Norovirus

Norovirus is actually a collection of similar Small Round Structured Viruses (SRSVs) and was known as ‘gastric flu’ for years until the eponymous causative agent was isolated after an outbreak in Norwalk, Ohio. Advances in DNA analysis then showed that Toronto virus, Mexico virus, Hawaii virus and Snow Mountain virus were all from the same family of Calciviridae.]

There are several key differences between influenza virus and Norovirus:

  • Norovirus is generally transmitted via the faeco-oral route and not by sneeze droplets
  • Carriers can be asymptomatic and still infectious
  • The “48hrs symptom free and you are safe to return to work” etc rule is nonsense – having recovered you may still be stool positive for up to a fortnight
  • Normal cleaning products and protocols do not kill Norovirus – including bleach, disinfectants, alcohol gels etc

Referring to The Telegraph (29/03/10)

Record numbers hit by Norovirus – Record numbers of people are falling ill with the winter vomiting bug, official figures show.

Cases of norovirus are significantly higher than normal for the time of year – with the unusually cold weather and a highly infectious strain to blame.

Since Christmas, the rate of new cases has far outstripped that seen two years ago, described by experts as the worst outbreak ever seen. Experts believe the coldest winter for 30 years has encouraged people to spend more time indoors, where the bug is spread more readily to others. In parts of the country, hospital wards and schools have even been forced to close in a bid to contain the outbreak.

Family doctors are also warning that they are seeing large numbers of patients with symptoms of the bug, with some contagious strains believed to be circulating. Although not dangerous for most healthy people, the infection usually results in two to three days of violent vomiting and extended periods away from work. In the case of young children and the elderly it can cause them to become dangerously dehydrated and even die.

According to the HPA, the number of laboratory confirmed cases during the past eight months is now higher than during the winter of 2007/2008, which at that stage was the worst on record.

This month a primary school, the Willows in Newbury in Berkshire, was forced to close for two days after 67 pupils, almost a third of the entire school roll, showed symptoms of the bug.

Norovirus outbreaks have also caused the closure of 152 hospital wards across England in recent weeks.

Some hospitals have had to close more than one ward in a bid to control the infection.  First Care, the absence management group who monitor more than 100,000 staff across Britain, said since February sickness levels from the illness had been above that of last year.

There was also a significant increase in mid-March when there 23 per cent more people off sick with norovirus than earlier in the month, their database shows.

Those with the infection are warned to drink plenty of fluids and practise good hygiene to avoid spreading the virus to others.

Although the infection rate has fallen since its peak earlier in the winter, it is still around 50 per cent higher than at the same time last year, with around 500 new laboratory confirmed cases a week earlier this month.

The figures show that in total, there were 7,302 confirmed cases of norovirus between July and the end of February this year – higher than during the same period last year, when there were 5,976.

The figure is already higher than the whole of 2007/08 when there were 6,009. The HPA collects figures on the vomiting bug from July to the following June – so that it can include the whole of a winter season in one year’s figures. For every confirmed laboratory case of the virus it is thought that there are hundreds more in the community.

In total, the HPA estimates that up to one million people could have been hit by norovirus this winter.

Prof Hugh Pennington, emeritus professor of bacteriology at Aberdeen University and an expert in infectious diseases, highlighted the cold winter and particularly virulent strains of the bug as factors behind its spread.

“There is some evidence that there are strains of the virus at the moment that are a bit better at getting about, a bit better at transmitting themselves,” he said.

“It may be that there is a seasonal element, that people were inside more because of the cold weather earlier this year, helping to spread the disease. It may also be that we have got better at recording cases. But, of course, these figures are just the tip of the iceberg. Most people with norovirus never even go to see their GP, mainly because they realise that there is no real treatment.”

Prof Steve Field, chairman of the Royal College of General Practitioners, also warned that the true number of cases was likely to be far in excess of official estimates.

“We are seeing quite a few people with diarrhoea, but without sending off every specimen for testing it is impossible to tell who has norovirus,” he said.

“This is an illness which is grossly unreported, by hundreds of thousands of cases.”

A spokesman for the HPA said: “The numbers of lab reports of norovirus only represent a small proportion of the actual numbers of people who will be infected as due it its relatively short time span most people will not see a doctor.”

The agency said that there were always fluctuations in the number of cases every year but that better reporting of the illness could be partly behind the increase. The HPA advises that those with the virus should follow strict hygiene rules, especially when handling food.

Chemex AntiBak is certified as effective against Norovirus

Remember: Hypochlorites such as bleach or chlorine tablets have a very limited effect on Norovirus and have many other drawbacks

Remember: Quats – the active biocide in many products also have limited efficacy against Norovirus

Remember – only Antibak is proven to give a log 5.4 kill against Norovirus and is used by many ambulance trusts for emergency decontaminations.

The HPA also signed off AntiBak as suitable for emergency decontaminations to remove Norovirus.

Some Simple Steps to Fight Norovirus

The theory is all very well, but what can you do in a practical sense to manage the risk? We suggest…

  • Review and Plan – HR, systems, procedures. Dealing with issues like this should be covered in your disaster recovery plan / business continuity strategy.
  • The steps are: Analyse Your Business > Assess the Risks > Develop Your Strategy > Develop Your Plan > Rehearse Your Plan.
  • Train your staff   Awareness is key. Hygiene is easy to train.
  • Hand Hygiene    Use proper soaps and sanitisers – training again! Hand wash posters. Sanitisers at reception for visitors. It all helps communicate the right message.
  • Surface Hygiene – Right product, right protocol, right frequency. Are your cleaners using products proven to be effective against Norovirus?
  • Concentrate on anything people touch – handles, push plates, buttons, phones, keyboards. Use a proper spray and blue roll or bactericidal wipes from a reputable supplier.
  • Put in a programme and stick to it.
  • Physical and Spatial      Are screens and barriers appropriate? Physical separation reduces risk especially in areas with frequent visitors, contact with members of the public etc.
  • Systems – Systematise it. Don’t have a day’s crusade and then forget all about it. In business there is too much going on to manage this yourselves. Systems like a hygiene programme are neither expensive nor difficult to put in place – it’s the discipline to stick to them that’s tough.

We would be delighted to speak to you if you have any questions regarding how we can help you safeguard your business and operations. Apart from high-level infection control we deal with a wide range of blue-chip organisations in some very diverse sectors.

Advice is confidential, without obligation and a telephone call away. Call our expert team on 0121 56 56 300 or email us at info@chemexuk.com