Our Latest Perspectives Posts

How a Norovirus Outbreak Ruined Summer Camp

Norovirus is notorious for spoiling a good time wherever it shows up, whether onboard a cruise ship1,2, in a restaurant3,4, or even at a musical performance5. In 2005, norovirus made fast work of a summer wrestling camp at a residential college. The camp closed early after over 100 people became sick.  A new scientific study6 of the outbreak provides evidence that norovirus is transmitted by contaminated surfaces and hand contact and airborne spread. It also shows a surface cleaning only approach—without disinfection—may actually increase the severity of an outbreak.

Outbreak Timeline

The timeline below tracks the percentages of the college surfaces testing positive for norovirus against cleaning and disinfecting activities:


The illness spread very quickly, as illustrated by the timeline; between July 5 and July 6, the number of sick individuals jumped from three to 38.  The researchers surmise that close physical contact and the common use of mats likely contributed to the rapid spread of the virus to over 100 people ultimately.  Three other camps that shared space with the wrestling camp were also affected by norovirus. These cases may have arisen from contact with contaminated surfaces or from being in close proximity to someone who was vomiting.  (When someone who is ill with norovirus vomits, the virus can become airborne and contaminate surfaces over wide vicinity.)  Surface swabbing of 10 surfaces (doorknobs and toilet seats) on July 21-22, prior to any cleaning or disinfecting, determined 40 percent of surfaces tested positive for norovirus.

Surfaces were cleaned with soap and water on July 30. On August 1, 73 percent of 51 surfaces swabbed (toilet handles and seats, bathroom sink faucet handles, bathroom doorknobs, walls, mattresses, urinal handles, chairs, drinking fountains, and floors) were found to be contaminated.  On August 14, surface cleaning with soap and water was followed by disinfecting with 5,000 mg/l free chlorine (2 cups of chlorine bleach per gallon of water) or disposable disinfecting wipes (quaternary ammonium wipes were used for surfaces that could be damaged by the bleach solution).  The next day, after resampling only those surfaces that had tested positive for norovirus on August 14, the percentage of surfaces testing positive for norovirus had declined to 33 percent.

Cleaning without Disinfecting May be Worse than Not Cleaning at All

Data from this study can help us understand how to help curtail the spread of norovirus in institutions, such as schools and college campuses. The authors conclude that the outbreak could have been fueled by cross-contaminating surfaces when, on July 30, cleaning with soap and water was not followed by disinfecting.  Cleaning cloths and sponges can spread the virus without destroying it. In this way, cleaning without disinfecting may be worse than not cleaning at all.

As this summer camp case study shows, when it comes to wrestling norovirus from contaminated surfaces, only cleaning followed by proper disinfecting will put norovirus “down for the count”.

Barbara M. Soule, R.N. MPA, CIC, is an Infection Preventionist and a member of the Water Quality & Health Council.


6Fankem, S.L. (2014). Outbreak of Norovirus Illness in a College Summer Camp:  Impact of Cleaning on Occurrence of Norovirus on Fomites, Journal of Environmental Health, v. 76, no. 8


The Surprising Sneeze
Written by Water Quality & Health Council

Video courtesy of Lydia Bourouiba and John Bush

Ahhh-choooo! An uncovered sneeze projects mucous particles into the air in a way that MIT scientists say permits the resulting “cloud” to travel farther than scientists had previously estimated (MIT press release). The short video above captures this “cloud” using high speed imaging. This research could help improve infection control in hospitals, workplaces, airplanes and other environments.

“Like a Puff Emerging from a Smokestack”

The MIT researchers tell us that a sneeze is more than an expulsion of mucous droplets; a sneeze is an expulsion of mucous droplets within a gas cloud, not unlike “a puff emerging from a smokestack”. The gas medium of this “puff” supports the buoyancy of small mucous droplets, carrying them from five to 200 times farther1 than they would travel in the absence of a gas cloud. In fact, when we sneeze, small droplets travel farther than large droplets because they are more readily entrained in swirling air currents within the cloud. In the absence of the gas cloud, we would expect larger droplets, which have greater momentum, to travel farther than smaller ones.

