THOUSANDS of people have been laid low after a fourfold increase in a violent stomach bug which is sweeping the country.
The highly infectious winter vomiting bug has led to a big rise in patients calling out their GPs and has hit hotel residents as well as several hospitals and nursing homes.
A fourfold increase in cases has been recorded by the disease watchdog compared with normal levels of the infection -- putting the outbreaks at one of their highest levels in years.
Doctors have warned that the elderly, pregnant women and small children are particularly vulnerable.
The HSE Head of Health Protection, Dr Kevin Kelleher, warned that special care should be taken with those most at risk.
He said: "Elderly people and infants should ensure they get plenty of fluids and a minority may have to be hospitalised."
Dr Paul McKeown of the Health Protection Surveillance Centre (HPSC) said a very infectious form of the virus was causing the outbreaks.
The infection causes severe vomiting and diarrhoea and can start with a sudden onset of explosive illness.
The virus is very resilient and can survive for weeks in the environment -- living on door and toilet handles, remote controls, light switches and worktops.Schools have also been hit by the bug and residents of two hotels have been the victims of outbreaks.
HPSC officials have been able to track the surge based on a tiny fraction of cases which are sent to laboratories for testing.
Normally, around 50 cases of the bug a week are officially recorded in this way – but recently that has jumped to 190.
The real number of victims runs into thousands as people recover at home.
It also has a major knock-on effect for businesses as staff take sick leave.
Workers remain infectious for up to 48 hours after the symptoms of the illness pass.
Dr McKeown of the HPSC said members of the public can help stop the spread of illness by respecting hospital and nursing home visitor restrictions and by using the alcohol gel supplied as they enter and leave the facilities.
"While outpatient departments and emergency departments are not affected, patients are asked not to attend hospital if they have been affected by vomiting and/or diarrhoea in the last 48 hours," he said.
"Handwashing with soap and water – especially after contact with someone who is ill and after using the toilet – is also extremely important, particularly if you are or have been sick.
"When it gets into hospitals or nursing homes, it can cause serious disruption, for example, ward closures, cancelled operations and added pressure on emergency departments."
He added: "It is important that ill and vulnerable patients in these settings do not become more ill than they already are."
Dr Austin O' Carroll, a GP in the north inner-city, said he was seeing a rise in cases among patients.
If they are children he asks their parent to bring them to the surgery in case they are suffering from another serious condition.
The spread of the disease is going through one of its high circulation phases and although it usually does not cause serious illness the symptoms are very debilitating.
The bug, known as the Norwalk virus, is most common at this time of the year, hence it is referred to as winter vomiting disease.
St Vincent's Hospital in Dublin yesterday appealed to the public not to bring children under 12 years of age because of a virulent outbreak.
A spokesman said 73 patients and 57 staff were affected with serious disruption to services.
He said: "We appreciate that Christmas is an important time for family visits but we know that the virus is being brought in from the community and we must apply strict visiting restrictions, including a ban on younger children's visits during the holiday period.
"People should avoid visiting the hospital if possible, should limit numbers to one person at a time if their visit is absolutely essential, should refrain from moving from one section of the hospital to another and should avoid canteens and any other food dispensing areas.
"People who have symptoms such as 'upset tummy' should not attend the hospital but contact their GP in the first instance if they have serious concerns."
Those with appointments to see doctors should turn up as normal, he added. The bug is mostly likely to thrive in closed environments but it appears to be very prevalent in the community as well this year.
A spokesman for the Irish Hotels Federation said managers are putting safeguards in place but "as is the case for all venues, where people gather there can be a risk at certain times of the year and this is something we are very vigilant against".