Missed phone calls, changing stories: How E. coli spread at the San Diego County Fair

More than 1.1 million people had already passed through the gates of the San Diego County Fair this summer by the time an E. coli outbreak forced the closure of all animal exhibits and rides.

News that a 2-year-old boy had died after picking up the particularly nasty infection, which was also contracted by three other children with animal contact at the fair, stirred alarm within the community. Many had already roamed the midway, stuffed themselves full of fair food and passed through the venue’s cavernous livestock barns en route to pig races, pony rides and the petting zoo.

Paul Sisson of The San Diego Union Tribune reports hundreds of emails and other documents obtained through Public Records Act requests show that, while the public health team was able to move quickly, more frequent county case reviews, a more modern medical records system and more prompt and accurate responses from families with infected children might have gotten the investigation started days earlier.

The decision to shut down the animal exhibits on June 29, records show, came after four days of a behind-the-scenes scramble by the county’s public health department. With one death already on the books, they decided to notify the public even though testing had not yet confirmed that all four of those first four cases had E. coli infections.

It quickly became clear those initial instincts were accurate. In the following weeks, an additional seven people, plus two more whose infections weren’t confirmed, came forward, including another young boy who nearly died after suffering severe complications that attacked his kidneys.

Records show that zeroing in on the fairgrounds was no simple task. Epidemiologists had to eliminate a broad range of possible locations, from restaurants to a busy daycare center, before they were able to zero in on the fairgrounds.

And there was plenty of other work that had to be done simultaneously. County records show that the department investigated 435 disease cases in June alone. Of those, there were 43 cases of shiga toxin-producing E. coli reported that month, forcing disease detectives to sift out the 11 eventually confirmed to be part of the outbreak.

Determining whether there are connections between cases requires interviews with each subject or their legal guardians. Depending on the type of pathogen involved, it’s a process that often relies on frail human memory to recall the finest possible details of possible exposure routes from foreign travel and foods consumed to places visited and close contact with others.

The investigative process doesn’t get started until the health department is notified, usually after a test result administered in a doctor’s office or hospital comes back positive.

Subjects often aren’t interviewed until weeks after they got infected because many infections have incubation periods measured in days or weeks and it usually takes time before individuals decide to seek medical attention and additional time for medical providers to make a diagnosis.

Often, those charged with reading these particularly fragile tea leaves learn to trust their instincts, and that was certainly the case with the fairgrounds outbreak.

Emails show that the county’s epidemiology team first began to suspect that it might have an outbreak on its hands on June 24, the day that 2-year-old Jedidiah King Cabezuela (right) was admitted to the intensive care unit at Rady Children’s Hospital with severe kidney problems.

While discussing his condition, an epidemiologist noted that the boy had visited the fair before he got sick. And, she said, the county had been notified just before Cabezuela’s death of another boy, this one 9 years old, who tested positive for the type of toxin produced by the E. coli strain causing so much difficulty for Cabezuela.

Though the 2-year-old and 9-year-old hadn’t eaten the same foods at the fair, and the older boy’s parents said he didn’t visit animal areas, the fact that both visited the same location was enough for the epidemiologist to suggest that the department “should at least keep an eye on” the 9-year-old, even though he never got sick enough to need hospitalization.

By Tuesday, June 25, the public health department received the news that Cabezuela died overnight, and that information pushed the team to begin a relentless search for similar shiga toxin-producing E. coli infections.

They quickly found a report of a 13-year-old girl who had a positive toxin test after visiting the fair on June 8. Her parents had told interviewers that she had contact with animals and had eaten fair food afterward without first washing her hands.

Another girl, this one age 11, had also had a positive test but her parents had not returned repeated calls for an interview. It would not become clear that she, too, had visited the fair and had contact with animals until her parents were finally reached on June 28, the same day that the county announced it would close all public animal exhibits.

Then there was the 9-year-old boy mentioned in that prescient June 24 email. His parents initially said that he had no animal contact at the fair, but in subsequent interviews those parents remembered that, yes, their son did visit the livestock barn when the family visited on June 13.