Coughs and Sneezes Spread DiseasesThe Sneeze

Sneezing is an involuntary response to triggers like allergies, colds, mold, mildew, dust, pepper, cold air, strong fumes and odors. Sneezing, a runny nose and coughing are efficient vehicles for spreading infectious illnesses like colds and flu. The sneeze projects mucous droplets forward where they may be inhaled by others or contaminate commonly touched surfaces.

The Centers for Disease Control and Prevention (CDC) notes that personal hygiene recommendations for preventing the spread of illness through sneezing has changed over the years (see website). The vintage poster at right from World War II urges the use of handkerchiefs to “trap the germs”. Modern CDC recommendations urge the use of disposable tissues and hand washing following tissue disposal. That’s a little different from raising your elbow to your face to cover up the sneeze, which the MIT press release suggests. If a disposable tissue is not available, the next best option is to cough or sneeze into your upper sleeve or elbow, not into your hands.

In their study of the fluid dynamics of the sneeze, the MIT researchers have made an important contribution to our knowledge of the propagation of infectious illnesses. According to the researchers, droplets less than about 50 micrometers in diameter can remain airborne long enough to reach ceiling ventilation units. Once entrained in these units, the potential reach of droplets could increase considerably. What are the implications, then, for ventilation systems, air filters and surface disinfection in the indoor environment? We look forward to future work building on this impressive foundation.

1The researchers found that droplets 100 micrometers (a micrometer is a millionth of a meter) in diameter travel five times farther than previously estimated. Droplets 10 micrometers in diameter travel 200 times farther.


Norovirus Season: It’s Not Over ‘Til It’s Over
Written by Linda Golodner

Norovirus Season  Its Not Over Til Its OverNorovirus—sometimes dubbed “the stomach bug” – is making notable appearances around the nation as winter gives way to spring. Asheville, North Carolina and Alexandria, Virginia schools closed their doors in recent days to disinfect in an effort to stem outbreaks. Virginia students on a class trip to New York City were hospitalized after becoming sick at a performance of “Phantom of the Opera.” Norovirus is being cited as a possible factor in four deaths in a Minneapolis Veterans Home, leading to a hold on new admissions. Weld County, Colorado health officials report at least five outbreaks, most in nursing homes. And norovirus still shows up on cruise ships. According to the Centers for Disease Control and Prevention (CDC), 80 percent of norovirus outbreaks occur between November and April. As the old saying goes, “it’s not over ‘til it’s over,” and norovirus season is definitely not yet over.

Most Vulnerable: The Young and the Old

Norovirus Stats

According to CDC, norovirus is the most common cause of acute gastroenteritis in the US each year, causing approximately:

  • 19-21 million cases of illness
  • 56,000-71,000 hospitalizations
  • 800 deaths

Not to be confused with the flu, which affects the respiratory system, norovirus is a highly contagious virus that targets the human gastrointestinal tract, resulting in diarrhea and profuse vomiting. The CDC notes norovirus can affect anyone, but that symptoms can be serious for some people, especially young children and older adults. Norovirus thrives in closed environments, such as daycare centers, nursing

Tips for Combating Norovirus

  • To protect yourself and others, wash your hands frequently with warm water and soap for at least 20 seconds (the time it takes to hum the “Happy Birthday Song” twice), and dry thoroughly.
  • Stay home if you are sick, and even after symptoms subside, take extra precautions to avoid spreading norovirus, e.g., wash hands frequently and avoid handling food for others for at least three days.
  • Disinfect frequently touched surfaces with a solution of bleach plus water (see posters below).

The Water Quality & Health Council worked with CDC, the Somerset County, New Jersey Department of Health and the American Chemistry Council to develop two downloadable posters on norovirus disinfection (downloadable here). “Clean-up and Disinfection for Norovirus (“Stomach Bug”)” gives directions for responding to a vomiting or diarrhea incident. “Help Prevent the Spread of Norovirus (“Stomach Bug”)” offers tips on disinfecting when norovirus is known to be affecting the community. It is our hope that these posters will be of use in schools, veterans’ homes, nursing homes, cruise ships, and other environments in which norovirus spreads easily.

