Archive for the ‘Front Page’ Category

Unusual Uses for Chlorine Bleach

Friday, July 29th, 2016

I have had the privilege of spending the last four years of my life on one of the most beautiful college campuses in Maryland. Everything I ever needed was within a short walking distance of my dorm room—the dining hall, library, mailroom, and student center, you name it! Yet even with all of these nearby resources, I spent most of my time in my room doing homework. This is the classic scenario for any undergraduate science major. Living in a building with more than 100 fellow students, the laundry room instantly became the most in-demand place in the entire residence hall. Keeping that in mind, I always ensured that I stocked up on two items each semester: detergent and bleach.

Bleach, chemically referred to as an aqueous solution of sodium hypochlorite (NaOCl), is one of the most common household chemicals used across the United States. Bleach is primarily used to whiten and brighten clothes, but there are other surprising uses! For starters, bleach is also used to remove certain stains and disinfect surfaces contaminated with pathogens. But what are some of the really unusual uses of bleach?

Cleaning Seashells

One of the most beautiful and memorable souvenirs you can take away from any sandy beach is a seashell. Most beachgoers will simply take the seashells home and place them on a dresser or into storage without completing one fundamental task—cleaning them! One pungent reminder is the awful odor they often carry.

While in the sea, mollusks absorb and process the minerals surrounding them, secreting calcium carbonate (CaCO3). The calcium carbonate forms an outer shell on the outside of their bodies, which continues to expand as the mollusk grows. When mollusks die, their shells are abandoned to the sea, many of which eventually appear on the beaches we frequent throughout the year. Knowing that sea creatures formerly lived in these shells should serve as a reminder to clean them promptly, and bleach is up to the task. According to Seashells.org, empty shells should be soaked in a 50-50 solution of water and bleach until the periostracum, the thin outer layer of skin, has disintegrated.

Flower Power

My family has a flower garden that sits next to the front door. When the garden is vacant, I enter the house through the garage. When the garden is in full bloom, I enter through the front door just so I can see the flowers.

Flowers possess everything they need in their natural habitat.  They collect nutrients from the soil through their roots. They absorb water through the roots, pushing the water up to the leaves via a specialized plant cell system called the xylem. The leaves are also responsible for providing the major source of food. Through photosynthesis and chlorophyll (the green pigment found in the leaves), plants use energy from sunlight to convert carbon dioxide (CO2) from the atmosphere and water into carbohydrates and oxygen.

When transferring flowers from soil to a vase, they are separated from their source of sustenance. While filling a vase with water and food additives serves as an effective substitute, cut flowers are still limited in their ability to receive essential nutrients, and are even more susceptible to wilting. But, the disinfecting power of bleach proves to be a suitable solution for this issue. Joan Rose, PhD, of the Water Quality & Health Council, suggests adding ¼ teaspoon of chlorine bleach to each quart of water in the vase. The addition of bleach preserves the clarity of the water and protects the flowers by destroying the bacteria that cause wilting. Although too much bleach will kill the flowers, a small amount is just enough to keep them in bloom for a long time!

Light The Way!

Bleach is not only used to lighten clothing, but homes as well! One fateful day in 2002, Brazilian mechanic Alfred Moser and his wife suffered through a citywide blackout. Although they experienced blackouts regularly, this time Moser decided to combat this power outage with his own man-made light, inspired by some advice from his boss. Mr. Moser successfully illuminated his home using only a plastic water bottle filled with water, a small amount of bleach, and sunlight! After the bottle was mostly filled with water, Moser added two capfuls of bleach and sealed it with a black cap. Next, Mr. Moser drilled a hole in one of his roof tiles, pushed the filled water bottle through, and applied polyester resin to prevent leakage.

When the sunlight strikes the bottle, it immediately illuminates the room below due to refraction of light. The addition of bleach prevents the water from turning green with algae when exposed to sunlight. It also prevents the water from clouding by destroying the microorganisms that could potentially reproduce inside of the bottle. Both the bleach and water must be replaced every five years in order to maintain its continuous use. Owners and renters of unlit homes across Brazil and other developing countries never have to worry about living in the dark again—at least during the daytime.

