An illustration of the Norovirus. The viruses are transmitted by fecally contaminated food or water, by person-to-person contact, and via aerosolization of the virus and subsequent contamination of surfaces. Noroviruses are the most common cause of viral gastroenteritis in humans, and affect people of all ages.

    Norovirus: your guide to the bug that spells trouble this winter

    9 December 2016

    It’s getting to that time of year when my surgery starts to get full of people with coughs, colds and other viral infections as well as those with the winter vomiting bug, more correctly known as norovirus. These highly contagious viruses are the most common cause of stomach infection in the UK, with an estimated 600,000 to one million cases each year, although this is probably a huge underestimate since many people do not report their symptoms.

    Perhaps more worryingly at the moment is that the latest figures from Public Health England (PHE) show that there are 45 per cent more cases now than at the same time last year. This has led some senior doctors to say that they fear this could be the straw that breaks the back of the NHS this winter. So far, 22 hospitals have had to close wards or restrict admission due to this infection and comes as hospitals have record levels of bed blocking and occupancy, with massive pressure on doctors to send people home from hospital as quickly as possible.

    Other names for noroviruses are ‘small round structured viruses’ (SRSV) or ‘Norwalk-like viruses’. The symptoms are fairly classical, typically of sudden nausea and projectile vomiting, watery diarrhoea, fever, stomach cramps, headache and aching limbs. The virus takes between 24 and 48 hours to take hold after infection, followed by symptoms that last up to three days. A person is still contagious 48 hours after their symptoms have cleared.

    You can get norovirus illness at any age and at any time of the year but it tends to be more common in winter, hence the name, but outbreaks are more common in semi-closed environments such as hospitals, nursing homes, schools and cruise ships.

    Norovirus is easily spread from person to person, usually after contact with an infected person or surface that has been contaminated with the virus. Faecal matter from the infected person contains the virus, meaning it can be found on toilet seats, handles and other hard surfaces. You can also get the virus from contaminated food and water, especially bivalve molluscs (oysters, mussels, clams, cockles and scallops).

    There is no specific treatment for the virus but to let the illness run its course, and so the advice is to not attend your doctor’s surgery in order to prevent spreading the infection further. While the symptoms are not pleasant, most people make a full recovery within a few days.

    Both vomiting and diarrhoea cause loss of water from the body. This means you need to drink plenty of liquids to replace lost fluids. Antidiarrhoeal medicines such as loperamide can ease symptoms, while paracetamol can help aches and pains. (Loperamide is not suitable for children.) Rehydration sachets such as Dioralyte are an easy way of rehydrating and replacing salts lost through diarrhoea and can be taken by both children and adults. Very young people and the elderly are at most risk of dehydration. Symptoms to look out for in severe dehydration include severe thirst, dry, wrinkled skin, irritability, an inability to pass urine, a weak pulse, sunken eyes and cold hands and feet.

    Because it is so contagious, the sensible thing is to stay at home and away from public places, and you should also disinfect all surfaces that have been contaminated by the virus such as toilets, bedding and walls. The best way to protect yourself is to practise good hygiene so always wash your hands after using the toilet, disinfect any surface that’s been contaminated with vomit or diarrhoea from the illness and don’t prepare food for others until three days after symptoms clear. Cleaners should wear gloves when disinfecting washrooms and toilets.

    Unfortunately, it is possible to get the infection several times and this is because there are many different types of norovirus and immunity after an infection only lasts for 14 weeks. Fortunately, noroviruses don’t have any long-term effects on health, but their short-term impact on the NHS this winter remains to be seen.