Linda Golodner is President Emeritus of the National Consumers League and Vice Chair of the Water Quality & Health Council.


Cleaning and Disinfecting Electronic Devices
Written by Joan B. Rose, PhD

Cell phones, computers, remote controls, touchpads…electronics are at our fingertips at every turn, and our fingertips are both boarding and landing sites for a wide variety of microbes. Is this a problem? There are lots of microbes–microscopic life forms–in and on us, and on surfaces all around us. Many are harmless and even helpful, but there are also those that spread sickness—germs—like colds, flu, MRSA and norovirus.

Shared Electronics May Present the Biggest Problem

Commonly touched and shared electronics, such as touch screens, remote controls and the keyboards of shared computers, need frequent cleaning and disinfection. This is particularly important in schools (where students regularly attend “computer lab”) and healthcare settings (where electronic medical records are becoming the norm), but also in the home, especially during cold and flu season.

Hand-washing is Part of the Solution

The US Centers for Disease Control and Prevention says frequent hand-washing is one of the most important things we can do to avoid getting sick and spreading germs to others. The hand-washing message is an important one in an age when our hands are so frequently occupied with electronic devices. It is never too late to learn how to wash hands properly (Put Your Hands Together video).


Professor Kelly Reynolds of the University of Arizona includes electronics as one of The Eight Germiest Items in Your Home, and notes some of the bacteria found on household electronics match bacteria found in the typical kitchen sponge. Now, I do not recommend using the kitchen sponge—which if not disinfected itself contains millions of bacteria—to clean keyboards and remotes, but that may not actually account for the similarity in bacterial populations between electronics and sponges.

Dr. Reynolds says that when we snack while using our electronics, food oils and crumbs transferred to keyboards and electronic surfaces set up a hospitable environment for germs. (The same thing happens in the moist environment of a damp sponge studded with food particles.) Some germs can thrive on the crumbs that rain down from your peanut butter sandwich to your computer keyboard as you check your email. Similarly, channel surfing with the remote control while snacking in front of the family TV is an ideal way to transfer bacteria to the remote control, potentially spreading germs to other family members. And what about TV remote controls in hotel rooms?

So what can we do to reduce bacteria and potential germs on electronic devices?  The table below gives basic directions for cleaning and disinfecting, based on Dr. Reynolds’ interview with Fox News.  A good rule of thumb is to clean and disinfect your electronics once per week, or more frequently especially if you or others are sick with an infectious illness.

Cleaning and Disinfecting Electronic Devices

Device Suggestion
Remote controls, computer keyboards, video game controllers, the computer mouse, and plastic and fabric smartphone and tablet covers Once a week, or more frequently if users are sick with colds, flu or other viruses…

  1. Disconnect devices and remove smartphone and tablet covers. 
  2. Remove all visible particles—food or otherwise–using a dry cloth or vacuum cleaner with appropriate attachment.
  3. Swab with a well-wrung-out, commercial, pre-moistened disinfecting wipei.
Touch screens
  1. Disconnect devices.
  2. Remove all visible particles—food or otherwise–using a dry cloth or vacuum cleaner with appropriate attachment.
  3. Clean with a scratch-free product designed for electronicsii.

Joan B. Rose, PhD, is the Homer Nowlin Chair in Water Research at Michigan State University and a member of the Water Quality and Health Council.

iWringing out your disinfecting wipe is important to avoid moisture seeping into the interiors of electronic devices. If a disinfecting wipe is unavailable, use pre-moistened alcohol-based eyeglass lens cleaner or mild soap and water on a cloth or paper towel.

iiThese products may or may not contain disinfectant.


Don’t Let the Stomach Bug Ruin Your Sports Tournament
Written by Bruce Bernard, PhD

The family trip to see our children play in a sports tournament has become almost as American as apple pie. Yet recent news reports demonstrate the fun of these events can be destroyed by the infamous norovirus (aka stomach bug). A recent youth football tournament in Las Vegas, for example, was marred by a visit from the stomach bug, sending some players to hospital emergency rooms instead of onto the playing field. A news report indicated 28 people went to the hospital and 90 to 100 players, coaches and parents exhibited symptoms of nausea, vomiting and diarrhea during the four-day event. One of the football games had to be forfeited due to illness; tournament organizers even dispensed with end-of-the-game handshakes between opposing teams to help prevent the spread of infection. A tournament spokesperson speculated in the news report that “some people might have caught the sickness before coming to the tournament, and spread it to others during long bus rides.”

