Preventing Communicable Diseases

1. Preventing CommunicableDiseases • 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

2. 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.

3. 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.

4. 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.

5. 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.

6. 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)

7. 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.

8. 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.

9. 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

10. 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.

11. 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”

12. 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.

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