For a common household item, bleach sure has some interesting and peculiar uses, yet all three have proven to be extremely useful! Now, I wonder if detergent is good for anything else too….

Dominique Williams is a 2016 summer intern for the American Chemistry Council Chlorine Chemistry Division. Dominique is a senior chemistry major at Stevenson University in Owings Mills, Maryland.

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Sepsis Explained

Friday, July 22nd, 2016

Sepsis is the body’s overwhelming and life-threatening response to infection. Sepsis causes inflammation throughout the body, which can lead to tissue damage, organ failure, and even death, according to the Centers for Disease Control and Prevention (CDC). Sepsis is a serious complication of septicemia, also known as bacteremia or blood poisoning. Septicemia occurs when a bacterial infection somewhere in the body (e.g., the skin, kidneys, urinary tract, abdominal area or lungs) spreads into the bloodstream.

We recently wrote about human Vibrio infections from contaminated shellfish and coastal and especially brackish waters. Some Vibrio infections progress to sepsis, which is why we highlighted the Louisiana Department of Wildlife and Fisheries advisory that fishermen in saltwater carry with them “basic disinfectant (chlorine bleach mixed one part bleach to four parts fresh water1 or tincture of iodine, or antibiotic ointment) and use if skin is punctured while handling fishing tackle, bait or fish.”

According to the Mayo Clinic website, sepsis is diagnosed when at least two of the following signs accompany a probable or confirmed infection:

  • Elevated body temperature of 101 degrees F (or greater) or a below normal body temperature of 8 degrees F (or less)
  • Heart rate higher than 90 beats per minute
  • Respiratory rate higher than 20 breaths per minute.

Severe sepsis is diagnosed with at least one more of the following, which indicate an organ may be failing:

  • Significantly decreased urine output
  • Abrupt change in mental status
  • Decrease in platelet count
  • Difficulty breathing
  • Abnormal heart pumping function
  • Abdominal pain

Toxins released into the bloodstream by some bacteria can cause extremely low blood pressure. Septic shock results when the patient does not respond to simple fluid replacement. Septic shock can lead to death. Whereas most people recover from mild sepsis, the Mayo Clinic website indicates a 50 percent mortality rate for septic shock. The image above, from the CDC Sepsis Fact Sheet, lists major strategies for preventing sepsis.

Who is Vulnerable to Sepsis?

Anyone can develop septicemia and sepsis, but according to the Mayo Clinic the most vulnerable include the very young and very old; patients taking immunosuppressive medications; cancer patients; long-term steroid users; people with long-standing diabetes, AIDS or cirrhosis; people with large burns or severe injuries; and people with infections, such as pneumonia, meningitis, cellulitis and urinary tract infections.

Sepsis Requires Treatment!

Sepsis is a medical emergency that requires treatment. There are more than one million cases of sepsis each year in the US. Sepsis can lead to septic shock and death; survivors of sepsis may suffer permanent organ damage and have to deal with life-changing health effects.

The CDC recommends calling your doctor or going to the emergency room immediately if you have any signs or symptoms of an infection or sepsis. CDC urges that you state, “I AM CONCERNED ABOUT SEPSIS” to ensure timely evaluation and treatment, which may include antibiotics, oxygen and intravenous fluids. The image below from the CDC Sepsis Fact Sheet may be helpful in determining when to seek medical attention. Forewarned is forearmed!

 

For more information on sepsis, please see www.cdc.gov/sepsis.

Barbara M. Soule, R.N. MPA, CIC, FSHEA is an Infection Preventionist and a member of the Water Quality & Health Council. Ralph Morris, MD, MPH, is a Physician and Preventive Medicine and Public Health official.

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1 Fishermen should prepare this solution daily, as bleach solutions weaken over time.