Norovirus, is a highly contagious virus; it is the leading cause of outbreaks of diarrhea and vomiting in the US. It is notorious for ruining many cruises. It spreads by contact with an infected person, touching a contaminated surface, eating contaminated food, or drinking contaminated water. Norovirus particles can float through the air and settle on surfaces. In 2010, a norovirus outbreak among the members of a girls’ travel soccer team was traced to a grocery bag filled with snacks (CDC study). It is thought that the bag of snacks was contaminated when a team member became ill in a bathroom in which the bag was stored. Team members were exposed to norovirus when they retrieved snacks from the bag.

Sports Travel: Lessons from the Field

1. Stay home if you are sick: Long bus rides in crowded conditions present the perfect opportunity for norovirus to spread. Real “team players” will want to prevent the spread the norovirus to their teammates. It is important to know that people can transfer norovirus to others for at least three days after being sick. Additionally, if players become sick while on the road, they should be kept as isolated as possible.

2. Don’t share water bottles or sports drink containers: Viruses can spread from person to person when drink containers or eating utensils are shared. Water bottles and sports drink containers should be labeled with team members’ names and never shared.

3. Don’t share mouth guards, keep them separate from other sports equipment and wash and disinfect after each use: Mouth guards can harbor pathogens. After scrubbing a mouth guard with cool water, let it dry out thoroughly, then soak it in products designed to clean dentures or orthodontic retainers. A mild solution of chlorine bleach (2 teaspoons bleach in 2 cups of water) can be used to help disinfect and deodorize mouth guards. After soaking in bleach solution, rinse well with plain water.
4. Wash hands thoroughly and often: Rest stops present the perfect opportunity for sports players to wash up while on the road, especially following a trip to the bathroom or before eating. Follow recommendations from the US Centers for Disease Control and Prevention for proper hand-washing.

5. Hand sanitizer may not be effective: Hand sanitizers may not be effective against norovirus. CDC notes that alcohol-based hand sanitizers can be used in addition to hand washing, but they should not be used as a substitute for washing with soap and water.

6. Be prepared to respond appropriately to a vomiting or diarrhea incident: The Water Quality & Health Council worked with CDC and other public health partners to develop a free downloadable “Clean-up and Disinfection for Norovirus (“Stomach Bug”) poster.” Keep this information handy for responding to norovirus “incidents.”

I have spent many, many weekends taking my kids to soccer games and tournaments, and I know all the work that goes into a sports trip (e.g., practice, team work, travel, family togetherness). ALL THIS CAN BE DESTROYED BY JUST ONE INFECTED PERSON! Protect your family and your team!

Bruce Bernard, PhD, is President of SRA Consulting, Inc., Associate Editor of the International Journal of Toxicology and lives in the Neck District of Dorchester County, Maryland.


The Thanksgiving Cook’s Quiz
Written by Linda Golodner

Calling all cooks: As Thanksgiving approaches, you are invited to test your knowledge of safe food handling with this quiz:

image0011. Which of the following should all Thanksgiving cooks assume as they begin dinner preparations?
a. All guests will arrive on time.
b. The raw turkey is contaminated with potentially harmful bacteria.
c. The mashed potatoes will be lumpy.
d. There will be no leftovers.

2. Turkeys should be refrigerated
a. While defrosting.
b. No later than two hours after serving.
c. All of the above.

3. To reduce the risk of foodborne illness, stuffing should be
a. Removed from the turkey cavity as soon as the turkey is fully cooked and out of the oven.
b. Smothered in gravy.
c. Made with oysters.
d. All of the above.

4. Kitchen work surfaces that contact raw foods should be
a. Washed with hot, soapy water, then disinfected with a bleach solution .
b. Wiped up with paper towel after the contact occurs.
c. Wiped up with the kitchen sponge.

