An outbreak report in the Journal of Infectious Diseases tells the fascinating story of a norovirus outbreak in a car (auto*) dealership in Oregon that was initially thought to be foodborne, but was eventually traced to contaminated surfaces on a baby changing table (diaper changing station*) in a public toilet (restroom*). The outbreak had a startlingly high attack rate, affecting 75% of 16 employees who attended a team meeting. A thorough investigation of the restaurant that provided the sandwiches for lunch turned out to be a blind alley following the recollection of a staff member of a toddler with “spraying” diarrhoea using the baby changing table in the public toilet of the dealership. The (generous) mother left the mess for the staff member to clean up, which was accomplished using, wait for it, dry paper towels.
The environmental investigation included samples from the baby changing table in the dealership and some ‘control’ samples from 14 baby changing tables in public toilets throughout the state. Norovirus of the same genotype as the outbreak strain was identified from the baby changing table in the car dealership, but norovirus was not identified from the control baby changing tables.
Some limitations of the outbreak include the fact that it is difficult to disentangle the relative importance of the environmental reservoir and secondary transmission via contaminated food. The PCR method used for environmental sampling does not assure that the norovirus RNA identified on the baby changing table was viable. Also, the environmental norovirus isolates could not be sequenced meaning that they could not be sequence-matched with the patient isolates.
Perhaps the most shocking part of the story is that the image of visible soiling on the baby changing table (after two rounds of cleaning) was consistently viewed on baby changing tables in public toilets. Or perhaps it’s even more shocking that only 3 of the 12 affected individuals actually took time off work. As a “survivor” of a norovirus outbreak that swept through the Otter household in 2012, I can vouch for the fact that a) you need to take time off work and b) you ought to take time off work!
One important discussion point was the finding of Dr Carling’s group that baby changing tables were least likely to be cleaned on cruise ships, a setting in which persistent norovirus outbreaks are common. This outbreak report and Dr Carling’s earlier work highlight an important deficiency in how to clean and disinfect baby changing tables in public toilets. As a frequent user over the past 14 months, I can vouch for the fact that, much like a hospital bed, turnover is high which pressurizes effective terminal disinfection! I agree with the authors that disinfection with a chlorine-containing disinfectant would be ideal, but question whether this is feasible in practice.
There’s surprisingly little data supporting the role of environmental contamination in the transmission of norovirus. I’m persuaded by the various outbreaks affecting separate cohorts of patients / staff on cruise ships or aeroplanes, but this outbreak is even more compelling due to the environmental findings. Quantifying the role of the environment in the transmission of norovirus is difficult to study because it always occurs in outbreaks (hence difficult to perform a controlled study). But I’d be interested to see whether the “prior room occupancy” concept that has been established for other environmentally-associated pathogens holds true for norovirus.
Article citation: Repp KK, Hostetler TP, Keene WE. A norovirus outbreak related to contaminated surfaces. J Infect Dis 2013;208:295-298.
Also, take a look at Dr Repp’s blog.
* = for my American readers! Current data indicates that around 40% of the readers of this blog are US based, 40% are UK based and 20% are rest of world!
Reflections on Infection Prevention and Control 
Jon, if you are looking for an article on the ease of spreading of norovirus, I think this is a good start.
Barker, “Effects of cleaning and disinfection in reducing the spread of Norovirus contamination via environmental surfaces”, J Barker, Journal of Hospital Infection, 2004, 58, 42-49
What intrigues me about this article is that it looks at serial transfer and at the limitations of single pass cleaning with a chlorinated disinfectant.
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Peter, yes the Barker / Bloomfield study was seminal. There have been several similar studies since then that reinforce the fact that norovirus and other viruses spread readily from hands to surfaces and from surfaces to hands. For example, this study evaluated norovirus transfer between foods and food contact surfaces. A few studies have evaluated the efficacy of various disinfectants for removing norovirus RNA from surfaces in the field. This recent study showed that multiple rounds of bleach disinfection were unable to eliminate norovirus from surfaces. Whilst the PCR method used to recover norovirus RNA from surfaces in this study does not measure viability, it seems likely that viable norovirus can survive for extended periods based on laboratory studies using surrogate viruses and data from the field such as this car dealership outbreak.
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Jon, thank you for this timely piece. I shared your post across my 9 cleaning industry groups and then to the corporate facility management groups there.
Ed Selkow
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Ed, good to know you’ve shared this story, which should be instructive for your groups. It’s more of a problem than a solution to share in your groups. In terms of how this outbreak should change practice, I think the best approach would be clear signage to ask parents to ensure hands are washed and surfaces are clean following use, and to report to staff if they or their child have had diarrhea or vomiting recently so that the room can be adequately disinfected using an appropriate agent.
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Great post which followed my moderately good post a week earlier! The title of my post was “S&%t was flying at an auto dealer!”. I think we both agree that the cleaning is sub-optimal in most settings including healthcare. Of course, cruise ships are ‘heaven’ not only to humans, but also to microbes. The title of one of my future blog posts will be “Who wants to clean your s$#t!” I am questioning the existing misconception that people who we minimally train and pay will enjoy the task of cleaning fecal matter!