Vibrio Infection: Rare, but Worth Knowing About

Friday, July 15th, 2016

Planning a beach vacation this summer? You should know about a group of naturally-occurring bacteria found in the warm coastal, especially brackish waters of the US that pose a rare but potentially serious risk to raw seafood consumers, anglers, commercial fishermen and others engaged in salt water-based activities. The culprits are several species of Vibrio bacteria. According to the Centers for Disease Control and Prevention (CDC), Vibrio are responsible for an estimated 80,000 cases of infection—known as vibriosis—in the US every year. When Vibrio invades the bloodstream, the result can be fatal. There are approximately 100 US deaths per year from vibriosis.

Vibrio bacteria are most prevalent in estuarine waters between May and October when water temperatures are elevated1 . CDC data indicate more than half of all reported vibriosis cases (65 percent) are caused by eating contaminated food. Thirty-five percent of cases are the result of people with open wounds and scrapes contacting Vibrio-affected waters.

Vibrio vulnificus

With a hospitalization rate of over 90 percent and with nearly 40 percent of cases leading to death,2 one of the Vibrio species in particular—Vibrio vulnificus—has been called the “most virulent foodborne pathogen in the United States.” Vibrio vulnificus also has been called a “flesh-eating bacteria” because of the toxins it releases that destroy human flesh. News reports chronicle rare but tragic instances of unsuspecting individuals who become infected with Vibrio vulnificus, resulting in progressive flesh destruction and limb amputation, a measure that may or may not save their life. Wound infections may start as redness and swelling at the site of the wound and progress throughout the body, according to CDC. The severe illness is characterized by “fever and chills, decreased blood pressure (septic shock), and blood-tinged blistering skin lesions.”

Louisiana’s Department of Wildlife and Fisheries warns fishermen to be aware that exposing open wounds to seawater containing Vibrio vulnificus “may lead to skin breakdown and ulceration.” A July 2014 advisory recommends fishermen in saltwater carry with them “basic disinfectant (chlorine bleach mixed one part bleach to four parts fresh water3 or tincture of iodine, or antibiotic ointment) and use if skin is punctured while handling fishing tackle, bait or fish.” The sooner one of these antiseptics is applied to a wound, the lower the risk of infection.

Are You Vibrio-vulnerable?

According to CDC, the most “Vibrio-vulnerable” are those with compromised immune systems, especially those with chronic liver disease. Although vibriosis is rare in healthy individuals, to reduce your risk of infection, avoid the following:

  • Consuming raw or undercooked shellfish
    • Consumers who want to eat raw bivalve shellfish should ask where the shellfish were harvested. Consumers should not eat raw Gulf Coast oysters, clams, or mussels from May to October unless they have been processed to kill the Vibrio vulnificus
  • Swallowing seawater
  • Contacting seawater when you have an open wound or scrape
  • Handling raw shellfish
    • Wear gloves and replace immediately if torn.

If you suspect Vibrio infection, seek medical attention quickly for potentially life-saving treatment.

Planning a beach vacation? Put your risk of Vibrio infection in perspective, exercise any relevant precautions, and enjoy!

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1 According to CDC, Vibrio species are most prevalent in saline waters of temperatures between 68 and 95 degrees Fahrenheit.

2 Oliver, J.D. (2005). “Wound infections caused by Vibrio vulnificus and other marine bacteria,” Epidemiol. Infect. Jun;133(3):383-91.

3 Fishermen should prepare this solution daily, as bleach solutions weaken over time.

Cleanup in the Aftermath of Flooding

Friday, June 17th, 2016

With record flooding in areas of Texas and the 2016 hurricane season just beginning, we think a word to the wise on cleanup in the aftermath of flooding is in order. First, assume that all flood waters are contaminated and that exposure to these waters may raise the risk of diarrhea, dysentery, and even hepatitis, skin and eye infections and respiratory disorders.

The first step in the cleanup operation is to remove flood water and sewage and dry the affected area. Powerful fans and enhanced ventilation are helpful for drying damp structural surfaces. Meanwhile, it is important to evaluate items contacted by flood waters, deciding what to discard and what to keep. Whenever possible, a disinfecting solution of water and chlorine bleach should be applied to affected surfaces of saved items.

