AY Honors/Biosafety/Answer Key

Biosafety

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1. Define the following terms:

a. Biosafety

Biosafety is defined as the discipline addressing the safe handling and containment of infectious microorganisms and hazardous biological materials; procedures intended to protect humans or animals against disease or harmful biological agents.

b. Biohazard

A biohazard is a biological substance that's dangerous to people or the environment. Many biohazards are made of bacteria or other microorganisms. Some biohazards are an unintentional side effect of biologists working with or studying toxins or viruses. One common type of biohazard is medical waste — things like used syringes or other tools contaminated with human blood, bacteria, or other microorganisms. The word biohazard was first used around 1973, from the Greek bio-, "life," and hazard, from the Old French hasard, "game of chance."

c. Risk Factor

A risk factor is something that increases a person's chances of developing a disease. For example, cigarette smoking is a risk factor for lung cancer and obesity is a risk factor for heart disease.

d. Biological material

Biological materials are natural biocompatible materials that comprise a whole or a part of a living structure or biomedical device that performs, augments, or replaces a natural function. Biological materials are most often engineered for medical, biotechnology and pharmaceutical applications.

e. Chemical or biological accident

A biological or chemical accident is the unintentional release of one or more hazardous substances which could harm human health and the environment. Chemical hazards are systems where chemical accidents could occur under certain circumstances. Such events include fires, explosions, leakages or release of toxic or hazardous materials that can cause people illness, injury, or disability. It may occur due to natural or human-made sources.

f. Chemical or biological incident

An incident is more general and accident is more specific, regarding hazardous materials. An incident can refer to any event – big or small, good or bad, intentional or unintentional. Accidents are always unintentional and they usually result in some damage or injury.

g. Pathogen

A pathogen is a bacterium, virus, or other microorganism that can cause disease. A pathogen may also be referred to as an infectious agent, or simply a germ.

h. Aerosols

Aerosols are a suspension of fine solid or liquid particles in gas. it is an abbreviation of "aero-solution." Smoke, fog, and mist are aerosols.

i. PPE

Personal protective equipment (PPE) is protective clothing, helmets, goggles, or other garments or equipment designed to protect the wearer's body from injury or infection. The hazards addressed by protective equipment include physical, electrical, heat, chemicals, biohazards, and airborne particulate matter.

2. Describe which PPEs are used by health professionals. What are they for? Discuss at least five other non-health care fields that routinely use PPE for protection from biohazards and why they are needed.

PPE used by health professionals

Gloves

Face mask

Face shield

Gown

Hazmat suit

Examples of Non-Healthcare professions that use PPE

• Wastewater (sewage) Engineer/technician/laborer
• Waste management (garbage)
• Cleaning Services
• Law Enforcement
• Fireman
• Agriculture
• Veterinary
• Manufacturing
• Coroners
• Property Management
• Food Preparation
• Slaughterhouse/Meatpacking Operations
• Laboratory
• Hazmat Operations
• Correctional Facilities

3. Differentiate between outbreak, epidemic, pandemic and endemic. Make a Venn diagram or chart that shows the things that are the same and those that are different.

• Outbreak: Refers to the number of cases (disease) that exceeds what would be expected.

• Endemic: An infection or disease that exists permanently in a particular region or population. For example, Malaria is a constant worry in parts of Africa.

• Epidemic: An outbreak of a disease that is actively spreading over a wide geographic area and affects an exceptionally high proportion of the population.

• Pandemic: A global endemic. It relates to geographic spread and is used to describe a disease that affects a whole country or the entire world.

An example of this is dengue fever. There are parts of the world where dengue fever is endemic, meaning that there are mosquitoes that are carrying dengue fever and transmitting it from person to person. But we also see imported cases and imported outbreaks in parts of the world where a disease is not endemic. There was an outbreak in the Big Island of Hawaii where somebody, unknown, must have come in with dengue fever, got bitten by mosquitoes, and then there were local chains of transmission where those mosquitoes then bit other people, they got dengue fever, and so on and so on. In this case, dengue fever is not endemic in the Big Island, however, there was an outbreak due to an imported disease with subsequent transmission.