With three, then four cases all reporting food consumption and animal contact at the fairgrounds, food inspectors descended on five different food vendors who sold items that the kids reported eating and found no traces of E. coli contamination.

Food poisoning ruled out, officials concluded that the E. coli exposure was most likely down to animals and, with the cooperation of the fair board, shut down all public access to animal exhibits and rides on June 29. Testing never did pinpoint the exact source of contamination, though the fair’s petting zoo and pony rides were ruled out.

Once public health nurses do their phone interviews and build up as clear a picture as they can of the circumstances surrounding each individual case, epidemiologists can begin looking for patterns, keeping an eye out for clusters of patients in specific geographic areas or with other commonalities such as foreign travel or consumption of tainted food.

A table of petting zoo outbreaks is available at https://www.barfblog.com/wp-content/uploads/2017/08/Petting-Zoo-Outbreaks-Table-7-26-17.xlsx

A timeline of the E. coli outbreak at the San Diego County Fair

May 31– San Diego County Fair opens

June 8 –11-year-old and 13-year-old girls visit fair

June 10 –13-year-old becomes ill

June 12 –11-year-old becomes ill after a second fair visit

June 13 – 9-year-old boy visits fair

June 15 – 2-year-old Jedidiah Cabezuela visits fair

June 16 – 9-year-old becomes ill

June 18 – Investigator call parents of 11-year-old, get no reply

June 19 – 13-year-old reports visiting animal areas at fair; Jedidiah becomes ill; county holds weekly analysis meeting

June 20 – Jedidiah admitted to Rady Children’s Hospital

June 21 – 4-year-old and 38-year-old who later test positive for E. coli infections visit fair

June 22 – Jedidiah diagnosed with severe E. coli infection; 6-year-old Ryan

Sadrabadi, 2-year-old Cristiano Lopez and his mother, Nicole Lopez, and another 2-year-old girl, visit the fair

June 23 – Family confirms Jedidiah visited fair’s animal exhibits; one-year-old girl later confirmed to have E. coli infection visits the fair

June 24 – Jedidiah dies from kidney failure; 9-year-old’s fair attendance confirmed, animal contact denied; County epidemiologist raises red flag about possible case cluster at fair; Nicole Lopez becomes ill, treated at Kaiser La Mesa

June 25 – County learns of Jedidiah’s death, begins exploring fair connections in depth

June 26 –Ryan, 2-year-old girl and 1-year-old become ill

June 28 – Family of 9-year-old revises statement, confirms visiting livestock barn; Family of 11-year-old confirms she visited sheep exhibit at fair; County announces E. coli cluster at Del Mar Fairgrounds; County inspects five food booths visited by first four cases, no E. coli found; Cristiano becomes ill

June 29 – County inspects all 160 food booths at fair, finds no E. coli contamination; All animal areas at the fair are closed; four-year-old becomes ill

June 30 – Ryan becomes ill diagnosed with E. coli infection

July 1 – 6-year-old’s case reported to county

July 2 – Cristiano admitted to Kaiser Permanente San Diego Medical Center with worsening symptoms, diagnosed with E. Coli infection

July 3 – 2-year-old girl and 4-year-old’s cases reported to county

July 4 – Fair closes with an attendance that exceeds 1.5 million; Cristiano’s infection reported to county; Cristiano transferred to Rady Children’s Hospital, undergoes dialysis for hemolytic uremic syndrome that attacks his kidneys

July 6 – 38-year-old becomes ill

July 9 – 38-year-old’s infection reported to county

July 10 – 30-year-old’s and 1-year-old’s infections reported to county

July 29 – Three families file claims against fair board, alleging they weren’t properly warned of E. coli risk

July 31 – Environmental and animal testing fail to reveal a clear source of outbreak, but exposure in fair’s livestock barn deemed “likely”

Best practices for planning events encouraging human-animal interactions

Zoonoses and Public Health

G. Erdozain , K. KuKanich , B. Chapman  and D. Powell

http://onlinelibrary.wiley.com/doi/10.1111/zph.12117/abstract?deniedAccess

Educational events encouraging human–animal interaction include the risk of zoonotic disease transmission. It is estimated that 14% of all disease in the US caused by Campylobacter spp., Cryptosporidium spp., Shiga toxin-producing Escherichia coli (STEC) O157, non-O157 STECs, Listeria monocytogenes, nontyphoidal Salmonella enterica and Yersinia enterocolitica were attributable to animal contact. This article reviews best practices for organizing events where human–animal interactions are encouraged, with the objective of lowering the risk of zoonotic disease transmission.