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

  • 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.
  • If an item got wet, assume it is contaminated.
  • Disinfecting works best when all loose dirt and debris are removed first. That’s why the Centers for Disease Control and Prevention recommends first washing surfaces with soap and warm, clean water. Next, use a household bleach solution to disinfect.
  • Prepare a bleach 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.
  • When addressing exterior surfaces, such as outdoor furniture, patios, decks and play equipment, keep surfaces wet with disinfecting solution for 10 minutes after removing loose dirt and debris with soap and warm, clear water. This may mean wetting the surface with disinfecting solution more than once.
  • 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.
  • 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.

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 With Your Private Well After the Flood” at: https://www.epa.gov/privatewells/what-do-your-private-well-after-flood.

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.

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The Terms of Germ Inactivation

Friday, May 20th, 2016

Reducing disease-causing microorganisms—aka “pathogens” or “germs”—on environmental surfaces is a matter of using the right agent for the task at hand.  You would no sooner wash your hands in a bleach solution after gardening than expect surgical instruments to be prepared by washing them in soapy water.

Terms that apply to germ reduction on surfaces—cleaning, sanitizing, disinfecting and sterilizing—have distinct definitions, but they are often misused.  To help you navigate these terms, please see the table below:

Vocabulary of Germ Inactivation on Environmental Surfaces1

TERM

PURPOSE

USE

EXAMPLES of AGENTS

NOTES

Cleaning

Removes visible dirt, impurities and pathogens using chemical or physical means.

Cleaning is appropriate when surfaces are visibly dirty.
When a surface is both visibly dirty and contaminated, and requires sanitizing or disinfecting, cleaning is the first step.

Water, detergent, enzymatic products

Cleaning does not remove all pathogens and does not necessarily kill them.  If cleaning tools are used on multiple surfaces before being sanitized, cross-contamination can occur.

Sanitizing

Lowers the number of pathogens on surfaces using chemical or physical means.  Pathogen numbers are lowered to a safe level, which is determined by a given public health standard or set of requirements.

Food-contact surfaces such as commercial deli slicers must be cleaned and sanitized on a regular basis. Other examples are the diaper-changing tables in day care centers and shared toys.

Water, detergent, enzymatic products, also liquid chemicals (e.g., alcohols, glutaraldehyde, formaldehyde, hydrogen peroxide, iodophors, ortho-phthalaldehyde, peracetic acid, phenolics, quaternary ammonium compounds, and sodium hypochlorite bleach solutions), wet pasteurization

Sanitizing works by cleaning and/or disinfecting to lower the risk of spreading infection. Sanitizing is often thought to be synonymous with disinfecting, but there is a subtle difference in that sanitizing lowers pathogen numbers to a particular standard.

Disinfecting

Kills many or all pathogens on surfaces (except bacterial spores) using chemical or physical means.
There are different degrees of disinfection depending on the purpose or use of the item being disinfected.

Low level disinfection is used for example for common items, such as toilets that do not pose significant risk while high level disinfection is used in healthcare for items that enter the body, such as endoscopes.

Liquid chemicals (e.g., alcohols, glutaraldehyde, formaldehyde, hydrogen peroxide, iodophors, ortho-phthalaldehyde, peracetic acid, phenolics, quaternary ammonium compounds, and sodium hypochlorite bleach solutions), wet pasteurization

For soiled surfaces, disinfecting should follow cleaning to ensure the disinfectant is not “used up” in reacting with dirt and other impurities.

Sterilizing

Destroys all forms of microbial life, including bacterial spores, using chemical or physical means.

Surgical instruments must be sterile.

Gamma and x-ray radiation
Ethylene oxide gas, steam under pressure, dry heat, hydrogen peroxide gas plasma, liquid peracetic acid

Sterilizing is preceded by cleaning.
There is no validity to the term “partially sterile.”

A Word about Antiseptics

Agents that kill germs on living tissue and skin are known as antiseptics.  Examples of antiseptics include alcohol in mouthwashes and chlorhexidine, and other anti-microbial agents in products designed to prepare skin surfaces for surgery or administering intravenous fluid.  CDC notes that antiseptics generally are not used on environmental surfaces.  By the same token, sanitizers, disinfectants and sterilants are not used as antiseptics because they can injure the skin and other tissues.

We hope this short article is a helpful resource in clarifying the terms of germ inactivation.

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1CDC sources include: Guideline for Disinfection and Sterilization in Healthcare Facilities, 2008 and
How to Clean and Disinfect Schools to Help Slow the Spread of Flu

Your Health in their Hands: Hand Hygiene in Healthcare Settings

Friday, May 13th, 2016

Would you be surprised to learn that healthcare professionals, on average, clean their hands less than half the number of times they should?  That statistic comes from a US Centers for Disease Control and Prevention (CDC) press release announcing a new campaign, “Clean Hands Count.” CDC is “urging healthcare professionals, patients, and patients’ loved ones to prevent healthcare-associated infections by keeping their hands clean.”

Logo for CDC’s new hand hygiene campaign

In an age of astounding advances in medical technology, it is ironic that one of the simplest methods known to avoid spreading pathogens is overlooked so often.  CDC estimates 722,000 infections are contracted each year in US hospitals, and that 75,000 patients die of these infections during their hospital stay.  Good hand hygiene will help reduce these infections and deaths.

CDC’s 2002 guidelines for hand hygiene in healthcare settings include a thorough review of soaps, alcohols, and other hand hygiene agents, how to select an agent, techniques for using each agent, skin care, and more.  CDC notes that alcohol-based hand sanitizers are the preferred method of hand cleaning when hands are not visibly dirty1.  That’s because alcohol-based cleaners:

  • Are more effective at killing potentially deadly germs on hands than soap
  • Require less time to apply
  • Are often more accessible than hand washing sinks
  • Produce reduced bacterial counts on hands compared to hand washing
  • Are less irritating and drying than soap and water

Setting the Record Straight
As part of its campaign, CDC is addressing hand hygiene “myths and misperceptions:”

Myth

Fact

Using alcohol-based hand sanitizer contributes to antibiotic resistance. Alcohol-based sanitizer kills germs quickly and in a different way than antibiotics.  Using these sanitizers does not contribute to antibiotic resistance.
Alcohol-based hand sanitizers kill all the germs found in healthcare settings. Alcohol-based sanitizers kill most of the bad germs found in healthcare settings, but they do not kill “C. diff,” a bacterial “super bug” infection that causes severe diarrhea.  Hand washing with soap and water is more effective than alcohol-based hand sanitizers against C. diff.
Alcohol-based hand sanitizers cause hands to develop dry skin. Alcohol-based hand sanitizers are less irritating to hands than frequent use of soap and water.
Patients in healthcare settings are powerless to avoid new infections. Patients and their loved ones can remind healthcare providers to clean their hands.  They can ask tactfully, e.g., “Would it be alright if you cleaned your hands before you examine me?” They should also “practice what they preach” and clean their own hands often.

How often hand hygiene is needed per worker shift depends upon the particular tasks to be done and the amount of contact with  the patient, patient equipment and patient environment.  CDC discusses observational studies in hospitals in which healthcare workers washed their hands on average 5 to 30 times per shift, but notes that some nurses washed their hands as many as 100 times per shift.

We commend CDC for its renewed focus on hand hygiene.  Given the fact that on any given day, about one in 25 hospital patients has at least one healthcare associated infection, we agree it’s time to reconsider the hygiene of the hands that heal.

Ralph Morris, MD, MPH, is a Physician and Preventive Medicine and Public Health official living in Bemidji, MN.
Barbara M. Soule, R.N. MPA, CIC, FSHEA is an Infection Preventionist and a member of the Water Quality & Health Council.

Click here to download this article.


1 Wash visibly dirty hands first with soap and water and then apply alcohol-based hand sanitizer.

Elizabethkingia anophelis Outbreak in Wisconsin: A Mystery for CDC Disease Detectives

Friday, April 29th, 2016

What causes a bacterium that is ubiquitous in soil, rivers, water reservoirs and the guts of mosquitoes to suddenly cause an outbreak of human infection? The bacterium is Elizabethkingia anophelis1, and the outbreak is affecting at least 12 Wisconsin counties. The common source of the outbreak remains a mystery at this time. According to the World Health Organization, the current US outbreak (it also includes one case each in Illinois and Michigan) is the largest of Elizabethkingia anophelis on record.

A Very Rare Infection

Although it is common in the environment, Elizabethkingia anophelis only rarely makes people sick, according to the US Centers for Disease Control and Prevention (CDC). In fact, most states typically report no more than five to ten Elizabethkingia anophelis infections per year. Currently, the Wisconsin Department of Health Services website notes 59 confirmed and four possible cases of infection, including 19 deaths.  Symptoms of infection include fever, shortness of breath, chills or cellulitis (a potentially serious bacterial skin infection).

Elizabethkingia anophelis is known as an opportunistic bacterium, which means it normally does not cause disease, but can do so under the right circumstances, such as when a human host’s immune system is compromised.  Most Elizabethkingia anophelis infections occur in people over the age of 65 and are associated with healthcare environments.  A few cases of infection with the bacterium in newborns were associated with meningitis. Elizabethkingia anophelis usually infects the bloodstream of adults but has also been isolated from respiratory systems or joints.

Though not considered a “superbug,” the bacterium is resistant to many antibiotics. According to the Wisconsin Department of Health Services, it has “identified effective antibiotic treatment for Elizabethkingia, and has alerted health care providers, infection preventionists and laboratories statewide.”

Because victims usually have severe underlying health conditions, it may be unclear whether the bacterium caused death or was a contributing factor in death. To complicate matters, the CDC lab in Atlanta is the only lab that can distinguish Elizabethkingia anophelis from the closely related Elizabethkingia meningoseptica, another emerging pathogen associated with infections in immunocompromised individuals and meningitis in newborns.  Therefore, it is possible that cases of Elizabethkingia anophelis are underreported.

Addressing the Outbreak

CDC and Wisconsin Department of Health Services “disease detectives” are working diligently to identify a common source of Elizabethkingia anophelis infection. Potential sources include food, water, medications, personal care products and medical equipment. Given the population affected thus far, healthcare facilities, including hospitals, nursing homes and long‐term care facilities are likely venues for investigation. Meanwhile, according to the Wisconsin Department of Health Services website, guidance from health officials is promoting more rapid identification of cases, timely treatment and improved outcomes for patients.

While not a concern for most healthy people, the current outbreak of Elizabethkingia anophelis infection is an excellent example of an unfolding disease investigation that includes the essential elements of disease monitoring, reporting and communicating.

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

Fred M. Reiff, PE, is a retired official from both the US Public Health Service and the Pan American Health Organization, and lives in the Reno, Nevada area. 

Ralph Morris, MD, MPH, is a Physician and Preventive Medicine and Public Health official living in Bemidji, Minnesota.
Click here to download this article.

 


1 Elizabethkingia anophelis was named after its CDC bacteriologist discoverer, Elizabeth O. King.

Aedes Mosquitoes: A Force in Human History

Friday, April 22nd, 2016

Aedes aegypti mosquito The female mosquito draws blood with a long, pointed mouthpart called a proboscis.
Image courtesy of the CDC website.

 

At the center of the current Zika virus epidemic is the humble insect vector, the Aedes mosquito, both aegypti and albopictus species.  The female Aedes 1acquires and transmits the virus by simply doing what she does—extracting blood from people, birds and other animals to obtain proteins needed to develop her eggs.  To many of us, mosquitoes are just a warm weather nuisance, but in his 2010 book, “Mosquito Empires:  Ecology and War in the Greater Caribbean,”2 J. R. McNeill demonstrates that the mosquito has impacted the course of human history.

A Mosquito’s Role in HistoryZika virus is only one of several flaviviruses spread by Aedes mosquitoes.  Aedes also transmit the viruses that cause yellow fever, dengue and chikungunya.   Most of these diseases originated in Africa.  According to McNeill3, the mosquito carriers might have crossed the Atlantic Ocean on slave ships hundreds of years ago.  McNeill makes the point that by the end of the 17th century, mosquitoes and the diseases they spread were playing a major role in shaping world events.