4. Develop a list of precautions that should be taken during an epidemic/pandemic.

Social Distancing

If the disease causing the outbreak does not have an effective treatment or vaccine, one of the only tools for slowing its spread is to keep people away from each other. This recommended separation distance depends on how the disease is spread. For COVID-19, which is spread by respiratory droplets, public health professionals recommend staying at least 6 feet (2 meters) from other people (especially strangers).

Face masks

A face mask should be worn when it is necessary to be in a public place during an epidemic which spreads by respiratory droplets. The mask will serve to reduce the amount of pathogens entering the wearer's mouth or nose, and also reduce the amount of pathogens emitted by the wearer. The latter point is especially important when the disease can be transmitted before the victim is aware of any symptoms.

Wearing a mask sends the message "I care about you, and if I am infected, I don't want to spread it to you."

When a mask is removed it should be placed in the laundry and the hands should be washed or sanitized as soon as possible.

Water Treatment/Hygiene

Some outbreaks, such as cholera, are spread through the use of water which has been contaminated by human feces. Proper sanitation prevents the cholera bacteria from getting into the water source in the first place. Water treatment kills any of the bacteria that may have been introduced into the water system. Water should be sterilized before drinking it, bathing with it, or cooking with it.

5. Chart, list, or illustrate the differences between isolation and quarantine.

Isolation and quarantine are public health practices used to protect the public by preventing exposure to people who have or may have a contagious disease.

Isolation

Isolation separates sick people with a contagious disease from people who are not sick. Hospitals use isolation for patients who have a known infectious disease that can be spread easily to others. Household members should use a separate bedroom and even a separate bathroom if possible. It is also recommended that the ill person should eat or be fed in their room away from other household members. Household items such as dishes, drinking glasses, cups, eating utensils, towels, bedding, or other items should not be shared with the person infected. It is important to prohibit all visitors and non-essential people from being in the home.

Quarantine

Quarantine separates and restricts the movement of people who were exposed to a contagious disease to see if they become sick. These people may have been exposed to a disease and do not know it, or they may have the disease but do not show symptoms. Quarantine helps to limit the spread of communicable disease. Quarantining means staying home and away from other people as much as possible for at least a 14-day period. This includes avoiding shopping, eating out, socializing, public places, and large crowds.

6. Choose two of the following historic diseases and answer: When did it occur? How many were infected? How was it spread? What were the symptoms? What were the biosafety precautions used? How was it abated?

• 1918 Influenza (Spanish Flu)

The 1918 influenza, originally known as the Spanish flu, occurred from January 1918 to December 1920, it infected 500 million people.

The close quarters and massive troop movements during World War I hastened the pandemic, and probably both increased transmission and augmented mutation. Some speculate the soldiers' immune systems were weakened by undernourishment, as well as the stresses of combat and chemical attacks, increasing their susceptibility. A large factor in the worldwide occurrence of this flu was increased travel. Modern transportation systems made it easier for soldiers, sailors, and civilian travelers to spread the disease.

The sick experienced such typical flu symptoms as chills, fever and fatigue.

When the flu hit, doctors and scientists were unsure what caused it or how to treat it. Unlike today, there were no effective vaccines or antivirals, drugs that treat the flu. Officials in some communities imposed quarantines, ordered citizens to wear masks and shut down public places, including schools, churches and theaters. People were advised to avoid shaking hands and to stay indoors, libraries put a halt on lending books and regulations were passed banning spitting. According to The New York Times, during the pandemic, Boy Scouts in New York City approached people they’d seen spitting on the street and gave them cards that read: “You are in violation of the Sanitary Code.”