Ripple: Arizona scientists to examine food safety practices after E. coli outbreak

In the spring of 2018, an E. coli O157 outbreak linked to romaine lettuce grown in the Yuma, Arizona area resulted in 210 reported illnesses from 36 states, 96 hospitalizations, 27 cases of hemolytic uremic syndrome (HUS) and five deaths.

The U.S. Food and Drug Administration has launched a new initiative with support from the Arizona Department of Agriculture, and in conjunction with the University of Arizona Cooperative Extension, the Wellton-Mohawk Irrigation and Drainage District (WMIDD), and members of the Yuma area leafy greens industry to better understand the ecology of human pathogens in the environment in the Yuma agricultural region. This initiative will be a multi-year study which will focus on how these pathogens survive, move and possibly contaminate produce prior to harvest. 

While the FDA, the Arizona Department of Agriculture and other state partners conducted an environmental assessment from June through August 2018 that narrowed the scope of the outbreak, the specific origin, the environmental distribution and the potential reservoirs of the outbreak strain remain unknown.

Between 2009 and 2017, FDA and partners at CDC identified 28 foodborne STEC outbreaks with known or suspected links to leafy greens. Like a lot of fresh produce, leafy greens are often eaten raw without a kill-step, such as cooking, that could eliminate pathogens that may be present.

Sounds like Yuma growers could use a Box of Rain. Or maybe more knowledge of the microbial ripple effect. May death be groovy for you, long-time Grateful Dead collaborator and lyricist Robert Hunter, who passed on Tuesday, aged 78.

UK factory put uncooked sausage in pre-packed sandwiches posing ‘danger to health’

James Cain of The Mirror reports a factory has been ordered to stop making food after it put uncooked sausages into pre-packed sandwiches.

The Middlesbrough-based factory has been told by health authorities it risked causing a listeria outbreak.

Café Class Ltd has been served with a hygiene emergency prohibition order for food safety practices that posed an “immediate danger to human health”.

A court this week heard how the company extended the use-by dates of boiled eggs, cheddar cheese and streaky bacon, putting consumers’ health at risk.

The risk to the public was so severe that the Food Standards Agency (FSA) issued an immediate product recall on sandwiches, wraps and salads made by the company.

Listeria has been in the spotlight this year after six people died after getting listeria from prepackaged sandwiches and salads served in UK hospitals.

In the unrelated case the company, which traded with stores including Londis, Nisa and North East Convenience Stores, faced court as Middlesbrough Council sought an emergency hygiene order to prevent it from making food, reports the Local Demoracy Reporting service for Teesside Live .

Company directors Shahid Nawaz and Mohammed Haris Abdullah arrived at Teesside Magistrates’ Court yesterday to hear Middlesbrough Council lay out the case against their company.

Andrew Perriman, prosecuting for the council , told magistrates that Café Class, based in Riverside Park, was visited by environmental health officers on September 9.

The inspection was arranged “to assess compliance with a hygiene improvement notice served earlier in the year as a result of allergy management concerns”.

But Mr Perriman said the officers were shocked to discover the factory was routinely placing ingredients on their use-by date in sandwiches, wraps and salads which would then be labelled with a four-day use-by date.

“In respect of cooked ham aspect used in the final product, it is specified by the manufacturer to be used within three days once opened,” said Mr Perriman.

But the officers found that once opened, the ham had been placed in a plastic container on September 8 and labelled with a use-by date of September 11.

Mr Perriman said it could be argued that if September 8 is counted as day one, this actually meant the ham was being used for four days.

In any case, the factory would continue to use the ham as an ingredient right up until the final use-by day.

But Mr Perriman added: “It was then placed into a sandwich and given a further four-day use by date.

