Infectious Disease Unit 6 Lesson 1
Reminder Getting Started Pick up your Infectious Disease Notes Objectives Identify five types of infectious agents Describe ways in which infections can spread Explain ways to prevent the spread of germs Explain how the immune system fights germs
Starter Take out a blank sheet of paper Put your name at the top of the paper Get three people in the classroom to write their name on the paper There must be at least one boy and one girl signature The third signature can be either boy or girl
Infectious Disease An infectious disease is any disease that is caused by an agent that can pass from one living thing to another.
Germs Infectious disease can be caused by agents called germs. Germs are microscopic organisms that invade the body and its cells.
Pathogens Another name for germs is pathogen. Pathogens are tiny organisms that cause communicable diseases.
Germs / Pathogens Germs / pathogens are so small that they cannot be seen by the naked eye. They also live almost anywhere.
Activity 1 How Germs Spread
Activity Wrap Up Respond to the following: List three ways that you have come in contact with germs today Identify three ways that you can reduce the spread of germs in your daily life.
Infection When a germ enters the body it is called an infection. Once inside the human body, the germ starts to reproduce and make more germs. When germs reproduce they release poisons that causes a person to become sick.
Types of Germs Each type of germ causes different symptoms. This is how doctors can diagnose most disease just by the symptoms a person is having.
Fungus A fungus is a type of germ that relies on other living or dead organisms to survive. Fungal infections are usually not life threatening. But there are a few that can cause sever health problems.
Fungus There are over 1.5 million types of different fungi on the Earth. Only about 300 can cause diseases in humans.
Fungus Fungi likes to grow in warm, dark, moist places. That is why most fungal infections affect the lungs, skin, and nails.
Name Symptoms/Signs Athletes Foot Itching Burning Lives on the feet and between toes. Scaling/peeling skin Nail Fungus Infection under the finger nails and toe nails Causes pain and tenderness Nails can become yellow and fall off Ringworm Typically affects the skin and scalp Usually starts as a small rash and then spreads out as the fungus consumes more creating a ring. Candida A fungus that infects the mouth, vagina, stomach, and urinary tract. Causes sores, blisters and pain
Protozoan A protozoan is a single celled organism. Most protozoan infections usually come from infected water or food. Which causes infections of the stomach and intestines.
Protozoan Infections Giardia is a protozoan infection of the small intestines and causes severe diarrhea. It is spread by coming in contact with food, water, or soil that has been contaminated with feces (poop) from infected humans or animals.
Parasites A parasite is an organism that lives in a host organism. A parasite draws nourishment from a host even to the point of killing the host. Some parasites can become very large.
Parasites A tapeworm is a type of parasite that lives in the intestines. Usually people become infected with tapeworms from eating raw or under cooked meat. Tapeworms usually live in the intestines.
Parasites After a long infection, the tapeworm can become large enough that an infected person can start becoming malnourished because the tapeworm is consuming the nutrients the body needs. Luckily we have medications that can treat tapeworms.
Bacteria Bacteria is a one-celled organism that is found everywhere. Bacteria loves to live in warm, dark, and moist places.
Assignment #1 With your partner come up with three places that bacteria would like to live in or on your body? 1. 2. 3.
Bacteria When bacteria reproduces it creates a foul smell. This is why your breath, feet, and arm pits all stink. It is bacteria growing in those areas.
Bacteria Bacteria causes diseases, but we also need bacteria in our body to keep us healthy. Healthy bacteria called probiotics live in our mouth and intestines and help with digestion.
Name Symptoms/Signs Strep Throat Sore throat Pain swallowing Fever Bad Breath Tuberculosis Bad cough that last 3 weeks or more Pain in chest Coughing up blood Fever and chills Sinus Infection Sinus pressure behind the eyes and checks Runny nose that last more than a week Dizziness Fever Bad Breath Urinary Track Infection Pain or burring during urination Urinating frequently
Types of Germs Most of us have had one or more of these infections. Luckily we can kill bacteria with antibiotics Antibiotics are drugs that kill or slow down the growth of bacteria.
