Regardless of where you're on holiday, you could come home with a nasty souvenir. Hélène Hofmanlooks at some of the illnesses you're most likely to pick up and how to avoid them
•Traveller's diarrhoea
According to the Health Protection Surveillance Centre (HPSC) about half of people will get traveller's diarrhoea during their holiday.
"Traveller's diarrhoea may not be as serious as some of the other diseases, but it will knock your holiday for six," says Dr Paul McKeown, consultant in public health at the HPSC.
"For many people it's caused by the change in diet, which leads to a change in bowel habits."
To minimise your chances of contracting traveller's diarrhoea, he recommends drinking bottled water and using it to brush your teeth; staying away from ice cubes; and ensuring that any food you can't peel or boil yourself has been thoroughly cooked before you eat it.
•Respiratory tract infections
Dr Nancy Gallagher from the Irish Society for Travel Medicine says that you are more likely to pick up a respiratory tract infection when you are away. These range in severity from a cold or flu to pneumonia.
"People are more susceptible when they're abroad," Gallagher says. "People who often get colds and flu might think of bringing an appropriate course of antibiotics just in case, but there is nothing really you can do to protect against them."
•Sexually Transmitted Diseases (STDs)
Anyone engaging in unprotected sex on their holiday is at risk of infections such as herpes, gonorrhoea, syphilis and Hepatitis B, which are all easily transmitted.
HIV and Hepatitis C do not transfer as easily during unprotected sex but still pose a risk.
"Compared to 10 or 20 years ago, people are increasingly prepared to have sexual adventures when they're away and this can lead to STDs if the proper precautions aren't taken," says McKeown. The only way to protect against STDs is to abstain or wear a condom.
•Mosquito-borne diseases
Holiday-makers travelling to certain parts of the world are at risk of mosquito-borne diseases such as dengue fever, yellow fever, malaria and chikungunya.
While you vaccinate against yellow fever and take tablets to prevent malaria, in many cases the only prevention is to avoid getting bitten by mosquitoes.
"To protect yourself use mosquito repellent which you can get at any pharmacy or at the airport," advises McKeown. "Wear long sleeves, long trousers, socks and shoes to minimise skin exposure. Insect screens and nets are also very useful."
It is also advisable to consult a member of the Irish Society for Travel Medicine (www.istm.ie) or the Tropical Medical Bureau (www.tmb.ie) to find out what precautions you need to take.
•Existing ailments
Taking medication along for existing ailments is advisable, as Gallagher warns that some people unexpectedly fall ill when away.
Whether you suffer from heart disease or hay fever, being prepared is important.
"Many people get what they would at home but on holidays. If you are on a lot of drugs, it is a good idea to take a doctor's letter with you in the event of something happening so that they will be aware of your problems," she says.
She also points out that it is important to note the name of any medication you are taking, and not just the brand or trade name, which may differ from country to country.