“Not only that, the packaging on the final product stated ‘once opened consume within 24 hours’.

He said this practice meant cooked ham with a use-by date of September 10 or 11 was actually being used in a product labelled with a use-by date of September 15 or 16.

“As a result, the three-day shelf life is exceeded by a further six days,” he said adding that this was “way past” safe limits.The company’s website says: “We here at Café Class carefully ensure that the standards of Food Agency are met at all times and any waste is disposed of appropriately.

“All our products are fully cooked but we do not send the food waste to landfill sites, thus helping the environment and fulfilling our responsibility towards the society.”

Uh huh.

Yes Minister: Dozens of people stricken by Salmonella-infected British eggs

Dozens of people have been poisoned after consuming British eggs contaminated with salmonella, an investigation has found, despite recent government assurances that the risk had been virtually eliminated.

Andrew Wasley of The Guardian reports at least 45 consumers have fallen ill since January this year in a major disease outbreak health officials have traced back to contaminated eggs and poultry farms.

Despite outbreaks of this strain occurring for more than three years, the government has issued no public warnings about the safety of hens’ eggs. In 2017, the Food Standards Agency (FSA) told the public that it was safe for vulnerable people, including pregnant women and the elderly to eat raw, runny or soft-boiled eggs. At the time the head of the FSA said: “The risk of salmonella is now so low you needn’t worry.”

Internal records obtained by the Bureau of Investigative Journalism and the Guardian show that 25 egg-laying poultry flocks in the UK have tested positive for salmonella in 2019 so far, seven of them contaminated with the most serious strains of the bacteria. Two egg-packing factories – one that supplies leading supermarkets – have also been contaminated, records show.

Eggs produced by the infected poultry flocks were placed under restrictions, meaning they cannot be sold to the public and must be sent for processing to kill the bacteria or be disposed of – while birds from infected flocks were culled.

However, some contaminated eggs did reach the public, with PHE confirming that 45 people had become ill after eating eggs infected with salmonella since January. The exact route to the public is unclear.

The government records also reveal that in 2018, 28 flocks tested positive for salmonella, four of them with dangerous strains.

According to PHE a further 55 human cases prior to 2019 were also being linked to the outbreak.

The revelations come just two years after the Food Standards Agency (FSA) declared that almost all eggs produced in the UK were free of salmonella. A major health scare in the 1980s had led to warnings that vulnerable groups should not consume raw or lightly cooked eggs – or food containing them – because of the salmonella risk. The then junior health minister Edwina Currie sparked a public outcry after saying “most” British egg production was infected with salmonella.

But in 2017 the FSA lifted the advice, stating the presence of salmonella in eggs had been “dramatically reduced” and that “British Lion” eggs – which cover about 90% of UK egg production – were safe to eat.

Speaking at the time, the then FSA chair Heather Hancock said: “We are now saying if there is a British Lion egg, you’re safe to do that. The risk of salmonella is now so low you needn’t worry. And that’s true whether you’re a fit healthy adult, or whether you’re pregnant or elderly or young. It’s only people on strictly medically supervised diets who need to avoid those eggs.”

PHE stated that it had been investigating this strain of salmonella for three years, despite the FSA clearing eggs for consumption.

The British Retail Consortium said: “Food safety remains a top priority for UK retailers and all UK sourced eggs are produced to the Lion code of practice. Retailers will comprehensively investigate any safety issues in our food supply and will take swift action as necessary.”

Uh-huh.

But we have training and audits: Dirty crates and vans used to deliver food by Asda

Assif Majid of BBC News writes that Watchdog’s reporter was given no training on keeping delivery crates and vans clean.

The reporter witnessed spillages, but was told by senior drivers that there was no need to clear it up during the delivery round.

Asda says it has a “clean as you go” policy and staff get full training.

Both Asda employees and customers have contacted the consumer programme with allegations about the cleanliness of the store’s delivery crates.

One driver told the programme: “There’s no cleaning process in place. The crates are used over and over again, even after spillages. Most, if not all, are dirty, from food, and things like smashed eggs.”

