INFECTIOUS DISEASES

Terminology Infection –Invasion of body by disease causing organism and the body’s reaction to its presence Antigen –Foreign invader –Stimulates a response from the immune system Antibody –Chemical compound made by immune system to destroy antigens and toxins Toxins –Chemicals released by the antigen

Infectious Agents Bacteria –One celled organism Virus –Smallest common pathogen Fungi –Plantlike microorganism Rickettsia –Virus like organism that requires a host Protozoa –Simplest animal organism, one celled Parasitic worms –Many celled organism ie leeches, tapeworms

Agent –Disease causing agent Reservoir –Humans, animals, soil Portal of exit –Respiratory system, blood, digestive system

Mode of transmission –Direct contact Physical contact –Indirect contact Handwashing between patients –Droplet contact sneeze –Vector borne insects

Chain of Infection Portal of entry –Digestive, respiratory, reproductive system The new host

Stages of Infection Incubation period –Organism invades and multiplies Prodromal period –General symptoms Clinical disease –Illness at its peak with specific symptoms Decline stage –Symptoms subside Recovery period –Still contagious

Immunizations/Vaccines Diptheria –Inflammation of the throat Whooping cough –Bacterial infection Hepatitis B –Viral infection affecting liver Haemophilius influenzae type B –Bacterial infection affecting heart and brain Tetanus –Bacterial infection of central nervous system

Immunizations/Vaccines Rubella –German measles Measles –Viral infection Polio –Viral infection causing paralysis Mumps –Viral infection of salivary glands Chicken pox –Viral infection with rash

Food Poisoning Sickens 76 million/yr, kills 5000 Salmonella poisoning –Poultry Trichinosis –Pork Listeria –Cheese, milk, yogurt E-coli –meat Botulism –Canned goods

Food Poisoning Avoiding food poisoning –Wash fruits and veggies –Thaw chicken in refrigerator –Wash hands after handling poultry –Thoroughly cook chicken, eggs, meats –Refrigerate foods quickly

Toxins Bacteria can release toxins near cells to destroy them Some toxins are very powerful ¼ teaspoon to toxin released by tetanus organism is strong enough to kill 10,000 people

Antibiotics Group of drugs that destroy or inhibit bacteria Not effective against viruses Rise of drug resistant bacteria –95% of hospitals have vancomycin resistant bacteria –40% of streptococcal pneumonia is resistant to antibiotics

Colds Acute rhinitis Approx 200 know rhinoviruses Can be transmitted by droplets (sneezing or coughing) Most common transmission hand contact –To prevent transmission wash hands frequently –Keep you hands away from your nose Incubation period hours

Influenza/Flu Flu epidemic of –Killed 50 million people in 18 months Virus very contagious in first 3 days Kills 40,000 people/yr and hospitalizes 300,000/yr Flu vaccine

Tuberculosis Bacterial infection of lungs chronic cough, weight loss, death Most commonly spread by coughing Antibiotic resistant strain in US

Pneumonia Respiratory infection Can be caused by bacterial, viral, parasitic or fungal causes Elderly die from pneumonia

Mononucleosis Spread by oral contact, blood transfusions is the usual age group Caused by Epstein-Barr virus Fever, sore throat, nausea, chills, rash enlarged spleen Mono spot –Blood test Life long immunity Bed rest –Avoid contact sports

Bacterial Meningitis Infection of membranes surrounding brain and spinal cord High fever, severe headache, stiff neck, nausea, vomiting, rash, flu like symptoms Kills approx 300 of the 3000 who get sick each yr in the US Higher rates in college students Vaccination –Given at year old check up –Entering high school students –Entering college students –Protects for 10 years

Lyme Disease Bacterial disease from infected deer ticks Symptoms in 30 days, small bumps around circular red rash with flu symptoms Later stages lead to disorders of nervous system, heart, chronic arthritis Treated with antibiotics Protect yourself from ticks while outdoors –Wear long pants and long sleeve shirts –Tuck your pants into your socks –Check yourself and your pets for ticks

Lyme Disease

Toxic Shock Syndrome Widespread infection related to tampons Develop shock Tampons should be changed every 4 hours, never longer then 8 hours

Hepatitis Viral inflammation of the liver Type A, B, C, D, E Type A –Related to poor sanitation, contaminated foods Contaminated vegetables from Mexico implicated in many outbreaks of hepatitis A –Found in developing countries –Vaccine is available

Hepatitis Type B –Related to sexual contact, blood transfusions, IVDA, tattooing, body piercing –Symptoms include jaundice, headache, pain over liver –If a coma develops only 10-20% survive –Vaccine available, must be given before kindergarten and to health care workers

Hepatitis Type C –Spread same way as type B –Kills 12,000/yr in US –2.7 million carry the hepatitis C virus –90% IVDA carry the hepatitis C virus

Hepatitis Type D –Found in people with type B –Difficult to treat Type E –Associated with water contamination –Rarely seen in US

SARS Severe Acute Respiratory Syndrome –Atypical pneumonia –Caused by a virus –First found in China –Extremely contagious

Avian Bird Flu H5N1 virus Found initially in Asian birds and has now spread to Europe Concerned that it may mutate and be easily transmitted to humans –So far it has killed about 100 people world wide Health officials fear a world wide epidemic killing millions