Fighting Disease History of Disease and the Immune System

What is disease? Disease is describing a condition in which the body is not functioning normally.

What Causes Disease? Dietary- deficiency in calories, minerals, vitamins – Goiter – Scurvy – Rickets

What Causes Disease? Genetics- inherited diseases – Hemophilia – Down Syndrome – PKU – High Cholesterol

What Causes Disease? Venoms/Toxins- from plants, snakes, etc. – Sea snake – Brown recluse spider – Poison Ivy

What Causes Disease? Infection by microorganisms- viruses, bacteria, protists, fungi – We will go over these during each classification

Historically… (hundreds of years ago) Physicians described the body as having 4 humours, that needed to be in balance – Black bile- melancholy – Yellow bile – Phlegm – Blood

Historically… (hundreds of years ago) If one was “bad” you let it out – Blood letting

Important People Ignaz Semmelweis (1844) - baby delivery suggestions Dr. John Snow (1854) - read Semmelweis’ work. – Noticed that Cholera patients all got water from same pump from the Thames River. – Closed the pump and epidemic ended in 24 hours

Important People Dr. Joseph Lister (1867) - sterile surgery- used carbolic acid to sterilize operating room – 50% mortality dropped to 10% mortality – Listerine mouthwash named after him in 1879.

Important People Robert Koch- concerned with cholera, TB, and Anthrax outbreaks; said caused by microorganisms – Koch’s postulates- finding the actual cause of a particular disease

Koch’s Postulates The pathogen should always be found in the body of a sick organism and should not be found in a healthy one. The pathogen must be isolated and grown in the laboratory in pure culture. When the cultured pathogens are placed in a new host, they should cause the same disease that infected the original host. The injected pathogen should be isolated from the second host. It should be identical to the original pathogen.

Koch’s Postulates pathogen in a sick organism not in a healthy one. pathogen grown in pure culture cultured pathogens placed in a new host, they should get the same disease pathogen reisolated from the second host- identical to the original

Agents of Disease Bacteria Viruses Protists – Ex: Plasmodium, Trypanosoma, Amoeba Worms – Tapeworms, hookworms, heartworms Fungi – Ringworms, jock itch, athlete’s foot

Spread of Disease Person to Person – Horizontal-person to person Exchange of body fluids: blood, semen, saliva Airborne disease Indirect- touching surfaces – Vertical- mother to child Syphilis, herpes, rubella

Spread of Disease Contaminated food and water – Sewage (E. coli, Cholera) – Protists (Amebic Dysentery) Carrier animals (vectors) – Insects (Malaria, Lyme Disease) – Mammals (Rabies)

Epidemiology Def.: science of how diseases occur and spread Epidemic- sudden increase of a disease prevalence in a region – Index case- first case in an epidemic, Patient Zero Pandemic- world-wide epidemic Endemic- constant low prevalence of a disease (common cold)

Epidemiology Outbreak- sudden unexpected occurrence of a disease in a limited demographic – Dr. John Snow’s map of Cholera outbreak 

Epidemiology Application – Who is at risk? – What behaviors put you at risk? – What is the infection rate? – What is the mortality rate? – What is the prevention?

Fighting Disease Prevention – Sanitation, washing hands

Fighting Disease Controlling growth of bacteria - Sterilization - Disinfectants - Food Processing

Fighting Disease Sterilization by heat- heat is used to kill bacteria -Autoclave-- typical 134 °C for 3 minutes or 121 °C for 15 minutes. - does’t work on all bacteria and viruses…Prions and some discovered organisms, Strain 121, can survive at temperatures above 121 °C.

Fighting Diseases Disinfectants– chemicals used to kill bacteria -concerns that over use of antibacterial soaps and detergents will cause bacteria to evolve and become resistant and harder to kill.

Fighting Disease Food Storage - refrigeration: cold temps slows the reproduction of bacteria - boiling: heat is used to kill bacteria - Canning: heat food before placing in a sterile container and sealing for long storage— usually has indefinite life span

Fighting Disease Pasteurization - heat a food (usually liquid) to kill SOME bacteria, mainly pathogenic microbes. (not sterilize) - Used on wine, beer, and milk to prolong shelf life - Not used on all food because is affects quality and flavor

Fighting Disease Antibiotics – Destroy cells wall structure – Prevent growth/replication of prokaryotes Alexander Fleming - discovered penicillin

Fighting Disease Vaccine – Weakened or dead version of a pathogen to trigger an immune response Edward Jenner - gave people cow pox to ward off small pox - first vaccination

Bacterial Diseases

Lyme Disease Cause: Borrelia burgdorferi Symptoms: fever, fatigue, headaches, muscle aches, joint aches, Bulls-eye shaped rash Transmission: tick bite Treatment: antibiotics

