Having norovirus can be an unpleasant and frightening experience, although most people make a full recovery within a couple of days.
There is no specific cure at present, meaning those who develop the condition have to let it run its course - typically 12 to 48 hours.
Wales Online is urging people to do all they can to avoid norovirus, also known as the winter vomiting bug, over the coming months.
It is characterised by a sudden sick feeling followed by forceful vomiting and watery diarrhoea, while other symptoms include a raised temperature, headaches, painful stomach cramps and aching limbs.
Although it is more common during the winter - hence its nickname - the virus can be caught at any time of the year.
Apart from trying to stay away from other people, Wales Online claims there are a number of simple measures everyone can take to stop the spread of the bug.
The most important is to wash your hands frequently, avoid sharing towels and flannels, and keep surfaces clean, as norovirus is easily spread by contact with an infected person, contaminated food or drink and contaminated surfaces or objects.
Washing any clothing or bedding that could have become contaminated is also recommended, as is flushing away any infected faeces or vomit in the toilet and then cleaning the toilet area.
In addition, avoid eating raw, unwashed produce and only eat oysters from a reliable source. Oysters have been known to carry the virus.
Due to its highly contagious nature, norovirus can also have a big impact on the NHS at a time when resources are already stretched.
Last year it caused major in hospitals nationwide, with health boards having to close wards to new patients.
Health chiefs were also forced to issue desperate pleas to visitors and prospective patients to do all they could to prevent the spread of the bug.
If you have norovirus, you may continue to be infectious for a short period after symptoms stop, so you should avoid food preparation and direct contact with other people for at least 48 hours after your symptoms have gone.
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