Bacteria After starting antibiotics most people start to feel better within 48 hours. When you are prescribed antibiotics, it is important to finish the full prescription even if you feel better. Otherwise the bacteria can change and become resistant to the antibiotic.
Antibiotics When germs become resistant the medication will not work and the germ becomes more powerful. We call these resistant germs that mutate Super Germs. These germs are extremely dangerous and deadly.
Next slide may be too graphic for some so if you need to look away, please do so now.
Flesh Eating Bacteria
Types of Germs The bad part about bacteria is that we do not build up immunity to bacterial infections. Immunity is your bodies ability to produce antibodies before you become sick. This means you can get infected again by bacteria and become sick.
Types of Germs A virus is the smallest disease causing organism. Viruses are very unique and specialized.
Viruses Unlike bacteria, viruses cannot reproduce by themselves. Viruses can only attach themselves to other cells and take them over. Once they take over the cells they are then able to reproduce and create more virus cells.
Name Symptoms/Signs Common Cold Runny nose Chest congestion Cough Influenza Fever Chills Cough Runny Nose Chest Congestions Vomiting Ebola Fever Chills Diarrhea Vomiting Chicken Pox Fever Headache Pox
Immune System So how do our bodies fight germs. Our bodies do a great job of fighting infections. The immune system is made up of organs and special cells that fight infections.
Immune System The first line of defense are physical barriers to stop germs from getting into the body. Some of the barriers are: Skin Hairs Tears Mucus Saliva and Stomach Acids
Skin The bodies has several layers The outer layers of the skin are tough and dead. This outer layer makes it difficult for germs to get through. The other layer of skin also falls off constantly taking germs with them.
Hair Your body is covered in hair. The hair around your eyes and in your nose traps germs and keeps them getting into the body. There are even small hairs inside the large airways to the lungs. These tiny cells are called cilia. Cilia helps keep germs out of the lungs.
Tears Our eyes are very porous Porous means easily air and liquid can pass. This means germs can easily enter the human body through the eyes. Your eyes produce tears that help wash out germs before they can enter.
Mucus Mucus is a sticky substance that exists in your nose, lungs, and digestive system. Mucus helps trap germs as well as destroy them.
Saliva and Stomach Acid Many germs enter our bodies through the mouth. Luckily saliva and stomach acids kill these germs before they can reproduce and cause illnesses.
Immune Response Just incase the first line of defense doesn t work, there is always the second line of defense. Once someone becomes infected with a germ the body starts a reaction called the immune response.
Immune Response The immune response is made up of a network of cells, tissues, and organs that work together to protect the body.
Immune Response Step 1: Inside the marrow of the bones macrophages are produced. Macrophages are germ fighting cells
Immune Response Step 2 A pathogen (germ) enters the body the macrophages ingest the pathogen This causes antigens to be displayed on the surface of the cell. Antigens are markers that tells the body there is something foreign inside
Immune Response Step 3: Macrophages release chemicals to stimulate helper T cells Helper T cells attach to the antigens Helper T cells starts the secondary immune response.
Immune Response Step 4 Helper T cells release chemicals to stimulate B cells B cells will name the specific antigen and create specific antibodies to kill the germ.
Immune Response Step 5 Antibodies are proteins that are made to kill specific germs They can only kill the germ they were made to kill. It is like a lock and key or puzzle pieces.
Immune Response Step 6 Once the antibody has attached to the invading germ it will send out a signal to macrophages to destroy it. The macrophages will engulf the antibody and the germ. The body gets rid of them through urine
Immune Response Step 7 T-suppressor cells will tell the immune system to rest once the infectious agents decrease. Without the T-suppressor cells the body would continue trying to fight off a disease that doesn t exists. This could lead to the body fighting healthy cells
Immune Response Step 8 Some B cells become memory B cells instead of creating antibodies. Memory B cells stay in the body for years ready to make more antibodies just in case the germ comes back.
Immune Response This makes it so that the germs can be attacked and killed quicker. Your body s ability to produce antibodies before you become sick is called immunity.