Another driver told the programme they are so concerned about poor hygiene, they are worried about their own family eating food from the crates.

Asda said the findings were “isolated examples and the opinion of individual colleagues”.

It added: “The findings do not reflect the extensive policies and training they have in place, which are supported by independent third party audits.”

The supermarket also says Watchdog’s researcher did not receive the full role-specific training because he didn’t do enough shifts.

Chartered environmental health practitioner Barrie Trevena said: “Even if the food you’re putting in is wrapped, the packages then become contaminated and then when the customer handles the cans and the packages, then that’s going to contaminate their worktop and fridge.”

The company said it delivered almost half a million orders each week, using their totes more than 2.5 million times, and it was inaccurate and misleading to suggest that it did not have policies or training in place at a business level.

Inconceivable.

Australian frozen meals recalled for Listeria

This recall is particularly notable because the meals are distributed to some of the most vulnerable in society.

The NSW Food Authority advises:

The Flagstaff Group Limited T/A Flagstaff Fine Foods is conducting a recall of the products below. The products have been available for sale at Meals on Wheels and community organisations in NSW, ACT, QLD and SA.

Product details:

Chicken Schnitzel with Gravy, 360g, Cardboard container clear film seal, Use By: 17/07/2020, 24/07/2020, 25/07/2020, 05/08/2020, 06/08/2020, 18/08/2020, 13/08/2020, 27/08/2020, 03/09/2020

Lamb Chop, 360g, Cardboard container clear film seal, Use By: 17/02/2020, 18/07/2020, 25/07/2020, 30/07/2020, 06/08/2020, 18/08/2020, 20/08/2020, 22/08/2020, 27/08/2020, 09/09/2020, 12/09/2020

Honey Mustard Beef, 360g, Cardboard container clear film seal, Use By: 28/07/2020, 25/08/2020

Pork in BBQ Sauce, 360g, Cardboard container clear film seal, Use By: 25/07/2020, 18/08/2020

Apricot and Fig Chicken, 360g, Cardboard container clear film seal, Use By: 15/08/2020

Vienna Schnitizel, 360g, Cardboard container clear film seal, Use By: 22/07/2020, 05/08/2020, 18/08/2020, 29/08/2020, 10/09/2020

Pork Apple and Cranberry Casserole, 360g, Cardboard container clear film seal, Use By: 12/08/2020, 01/09/2020

Roast Beef, 360g, Cardboard container clear film seal, Use By: 21/07/2020, 25/07/2020, 01/08/2020, 06/08/2020, 18/08/2020, 22/08/2020, 29/08/2020, 05/09/2020, 12/09/2020

Problem: The recall is due to a potential microbial (Listeria monocytogenes) contamination.

Food safety hazard: Listeria may cause illness in pregnant women and their unborn babies, the elderly and people with low immune systems.

Country of origin: Australia

What to do: Consumers should not consume this product and should return the product to the place of purchase for a full refund. If you are concerned about your health, you should seek medical advice.

For further information please contact:

The Flagstaff Group Limited T/A Flagstaff Fine Foods
Ph. 02 4272 0208
www.flagstaffgroup.com.au

Australian Capital Territory food safety record improves after education model introduced

I’m not sure I buy it.

Not enough critical questions answered, coupled with numerical spin.

Jasper Lindell of The Canberra Times reports the number of improvement notices issued to ACT businesses for not complying with food safety requirements more than halved in the last financial year, with ACT Health confident there were fewer serious safety breaches.

Eighty-seven improvement notices were issued in 2018-19, down from 341 in 2017-18. More than 600 were issued in 2015-16, according to figures from ACT Health.

In 2017-18, 2443 inspections were carried out while 2552 inspections were completed in 2018-19.

The targeted amount in both years was 2500 inspections.

The executive branch manager of the ACT Health Protection Service, Conrad Barr, said food businesses in the ACT demonstrated a high level of compliance with safety standards.

“We are focused on protecting the community with our food safety inspectors doing over 2500 inspections every year.

“We also aim to strike the right balance of regulation with our compliance activity, actively working with businesses to rectify any issues that are identified,” he said.

