1. Preventing Infectious Diseases
What are infectious diseases and how can they be prevented?

2. Do Now
Write a few sentences about how being ill could affect a person’s quality of life.
How does a temporary sickness or infection, like a cold or the flu, affect quality of life?
What about a more serious or longer-lasting illness?
While working on the Do-Now, please have your hw out to be collected.

3. Objectives At lesson’s end, we will be able to:
☐ Summarize direct and indirect ways common infectious diseases can be transmitted.
☐ Describe how common food-borne diseases are transmitted.
☐ Explain the relationship between injection drug use and transmission of blood-borne diseases.
☐ Summarize the ways to prevent the spread of infectious diseases.

4. What is disease?
Disease: any destructive process that can affect a living organism.
“Dis + ease” = Not at ease. It is widely used to describe an illness or infection that disrupts the function of or causes harm to the body.
What are some illness or diseases that you have heard of?
One way experts understand diseases is to look at how people get them. Some diseases are contracted from other people, or things in the environment, also known as infectious diseases. Some of them are not, which are called noninfectious diseases.

5. Infectious Diseases
Infectious diseases: diseases that can be passed by contact with pathogens (germs) or organisms that cause diseases.
When someone gets one of these types of germs in their body, we say that this person has been infected with the disease.
An infection occurs when pathogens enter the body, multiply, and begin to damage body cells. If the body is unable to resist or fight off the infection, the disease will develop.
You have all received a handout which lists the different pathogens that cause disease, defines and explains how they work.

6. Bacteria
Bacteria are single-cell living organisms that are found in the air, soil, water, and inside the bodies of other living things.
Many play a helpful role, such as helping to digest food or breakdown waste materials.
Others can cause disease in humans, plants, and animals. Examples of diseases caused by bacteria are: Strep Throat, Tetanus, Tuberculosis.

7. Bacteria (cont’d.) Strep Throat (Group A Streptococcus) Tuberculosis
Tetanus Bacteria

8. Viruses
Viruses are made up of genetic material surrounded by a coating of protein. They are NOT living organisms, and cannot reproduce without the aid of a living host cell. Host cells are cells in which the virus is found.
Examples of diseases caused by viruses are: the common cold, chicken pox, warts, hepatitis (a, b, c), mumps, measles, hiv/aids.
Viruses typically go away on their own with your immune system defending yourself against it. Sometimes, however, complications may arise that require a doctor’s help. Antiviral medication can help ease the symptoms, and prevent infection in people at risk.

9. Varicella-Zoster Virus
Viruses (cont’d)
Varicella-Zoster Virus
(Chicken Pox)
HIV
The Flu
Hepatitis B

10. Protozoa
Protozoa are living organisms that consist of a simple, single cell. They display animal-like characteristics, such as mobility and heterotrophy.
They play a useful role in the food chain, and some can eat harmful bacteria.
Others are parasites and can transmit disease to their host. Diseases include Malaria, Sleeping Sickness, Dysentery.
Sleeping sickness: blood of the host is infected, and causes fever, weakness and lethargy, which leads to weight loss and anemia. Can be fatal if untreated.
Dysentery: inflammation of gastrointestinal tract, especially the colon. Symptoms include mild stomach pains, diarrhea, nausea, fever, vomitting, weight loss, and muscle aches.

11. Protozoa
Malaria
Sleeping Sickness
Dysentery

12. Fungi
Fungi (fun-jai / fun-guy) are living organisms that share characteristics of both plants and animals. Mushrooms, yeast, and molds are all types of fungi.
Types of fungi infections: Yeast Infections, Ringworm, Athlete’s Foot
Yeast infections: occur when there are too many yeast cells in the area. Most infections are caused by a type called Candida Albicans. Causes itching, soreness, and some cases of thick, clumpy, white discharge that has no odor and looks like cottage cheese.
Ringworm: caused by dermatophytes, grows on the skin, and spreads out in rings. Usually from sharing hats, combs, brushes; can be spread onto towels, clothing, or sports equipment.
Athlete’s foot: ringworm of the foot; causes scaling, flaking, and itching of area. Can be infected by walking barefoot in infected area or towel. Spreads to areas that are hot and moist, such as insulation, body heat, and sweat.

13. Macroconidia (Ringworm)
Fungi
Tinea Pedis
(Athlete’s Foot)
Yeast Infection
Macroconidia (Ringworm)

14. Parasites
Parasites: living organisms that line on or outside other living organisms and get food, shelter, or other things they need to survive from the host.
Parasites usually benefit from the connection, and the host is often harmed.
Some parasites enter a person’s body through contaminated food or water, and can cause diarrhea or other digestive problems.
Other types of parasites can spread disease to their hosts.

