Family doctor

Key points

It is strongly advisable to seek detailed professional advice, at least 6 weeks before travelling to an area where there is rabies.

• If bitten or scratched by an animal in countries where rabies is common (Asia, Africa, Central & South America) you should seek medical advice as soon as possible, even if you have had prior vaccination as further treatment is needed..

• Rabies is almost always fatal if the illness develops. Vaccination after potential exposure to rabies is the cornerstone of treatment and is very effective in preventing the illness.

• People at particularly high risk can be vaccinated before potential exposure to the rabies virus.

• If you receive treatment for rabies whilst overseas make sure you get detailed information of the treatment.

• Rabies is not found in New Zealand.

 What is Rabies?

Rabies is an infection that occurs in animals and humans. It is caused by a group of viruses known as Lyssa viruses. The rabies virus is transmitted to humans by dog bites in ~99% of cases, however other animals such as cats, ferrets, and bats may transmit rabies. Rabies cannot be transmitted across in tact skin, it gets into the body when saliva from an infected animal comes into contact with a wound.

 The time between getting bitten by an animal with rabies and developing the infection is very variable. Typically an infection takes 1-3 months to develop. However in some cases infection can develop <1 week after a bite, or >1 year after a bite. The bottom line is that medical advice should be sought promptly after suspected exposure to rabies as the infection can develop quickly.

A rabies infection results in an acute encephalitis or meningoencephalitis, this is essentially a swelling of the brain. Symptoms include; hyperactivity, excited behavior, hydrophobia (an aversion to water), and aerophobia (an aversion to air), and paralysis. When a rabies infection develops the illness is almost always fatal. The progression from the onset of symptoms, to coma, and then death takes around 10 days. Given the fact that a rabies infection, once it develops, is so fatal, the focus in treatment is prevention.

Where rabies is a risk?

Around 95% of cases of rabies occur in either Asia of Africa, with the highest rates occurring in rural settings. India currently has the highest number of deaths due to rabies. Other high risk areas include Central and South America.

It should be noted that it is not necessarily obvious when an animal has rabies. If you have been bitten or scratched by an animal, particularly a dog, in a country where rabies is known to commonly occur you should seek medical advice as soon as possible.

Rabies in New Zealand?

Thankfully New Zealand is considered rabies free. Stringent policies surrounding the importation and quarantine of dogs coming into New Zealand continue to keep New Zealand this way. If bitten or scratched by an animal in New Zealand rabies is not something to worry about.

In saying this, if you have been bitten or scratched by an animal you should always see your doctor as bites and scratches can easily become infected. You may require antibiotics, a tetanus booster (if you haven’t had one in the previous 5-10 years), and help with wound care.

Prevention of rabies?

General advice?

When travelling to countries where rabies is known to be common you should avoid close contact with animals, particularly dogs. Children are at the greatest risk of becoming infected as they are more likely to play with animals, and less likely to tell someone if they been bitten or scratched.

Vaccination before you go overseas?

In some cases pre-exposure prophylaxis with a rabies vaccine may be advisable. This means receiving a vaccination before having any suspected exposure to rabies. This is usually reserved for people visiting countries where rabies is common who are planning to be in contact with animals, staying in rural areas where medical care would be hard to access, or staying in the area for longer than a month.

With pre-exposure prophylaxis the vaccine is given as an injection into a muscle (in the upper arm for adults, in the thigh for young children). The vaccine used in New Zealand is VERORAB™ which is the World Health Organization recommended protection against rabies. The vaccine contains the inactive rabies virus and allows your immune system to develop a response against the virus before it causes an infection. Ideally the vaccination process should be started 6 weeks prior to travelling.

Initially the vaccination will consist of;

• 3 injections; the first on day 0, the second on day 7, and the third on day 28.

If you remain at risk of coming into contact with rabies boosters will be given;

• The first booster 1 year after initially being vaccinated.

• Subsequent boosters every 5 years.

The vaccine will not give you or your child rabies.

As with all vaccines 100% protection cannot be guaranteed.

As with all vaccines there are very small risks of having a severe reaction to the vaccine.

What to do if you suspect you have been exposed to the rabies virus?

There are a number of precautions which should be taken as soon as possible after exposure is suspected (bites or scratches from an animal in areas where rabies is known to be common);

Clean your wound well. Flush with lots of clean water and soap. Follow this with the application of 70% alcohol or iodine tincture if possible.

Do not close the wound immediately.

Seek medical advice as soon as possible.

If it is suspected that you have been exposed to the rabies virus you will receive something called post exposure prophylaxis. This means being vaccinated after you have been exposed to the virus. This is very effective in preventing rabies infection if received promptly. The vaccine is given as an injection into a muscle (in the upper arm for adults, in the thigh for young children). The vaccine contains the inactive rabies virus and allows your immune system to develop a response against the virus before it causes an infection. The vaccine used in New Zealand is VERORAB™ which is the World Health Organization recommended protection against rabies.

The vaccination regimen will consist of;

• 5 injections; the first injection should be given on day 0 (the day of exposure ideally), then day 3, day 7, day 14, and a final injection on day 28.

If you have been given pre-exposure prophylaxis (a vaccine for rabies without suspected exposure) you should still seek medical advice following a animal bite or scratch in areas where rabies is common. It is advised that in a previously vaccinated person, you should still receive 2 vaccines against the rabies virus. The first should ideally be on the day of exposure, and the second 3 days after exposure.

If you have had no prior rabies vaccination before travel ,In addition to being fully vaccinated immediately following potential exposure to rabies you should receive treatment with rabies immunoglobulin (either HRIG or ERIG).

This will give your body some immunity against the virus while the vaccine becomes effective. Speed is of the essence and it should be given on the day of exposure ideally. The rabies immunoglobulin will be injected into the wound itself, and the area around the wound.

In some countries where rabies is common rabies immunoglobulin is in short supply or unavailable ( eg most of Africa, Bali) . In the event of potential exposure (and no prior vaccination) where you cannot receive treatment with rabies immunoglobulin it is strongly advised that you interrupt your travel plans and urgently seek full treatment. This may require returning to New Zealand. At this point, it is important to emphasize comprehensive travel insurance is essential.

If you receive treatment for rabies following an animal bite in a country where rabies is common it is advised that you obtain detailed information of what treatment you have received.

With any animal bite it is advised you see your doctor. You may require antibiotics to prevent other infections and a tetanus booster (if you haven’t had one in the previous 5-10 years).

Other information

The CDC has a good outline of Rabies and further links