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It's always something: Emerging Diseases

Oct. 1, 2010
Over the years, many diseases have captured headlines and made us all aware of our susceptibility.
by Noel Kelsch, RDHAP[email protected]

Over the years, many diseases have captured headlines and made us all aware of our susceptibility. Diseases such as severe acute respiratory syndrome (SARS), Norwalk-like viruses (NLV), community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA), and Legionnaires' disease capture imaginations, giving many health-care professionals a much-needed wake-up call. As diseases emerge into the spotlight, many concepts in prevention can finally be grasped and the importance of standard precautions in the medical setting brought to the forefront in health care and the public sector.

It will always be something

Throughout history, diseases have emerged. Since the time of the Bible, we have been exposed to "plagues." In Exodus, they discuss the three plagues that affected "all the land of Egypt." This has continued to happen throughout history.

That old saying "the more things change, the more they stay the same" applies to emerging diseases. Though the names and symptoms of diseases change from year to year, there will always be a newly emerging disease that puts the fear of death in us all.

The key to preventing these epidemics is to understand prevention protocols and the health-care professional's role in emerging diseases. Most diseases can be prevented simply by following the guidelines we have been given.

By observing history, we can all make an educated guess about possible future disease and the preventive measures that need to be aligned with these emerging diseases.

Our grandparents were given much hope about the future of epidemics with the use of isolation, antibiotics, and vaccines. They thought contagious diseases would be a thing of the past. Many diseases have been prevented, but that philosophy did not completely come to fruition as antibiotic-resistant strains of pathogens evolved and new contagious diseases occurred.1

According to the Centers for Disease Control and Prevention, some of the emerging diseases in U.S. history have included:

  • 1793, Philadelphia: more than 4,000 residents died from yellow fever.
  • 1832, New York City: over 3,000 people killed in a cholera epidemic. A few months later, cholera took the lives of 4,340 people in New Orleans.
  • 1848, New York City: more than 5,000 deaths caused by cholera.
  • 1853, New Orleans: yellow fever killed 7,790.
  • 1867, New Orleans: 3,093 perished from yellow fever.
  • 1878, Southern states: over 13,000 people died from yellow fever in lower Mississippi Valley.
  • 1916, nationwide: over 7,000 deaths occurred and 27,363 cases were reported of polio (infantile paralysis) in America's worst polio epidemic.
  • 1918, nationwide: outbreak of Spanish influenza killed over 500,000 people in the worst single U.S. epidemic.
  • 1949, nationwide: 2,720 deaths occurred from polio, and 42,173 cases were reported.
  • 1952, nationwide: polio killed 3,300; 57,628 cases reported.
  • 1981-2005: Total estimated U.S. AIDS cases, 988,376; total estimated AIDS deaths: 550,394.
  • 2009 to present: Influenza, H1N1 epidemic (swine flu)

This process has never stopped and never will. It is called evolutionary biology – pathogens will always continue to evolve. Since their reproduction rates are so incredibly quick and generation times so short, microorganisms evolve at incredible rates. This explains the rapid development of antibiotic-resistant strains of many pathogens.

A prime example of that process is the A/H1N1 influenza virus. First thought to be evolving simply from the swine flu, this amazing virus is much like you and me. When we were created and our parent sperm and egg united, we took characteristics from each of our parents. This virus took characteristics from one virus that infected a host and another virus that had infected a host in a process called reassortment.

Recent studies have shown that A/H1N1 went one step further with a process called quadruple reassortment, combining avian and human genes into the assortment.2 Its characteristics are varied, complicated, and ever-evolving.

Precautions for prevention still fall into the same categories we have always been given.

Why do some people do OK and others die?

The "disease triangle" that we all learned in microbiology determines much about the outcome and prevalence of disease in an individual. With this concept, three factors have to be present before a disease can occur: genetics, environment, and pathogen.

Ulcers are a perfect example. When I was a kid, the doctor told my father he had ulcers as a result of having four rambunctious children and the stress of working two jobs – the environment he lived with daily. Years later, the doctor revealed that my dad had an inherited acidic stomach – the genetic factor. Having a genetic factor can make you more susceptible to specific diseases.

A few years ago, the doctor explained there was another piece to this puzzle: Helicobacter pylori, a bacterium that is present in almost all ulcers. The triangle was complete. Genetics, environment, and the presence of a pathogen brought this disease on. Once my father was treated for Helicobacter pylori, the disease did not reoccur. All these factors must be present for disease to occur. Determining these factors and addressing them will stop the disease from occurring.

Public health's role

The role of public health sciences is to anticipate the process and have public health practices ready to cope with each new contagious disease as it emerges. Many of those public health processes are already in place, and we should be utilizing them in our daily practice. Since we do not know when a new disease is going to emerge, having those protocols in place can prevent it from occurring in the first place.

It is the health-care professional's role to stay aware of the latest information available on emerging diseases and to follow the guidelines we are given with each disease. We have a responsibility to help prevent a disease from becoming an epidemic. Concepts in public health can be simply implemented that will prevent the progression of disease. Examples include:

  • Early detection
  • Rapid diagnosis
  • Treatment with antibiotics or antiviral
  • Strategies such as quarantine and isolation
  • Distancing (avoiding having people congregate in large groups where transmission can occur; this includes cancelling unnecessary meetings and school)

What are standard precautions?

