Nausea, diarrhoea and vomiting have been plaguing more of us this season than usual.The Government Health Department said it doesn’t know the actual figures, but confirmed the numbers are significantly higher.In fact the increase has prompted the epidemiology department to create a Prevention of Diarrhoea and Vomiting leaflet.The department’s assessment officer, Dy-Juan DeRoza, said environmental health officers have had several reports from nursery schools and others in the community of cases of diarrhoea and vomiting.The one-page leaflet is now being given to nursery schools to help stem the problem there.However children are not the only ones experiencing gastroenteritis. Edward Schultz, head of Emergency at King Edward VII Memorial Hospital, confirmed that the numbers of people coming to the department with this complaint have increased in recent weeks.Ninety-three patients were seen at KEMH’s Emergency Department for gastroenteritis between January 23 and February 2. Thirty-six of them were under 18.What is causing it?According to Ms DeRoza, it’s difficult to say why there’s been an increase and it’s even difficult determine what has caused it. Unless lab tests are done on actual specimen of diarrhoeal stool, it’s impossible to be sure what the actual stomach bug was.While it’s not impossible to get these specimen, the reality is most people don’t bother. And relying on physician reporting to collect data on gastroenteritis doesn’t give a true picture of the actual occurrence, Ms DeRoza explained.“The Epidemiology and Surveillance Unit recognises that physician reporting only captures the tip of the iceberg,” she said.The method of surveillance allows the unit to monitor trends but does not stop the problem from spreading, she added.“Recognising that the majority of persons who become ill do not seek medical care, and even fewer submit specimens, it is difficult to determine the causative agent/agents causing the current increase in cases,” said Ms DeRoza. “The Department of Health therefore encourages ill persons to seek medical care and submit specimens as this may aid in stopping further spread of the illness.”Many of the current cases appear to have passed from person to person, a feature of the norovirus and rotavirus. A chart supplied by the Department of Health describes symptoms of the norovirus as nausea, vomiting, abdominal cramping, diarrhoea, fever, myalgia and headache. Rotavirus symptoms include vomiting, watery diarrhoea and a low-grade fever. Persons exposed the norovirus may experience symptoms 12 to 48 hours later and can expect to be unwell for 12 to 60 hours.Persons exposed to the rotavirus may experience symptoms one to three days later and the symptoms may last from four to eight days. (See the complete chart on our website).Once you know you have gastroenteritis, irrespective of what caused it and whether it’s just vomiting or diarrhoea, you should stay home until the conditions pass.This strong suggestion from the Department of Health is to help prevent spread of the infection.Its Prevention of Diarrhoea and Vomiting leaflet is clear:l Persons who have symptoms of vomiting and diarrhoea should not attend work and should not handle food for others while ill;l Professional food handlers should consult their physician or the Department of Health before returning to work. Food that may have been contaminated by an ill person should be disposed of properly;l Children with diarrhoea and/or vomiting should not attend school or day care centres;l Children in diapers with diarrhoea should not use wading/swimming pools.