5. As the refrigerator becomes packed with ingredients for the Thanksgiving feast, it is important to remember to
a. Separate raw turkey from ready-to-eat foods.
b. Keep the raw turkey on a lower shelf than the raw fruits and vegetables.
c. Keep the refrigerator temperature at 40 degrees Fahrenheit or lower.
d. All of the above.

Correct Answers:
#1 Correct answer: b. According to Professor David Weber of the University of North Carolina, cooks should assume that all raw fowl is infected with Salmonella bacteria and take steps to reduce exposure to these bacteria (see: Avoiding nasty germs and flaming turkeys on Thanksgiving).

#2 Correct answer: c. Turkeys should be defrosted in the refrigerator–and not at room temperature–to avoid bacteria on the turkey rapidly multiplying at room temperature. To defrost a turkey in the fridge, keep turkey in its original wrapper and place it on a tray to catch any juices that may leak. Place the turkey in the tray on a low shelf separated from ready-to-eat foods. A thawed turkey can remain in the refrigerator for one to two days (see: Minnesota Department of Health website).

#3 Correct answer: a. Stuffing is a “hospitable place” for bacteria to grow, so reduce your risk of foodborne illness by removing it from the turkey as soon as the bird is cooked (see: Avoiding nasty germs and flaming turkeys on Thanksgiving). Many “foodies” also suggest that stuffing not be cooked in the turkey because although the turkey may be thoroughly cooked to doneness at 165 degrees Fahrenheit, the stuffing might not reach the same temperature until the turkey is overcooked. They prefer to make “dressing,” which is what you can name your delicious stuffing recipe if you cook it outside of the turkey on the stove top and heat it in the oven before serving it.

#4 Correct answer: a. The US Centers for Disease Control and Prevention and the Water Quality and Health Council recommend disinfecting all kitchen surfaces that contact raw foods. The best way to do that is to first wash surfaces with hot, soapy water, rinse and then disinfect by applying a very dilute bleach solution of household laundry bleach (see Cleaning vs. Disinfecting: What’s the Difference?). Simply wiping up with a paper towel may help clean the surface but it does nothing to disinfect it if foodborne pathogens are around. Similarly, a kitchen sponge may help clean the surface but it cannot disinfect it. Kitchen sponges are notorious vehicles for spreading bacteria around the kitchen. The Water Quality & Health Council recommends microwaving kitchen sponges for two minutes on high power to disinfect them. They must be very wet, never dry!

#5 Correct answer: d. The US Centers for Disease Control and Prevention warns juices from raw poultry can spread bacteria inside your fridge, so separate raw poultry from ready-to-eat foods such as raw fruits and vegetables. Keep raw turkey on a lower shelf than your ready-to-eat foods to avoid stray juices dripping and contaminating them. The US Food and Drug Administration recommends maintaining the refrigerator temperature at or below 40 degrees Fahrenheit. It is especially important to check refrigerator temperature when it is tightly packed.

Have a happy, and healthy Thanksgiving!

Linda Golodner is President Emeritus of the National Consumers League and Vice Chair of the Water Quality & Health Council.


Combating Antibiotic Resistance with Surface Disinfection
Written by Barbara Soule, RN, MPA, CIC

Antibiotic Resistance Threats in the United States, 2013Antibiotic resistant microorganisms pose a serious threat to public health worldwide. According to a new report by the US Centers for Disease Control and Prevention (CDC), at least 2,000,000 people in the US acquire antibiotic resistant infections every year, and at least 23,000 people die of these infections.

Antibiotic resistant infections are most common among those in the general population, but deaths from these infections occur most frequently in hospital patients and nursing home residents. The CDC report takes stock of the threat of antibiotic resistant infections and describes four core strategies to combat them:

  • Improving the use of antibiotics1
  • Tracking resistant bacteria
  • Promoting the development of new antibiotics and new diagnostic tests for resistant bacteria
  • Preventing infections and preventing the spread of resistance

This article focuses on preventing infection by targeted environmental surface disinfection with the goal of avoiding the use of antibiotics in the first place. Reducing antibiotic use in healthcare facilities, according to CDC, has been shown to reduce resistance in those environments, a promising step in the right direction. Infection prevention should be a priority in all healthcare settings.

