Infectious Diseases Diseases caused by a virus, bacterium, protist or fungus and are spread from an infected organism or the environment to another organism Biological Vector: disease carrying organism (rats, birds, dogs, cats, mosquitoes, fleas, flies) People can be carriers too!

Louis Pasteur French Chemist Realized that microorganisms could cause diseases in humans. Pasteurization: the process of heating a liquid to a specific temperature to kills most bacteria. Virus: a minute piece of genetic material surrounded by a protein coating that infects and multiplies in host cells The connection between viruses and disease transmission was not understood until the late 1800’s and early 1900’s

Surgery Through History Past: bloody aprons, dirty tools and street clothes were commonplace Present: disinfectants, sterilized tools, antiseptics and protective (sterile) clothing. Joseph Lister: one of the first surgeons to promote keeping things clean during surgery.

CDC Centers for Disease Control and Prevention –An arm of the US Department of Health –Monitor the spread of diseases in the US and worldwide. –Located in Decatur, GA (east of Atlanta near Emory University) –Study known pathogens for improved treatments –Working to be prepared for emerging health threats –Provide health and safety information to the public –

Sexually Transmitted Diseases STD’s Infectious diseases that are passed from person to person through sexual contact Bacterial STD’s - treated with antibiotics –Gonorrhea –Chlamydia –Syphilis Viral STD’s – treated with antiviral drugs –Genital Herpes –HIV

Bacterial STD’s Gonorrhea and Chlamydia –May be present for some time before symptoms appear. –Symptoms: painful urination, genital discharge and genital sores. –Usually respond to antibiotics –Left untreated, they can leave patients sterile or with permanent damage to reproductive organs Syphilis: caused be a spiral shaped bacterium –Has 3 stages: 1.Sores on mouth or genitals (10 to 14 days) 2.Involve rash, fever and swollen lymph glands (up to a year) 3.Affects cardiovascular and nervous systems

Viral STD’s Genital Herpes –Lifelong viral STD –Causes painful blisters on sex organs –Can be transmitted through sexual contact or from mother to child in childbirth –Goes dormant and then flairs up suddenly –No cure and no vaccine, but can be treated with antiviral medicines Human Immunodeficiency Virus (HIV)

HIV Exists in blood and other body fluids Can hide in the body’s cell for years Transmitted by having unprotected sex, and reusing infected hypodermic needles Early on was transmitted through blood transfusions but now the blood supply is screened to prevent this. Can be transmitted from mother to child through the placenta. The virus cannot multiply outside the body Cannot be transmitted through casual contact such as touching an infected person or objects that they have touched.

Acquired Immune Deficiency Syndrome (AIDS) Attacks the body’s immune system –Enters the T-cells and multiplies –Infected Helper T cells burst and infect more T-cells –When T-cells are destroyed, not enough B-cells are activated to produce antibodies –The body can no longer fight invading antigens and is unable to fight HIV and other pathogens –Most AIDS patients die from other diseases such as TB, pneumonia or cancer. –The is no known cure but we have developed a series of medicines that interfere with the way the virus multiplies in the host cell (called AZT)

Fighting Disease Washing wounds with soap and water is the first step to disease prevention Cleaning with and antiseptic and covering with a sterile bandage are other steps Washing hands (and entire the body) can help prevent the spread of disease Regular flossing and brushing teeth can also prevent the spread of disease Healthy habits (nutrition, sleep, exercise) can make the body less susceptible to disease