Viruses Require living cells to reproduce, inactive by themselves. Penetrates a host cell, takes control of the cell to manufacture more viruses. Usually run their course & eventually are killed by immune system. Antibiotics do not work against viruses. Include Common cold Influenza (flu) Viral pneumonia Viral hepatitis Polio AIDS Chicken pox herpes VIRAL INFECTION

Bacteria Live almost everywhere on Earth, most harmless & many essential for life. Aide in digestion of food & make vitamins. Enter body & multiply through cell division. Some produce toxins i.e. tetanus. Most can be treated w/ antibiotics. Include Bacterial foodborne illness Strep throat Gonorrhea Lyme disease Bacterial pinkeye

Fungi Plantlike organisms i.e. molds & yeasts Include Athlete’s foot Ringworm Vaginal yeast infection Protozoans Most harmless, some can causes disease in people w/ weakened immune systems. Include Malaria Dysentery

Rickettsias Resemble bacteria, like viruses, multiply by invading cells of another life form. Enter humans through bites of insects such as fleas or lice Include Typhus Rocky Mountain spotted fever

Direct contact Direct contact w/ an infected person or animal. Touching, biting, kissing & sexual contact. Spread through… Sneezing & coughing into nearby person’s eyes, nose or mouth. Pregnant woman to unborn child through placenta. Tetanus from a puncture wound. Indirect contact Contaminated objects Persons # 1 sneezes onto a table or hand then touching the table. Person # 2 touches the table then touches nose or eyes Vectors Mosquito takes in pathogens from person # 1. Mosquito then transmits pathogens into person # 2. Water & food Carless handling & storage of food. Salmonella bacteria in undercooked poultry Water supplies that become contaminated w/ human or animal feces.

Airborne transmission Pathogens from sneeze or cough float in air for a long time & travel long distances. Diseases include chicken pox, tuberculosis (TB) and influenza.

1.Most efficient & effective way is to wash hands regularly with anti antibacterial soap. 2.Cover mouth w/ elbow when you sneeze and cough. If you cover mouth w/ hand, you are likely to touch an inanimate object & transmit pathogens. 3. Get vaccinations Not always necessary to get every vaccination every year. More necessary for young children & elderly people with weaker immune systems. All children should receive standard vaccinations from pediatrician MMR (measles, mumps, rubella) TB Hepatitis C (necessary for college).

Eat a balanced diet, regular physical activity & avoiding alcohol, tobacco & other drugs. Promotes growth & flow of white blood cells (immune system) & drugs are known to slow down body’s vital process’. Avoid sharing eating utensils, makeup, combs & brushes & other personal items. Prepare & store food safely. Avoid unnecessary contact w/ ill individuals. Take care of yourself when ill, cover mouth when sneezing or coughing, wash hands regularly. Get vaccinated against particular diseases. Abstinence from sexual activity. STI’s can be transmitted vaginally, anally & orally. Manage stress. Has been shown to weaken immune system.

1.List five types of common pathogens, and identify one disease each type of pathogen causes. 2.Describe three ways in which pathogens spread and three healthful behaviors to limit their spread. 3.What are five ways you can reduce your risk of getting a communicable disease?

Skin First line of defense. Few pathogens can pass through layer of dead skin cells. Tears & saliva Contain enzymes that destroy or disable pathogens. Mucus membranes Line mouth, nose & bronchial tubes. Produce mucus that traps pathogens. Carries trapped pathogens to other areas of body for disposal. Cilia Hair like projections lining parts of the respiratory system. Sweep pathogens & mucus to throat to be swallowed or coughed out. Gastric juice Stomach destroys pathogens that enter body through nose & mouth.

Two major defense strategies Inflammatory response a.k.a. non-specific Works against all types of pathogens Purpose is to prevent further tissue injury & halt invading pathogens. Symptoms include area becoming hot, swollen, red or painful due to increase in blood flow to area. Specific defense Work against particular pathogens. Utilized when body recognizes certain pathogens and destroys them.

