Latest figures from the Health Protection Agency (HPA) show there have been 4,407 laboratory confirmed cases of norovirus this season (from week 27 to week 01 2013). The latest figures are 56 per cent higher than the number of cases reported at this point last year, when there were 2,828 cases.
The report shows that there has been a continuation in the downward trend in the number of confirmed cases over the last week with a 32 per cent drop on the previous week (257 week 52 to 175 in week 01 2013).
This shows the unpredictability of the norovirus season where the number of confirmed cases rises and falls. However, there will still be new cases arising before the season ends.
During the two weeks up to January 13 there were 39 hospital outbreaks reported, compared to 33 in the previous fortnight, bringing the total of outbreaks for the season to 728.
A new strain of norovirus called Sydney 2012 has been circulating this season. Although this was detected through HPA surveillance at the start of the season it was not the dominant strain at that time. Later testing has revealed that it is now the dominant strain. This could be an explanatory factor in why there was an early start to the season.
John Harris, an expert in norovirus from the HPA said:
“Norovirus activity always varies from year to year and although we might have expected cases to rise again now we have passed the New Year period this hasn’t been the case. We can’t read anything into this fall and don’t know how busy the rest of the season will be. The busiest months are normally from December to April, so further cases will occur but we can’t say if there will be further significant increases in the number of laboratory reports.
“There have been reports in the media of people with symptoms of norovirus attending their local hospital but we would urge people not to do this. If you think you may have the illness then it is important to stay away from any healthcare facility and care homes to avoid spreading it to people who may have underlying health conditions and already be vulnerable. If you need advice it is best to phone NHS Direct or your doctor.”
Norovirus can be transmitted by contact with contaminated surfaces or objects, by contact with an infected person, or by the consumption of contaminated food or water. Symptoms of norovirus include a sudden onset of vomiting and/or diarrhoea. Some people may have a temperature, headache and stomach cramps. The symptoms only last for a couple of days and there are no long-term effects. Maintaining good hand hygiene is also important to help prevent it spreading.