However, a second, highly contagious wave of influenza appeared with a vengeance in the fall of that same year. Victims died within hours or days of developing symptoms, their skin turning blue and their lungs filling with fluid that caused them to suffocate. In just one year, 1918, the average life expectancy in America plummeted by a dozen years.

After the lethal second wave struck in late 1918, new cases dropped abruptly – almost to nothing after the peak in the second wave. One explanation for the rapid decline in the lethality of the disease is that doctors became more effective in prevention and treatment of the pneumonia that developed after the victims had contracted the virus. Another theory holds that the virus mutated extremely rapidly to a less lethal strain. This is a common occurrence with influenza viruses: there is a tendency for pathogenic viruses to become less lethal with time, as the hosts of more dangerous strains tend to die out.

11. Explain why it is so important to remove medical gloves properly. Demonstrate the proper way to remove medical gloves without transferring pathogens from the gloves to your hands through the following exercise:

The skin is your body’s largest organ. It protects your organs and acts as a barrier that guards against micro-organisms and chemicals; but as protective as skin is, it needs protection, too. That’s because while skin is working hard to keep contaminants out, some actually absorb through unless you’re wearing PPE. Then there’s the risk of cross contamination or carrying a contaminant elsewhere. Even if you were wearing gloves while working with the contaminant, if you remove disposable gloves incorrectly, it can deposit the very same hazard back onto the skin that you thought you’d protected.

12. Regarding the cleaning of hands:

a. Why is hand washing recommended rather than hand sanitizing whenever possible?

Hand washing reduces the amounts of all types of germs and chemicals on hands. But if soap and water are not available, using a hand sanitizer with at least 60% alcohol can help you avoid getting sick and spreading germs to others.

Hand sanitizers may not be as effective when hands are visibly dirty or greasy. When hands are heavily soiled or greasy, hand sanitizers may not work well. Hand washing with soap and water is recommended in such circumstances.

Hand sanitizers also might not remove harmful chemicals, like pesticides and heavy metals, from hands. Although few studies have been conducted, hand sanitizers probably cannot remove or inactivate many types of harmful chemicals. In one study, people who reported using hand sanitizer to clean hands had increased levels of pesticides in their bodies.

c. What song have you found that is long enough that you can sing it completely while scrubbing your hands?

Singing the Pathfinder Song at a good regular tempo can easily take up to 30 seconds!

e. Make a video or other presentation to demonstrate to your instructor how to properly wash and dry your hands.

The World Health Organization recommends the technique shown in this video. You will need to make your own video (or a poster, or a live demonstration, or some other creative method to illustrate the method).

13. Regarding hand sanitizer:

a. Why is 70% isopropyl alcohol the most effective concentration as the main cleansing sanitizer ingredient?

70% alcohol takes a longer time to evaporate from any surface, hence there is enough contact time. In the case of 100% alcohol, evaporation will be very fast, contact time will be less and it will not be so effective against microbes.

70 % isopropyl alcohol solution kills microorganisms by dissolving the plasma membrane of the cell wall. Plasma membrane of gram negative bacteria consist of thin layer of peptidoglycon that is easily destroyed by the alcohol.

Water plays key important role which used to denature the proteins of cell membrane and acts as a catalyst in the reaction. Contact time of the alcohol with the organism also plays an important role. A 70% solution of alcohol takes more time in evaporation from the surface, increasing the contact time. Therefore, 70% isopropyl alcohol fulfills the both requirements.

The 100% isopropyl alcohol coagulates the proteins instantly by creating a protein layer that protects the other proteins from further coagulation. Because of this, microbes are not killed but remain in a dormant stage.

c. Explain when it is appropriate to use hand sanitizer instead of soap and water.

Hand sanitizer can be used when soap and water are not readily available. Using soap and water is always the more effective way to wash your hands.

14. Regarding face masks:

b. Learn how to improvise a face mask using materials commonly found around your home.

YouTube video with U.S. Surgeon General demonstrating a technique: