DOG BITE AND ITS MANAGEMENT

INTRODUCTION

Rabies is an acute infection of the CNS. Rabies is caused by rabies virus (Rabdoviridiae family)

Transmission: Through saliva of infected animal

Mode of transmission: Animal bites, licks on abrasion

Incubation period: 4 to 8 weeks (9-90 days)

Variation of incubation period: depends on site of bite

Human is dead end host

Family: Rhabdoviridae

Genus: Lyssavirus

Shape: Rod or bullet shaped

Nucleocapsid: Helical

Genome: Single stranded RNA with negative polarity, hence

 posses their own RNA depended RNA polymerase. Replicates 

in cell cytoplasm. Envelope: contains virus encoded glycoproteins

HISTORY

Louis Pasteur was the first person to diagnose that rabies targeted the CNS.Also 

determined that nervous tissue of an infected human or animal also contained the 

virus.In 1890 created the rabies vaccine and saved 9 year old Joseph Meister after he 

had been bit by a rabid dog.

EPIDEMIOLOGY

87 countries contain Rabies, but more cases are reported in Asia.In Indo-Pakistan rabies 

is a major public health problem mainly due to presence of a large number of stray 

dogs.More than 30,000 people died of Rabies every year in Asia. Every year 10 million 

people require treatment and protection from Rabies which is great Financial loss. 

Estimated Annual Human Rabies Cases 2005

 North America 4 - 8, Europe 10 - 20, Latin America 200 - 400, Africa 500 - 1,000

,Asia 30,000 - 40,000

FREE RABIES ZONE

 Australia, Ireland, Japan, New Zealand ,China ,Iceland etc

VIRUS AND ANIMAL SUSCEPTIBILITY

Heat: 500 C for 1 hour. Ultraviolet light. Inactivated by CO2 (e.g., dry ice). Chemicals: Ether, alcohol, detergents, trypsin .Extreme of ph

SYMPTOMS

 Prodromal symptoms

•Headache, malaise, sore throat, low fever, pain at the site of bite

Excitation Symptoms

sensory system involvement

•Aero phobia, excitation of N.S.

Motor system

•increase reflexes, muscle spasm,

Sympathetic involvement

• dilatation of Pupils. increase perspiration, salivation and Lacrimation,

•Mental changes: fear of death, anger, irritability and depression

•Hydrophobia ( Fear of water)

•sight or sound of water may produce spasm of degulation the duration of illness is 2-3 days may be prolonged to 5-6 days

•Stage of paralysis & coma

•DEATH / Recovery

•The rabies infection and the symptoms that accompany it is classified by five stages:

•1. Incubation (1-3 months)

•2. Prodromal, where first symptoms occur

•3. Acute neurological phase

•4. Coma

•5. Death or recovery

Acute neurological phase (2-7 days)

Occurs 80% of the cases and is ‘Furious’ form

Nervousness, hallucination, bizarre behavior

Increase sympathetic activity: Lacrimation pupillary dilatation, salivation

 Hydrophobia: Due to painful spasm of throat muscles

 Aerophobia: breathing difficulty against blowing air

Neurological deficit(‘dumb’):

Involves spinal cord

Ascending paralysis

Coma

EXPOSURE

•category I – touching or feeding animals, licks on the skin 

No treatment is required

•category II - nibbling of uncovered skin, minor scratches or abrasions without 
bleeding, licks on broken skin

Immediate vaccination

•category III – single or multiple transdermal bites or scratches, contamination of 
mucous membrane with saliva from licks; exposure to bat bites or scratches

 Immediate vaccination and administration of rabies 

immune globulin are recommended in addition to

 immediate washing and flushing of all bite wounds and

 scratches

Vaccine Candidate

Preexposure:

•Rabies virus contacts: Research and laboratory workers

•Rabid animal contacts: Veterinarians, zoo keepers

Postexposure: depends on

•Nature of biting animal

•Provocative or unprovocative bite

•Severity of the bite

Availability of the animal

POST EXPOSURE PROPHYLAXIS

VACCINE

•Intramuscular doses of 1 ml or 0.5 ml given as four to five doses over four 

weeks.

• For rabies-exposed patients who have previously undergone complete pre-

exposure vaccination or post-exposure treatment with cell-derived rabies 

vaccines, two intramuscular doses of a cell-derived vaccine separated by three 

days are sufficient.

One dose of the vaccine should be administered on days 0, 3, 7, 14 and 30. 

All intramuscular injections must be given into the deltoid region or, in small children, 

into the anterolateral area of the thigh muscle. Vaccine should never be 

administered in the gluteal region.

LOCAL WOUND MANAGEMENT

REFERENCES

•Jawetz, Melnick, Adelberg. Medical Microbiology. 25th ed. Lange publication; 2010.

•Kenneth J.R, C. George Ray, editors. Sherris Medical Microbiology.4th edition. McGraw-Hill, Inc; 2004.

•Alan L. Rothman. Current topics in Microbiology and Immunology, vol 336: Springer-Verlag Berlin Heidelberg, 2010.

•Nipah virus infection: WHO