Tetanus (Lock jaw) Cause: Clostridium tetani Toxins released by bacteria interfere with nervous system Symptoms: Severe muscle spasms and possibly death Transmission: Commonly contracted from deep puncture wound or self-piercing with contaminated materials

Tetanus (Lock jaw) Treatment: – Clean wound – Mild: given antibodies against it, with antibiotics, and a vaccine – Severe: same as above, muscle relaxers or even paralytic drugs to stop the spasming

Tuberculosis (TB) Affects nearly 1/3 of the world’s population Cause: Mycobacterium tuberculosis Symptoms: Fatigue, weight loss, fever, chronic cough Tubercles form in lungs (dormant form) Transmission: Spread through cough Treatment: long term antibiotic treatment (6-12 months)

Gonorrhea Cause: Neisseria gonorrhoeae Male symptoms: – Thick, foul-smelling discharge from penis – Painful urination – Testiculur and abdominal pain Female symptoms: – Pus-like vaginal discharge – Pain urinating – Bleeding after intercourse Transmission: oral, anal, or vaginal sex Treatment: with antibiotics

Chlamydia One of the most common STIs on college campuses Cause: Chlamydia trachomatis Symptoms: Burning during urination, discharge from the penis or vagina, pain and itching Transmission: oral, anal, or vaginal sex; mother to child during childbirth through vaginal canal Treatment: with antibiotics

Strep Throat Cause: Streptococcus pyogenes, certain strains cause scarlet fever and Toxic Shock Syndrome Symptoms: fever, sore throat, swollen glands Transmission: respiratory droplets (coughing sneezing) Treatment: antibiotics can cause it to go away faster Purple  gram +

Tooth Decay Cause: Streptococcus mutans, bacteria doubles in 24 hours Symptoms: Destruction of tooth enamel Transmission: resident in mouth Treatment: brush and floss daily

Bacterial meningitis Cause: Neisseria meningitis Symptoms: high fever, headache, stiff neck, nausea, fatigue Transmission: most common in college dorms Treatment: antibiotics, early detection is essential

Anthrax Used in Bioterrorism Cause: Bacillus anthracis, a spore-forming bacteria Transmission/Symptoms of varying types: – Spread by eating undercooked meat (vomiting and diarrhea, possible death) – breathing in spores (usually fatal) – skin contact (ulcers, rashes, not fatal) Treatment: oral and IV antibiotics

Botulism- food poisoning Cause: Clostridium botulinum Symptoms: blurred vision, slurred speech, difficulty swallowing, muscle weakness, paralysis Transmission: From a wound, contaminated food Treatment: antibiotics FACTOID: Botox is a toxin secreted by Clostridium botulinum

Staphylococcus aureus Pets can carry bacteria as well! Staphylococcus aureus – Gram + – Cause: Staphylococcus aureus – Symptoms: nausea, cramping, retching; some individuals may not show symptoms – Transmission: eating contaminated food, contaminated air, individuals and surfaces PETS!

Viral Diseases

HIV (Human Immunodeficiency Virus) 1. The HIV virus infects cells of the immune system called Helper T cells. a. Normally Helper T cells activate cells that produce antibodies and cells that destroy cells infected by a pathogen. b. When a Helper T cell is infected by the HIV virus, the immune system cannot fight off infections from pathogens such as bacteria and other viruses.

HIV (Human Immunodeficiency Virus) c. HIV can cause AIDS (Acquired Immunodeficiency Syndrome) when enough Helper T cells are infected so the immune system does not work properly. d. People with HIV infections can get sick easily because their immune system does not work properly. People with AIDS do not die from the HIV virus, but from these other infections.

HIV (Human Immunodeficiency Virus) Cause: Cause: – Human Immunodeficiency Virus Symptoms: Symptoms: – Fever, headache, tiredness, enlarged lymph nodes – AIDS (Acquired Immunodeficiency Syndrome) weight loss, fatigue, memory loss weight loss, fatigue, memory loss – Destroys Helper T cells (part of immune system) body cannot fight off illnesses caused by bacteria, other viruses, fungi, or parasites. body cannot fight off illnesses caused by bacteria, other viruses, fungi, or parasites. Ultimately leads to death Ultimately leads to death

HIV (continued) Treatment: Treatment: – Reverse Transcriptase (RT) inhibitors & Protease Inhibitors- stops the virus from making copies of itself Transmission: Transmission: – sexually (orally, vaginally) – Blood (needles, or through mucus membranes) – Breast milk mother to child – NOT from kissing, touching, insects bites Status: Status: – No vaccine, several medicines to prevent spread in body – Worldwide: In 2004, 40 million people living with HIV/AIDS, 5 million newly infected, and 3.1 million deaths Prevention: Prevention: – Abstinence, Safe sex (Condoms!), avoidance or risky behaviors associated with sex and drug use

Common Cold Causes: Causes: – 200+ viruses can cause it, including rhinoviruses – No evidence for weather causing a cold Symptoms: Symptoms: – Runny nose, sore throat, headache, cough Treatment: Treatment: – Antihistamines, decongestants & glycerin based cough suppressants – NSAIDS (ibuprofen) Transmission: Transmission: – Inhaling drops of mucus full of rhinovirus – Touching contaminated surfaces – Wash your hands!

