Rabies

Rabies virus is found in the saliva of an infected animal. The virus is spread to humans by a bite or scratch, or when saliva from an infected animal comes into contact with broken skin or mucous membranes (eyes, nose, or mouth). Infection does not occur through intact skin.

Infection may occur from droplet spread. This is of concern when venturing into caves inhabited by bats.

It can also be spread via organ transplantation from an undiagnosed donor may result in rabies in the recipient, although this is rare.²

The risk of developing rabies after a bite by a rabid animal varies with the site and severity of the wound.

Following exposure, the virus travels to the central nervous system. It replicates in the brain and spreads to many different tissues.

Not all individuals exposed to rabies virus develop the disease but, once symptoms occur, rabies is almost invariably fatal.¹

Rabies exists on all continents except Antarctica, although some countries are rabies-free (including the UK). The risk of human cases is highest in countries where the virus circulates in dogs.

According to the World Health Organisation (WHO), more than 95% of human cases occur in Africa and Asia, mainly in rural communities where measures to prevent dog to human spread have not been implemented.³ The limited availability of treatment in some countries contributes to the high death rates.

Further details for rabies risk can be found here.⁴

The incubation period of rabies is usually between 3-12 weeks (in rare cases it can be as short as 4 days or as long as 19 years).

Early symptoms are often non-specific and can include:

• Headache
• Muscle pain
• Tiredness
• Tingling or prickling sensation at site of bite or scratch⁵

The disease can develop into the ‘furious’ form or ‘paralytic’ form.

Symptoms of furious rabies can include:

• Hyperactivity
• Fluctuating consciousness
• Hydrophobic spasms (a reflex contraction of respiratory muscles following attempts to drink water)
• After a few days, death occurs by cardio-respiratory arrest

Paralytic rabies accounts for about 30%of human cases. With this form of rabies:

• Gradual paralysis of the muscles occurs starting at the site of the bite or scratch
• Coma slowly develops
• Eventually death occurs within 1-3 weeks⁶

Once the symptoms of rabies have appeared, the disease is always almost fatal.

All travellers who have had a possible exposure to the rabies virus should seek medical attention without delay.

Preventative therapy for rabies include:

• Wound care -washing wound well and treating with a suitable disinfectant (such as 40-70% alcohol, povidone-iodine)
• Active and passive immunisation – if treatment before the symptoms is not carried out then death is almost certain
• Seek urgent medical attention as soon as possible

Post-exposure prophylaxis:

• Rabies vaccine
• In non-immunised individuals, human rabies-specific immunoglobulin (HRIG) is also given

Receiving rabies vaccination before travel does not eliminate the need for additional doses if exposed to the virus. However, it does simplify and shorten the post-exposure prophylaxis regimen and eliminates the need for rabies immunoglobulin which is in short supply in many countries. Additionally a tetanus vaccine may be necessary.

Symptomatic rabies is almost fatal and the treatment aims to alleviate suffering and support vital functions.⁶

All travellers visiting rabies endemic areas should be aware of the risk of rabies and be advised to avoid contact with both wild and domestic animals (including bats, particularly dogs and cats).

Travellers should be advised:

• Not to approach animals (rabid animals may not always show signs of the disease)
• Not to attempt to pick up an unusually tame animal or one that appears to be unwell
• Not to attract stray animals by offering food or by being careless with litter
• To be aware that certain activities may attract dogs (e.g. running, cycling)

Children are more vulnerable to rabies than adults as they are less likely to comprehend the risk of animal contact, less able to defend themselves from an animal attack and may not report a potential exposure.

All travellers to endemic areas should be aware of immediate wound care and advised to seek medical attention immediately if they suspect risk of infection.

More information regarding rabies awareness can be found here.⁷

In the UK, people whose work puts them at risk of rabies are advised to get vaccinated against rabies. This is available on the NHS and includes people who:

• Work with the rabies virus in laboratories

• Come into contact with imported animals and species of bats
• Healthcare workers who come into contact with patients with rabies

In addition, travellers visiting a high risk area of rabies may be advised to have the vaccine. This is not available on the NHS and must be paid for. This includes:

• Travellers (including people who are trekking) to parts of the world at risk of rabies where medical treatment may not be available.

• People visiting parts of the world which may not have enough supply of rabies vaccines to give if they are bitten
• People travelling to parts of the world where rabies is common
• People involved in activities (such as running and cycling) which put them at greater risk
• People travelling to parts of the world where rabies is common, who will be there for over a month⁸

There are two rabies vaccines available in the UK, both of which are inactivated. The vaccine is highly effective. It stimulates the body to make antibodies against the rabies virus. These antibodies protect against illness should infection with the virus occur.

Pre-exposure prophylaxis for travellers include 3 or 4 doses given on:

• Days 0, 7, 21-28

This is the preferred schedule where there is sufficient time to complete the 21-28 day course

• Day 0, 3, 7, 365

A single booster dose is given opportunistically at any time from one year after the initial primary course. The need for boosters will depend on the activities being undertaken by the traveller, the rabies risk in the country being visited and the ability to access post-exposure medical care and rabies biologics. A booster may also be considered for those travellers with primary vaccination more than five years previously.

Post-exposure prophylaxis: this may be 2 or 5 further doses of the injection (depending on the level of risk and immunisation status).

If no previous complete immunisation has been obtained, an additional injection of human rabies-specific immunoglobulin (HRIG) will also be required. This protects from rabies for a short time, giving time for the body to produce the antibodies.^7,9

This information is taken from trusted third party websites, NaTHNaC (Travel Health Pro) and EMIS (Patient info) and use of all information has been licenced under the Open Government. Licence http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/

Although the materials are being used/replicated under the provisions of the Open Government Licence this in no way represents endorsement of Traveljab.co.uk by NaTHNaC, Emis, Public Health England, the NHS or the Department of Health and Social Care.

1. Travel Health Pro: Rabies – diseases in brief
2. Centers of Disease Control and Prevention (CDC): How is rabies transmitted
3. World Health Organisation (WHO): Rabies
4. World Health Organisation (WHO): Rabies, countries or areas at high risk
5. NHS: Rabies – Overview
6. Travel Health Pro: Rabies factsheets
7. Public Health England: Rabies – vaccine update
8. NHS: Rabies – vaccination
9. The Green Book: Chapter 27 – Rabies