If you are travelling overseas, travel vaccinations against some diseases are compulsory. There is, however, one disease which is usually fatal without prompt treatment and where a pre-travel vaccination is not compulsory: rabies.
Rabies is a viral disease which attacks the nervous system and is caught from infected animals. It's fatal unless treated promptly, something which can be impossible in remote areas of the world where medical facilities are scarce or inadequate.
There are over 150 countries in the world where rabies exists. Around 55,000 people die annually in the world from the disease.
The UK has been rabies-free for more than a century, apart from one species of bat which may carry it. But recently a UK man died after being infected after being scratched by a cat in Morocco, highlighting the importance of taking proper precautions when travelling abroad.
How do you catch rabies?
Animals transfer the virus through their saliva. It's carried by dogs, cats, bats, foxes, raccoons, mongooses and jackals.
Dr Mike Brown, consultant in Infectious Diseases and Tropical Medicine at University College London Hospitals says: "People often imagine a rabid animal to be foaming at the mouth and behaving aggressively, whereas you are just as likely to be infected by an 'Andrex puppy' lookalike.
"An infected animal can transfer rabies through a bite, scratch or even by licking an open wound or broken skin. Bats can pose a problem: it's possible to be bitten when you are sleeping and not notice the bite. Check your skin if you sleep in the open or where there are bats in countries with rabies."
Where you're most at risk
If you are travelling overseas to a country which has a high incidence of rabies - for example, India - you can protect yourself by having a vaccination.
Before you travel, check if the country you are visiting is on the high-risk list. Asia, especially India, is a high-risk area, but so are countries like South America, Egypt and Turkey.
In the UK, there is a rare species of wild bat which can carry rabies. It's highly unlikely you'll contract the disease here, but if you ever have to handle a bat - even a dead one - take care and wear thick gloves.
Why vaccination is so important
Almost without exception, if you are infected, are not vaccinated and not able to access treatment quickly, rabies is fatal.
It's important to plan your vaccination because the injections - up to three - are given several weeks apart. You should allow at least two months before you intend to travel to be fully vaccinated. But if eight weeks in advance isn't possible, having part of the vaccination treatment is still worthwhile.
The jab is an inactive vaccine, so you cannot catch the virus by being vaccinated.
Side effects of the rabies vaccine are usually very mild, but some people experience a little soreness, redness and swelling at the injection site. Rarely patients might notice a mild fever, headache, vomiting or a rash.
Brown advises: "If you are visiting a country for longer than four weeks, or if it's a remote region, you should be vaccinated. The longer you are in a country where there is rabies, the greater the risk of being infected.
"If you are travelling off the beaten track and you are in contact with a rabid animal, it's unlikely you will be able to access the right treatment quickly enough. This is because there are few medical facilities in remote areas. Those which exist rarely have human rabies-specific immunoglobulin (HRIG). This offers very rapid, short-term protection for anyone who has been bitten and not vaccinated. Sometimes the only option is to be flown back to the UK or another country offering HRIG."
You will also need to be vaccinated against rabies with either two or five booster doses of vaccine, depending on your risk, as soon as possible.
What to do if you're bitten or scratched
If you are bitten, scratched or licked (on a skin lesion) by an unknown animal in a country where there is rabies, it's best to assume you could be infected.
Brown says: "Wash the wound well with soap and running water as soon as possible. You can also use alcohol-based disinfectant to wash it. Seek medical help. If you are not vaccinated or fully vaccinated, you may have to return to the UK for treatment, promptly; this means within hours."
But even if you have been vaccinated, you will still need to seek medical attention and further treatment.
Once the initial symptoms of rabies appear, anywhere from three to 12 weeks post-exposure: fever, headache, muscle aches and pains, treatment is unsuccessful. This is why you should always seek medical advice if there is a possibility you could have been infected, even if you have no symptoms.
Rabies is serious; it's important to be aware of how you may be at risk and plan your vaccination well in advance of your travel.