The decline in food safety breaches followed the introduction in 2017 of a model to educate businesses and their staff in food safety requirements, after five years of inspection pass rates falling well below the targets.

ACT Health has collaborated with the Canberra Business Chamber and Access Canberra to run information seminars for food businesses, community groups and event organisers.

Proactive inspections provided a chance for food businesses to discuss food safety issues directly with public health officers, while seminars and self-assessment options were made available to businesses, a spokeswoman for the directorate told the Sunday Canberra Times.

Common food safety issues found in ACT food businesses include a lack of handwashing facilities, poor temperature control and live pests.

Inspectors also identified inadequate cleaning and sanitation, no food-grade thermometer at the time of the inspection, or no nominated food safety supervisor.

Despite strong public support, the ACT government in 2015 ditched its proposal for a “scores on doors” system of restaurant safety ratings, which has been used in other parts of Australia and globally.

Ignoring the safety: Listeria meat firm in Spain knew its products were infected, months before outbreak

That safety is always going off. We won’t get caught. No one got sick yesterday, so there’s a greater chance no one will get sick today.

These basics of the human psyche continue to undermine tragedies from Bhopal to BP to the Challenger and food safety.

But with all the toys and technology, you’ll be found out – so act accordingly, even if decent humanity is not enough against the directive of profit.

What’s going on in Spain is strikingly similar to what happened in New Zealand in 2012. More about that later.

In Aug. 2019, an outbreak of listeriosis in Spain was detected and reported to the World Health Organization (WHO) on Aug. 16, 2019.
To date, three people have died and more than 200 have been sickened from Listeria linked to chilled roasted pork meat products manufactured in southern Spain by Seville-based Magrudis Company and sold under the brand name La Mechá.

James Warren of EuroWeekly reports today that according to sources from Seville City Council and the Ministry of Health, the Laboratorios Microal sounded the alarm on February 18, 2019 after samples of the shredded meat product were sent to them for evaluation.

Mariano Barroso, the manager of the quality control and research at Microal, said that of the two samples that were submitted, one came back as positive.

A further test to determine the level of contamination was requested by the laboratory but the food manufacturer refused to agree to the tests.

Barrosco went on to clarify that the company did not inform the authorities as “in their line of work it is common to find forms of bacteria. It is the role of the manufacturer to remove the product from its production lines.”

In July 2012, a meat processor, its director and an employee have admitted selling Listeria-contaminated meat to the Hawke’s Bay Hospital in New Zealand and omitting to provide test results showing meat had tested positive.

The Hawke’s Bay District Health Board discovered cold ready to eat meats supplied by the company was contaminated in July 2012, after a number of Listeria cases had been linked to the hospital kitchen.

The outbreak claimed the life of 68-year-old Patricia Hutchinson on June 9 that year, and contributed to the death of an 81-year-old woman on July 9. Two other people were infected.

When the health board discovered a link between the infections and the hospital kitchen it sent 62 unopened plastic pouches of Bay Cuisine meat products to ESR for testing. All the pouches were found to contain Listeria.

A summary of facts complied by the Ministry for Primary Industries said the company had the contract to supply the hospital since 2002.

The summary states that on July 9, 2012 the DHB requested copies of all test results Bay Cuisine had carried out for Listeria. Production manager Christopher Mackie replied by telling the DHB a batch of corned silverside had tested negative for Listeria, when in fact it had tested “presumptive positive”.

The following day an officer from the Ministry, investigating the Listeria cases at the hospital, requested test results. Mackie sent these on July 13 but again omitted reports showing that some products had tested “presumptive positive”.

But analysis of cellphone text messages between MacKie and company director Garth Wise show that on the evening of July 12 Wise had sent a text to Mackie suggesting that he “hold back the presumptive listeria ones [results] as there is only 3 or 4 of them and we just send the good”.

A subsequent search of the Bay Cuisine premises by the Ministry found the company had not provided the original, correct spreadsheet to the Ministry. This spreadsheet showed positive Listeria tests for meat products on June 18 and July 10.

