.

Vaccine is applied by intradermal or intramuscular injection in schedules requiring several doses (4 or 5 doses by intramuscular injection, depending on the vaccine used) with the first dose being administered as soon as possible after exposure and the last dose within 28 days for intramuscular or 90 days for intradermal vaccination

  • Tetanus prophylaxis and anti-bacterial treatment when required
  • No sutures or wound closure advised unless unavoidable

Prevention & Precautions

Vaccination as Prophylaxis

For travelers with a foreseeable significant risk of exposure to rabies or traveling to a hyper-endemic area where modern rabies vaccine may not be available

Type of vaccine: Modern vaccine (cell cultured or embryonated egg vaccine)

Number of doses: Three (3), on days 0, 7 and 21-28, given i.m. (1 ml/dose) or i.d. (0.1ml/dose)

Booster: After one year, and thereafter every 5-10 years, depending upon risk of exposure

Contraindications: Severe adverse reaction to previous dose

Adverse reactions: Minor local or systemic reactions

Before departure: Pre-exposure prophylaxis for those planning a prolonged stay or visiting hyperendemic areas, parks and game reserves in endemic countries.

Precautions

Avoid contact with wild animals and stray domestic animals particularly dogs and cats in rabies endemic areas.

If bitten by an animal that is potentially infected with rabies, or after other suspect contact, immediately clean the wound thoroughly with disinfectant or with soap or detergent and water.

Medical assistance should be sought immediately.

References organisation/ support

International Travel & Health, WHO 2006

Control of Communicable Diseases Manual, 18th Edition by David L. Heymann, MD, Editor, 2004

http://travelhealth.co.uk/

Last Reviewed : 26 April 2012
Writer : Dr. Norhayati bt. Rusli
Accreditor : Dr. Nor Mimiroslina bt Che Omar
Reviewer : Dr. Muhaini bt. Othman