Rabies

Disease Risk Areas

Occurs in all continents except Australasia. Some countries are thought to be normally "rabies-free".

Transmission

Via the bite of a rabid animal or through mucous membranes (less common).

Pre-Exposure Vaccination

This can be considered for:
(a) to those travelling to countries where rabies is present and who intend to have regular contact with animals (e.g. veterinarians or zoologists)
(b) to those travelling to countries where rabies is endemic and if who will be more than 24 hours away from a reliable source of post-exposure vaccine and (ideally) rabies specific immunoglobulin.
Although pre-exposure vaccination is likely to give excellent protection post-exposure boosters (usually 2 doses) should still be sought as soon as possible after an exposure to ensure maximum protection.

Post-Exposure Vacinnation

Is also very effective if a reliable vaccine is commenced according to manufacturer's instructions within 24 hours.
Those not previously vaccinated (or up to date with boosters) should also ideally receive rabies hyperimmunoglobulin to give immediate passive protection.
Immunoglobulin is unlikely to be of benefit more than 7 days after exposure (W.H.O).
The immunoglobulin dose is calculated by patient's weight and administered half around the wound and half intramuscularly.

Vaccines

Human Diploid cell
Always confirm details with manufacturer's literature.
Type: Inactivated (not live)
Primary course: 3 doses
Dosage/route: 1ml subcutaneous (S/C) or 0.1ml intradermal (I/D) (see note below)
Intervals: Days 0, 7 and either 21 or 28
Boosters: 2-3 yearly
Rabies vaccine can be given to infants at the same dosage as for adults.

Side effects
Local discomfort, malaise and occassional systemic reactions are occasionally reported.

Contraindications
Hypersensitivity to a preceding dose. Pre-exposure vaccine should only be given to pregnant women if they are at high risk.

Availability
The rabies vaccine available in Britain is Diploid Cell Vaccine supplied by Pasteur Merieux.

Imovax Rabies Vero
Type: Inactivated (not live)
Primary Course: 2 doses
Dosage/route: 0.5 ml by subcutaneous or intramuscular route
Interval: 1 month apart
Boosters: 1 year later

Side Effects
Local minor reactions like redness and slight induration of the injection site. Rare febrile illness.

Contra indications
In view of the gravity of the disease and the essential character of this treatment all contra indications are secondary in case of rabid contamination.

Note
The intradermal route for pre-exposure vaccination is not covered in Britain by the manufacturers licence but it is in USA.
It has however been shown to be effective if performed correctly but when the intra-dermal route is used maximum protection may not be achieved until about 30 days after the end of the course (see 'Health Information for International Travel - published by CDC Atlanta. USA).
If the traveller will be taking chloroquine or mefloquine for malaria prophylaxis the I/D course of vaccine should ideally be completed before starting prophylaxis.
A rapid schedule using multiple intra-dermal (I/D) doses (e.g. 4 doses with a single dose into each limb) have been used effectively for rapid post-exposure immunisation (see 'Immunisation against Infectious Disease' - Green book - published by the UK Departments of Health) .
This is an unlicensed option for pre-exposure vaccination if there is insufficient time for a recommended course. The traveller must be told this method usually gives good but less certain protection and protection is not immediate.

Current Notes
12/09/98 The Pasteur Merieux rabies vaccine is now fully available.
16/08/97 Shortage of Rabies Vaccine. A failure in production at Pasteur Merieux UK means that supplies of rabies vaccine will not be available until October 1997. This is the only licenced rabies vaccine in Britain. The Department of Health advises that an alternative vaccine, Rabivac, from Behring of Germany may be obtained by doctors on a named patient basis from IDIS Ltd. Tel:0181 410 0700. Fax:0181 410 0800. For those a risk who are not able to receive vaccine due to the shortage, the importance of post-exposure vaccination should be emphasised.
22/10/96 Imported rabies in the UK
A case of rabies was confirmed by the Central Veterinary Laboratory, Weybridge,following the death of a 19yr old youth who had returned to the UK from Nigeria 3 weeks earlier. He developed fever & altered behaviour, was aggressive, confused, hyperventilating & had spasms lasting for a few seconds. As malarial parasites were seen on blood film, the initial diagnosis was of Falciparum malaria and he was treated with quinine and transferred to another hospital where he died the same day. There have not been any cases of indigenous rabies in the UK since 1902 and only 20 imported into England & Wales since 1946.