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Thanks Salah. I enjoyed your blog on this outbreak, and I look forward to your future post! I do indeed agree that cleaning is sub-optimal in most settings including healthcare, as aptly demonstrated by Phil Carling’s work. The issue of training, paying and motivating cleaning / housekeeping / janitorial staff is a thorny one but big strides forward can be taken with minimal investment.
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I am also surprised by the fact that so many continued to work when stricken with norovirus. There should be a company policy for the protection of others that you do not come to work when having symptoms of an illness that could be contagious. And the car dealership really needs to hire housekeepers or train staff to disinfect the restrooms.
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It’s incredible really that they were allowed to continue working. The NHS Choices website has some useful advice on gastroenteritis, and advises not returning to work for at least 48 hours after the last bout of diarrhea or vomiting http://www.nhs.uk/Conditions/Gastroenteritis/Pages/Introduction.aspx . However, beware, under 1s can continue to shed the virus at high concentrations for a longer period, as we found out when our son spread norovirus to several friends a week after his symptoms resolved. Oh, the guilt!
There’s a fascinating study here showing that institutions with a 72 hour exclusion policy had less viral gastroenteritis transmission among staff than institutions with a 48 hour exclusion policy. So, it’s not only a case of whether staff take time off, how long they stay away is also important.
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Thank you for blogging about my article! This was a very interesting outbreak and I am happy to answer any questions you or your readers may have. For more Oregon outbreak fun see this outbreak that has actually been cited in multiple lawsuits for banning plastic bags:
http://jid.oxfordjournals.org/content/205/11/1639.short
and this one just out today about deer-feces-contaminated-strawberries:
http://cid.oxfordjournals.org/content/early/2013/07/21/cid.cit468.abstract?keytype=ref&ijkey=v4lNzyKNI8N5Xuy
Epidemiology is so fun!
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Thanks Dr Repp for taking the time to read the blog and comment. Do you have an explanation as to why so few staff took time off work? Also, have any changes been implemented in the state regarding guidance for cleaning baby changing stations?
It certainly looks like you have some interesting outbreaks to deal with. Great sleuthing to trace the E. coli O157 outbreak to the farm. Must have been quite a buzz to find PFGE matches. I’d not seen the one about plastic bags, which demonstrates how far contamination spreads.
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Most employees took one day off work – it just happened to be a weekend day where there weren’t many people working anyway. You have to remember that these people are not food handlers, so they are not required by law to abstain from work for any specified time. There have been no law changes for cleaning diaper changing stations at this point. However, there has been a lot of talk in the professional cleaning community and hospital infection control, so I expect many internal policies are being modified. Thanks again!
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I see, that makes sense regarding time off. Leaving the risk of contaminating a “product” (e.g. foodstuff) aside, I suspect that one day off is not sufficient to protect your colleagues, as suggested by this article about the time of exclusion from work and the risk of spread among colleagues. It’s good when research effects practice change!
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Hi Jon, Thank you for sharing of this outbreak investigation outcome. I also appreciate the subsequent link to the program synopsis of the 2013 International Infection Control Conference in Geneva.
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Thank you for the post Jon, it was very informative and intriguing. As medical staff and researchers, we know that even after the symptoms have resolved, one may continue to shed the virus unknowingly for the next few days. However, this concept is so easily forgotten or is completely novel to the general population (especially children). Additonally, there are many common infectious diseases plaguing the general population that follow a similar concept (contagious even after resolution) that the general population may not be aware of.
Has their been any qualitative studies completed in high-risk settings such as nursing-homes that looks into the knowledge and behavioral patterns of staff and patient during times of illness such as the norovirus or influenza?
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Smit, couldn’t find anything about knowledge and staff attitudes towards norovirus. But there’s a few studies about this for influenza. Staff knowledge is, as you may expect, less than you would hope for. I suspect the same would also be true for noro.
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Nice article. On a whole, the Japanese are pretty well educated on Norovirus and it is rare to not see a bottle of disinfectant wash that works on the virus in a public toilet (Most big places that is). But, I think the same mentality in regard to taking time off work in the non-health care sector is similar to the US. On the other hand, our hospital has a mandatory 72 hour waiting period before staff can come back to work. We also have all door handles, railings and anywhere where people tend to touch wiped down with a bleach solution 3 times a day. I am interested in what hospitals in the US do in the seasons when Norovirus is most active?
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Thanks David. I’m not surprised to hear that the Japanese are disinfectant heavy, so to speak. Also not surprised to hear that work goes on regardless in Japan. I’ve not seen any disinfectants (other than alcohol hand gel dispensers) in baby change rooms / public toilets in US or UK hospitals, but there may well be some out there who do it. I suspect the perceived risk of accident and subsequent litigation may be a factor in not going down that road for some.
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Good article. Hygiene is always the key thing to watch for. Preventing virusses and bacteria is nr 1.
Gr,
Symptomen buikgriep
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