Infection Prevention by Surface Disinfection in the Healthcare Setting

According to CDC, risks of infection are increasing, not only due to emerging antibiotic resistant microbes such as Methicillin-resistant Staphylococcus aureus (MRSA) and Vancomycin-resistant Enterococcus (VRE), but also due to the increase in susceptible populations, such as dialysis patients and residents of long term care facilities. Infection prevention by targeted environmental surface disinfection is one critical factor in reducing illness and death in these populations.

Contaminated surfaces can be the source of a wide variety of bacteria and viruses – posing significant health risks to patients and healthcare professionals alike. After cleaning frequently touched surfaces, such as bathroom fixtures, doorknobs and handrails, for example, disinfecting them provides an additional safeguard against the transmission of illnesses. The CDC Guidelines for Environmental Infection Control in Health-Care Facilities provide evidence-based recommendations for preventing “environmentally-mediated” infections.

Targeted disinfection halts the spread of pathogens from environmental surfaces to human hosts; it is only one part of CDC’s plan to combat antimicrobial resistance, but as a direct, effective measure, it should be implemented in healthcare settings without question.

C. difficile: An Urgent Threat, Destroyed by Bleach Wipes

C. difficile is one of the top hospital- and nursing home-acquired pathogens in the US. It causes life-threatening diarrhea, and CDC classifies “C. diff” as an “Urgent Threat.” Although resistance to the antibiotics used to treat C. difficile infections is not yet a problem, the infection spreads rapidly because it is naturally resistant to many drugs used to treat other infections, such as fluoroquinolone antibiotics. A new strain of C. difficile that emerged in 2000 increased death rates by 400 percent by 2007, according to CDC.

In a 2011 publication, Dr. Robert Orenstein of the Mayo Clinic Arizona showed the use of wipes moistened with a 10 percent hypochlorite bleach solution reduced hospital-acquired C. difficile infections by 92 percent over a six-month period. This result was achieved without any other interventions, such as increased attention to hand hygiene. The results were sustained for over one year with only two infections in 12 months. Meanwhile, infection rates in other units in the study hospital remained high.

Barbara M. Soule, R.N. MPA, CIC, is an Infection Preventionist and a member of the Water Quality & Health Council.

1See, for example, the Get Smart About Antibiotics program.


Five Steps to a Healthier Home
Written by Ralph Morris, MD

Five Steps to a Healthier Home
Image from CDC Website

Do you know that by making a few changes to your household habits you can dramatically reduce your family’s risk of disease?  The US Centers for Disease Control and Prevention (CDC) reports that just seven pathogens are responsible for about 90 percent of gastrointestinal illnesses, hospitalizations and deaths.  These pathogens can cause fever, nausea, vomiting and diarrhea, and in some cases, even death.  A recent CNN article lists strategies that can help reduce household exposure to pathogens, thereby reducing your family’s risk of illness:

  • Close the toilet lid before you flush.  Flushing agitates the toilet contents, forcing a fine spray of contaminated water into the air that can settle on surfaces such as toothbrushes and hand towels. Closing the lid helps confine the spray, reducing the family’s exposure to germs like norovirus.
  • Double-bag raw meats and store them on the lowest shelf of the refrigerator. The CDC estimates 48 million cases of foodborne illness in the US annually.  One problem is the spread of foodborne pathogens, such as Campylobacter, Salmonella and Listeria, through raw meat juices.  Although these pathogens are destroyed by cooking, they should be assumed to be present in all raw meats stored in the fridge.  To prevent meat juices dripping onto and contaminating foods eaten fresh, double-bag raw meats and do not store them above foods eaten fresh. 
  • Leave your shoes at the door.  Our shoes provide a barrier from contact with the outside world underfoot.  Avoid transporting Toxoplama from soils or Salmonella from animal feces into your home. Leave your shoes at the door and opt for comfortable indoor slippers.
  • Wash your hands.   This is a basic step that CDC says is one of the most important things we can do to reduce our exposure to germs that can make us sick.  Wash your hands before and after handling food, after using the toilet and after changing diapers, or contacting pets or pet food.  One recent study found only five percent of individuals observed in restrooms throughout a college town exhibit hand-washing behavior that conforms to CDC recommendations to wash with clean, running water and soap for at least 20 seconds followed by rinsing and thorough drying.
  • Remember:  “Chlorine bleach is your friend.” So says Professor Douglas Powell of Kansas State University, who is quoted in the CNN article. Dilute solutions of chlorine bleach are effective against all of the seven pathogens that can wreak havoc with our health.  Many people over-estimate the amount of bleach that must be added to water to destroy common pathogens. A little goes a long way, and the new concentrated formulations require even less bleach added to water to make up a germ-busting solution (See How to Use High Strength Bleach).  The Water Quality & Health Council’s downloadable surface disinfection posters provide specific directions for mixing bleach solutions for various tasks including preventing norovirus, cleaning up after a norovirus incident, and destroying germs on daycare and food preparation surfaces. 