In 2009, the operator of a yakiniku barbecue restaurant chain linked to four deaths and 70 illnesses from E. coli O111 in raw beef in Japan admitted it had not tested raw meat served at its outlets for bacteria, as required by the health ministry.

“We’d never had a positive result [from a bacteria test], not once. So we assumed our meat would always be bacteria-free.”

Same story, varying locales.

Shurley shum mistake: Wiki Famous People, Doug Powell

I don’t know where this stuff comes from (and I’d get someone to update the wiki entry but there’s enough barriers to editing that it slipped my mind).

Kansas State University professor, editor, and food safety expert.

Haven’t been at Kansas State since 2013.

Doug is one of the famous and trending celeb who is popular for being a Teacher. As of 2018 Doug Powell is 55 years old years old. Doug Powell is a member of famous Teacher list (one of you younger folks wanna tell me what the famous teacher list is, and I’d imagine I’m on it for the wrong reasons.

One of the precious celeb listed in Teacher list.

I am precious.

Not Much is known about Doug family and relationships. All information about his private life is concealed. We will update you soon.

Just read barfblog.com, my life is an open book, successes and failures, I own them all.

Estimated Net Worth in 2019: $100K-$1M (Approx.)

Really? Cool. Will the bank accept that?

This is the asset that matters most (upper left).

Ethanol may not be so good: Better hand hygiene for flu prevention

The American Society for Microbiology says rubbing hands with ethanol-based sanitizers should provide a formidable defense against infection from flu viruses, which can thrive and spread in saliva and mucus. But findings published this week in mSphere challenge that notion — and suggest that there’s room for improvement in this approach to hand hygiene.

The influenza A virus (IAV) remains infectious in wet mucus from infected patients, even after being exposed to an ethanol-based disinfectant (EBD) for two full minutes, report researchers at Kyoto Profectural University of Medicine, in Japan. Fully deactivating the virus, they found, required nearly four minutes of exposure to the EBD.

The secret to the viral survival was the thick consistency of sputum, the researchers found. The substance’s thick hydrogel structure kept the ethanol from reaching and deactivating the IAV. 

“The physical properties of mucus protect the virus from inactivation,” said physician and molecular gastroenterologist Ryohei Hirose, Ph.D, MD., who led the study with Takaaki Nakaya, PhD, an infectious disease researcher at the same school. “Until the mucus has completely dried, infectious IAV can remain on the hands and fingers, even after appropriate antiseptic hand rubbing.

The study suggests that a splash of hand sanitizer, quickly applied, isn’t sufficient to stop IAV. Health care providers should be particularly cautious: If they don’t adequately inactivate the virus between patients, they could enable its spread, Hirose said. 

The researchers first studied the physical properties of mucus and found — as they predicted — that ethanol spreads more slowly through the viscous substance than it does through saline. Then, in a clinical component, they analyzed sputum that had been collected from IAV-infected patients and dabbed on human fingers. (The goal, said Hirose, was to simulate situations in which medical staff could transmit the virus.) After two minutes of exposure to EBD, the IAV virus remained active in the mucus on the fingertips. By four minutes, however, the virus had been deactivated.

Previous studies have suggested that ethanol-based disinfectants, or EBDs, are effective against IAV. The new work challenges those conclusions. Hirose suspects he knows why: Most studies on EBDs test the disinfectants on mucus that has already dried. When he and his colleagues repeated their experiments using fully dried mucus, they found that hand rubbing inactivated the virus within 30 seconds. In addition, the fingertip test used by Hirose and his colleagues may not exactly replicate the effects of hand rubbing, which through convection might be more effective at spreading the EBD.
 For flu prevention, both the Centers for Disease Control and Prevention and the World Health Organization recommend hand hygiene practices that include using EBDs for 15-30 seconds. That’s not enough rubbing to prevent IAV transmission, said Hirose. 
 The study wasn’t all bad news: The researchers did identify a hand hygiene strategy that works, also sanctioned by the WHO and CDC. It’s simple: Wash hands, don’t just rub them. Washing hands with an antiseptic soap, they found, deactivated the virus within 30 seconds, regardless of whether the mucus remained wet or had dried.