Preventing Communicable Diseases Immune System – a network of cells, tissues, organs, and chemicals that fight pathogens. First line of Defense- Physical and Chemical: skin, mucous membranes, cilia enzymes in tears, saliva, gastric juices

Inflammatory Response A reaction to tissue damage caused by injury or infection. (hot, swollen, red, painful) Release of Phagocytes – a white blood cell that attacks invading pathogens. (Pus- a collection of dead white blood cells and damaged tissues) Repair now begins at injured site.

Specific Defenses When certain pathogens enter the body, the body’s immune response will recognize this pathogen and send out specific antigens- a substance that is capable of triggering an immune response. This response is what we call immunity – the state of being protected against a certain disease.

Battling Specific Diseases Lymphocyte- a specialized white blood cell that coordinates and performs many of the functions of specific immunity. Two Types – “T” cells and “B” cells (Helper “T” cells, Killer “T” cells, Suppressor “T” cells) “B” cells produce antibodies – a protein that acts against a specific antigen. An antibody will either mark a cell for destruction, destroy the antigen or block the virus from entering the body.

Memory Lymphocytes Some “B” and “T” cells actually have a memory and circulate through the body looking for “bad” invaders who have been there before- if found, they begin the attack to prevent illnesses. Active immunity- developed by your body Artificial immunity- vaccine- a preparation of dead or weakened pathogens that are introduced into the body to stimulate an immune response.

Vaccines Live virus vaccines – made from pathogens grown under special lab conditions to make them lose most of their disease causing properties. (measles, mumps, rubella, chicken pox) Killed virus vaccines – inactivated pathogens. Still cause an immune response and antibodies are produced. (flu shots, polio, rabies, hepatitis A) Toxoids – inactivated toxins from pathogens (tetanus, diptheria) used to stimulate production of antibodies. New and second generation vaccines- developed by scientists using new technologies. (hepatitus B)

Common Communicable Diseases Respiratory Infections (URI) most caused by viruses and bacteria avoid contact with infected people smoking can reduce chances of fighting uri’s Common Cold- runny nose, sneezing, sore throat, headache Influenza- fever, chills, dry cough, joint pain, runny nose, sore throat, extreme fatigue Pneumonia- an infection of the lungs in which the air sacs fill with pus and other liquids.

Strep Throat –(bacterial infection) sore throat, fever, enlarged lymph nodes. Treated with antibiotics. Tuberculosis – (Bacterial) attacks the lungs. fatigue, coughing (blood), fever, night sweats, and weight loss. Hepatitis- inflammation of the liver. Caused by chemicals and many other pathogens. No cure – but vaccines for A and B. “A” – spread through contact with feces of an infected person. Not washing hands properly before handling objects or food. Jaundice- yellowing of skin and eyes. “B” – more serious than “A”. Found in most bodily fluids, especially blood. Transmitted sexually. Drug use, piercings, tatoos, etc. “C” – most common, transmitted by direct contact with infected blood.

Other Common Diseases Mononucleosis- virus, spread by direct contact sharing utensils, kissing- “kissing disease”. Chills, fever, sore throat, fatigue and swollen lymph nodes. Measles – virus, spread by coughs, sneeze, close contact-highly contagious. Fever, red eyes, runny nose, cough, bumpy red rash. Encephalitis – virus, transmitted by mosquitoes. Causing swelling of the brain. Headaches, fever, hallucinations, confusion, paralysis. Meningitis – Virus or bacteria cause inflammation of the membranes that cover the brain. Fever, headache, nausea, vomiting, stiff neck

Emerging Diseases Emerging infections –communicable diseases whose occurrence in humans has increased within the past two decades or threatens to increase in the future. Avian Influenza- “Bird Flu” (direct contact with infected birds or contaminated surfaces. No vaccine, no cure.

H1N1 Virus- respiratory virus normally found in pigs H1N1 Virus- respiratory virus normally found in pigs. Symptoms- fever, sore throat, runny nose, body aches, and fatigue. Salmonella and E.Coli – bacterial, acquired by eating contaminated food. Store and cook foods properly. Giardia –a microorganism that infects the digestive system. “Recreational water illness”

HIV / AIDS – Lyme Disease – spread by tick bites. West Nile Virus – spread by infected mosquitoes. bird- mosquito-human SARS – viral illness first reported in Asia. Mad Cow Disease- “bovine spongiform encephalopathy” Epidemic- a disease outbreak that affects many people in the same place and at the same time.

How diseases affect the world- Pandemic – a global outbreak of an infectious disease. Travel- tourism and trade Mutation of Pathogens-