T Cells & B Cells Helper T cells trigger production of B cells and killer T cells. Killer T cells attack & destroy infected body cells. Suppressor T cells “turn off” or suppress helper T cells when infection has been cleared. B cells produce antibody specific to a particular pathogen. Memory lymphocytes Some T & B cells become memory cells & circulate through bloodstream & lymphatic system. Triggered when former invader comes into the body.

Active Protects you from measles, chicken pox, etc. Acquired naturally when body is exposed to antigens from invading pathogens. Acquired artificially from a vaccine Vaccine causes body to produce antibodies without causing the illness. Body exposed to small amount of disease Most active immunities last a lifetime, some need to be repeated. Passive Receiving antibodies from another person or an animal. Short-lived, usually lasting only weeks to months. Natural passive occur from mother to child during pregnancy or nursing.

Should be vaccinated against… Tetanus Diphtheria Measles Mumps Rubella Hepatitis B Can be administered and recommended by family physician and local health department. Most high schools & colleges require students show proof of current immunizations.

1.List three physical and chemical barriers that pathogens encounter when they try to enter the human body. 2.What is the difference between active immunity and passive immunity? 3.Where can you go to find out which immunizations you need?

Respiratory infections Most common communicable diseases. Caused by bacteria or viruses. Prevention includes avoiding contact w/ infected people, washing hands, keeping hands away from eyes and nose. Common cold Viral infection that causes inflammation of the mucous membranes that line nose and throat. Symptoms include runny nose, sneezing and sore throat. Most common transmission from rubbing eyes or nose after hand-to-hand contact with contaminated object. No cure. Treatment is for relief of symptoms. Most clear up in a week or so. Influenza One of the top 10 causes of death in the U.S. Viral infection of respiratory tract. Symptoms include high fever, fatigue, headache, muscle aches and cough. Most often spread through airborne transmission. Can also be spread through direct or indirect contact. Treatment includes antiviral drugs, proper nutrition and plenty of rest and fluids.

Pneumonia One of the top ten causes of death in the U.S. Can be bacterial or viral. Symptoms include similar to those of influenza. Treatment includes antiviral drugs for viral infection and antibiotics for bacterial infection. Strep throat Often bacterial infection spread by direct contact through droplets that are coughed or sneezed into air. Symptoms include sore throat, fever and enlarged lymph nodes in neck. If left untreated, can lead to inflammation of kidneys and rheumatic fever. Treatment includes antibiotics. Tuberculosis Airborne, bacterial disease spread by coughing or sneezing of infected person. Most people with bacteria never develop disease because of body’s defenses. Symptoms include fatigue, coughing (sometimes blood), fever, night sweats and weight loss. Treated with antibiotics.

Hepatitis Inflammation of the liver caused by chemicals including drugs and alcohol and many different pathogens. No cure, but vaccines available for types A & B. Hepatitis A One of the top 10 communicable diseases in U.S. (about 1.5 million worldwide). Most commonly spread through feces of infected person. Person A does not wash hands properly and touches objects of food or direct contact, i.e. shaking hands with person B and person B touches eyes, nose or mouth. Symptoms include fever, nausea, vomiting, fatigue abdominal pain and jaundice.

Hepatitis B More serious than type A. Found in most bodily fluids, especially blood. Most often transmitted through sexual contact, or needles shared by infected drug users. Can cause severe liver damage including liver failure and cirrhosis or scarring of liver. Hepatitis C Most common blood-borne infection in U.S. (about 4 million Americans), Transmitted by direct contact w/ infected blood through contaminated needles. Can lead to chronic liver disease, liver cancer and liver failure. Up to 90% of those infected don’t know they are infected until years later after routine tests show liver damage.

1.Compare and contrast the common cold and the flu. 2.What are three ways you can reduce your risk of getting influenza? 3.What are emerging infections?