Seven Problematic Pathogens

  • Norovirus-Very common and contagious foodborne illness; spread by contaminated food (including undercooked shellfish) or contact with contaminated surface or mucous droplets.
  • SalmonellaFound on raw poultry, ground beef and eggs and animal feces. Also found on the skin of animals, such as turtles, snakes and baby chicks.
  • Clostridium perfringens – Found on raw meat and poultry; infections are common when foods are prepared in large quantities and kept warm for a long time before serving.
  • Campylobacter– Found on raw poultry meats and unpasteurized dairy products.
  • Staphyloccus aureus– Found on foods made by hand that require no cooking, such as sliced meat, puddings, some pastries and sandwiches.
  • Toxoplasma gondii– Found on raw meats, in soils and sand boxes and cat litter boxes.
  • Listeria-Found on raw meats, produce, dairy, and may grow on refrigerated foods.

Ralph Morris, MD, MPH, is a Physician and Preventive Medicine and Public Health official living in Bemidji, MN.


How to Use High Strength Bleach

How to Use High Strength BleachChlorine bleach—popularly used for whitening and destroying germs in the laundry and on hard surfaces—is now available in a “high strength” form.   The same disinfecting power of chlorine chemistry is now delivered in a smaller container, reducing the amount of bleach required for each task and cutting down on packaging waste.  The smaller container also means more open space on your storage shelf.  But just as many laundry detergents now come in smaller containers and you use less for a load, the same is true for the new high strength bleach.

 Concentrated bleach is an 8.25 percent solution of sodium hypochlorite, up from the “regular bleach” concentration of 5.25 percent. The bottom line for consumers is that they will need to add about 1/3 less bleach to water than they used before for laundry and household disinfection.  For example, if you normally added one tablespoon of regular bleach to a gallon of water to disinfect food-contact surfaces in the kitchen, you may now use just two teaspoons of high strength bleach in a gallon of water to accomplish the same task just as effectively. The table below provides conversions between regular and high strength bleach dilutions for some common disinfection chores.

Converting between Regular Strength and High Strength Bleach

Note: Make bleach solutions fresh daily as they break down over time. Never combine ammonia-containing products with bleach and keep all cleaning and disinfecting products out of the reach of children.


Regular Strength Bleach in 1 Gallon of Water

High Strength Bleach in 1 Gallon of Water

Cleanup/disinfection following vomiting or diarrhea on a porous surface (e.g., wood)

1 2/3 cup

1 cup

Wall and floor disinfection following flooding

¾ cup

½ cup

Laundry disinfection and whitening (for a full load of laundry in a washing machine)

½ cup

1/3 cup

Disinfecting nonporous surfaces (e.g., vinyl, ceramic tile, porcelain) against norovirus (“the stomach bug”)

1/3 cup

¼ cup

Disinfecting the diaper changing area; disinfecting hard surfaces against flu transmission

¼ cup

2 ½ tablespoons

Disinfecting kitchen cloths

3 tablespoons

2 tablespoons

Routine disinfection of food-contact surfaces

1 tablespoon

2 teaspoons

Reference: http://www.maine.gov/dhhs/mecdc/environmental-health/water/documents/CloroxConcentratedDosageGuidance.pdf

Working with Bleach

Although high strength bleach is more concentrated than the old formulation, the same safety precautions apply, and there is no significant increase in risk associated with exposure to high strength bleach.

