Page content: Pre-exposure prophylaxis | Post-exposure treatment for persons bitten or scratched | Post-exposure treatment - not previously vaccinated against rabies | Post-exposure treatment - previously vaccinated against rabies | Further information

Pre-exposure prophylaxis

Pre-exposure vaccination should be recommended to those people whose occupation or recreational activities place them at increased risk of being bitten or scratched by a bat. For example:

• bat carers, bat handlers, researchers and students
• veterinarians and veterinary assistants
• veterinary laboratory staff
• fruit pickers
• wildlife officers (including local government officers)
• managers of display or research colonies of bats
• power line workers who frequently remove bats from power lines.

Pre-exposure vaccination should also be recommended for travellers who will be spending prolonged periods (i.e. more than one month) in rural parts of rabies endemic areas. The World Health Organization maintains data on rabies infected countries - see www.who.int/csr

Pre-exposure prophylaxis consists of three deep subcutaneous or intramuscular doses of 1.0 mL rabies vaccine given on days 0, 7 and 28. Doses should be given in the deltoid area, as rabies neutralising antibody titres may be reduced after administration in other sites. In children, administration into the anterolateral aspect of the thigh is also acceptable.

The vaccine should not be administered by the intradermal route.

Post-exposure treatment for persons bitten or scratched

The decision to offer post-exposure prophylaxis to a potentially exposed person should be made in consultation with the Department of Human Services. If post-exposure prophylaxis is indicated, the Department of Human Services will arrange for rapid delivery of vaccine and immunoglobulin as required.

Post-exposure treatment should be considered in the following scenarios:

• person bitten or scratched by bats in Australia
• person bitten or scratched by any animal in a country with endemic rabies.

Assessment
Rabies virus and other lyssaviruses are usually transmitted to humans via bites or scratches which provide direct access of the virus in saliva to exposed tissue and nerve endings, or where mucous membrane such as eyes, nose or mouth exposure to bat saliva has occurred. This means that people would not be exposed to lyssavirus through tactile contact with bats alone or other animals where parenteral or mucous membrane exposure does not occur. Contact such as patting bats (Australia) or other animals or exposure to their urine and faeces does not constitute a possible exposure to ABL, although bat urine and faeces may carry other human pathogens. Pre-exposure vaccination should however be offered if the person has ongoing contact with bats.

If the exposure is connected to an Australian bat, where possible without placing other persons at risk of exposure, the bat should be kept so that the Department of Human Services can arrange for testing of the bat.

First aid
Proper cleansing of the wound is the single most effective measure for reducing the transmission of classic rabies virus.

Where a person has been injured by a potentially infected animal, the wound should be washed thoroughly for approximately five minutes as soon as possible with soap and water. If available, a virucidal antiseptic such as povidone-iodine, iodine tincture, aqueous iodine solution or alcohol (ethanol) should be applied after washing. Exposed mucous membranes such as eyes, nose or mouth should be flushed well with water.

Post-exposure treatment - not previously vaccinated against rabies

Rabies vaccine
Post-exposure prophylaxis for persons not previously immunised against rabies consists of five doses of 1.0 mL of rabies vaccine given as deep subcutaneous or intramuscular injection, on days 0, 3, 7, 14 and 28. Doses should be given in the deltoid area, as rabies neutralising antibody titres may be reduced after administration in other sites. In children, administration into the anterolateral aspect of the thigh is also acceptable. The vaccine should not be administered by the intradermal route.

Rabies immunoglobulin
Rabies immunoglobulin (RIG) should be given as a single dose at the same time as the first dose of the post-exposure vaccination course. The dose for RIG is 20 International Units (IU) per kilogram of body mass. RIG should be infiltrated in and around all wounds using as much of the calculated dose as possible, and the remainder administered intramuscularly. It should not be given at the same site as the vaccine, and if administered in the buttock, care should be taken to ensure that the dose is given intramuscularly and not into adipose tissue.

Although the RIG and first dose of rabies vaccine should preferably be given on the same day, if necessary the RIG can be given up to seven days after the first dose of vaccine, but not thereafter.

RIG should be infiltrated into finger wounds using a 25 or 26 gauge needle, and to avoid a compartment compression syndrome the RIG should be infiltrated very slowly, and should not cause the adjacent finger tissue to go pale or white. If necessary a ring-block using local anaesthesia may be required. If the wounds are severe and the calculated volume of RIG is inadequate for complete infiltration, the RIG may be diluted in saline to make up an adequate volume for the infiltration of all wounds, but as most bat bites are small and fine, this should not be necessary.

Post-exposure treatment - previously vaccinated against rabies

Post-exposure prophylaxis for persons who have previously completed the recommended course of either pre-exposure vaccination or post-exposure prophylaxis or who have documented rabies neutralising antibodies, comprises a total of two doses of rabies vaccine (1.0 mL each) given by either deep subcutaneous or intramuscular injection on day 0 and day 3. In cases where prior vaccination status is uncertain, or the person has been vaccinated by inappropriate intradermal injection, a full course of post-exposure prophylaxis (RIG plus five doses of vaccine) should be offered. It is therefore advisable to ensure that people are given adequate written documentation as to any RIG and vaccines administered.

(Note that product information recommends a routine 6th dose at 90 days. This dose is not considered necessary, except for immunosuppressed persons. See the current edition of the Australian immunisation handbook, National Health and Medical Research Council, for more information).

Further information

• Your local doctor
• Better Health Channel
• Victorian Department of Human Services, Telephone: 1300 651 160