15. How Malaria is Transmitted
Parasites
How Malaria is Transmitted
Parasitic Worms

16. How Infectious Diseases Spread
Direct Contact: pathogen is transmitted by person-to-person contact. Other people get the disease from contact with the infected person. Depending on where the pathogen is, this can happen through touching an infected person’s skin, or when infected blood, mucus, or other body fluids get inside another person’s body.
Indirect Contact: Infected person’s skin or body fluids don’t directly touch or enter the other person through human-to-human contact. The pathogen gets on or travels through something else, and then the healthy person comes in contact with that thing.

17. Examples of Indirect Contact
✦ Touching an infected doorknob and then touching your own body.
✦ An infected person coughs or sneezes without covering the nose and mouth, and the droplets of mucus or saliva containing the pathogen can be passed airborne.
✦ Animals or insects can pass pathogens from one person to another if they bite someone who is infected and then bite another person.
✦ Person eats or drinks contaminated food or water.
✦ Needles, syringes or other equipment used by or on an infected person can contain traces of blood or other infected body fluids. If these items are not properly sterilized before used by or on someone else, the pathogen can get into the other person’s body.

18. Noninfectious Disease
Noninfectious Diseases are diseases that develop inside a person’s body, and cannot be “caught” or passed to other people.
Some examples of noninfectious diseases are: Cancer, diabetes, celiac disease, irritable bowel syndrome, fibromyalgia, narcolepsy, osteoporosis, etc.

19. Infectious vs. Noninfectious
So which of the illnesses and diseases you named earlier are infectious?
- Is this disease transmitted by direct or indirect contact?
- Is it passed through the air? Food? Blood?
Infectious diseases vary in how easily they are transmitted. For example, you cannot get HIV from casual, everyday contact with someone who has the virus, but you could get a cold or the flu in this way. (i.e. talking to someone in a close distance; hugging)

20. Ways To Prevent Infectious Diseases
When you know how infectious diseases are transmitted, you can understand ways to prevent their spread by breaking the chain of infection at any point.
With your partner, brainstorm ways to stop or prevent infection. Think about strategies that could help prevent or stop infection from spreading.
*Think of ways you could prevent becoming infected in the first place, and then ways you could stop an infection from spreading to others.

21. Ways to PREVENT INFECTION
- Eliminate the source of the pathogen: Throw away spoiled food, drain a pond with contaminated water, quarantine or isolate an infected animal/person.
- Handle and dispose of body fluids appropriately: Properly and promptly clean up blood, vomit, or feces. Dispose of body fluids in special containers marked for that purpose.
- Safely handle and dispose of contaminated items: Sterilize needles and other equipment. Never reuse needles or syringes, and throw away sharp items in sealed containers.
- Keep food safe: Cook foods to proper temperature. Keep hot foods hot, and cold foods cold. Refrigerate leftovers. Throw away food that looks or smells spoiled. Don’t use the same cutting board to cut raw meat and then cut vegetables or other foods.

22. Ways to PREVENT INFECTION
- Protect yourself: Wash your hands frequently. Always use sterile equipment. Bandage any wound or break in your skin promptly. Wear latex gloves when cleaning blood or other body fluids. Wear a mask that covers your nose and mouth when around people who are ill. Don’t let another person’s body fluids enter your body. Never share needles for any reason. Be up to date on recommended vaccines or immunizations.

23. Ways to STOP SPREAD OF INFECTION
- Don’t spread germs to others: Don’t hug or kiss other people when they’re or you’re sick. Cover your nose and mouth when you sneeze or cough. Wear a mask that covers the nose and mouth when sick. Bandage any wound or break in the skin promptly.
- Don’t spread germs to objects: Wash hands frequently when sick. Try not to touch doorknobs, railings, or other objects that other people touch. Dispose of tissues immediately after use. Wash plates, cups and other eating utensils with soap and hot water.
- Don’t spread germs to food: Wash your hands after using the bathroom. Don’t use fingers to eat from a jar, bag or box of food. Don’t put a used utensil back into a jar or other container of food.

24. Ways to STOP SPREAD OF INFECTION
- Keep your immune system strong by following healthy habits: Get enough rest and sleep. Eat healthy foods. Be physically active. Take steps to reduce or manage stress. Practice good hygiene. Get proper treatment for infections or other illnesses. The immune system is the body’s system of defense against disease!

25. Assessing My Health Habits
Take out your Assessing My Health Habits sheet and privately review your responses for questions 1 to 6.
These are some health habits related to preventing infectious disease.
- How are you doing in this area?
- Could you improve any of these habits?
- Are there other actions you could add to help prevent infectious diseases?

26. Infectious Disease Detective
You will receive the Infectious Disease Detective activity sheet. With your partner, complete the 4 case studies.
Analyze how the infection was transmitted and what could have been done to prevent or stop the spread of infection.

27. Homework Write a 1-paragraph response to the following question:
What is one behavior that you plan to do today in order to reduce your risk of getting an infectious disease?

28. Exit Ticket
Write your name on a sheet of paper, and complete the following questions:
1) What are the two types of diseases?
2) What are two ways disease can spread?
3) Name two out of many pathogens that causes infectious diseases.
*COLLECTED AND GRADED AS CLASSWORK!