European colonizers paid a heavy toll in human life in the Americas, and this was due in no small part to Aedes-transmitted diseases.  One example offered by McNeill is a campaign by Scotland between 1697 and 1698 to establish a lucrative trading colony in Panama.  The project was thwarted when over 1,700 Scots, about 70% of those sent to Panama, succumbed to “fever,” which McNeill interprets as dengue, yellow fever and malaria (spread by the Anopheles mosquito), illnesses against which the Scots had no defenses.  The financial debt resulting from the failed enterprise was so great, according to the author, that it was a factor in Scotland’s acceptance of union with England.

In another example, McNeill describes Napoleon’s 1804 decision to sell 827,000 square miles of the mid-section of North America to the United States for $15 million, at the bargain rate of $18/square mile.  Napoleon’s willingness to sell the land was catalyzed by the discouraging loss of nearly 55,000 troops sent to St. Domingue (modern day Haiti) to quell a slave insurrection following the French Revolution.  In both of these examples, the modest mosquito proved a mighty force against invaders who bore no immunity against the diseases they spread. We could say of these examples, “the proboscis was mightier than the sword.”

Now, Zika

According to the World Health Organization (WHO), Zika virus was first identified in 1947 in Uganda in rhesus monkeys.  In 1952, it was identified in humans in Uganda and the United Republic of Tanzania.  Confined to Africa, Southeast Asia and the Pacific Islands until 2015, the Pan American Health Organization alerted the world to the first confirmed Zika virus infections in Brazil in May of that year.  Aedes aegypti is present in over 100 countries, the mosquito has “high competence as a vector,” and there is a possibility that Zika virus will begin to be transmitted in the US, according to an article4 in the April, 2016 edition of the American Journal of Public Health.

The virus has devastated families with Zika-affected babies born with the birth defect known as microcephaly.  The US Centers for Disease Control and Prevention (CDC) announced in an April 13 media statement that it has concluded that Zika virus causes microcephaly and other severe fetal brain defects.  This affirms CDC’s earlier guidance to pregnant women and their partners to take steps to avoid Zika infection, including avoiding travel to areas where Zika is actively spreading.  It seems we are learning more about Zika virus every day.  The WHO reports a scientific consensus that Zika virus also causes Guillain-Barre syndrome, a neurological condition that could lead to paralysis and death.

Better diagnostic testing and a vaccine for use against Zika virus are needed, according to Teixieria et al., who call for “a joint effort of the national and international scientific communities, public health policymakers and funders.”  Unlike the historical examples described by McNeill, public health professionals today have advanced technologies and rapid communication methods to combat the Zika virus and its mosquito carrier in ways that could not have been imagined hundreds of years ago.  These include national disease tracking networks and genomic analysis.

Only time will tell what impact Zika virus will have on the course of modern history.

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

Barbara M. Soule, R.N. MPA, CIC, FSHEA is an Infection Preventionist and a member of the Water Quality & Health Council.
Click here to download this article.


1 Mainly aegypti species and potentially albopictus

2 McNeill, J.R. Mosquito Empires:  Ecology and War in the Greater Caribbean, 1620-1914.  New York, NY:  Cambridge University Press; 2010.

3 McNeill, J. Aedes Rides Again:  Mosquitoes and Flaviviruses in the Americas, American Journal of Public Health (April 2016), Vol. 106, No. 4, pp. 596-7.

4 Teixeira, M.G., Costa, M.C.N., de Oliveira, W. K, Nunes, M.L. and Rodrigues, L.C.  The Epidemic of Zika Virus-Related Microcephaly in Brazil:  Detection, Control, Etiology, and Future Scenarios.  American Journal of Public Health (April 2016), Vol. 106, No. 4, pp. 601-5.

Avoiding MRSA at the Gym

Friday, March 11th, 2016

A healthy workout in the gym should leave you with a feeling of well-being and nothing worse than a duffle bag full of sweaty clothes.  It should not leave you with a MRSA skin infection.