Immune Response Your abilities to remember germs and how to fight them is why once you have had a certain disease, like chicken pox, you rarely catch them again.
Vaccines We can not kill viruses like we can kill bacteria with antibiotics. We do however have vaccines. A vaccine is a substance that is used to make a person immune to a certain disease.
Vaccines When someone gets a vaccine they are given a dead and weakened virus germ. Once the dead and weakened virus germ is in the body, the immune system starts to fight the virus by creating antibodies.
Vaccines Vaccines only prevent a viral infection. It will not work once the person has a virus. The only thing that can help once you have a virus is the human body itself.
Immune Response This means that antibodies are created and stay in the body. When we become infected with full blown virus, the antibodies quickly attach themselves to the germ. This allows the antibodies to quickly destroy the germ before you even get sick.
Reminder Getting Started Take out your Infectious Disease Notes If you missed any of the notes yesterday We will be turning in your notes tomorrow Objectives Identify five types of infectious agents Describe ways in which infections can spread Explain ways to prevent the spread of germs Explain how the immune system fights germs
How Germs Spread A vector is anything carrying a germ Germs can spread by: Person to person Animal to person Insect to person Food and water to person
How Germs Spread Direct contact means you come in contact with the vector directly. Coughing or sneezing Kissing Animal bite Sexual contact
How Germs are Spread Indirect contact is coming in contact with something the vector has come in contact with Food Doorknobs Counter tops
Assignment #2 With a partner decide if the germ was spread through direct or indirect contact. Then state a way to have prevented the germ from being spread. 1. Someone sneezing on the lunch table during the previous lunch. When you sit down, you put your roll on the table. 2. You are out playing night games and a mosquito bites your arm. 3. You are out on a hike and come across what looks like a fresh stream. You take a drink.
Assignment #2 1. Someone sneezing on the lunch table during the previous lunch. When you sit down, you put your roll on the table. INDIRECT 2. You are out playing night games and a mosquito bites your arm. DIRECT 3. You are out on a hike and come across what looks like a fresh stream. You take a drink. INDIRECT
Protection from Infections Although our immune system is amazing, we need to do our part to protect ourselves from germs.
Protection from Infections Wash your hands with soap and water. Avoid contact with people who have a contagious infection If you are infected stay home Do not share food or drink Eat a balanced diet Get plenty of rest Stay current on your vaccinations
Quick Check 1. A(n) is a drug that kills bacteria or slows the growth of bacteria. 2. Arrange the following steps in the immune response in the correct order. A. Phagocytes engulf the dead germ and remove it through waste. B. Inside the bone marrow T-cells and B-cells are made. C. T-cells signal the B cells. D. B-cells make antibodies. 3. Which of the following is a symptom of the common cold? A. Rash B. Diarrhea C. Runny nose D. Vomiting 4. Antibiotics are drugs that are used to treat A. Viral infections B. Bacterial infections C. The flu D. HIV 5. Which of the following is NOT a first-line defense against germs? A. Skin B. Tears C. Saliva D. Fever 6. Which is of the following disease is NOT an infectious disease? A. Strep throat B. Cancer C. Influenza (the flu) D. Ebola
Quick Check 1. A(n) ANTIBOITIC is a drug that kills bacteria or slows the growth of bacteria. 2. Arrange the following steps in the immune response in the correct order. B, C, D, A A. Phagocytes engulf the dead germ and remove it through waste. B. Inside the bone marrow T-cells and B-cells are made. C. T-cells signal the B cells. D. B-cells make antibodies. 3. Which of the following is a symptom of the common cold? A. Rash B. Diarrhea C. Runny nose D. Vomiting 4. Antibiotics are drugs that are used to treat A. Viral infections B. Bacterial infections C. The flu D. HIV 5. Which of the following is NOT a first-line defense against germs? A. Skin B. Tears C. Saliva D. Fever 6. Which is of the following disease is NOT an infectious disease? A. Strep throat B. Cancer C. Influenza (the flu) D. Ebola