They are the guidelines recommended by the CDC for reducing the risk of transmission of blood-borne and other pathogens in health-care settings. The standard precautions incorporated the major features of universal precautions (designed to reduce the risk of transmission of blood-borne pathogens) and body substance isolation (designed to reduce the risk of pathogens from moist body substances) and apply them to all patients receiving care in a health- care setting regardless of their diagnosis or presumed infection status.

Standard precautions apply to blood, all body fluids, secretions, and excretions except sweat, regardless of whether or not they contain blood; intact skin; and mucous membranes. The precautions are designed to reduce the risk of transmission of microorganisms from both recognized and unrecognized sources of infection in health-care settings.

These precautions are the basic principles of disease prevention and include personal protective equipment, barrier protection, and vaccination. Using these standards is the difference between life and death.

Diseases are spread in a variety of methods.

The chain of infection has not changed. You must have all the links present in the chain for a disease to occur. The more links you remove the less likely a disease will occur. So what can we do? For each part of the chain, there is some simple step we can perform. Here are some examples:

  • Chain link: An adequate number of pathogens or disease-causing organisms to cause disease. Prevention: 1) Do not allow sick clients to come for appointments unless it is an emergency; isolate them when they are identified. 2) Have sick staff members remain at home. 3) Review every patient's health history every time they come in the office. Include questions about foreign travel and exposure to disease at home (tuberculosis, mumps, measles, chicken pox, etc.).
  • Chain link: A reservoir or source that allows the pathogen to survive and multiply (blood, for example). Prevention: 1) Heat sterilize all heat tolerant items, including handpieces. Do not reuse disposable items. 2) Use a disposable bib clip or autoclave your bib clip. 3) Change masks whenever they becomes soiled or moist, and between each patient. 4) Use proper personal protective equipment (food handlers' gloves or the gloves that you purchase in the grocery store are not the same as medical grade gloves and do not afford the protection that is needed in the dental setting).
  • Chain link: A mode of transmission from the source to the host. Prevention: 1) Follow the CDC guidelines for washing your hands. Encourage patients to wash their hands. 2) Clean and disinfect all patient contact surfaces.
  • Chain link: An entrance through which the pathogen may enter the host. Prevention: 1) Do not work with open lesions. 2) Wear proper personal protective equipment as a barrier between you and the pathogen.
  • Chain link: A susceptible host (such as someone who is not immune). Prevention: 1) Keep your vaccinations current. 2) Eat properly. 3) Get plenty of rest. 4) Exercise. 5) Eliminate stress in your life. 6) Find laughter in your life.

    Each time a new disease emerges, we each have a responsibility to be aware of the precautions surrounding it. Staying updated on emerging diseases and preventive measures makes a difference in epidemic proportions.

    1. MMWR July 30, 1999 /48(29);621-629, Achievements in Public Health, 1900-1999: Control of Infectious Diseases.
    Noel Brandon Kelsch, RDHAP, is a syndicated columnist, writer, speaker, and cartoonist. She is a member of the Organization for Safety and Asepsis Procedures and has received many national awards. Kelsch owns her dental hygiene practice that focuses on access to care for all. She has devoted much of her 35 years in dentistry to educating people about the devastating effects of methamphetamine and drug use. She is immediate past president of the California Dental Hygienists' Association, and is on the board of directors for the Simi Valley Free Clinic.
    Where Do You Learn About Emerging Diseases and Protocols?
    • OSAP: The leading source of education and information promoting evidence-based infection control and safety policies and practices in dentistry. They have updated information on prevention of emerging diseases.
    • OSHA: They protect the health and safety of America's workers. They have preventive materials and information on infection control that focuses on the safety of the dental health care provider. They want you to return home safely after you work.
    • State and county health department: They protect the community and implement the guidelines that have been given.
    • NFID: National Foundation for Infectious Diseases has updated information on immunization protocols.
    • CDC: The Centers for Disease Control and Prevention has the expertise, information, and tools that people and communities need to protect their health. They do this through health promotion and readiness for new health threats. One vital part of their Web site is: Prevention and Control of Influenza: Recommendation of the Advisory Committee on Immunization Practices (ACIP) ( This is updated regularly. Please visit this site for information on flu vaccination for the 2010-2011 flu seasons. To stay updated on preventive recommendations weekly, visit: CDC Influenza Branch Weekly Influenza (

    What should I be aware of? Emerging and re-emerging diseases

    There are a variety of reasons that some diseases have become more prevalent or have reemerged in the United States over the past decade. International travel, entry into the country without medical evaluation, importing, lack of adherence to vaccination recommendations, and evolution of viruses and bacteria (including resistance to antibiotics) have all played a role in the increase of disease in the United States. The National Institute of Allergy and Infectious Disease lists the following as re-emerging diseases in the United States:

    • Anthrax
    • Antimicrobial resistance
    • Botulism
    • Campylobacteriosis
    • SARS
    • Dengue fever
    • Ehrlichiosis
    • E. coli
    • Influenza, including A/H1N1
    • Group A streptococcal infections
    • Hepatitis
    • Lyme disease
    • Plague
    • Prion diseases
    • SARS
    • Salmonellosis/salmonella
    • Shigellosis/shigella
    • Smallpox
    • Tuberculosis
    • Tularemia
    • West Nile virus
    As we look at these diseases and the precautions that surround them, standard precautions should be at the forefront of every task we perform in dentistry.

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