Bleach is safe when used as directed on the product label. Always keep bleach and all cleaning products out of the reach of children.

Bleach products have a shelf life – check the date on the bottle to make sure your bleach will be effective when you need it.

Linda Golodner is President Emeritus of the National Consumers League and Vice Chair of the Water Quality & Health Council.


After the Flood: Tips for Safe Cleanup
Written by Chris Wiant, M.P.H., Ph.D.

After the Flood

In addition to wiping out roads and buildings, massive flooding such as that seen in Colorado this summer can result in unanticipated hazards from tainted floodwaters.  The problem arises when pathogen-laden wastewater and fecal material from animals mingles with floodwater.  Disease risks from exposure to waterborne germs carried by floodwater include dysentery and hepatitis as well as skin infection, eye infections and respiratory disorders.

To help prevent disease transmission associated with flood cleanup, the Water Quality and Health Council
offers the following tips:

    • If an item got wet, assume it is contaminated.
    • Disinfecting works best when all loose dirt and debris are removed first.
    • Use a disinfecting solution (3/4 cup regular strength chlorine bleach or 1/2 cup concentrated bleach to one gallon of water) to disinfect walls, floors and other surfaces touched by floodwaters.  Keep the area wet for at least two minutes, then rinse thoroughly and dry.
    • Carpets and rugs that have been soaked for more than 24 hours should be discarded.  If carpets and rugs were soaked for less than 24 hours, evaluate as follows:  Carpets that contacted sewage-contaminated floodwater should be discarded. Carpets contacted only clean basement seepage or lawn runoff into a sub-basement, for example, may be dried and cleaned.  Washable throw rugs usually can be cleaned adequately in a washing machine.  For more information on cleaning flood-damaged carpets and rugs, see this North Dakota State University website.
  • When addressing exterior surfaces, such as outdoor furniture, patios, decks and play equipment, keep surfaces wet for 10 minutes (this may mean wetting the surface more than once), then rinse thoroughly and dry.
  • Chlorine bleach solutions degrade quickly- be sure to make a fresh solution daily as needed. Unused solution may be discharged into toilet or sink.
  • Contaminated clothing should be washed in the hottest possible water with detergent and chlorine bleach if fabric instructions permit.
  • When using a disinfecting solution to clean up after a flood, remember to:
    • Wear gloves and protective clothing.  Do not touch your face or eyes.
    • Change the disinfecting solution often and whenever it is cloudy.
    • Be thorough. Wash and dry everything well.
    • When finished, wash your hands thoroughly with soap and water for at least 20 seconds, even if you have worn gloves.

Disinfecting Private Wells

If the wellhead has been submerged by floodwaters, the well has most likely been contaminated.

If microbial contamination is suspected (if well was flooded or if water is unusually cloudy, odorous or tastes different), immediate disinfection is recommended.  If contamination is discovered through water sampling, disinfection is required.  Private well water consumers may choose to have their water sampled again immediately after disinfecting to be certain water is safe to drink.  Thereafter, periodic sampling can help provide assurance of good drinking water quality.

Consumers of private well water may contact the local health department for advice on well disinfection.  This task can be carried out either by ground water professionals or by the homeowner using an array of information resources available from state and local health departments and government agencies.  See, for example, the US Environmental Protection Agency’s website, “What to Do After the Flood” at:  http://water.epa.gov/drink/info/well/whatdo.cfm

Note:  Depending on the local geology, it is possible for an aquifer (underground water-bearing formation) to become contaminated by floodwater.  In such cases, disinfecting the well may not ensure safe water.  Aquifer contamination by floodwaters usually clears up after a period of time, but until water sampling confirms good water quality, the household served by a private well should disinfect all water used for drinking and food preparation.

Chris Wiant, M.P.H., Ph.D., is president and CEO of the Caring for Colorado Foundation. He is also chair of the Water Quality & Health Council.


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