Influenza “the flu” Cause: influenza (Types A,B & C) Cause: influenza (Types A,B & C) Symptoms: Symptoms: – Fever, headache, fatigue, body aches, congestion Treatment: Treatment: – CDC currently recommends NOT taking medications for flu due to growing virus resistance. Transmission: Transmission: – Inhaling drops of mucus full of influenza virus – Touching contaminated surfaces Status: Status: – Vaccines present, BUT it changes yearly (RNA virus) – Threat of flu pandemics worldwide

Smallpox Cause: Variola Symptoms: – High fever, body aches, small raised bumps all over body Treatment: – no proven treatment for smallpox – Most recover, 30% mortality Transmission: – inhaling droplets of affected saliva – face-to-face contact with an infected person Status: – Vaccine present – Can be fatal – Eradicated worldwide, last naturally occurring in 1977

Herpes Simplex I Cause: (HSV-1) Cause: (HSV-1) – Herpes Simplex Virus Type 1 Symptoms: Symptoms: – Cold sores around mouth Treatment: Treatment: – Topical medication to reduce outbreaks – Antiviral medication to reduce number of outbreaks Transmission: Transmission: – Kissing, eating/drinking after one another Status: Status: – No vaccine, no cure! HSV-1

Cause: (HSV-2) Cause: (HSV-2) – Herpes Simplex Virus Type 2 Symptoms: Symptoms: – Pain, itching, blisters on genitals, anus and thighs Treatment: Treatment: – medication to reduce symptoms and reduce number of outbreaks Transmission: Transmission: – Sexually transmitted, may not be showing signs, oral or vaginal sex Status: Status: – No vaccination, no cure! – 1 out of 5 adolescents and adults have had HSV-2 in the US! Perianal HSV-2 Herpes Simplex II

Human Papillomavirus (HPV-warts) Cause: >100 strains of Human Papillomavirus (HPV) Cause: >100 strains of Human Papillomavirus (HPV) Symptoms: Symptoms: – Raised or flat, single or multiple swellings on any genital surface, male or female, can appear cauliflower-like – Can cause cervical cancer in women – No visible signs may occur Treatment: Treatment: – Topical creams are available, doctors may freeze or burn them off – May remove warts but virus is still present in the body and warts may return Transmission: Transmission: – Very contagious – sexual contact with infected partner, may not be showing signs Status: Status: – 6.2 million new cases a year in U.S. – No cure! – Tests available for presence in women – Gardasil- new vaccine that prevents the 4 highest risk strains of HPV

Hepatitis B Cause: Hepatitis B virus (HBV) Cause: Hepatitis B virus (HBV) Symptoms: Symptoms: – Cirrhosis (scarring of the liver), liver cancer, liver failure, death – May not look sick Treatment: Treatment: – Interferon- slows the growth of HBV Transmission: Transmission: – Any sexual contact – Blood contact (needles, razors, etc.) Status: Status: – Vaccine is available – 1.25 million American live with chronic hepatitis B Female Cambodian patient with a distended abdomen due to a hepatoma resulting from chronic hepatitis B infection Juandice

Rabies Cause: rabies virus Cause: rabies virus Symptoms: Symptoms: – Fever, headache, paralysis, hydrophobia, hallucinations, foaming at the mouth, ultimately death Treatment: no successful treatment Treatment: no successful treatment Transmission: Transmission: – bite from an infected mammal (carnivores and bats) Status: Status: – Cases have reduced in domestic animals greatly – Vaccine is available, only given to people at high risk of infection

Ebola Hemorrhagic Fever Cause: Cause: – 1 of 4 Ebola viruses Symptoms: Symptoms: – Fever, headache, muscle/joint pain, red eyes, skin rash – Diarrhea, vomiting, rash, internal and external bleeding Treatment: Treatment: – No standard treatment – Some patients recover but majority die, usually because the lack of immune response Transmission: Transmission: – Contaminated body fluids: Blood, mucus, semen, syringes – Air transmission in monkey Ebola-Reston virus only Status: Status: – Only identified in 1976 with few devastating outbreaks – RNA virus Electron micrograph of ebola virus

Other viral diseases Polio Polio Flu Flu Hepatitis Hepatitis Cold Cold Shingles/ chicken pox Shingles/ chicken pox Hanta Hanta SARS SARS Stomach virus (viral gastroenteritis) Stomach virus (viral gastroenteritis) Viral meningitis Viral meningitis Rubella, Measles, mumps Rubella, Measles, mumps Polio Measles Rubella