The onset of the winter months, especially the cold, dry conditions associated with this time of year, brings with it an increase in viral infections. Some of these viruses produce symptoms similar to a heavy cold, whereas others can cause stomach upsets leading to sickness and diarrhoea. Whatever the symptoms, the possibility of an influx of patients means that medical professionals need to be prepared for a considerable increase in workload. Norwalk virus At this time of year, the highly infectious Norwalk virus - otherwise known as winter vomiting disease or small round structured virus (SRSV) - can strike. It can affect between 600,000 and a million people each year in the United Kingdom (according to BUPA), and puts significant strain on the country's health service. The virus, named Norwalk after the town in Ohio where it was first discovered, is highly infectious and quickly takes hold, causing sufferers to experience a sudden onset of vomiting. Although winter vomiting disease is unpleasant, it is not fatal, and usually passes within a few days, with symptoms including fever, diarrhoea and projectile vomiting lasting up to 36 hours. However, due to the vomiting, the virus can become airborne and spread rapidly. A lack of good hygiene can also add to its virulence.

Worse in winter

Norwalk virus is thought to occur more in winter because people spend more of their time indoors out of the cold weather and once one person has the virus, there's very little to stop it spreading. It is also thought that, for those who do brave the elements, cold, dry air affects the linings of the nasal passage and upper respiratory tract, making them drier and more vulnerable to viral infection. The rise in viscosity of bronchial mucous seems to reduce the ability of the body to fight offending micro-organisms, such as the SRSV, that may be in the atmosphere. No one particular group is more susceptible to winter vomiting disease. However, smoky environments may serve to spread the disease more quickly, as smoke helps to weaken the immune system.

Close contact

Schools, hospitals and nursing homes are greatly affected, as the disease spreads more quickly where people are in close contact. Between 1992 and 2000, the number of reported outbreaks of winter vomiting disease included 754 outbreaks in hospitals, 724 in residential care homes and 73 in schools. The effect of this disease on a hospital can be quite dramatic. In the case of Glasgow's Victoria Infirmary, operations had to be postponed, new patients were turned away and the hospital was closed to emergencies. Staff shortages also occurred as staff contracted the disease, adding pressure on remaining staff.

The outbreaks that occurred at a number of hospitals across Scotland and Northern England in January 2002 were widely publicised. Although, at the time, the number of cases were high, they were not unexpectedly so. According to the Public Health Laboratory Service, there were 277 laboratory reports in the first four weeks of 2002, compared with 163 reports during the same period of 2001. While it is accepted that not everyone consults their doctor if they get the disease, the levels reported in 2001 were actually the lowest since 1993.

Be prepared With families gathering to celebrate Christmas, and the party season in full swing, there is a rise in this disease just after the Christmas period, with levels of infection tailing off by the end of February. This is a busy time for most people, but good hygiene, including proper hand-washing, should not be overlooked. Back to top Other health features