What is MRSA?

MRSA, or “Methicillin-resistant Staphylococcus aureus,” is a type of staph bacteria that is, according to the US Centers for Disease Control and Prevention (CDC), resistant to common antibiotics.  CDC   reports that about two in every 100 people carry MRSA on their bodies, with no symptoms of infection.

A MRSA infection may at first be mistaken for a spider bite.  It may appear as a bump or infected area on the skin and could be accompanied by a fever.  The CDC website provides photos of MRSA skin infections to help the public identify this potentially serious infection.

Older people and those with compromised immune systems are most vulnerable to MRSA infection.  For that reason, healthcare facilities are the most common environment of MRSA transmission.  In otherwise healthy people, however, MRSA infections are usually mild and improve after a few days of oral antibiotic treatment if the infection is sensitive to the antibiotic.  Those infections are called “community-associated MRSA,” and are common in environments in which healthy people interact in close quarters; your gym is just such an environment.

Within the gym, intentional skin-to-skin contact (e.g., during wrestling and martial arts training) and unintentional skin contact between teammates during practice and competition (e. g., volleyball) are documented risk factors for MRSA transmission, according to a 2008 review of MRSA infection in athletes1.  Skin damage during exercise, e.g., mat burns, broken blisters, and other workout related injuries that abrade the skin, represent another common risk factor, particularly if broken skin contacts MRSA-contaminated surfaces.

Tips for avoiding MRSA infections at the gym:

  • WASH YOUR HANDS – thoroughly with soap and water before and after your workout and after using the bathroom; bar soap should not be shared during MRSA outbreaks; use liquid soap instead
  • SHOWER – promptly after any skin-to-skin contact; use liquid soap
  • OTHER PEOPLE’S OPEN WOUNDS – don’t touch wounds or bandages
  • YOUR OWN OPEN WOUNDS –
    • Cover and protect with clean bandages
    • Avoid using whirlpools, therapy pools and swimming pools
  • DISINFECT EQUIPMENT – wipe down exercise equipment (e.g., wrestling mats and the bench press), before and after use, with disinfecting wipes; use bleach wipes or other EPA-registered products that are effective against MRSA.
  • DON’T SHARE –
    • Razors with others; according to the 2008 review of MRSA transmission in the gym, razors create tiny lacerations, which increase the risk of acquiring MRSA from others
    • Towels with others; if shared towels have not been laundered between uses, they may be contaminated with MRSA
  • AVOID REUSING UNLAUNDERED EXERCISE CLOTHES – use fresh, clean clothes for each workout
  • LAUNDER – sweaty gym clothes and towels promptly after your workout; if laundering instructions permit, use chlorine bleach

A final tip:  Keep up the good work at the gym.  In the grand scheme of things, the benefits of working out greatly overshadow the risk of MRSA infection.  Why not increase your benefits by following these tips?

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

Bruce Bernard, PhD, is President of SRA Consulting, Inc., and Associate Editor of the International Journal of Toxicology, and lives in Cambridge, MD.

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1 Cohen, P.R. (2008).  “The skin in the gym:  a comprehensive review of the cutaneous manifestations of community-acquired methicillin-resistant Staphylococcus aureus infection in athletes,” Clinics in Dermatology, 26, 16-26.

Understanding Norovirus in Less than Three Minutes

Friday, February 26th, 2016

Norovirus:  It’s the leading cause of outbreaks of diarrhea and vomiting in the US.  The virus can spread like wildfire through homes, schools, healthcare facilities, sports teams, child care centers and nursing homes.  Norovirus causes an average of 20 million cases of illness each year, including tens of thousands of hospitalizations and hundreds of deaths, mostly among young children and the elderly.  The winter months are usually the busiest season for norovirus.

There is no vaccine to prevent norovirus, but understanding how it spreads can go a long way to avoiding it.  The CDC animated video above presents the facts about norovirus in a clever, simple-to-understand way.  My hope is that this video will go as “viral” as norovirus itself.  Share it widely, and be well.

For more information on norovirus, please see this CDC webpage.

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

Click here to download this article.

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