BIO54 MIDTERM #2: Infectious Disease

Pathogens

Pathogens

disease-causing agents found in air and food and on nearly every object or person

Endemic

diseases that are present at expected prevalence rates (ex: common cold in the winter)

Epidemic

when a disease occurs at rates higher than projected, endemic numbers (ex: the flu epidemic worldwide in 1918 that killed 40 million people around the world)

Pandemic

an epidemic that occurs globally

Mysophobia

an obsessive fear of becoming infected with germs

Risk factors you can control: (modifiable)

- too much stress

- poor diet

- low fitness level

- lack of sleep

- misuse or abuse of legal/illegal drugs

- poor personal hygiene

- high risk behavior

Risk factors you typically cannot control: (non-modifiable)

- heredity

- aging

- environmental conditions

- organism virulence and resistance to antibiotics

Inflammatory Response

It is the result of the defense mechanism. A reaction of the body's immune system with the foreign microorganism or subject, producing pain and fever (mild fever is a protective because it kills the disease causing microorganism).

Antigen

any substance capable of triggering an immune response

Antibody

the body's response to an antigen is the formation of antibodies

Humoral Immunity

- the body's major defense against many bacteria and poisonous substances, called toxins.

- performed through the antibodies secreted by blood cells and circulating in the blood and body fluids

Cell-Mediated Immunity

specialized white blood cells called lymphocytes attack and destroy foreign invaders

Autoimmune Disease

- when the immune system misfires, fights against its own proteins and makes antibodies agains them

- antibodies target the body's own tissue and attempt to destroy it

Vaccine

consists of a killed or attenuated version of a disease-causing microorganism or of an antigen that is similar to but less dangerous that the disease antigen

Acquired Immunity

basically a vaccine

Natural Immunity

got the disease itself and then got rid of it without any vaccination

Passive Immunity

From mother to the baby

Types of Bacteria

- three urgent resistant bacterial threats

- staphylococcal infections

- clostridium difficile (C. difficile)

- Streptococcal infections

- meningitis

- pneumonia

- tuberculosis

- tick borne bacterial diseases (Lyme disease)

- escherichia coli (e. coli)

Antibiotics

used to treat bacterial infections

Staphylococcal Infections

occur when the bacteria enter the body through a break in the skin; they can then cause a locked infection.

Clostridium Difficile (C. difficile)

highly resistant bacterial pathogen that causes significant problems

Streptococcal Infections

commonly occur in the throat and can cause strep throat and scarlet fever

Meningitis

inflammation of the meninges, the membranes that surround the brain and spinal cord

Pneumonia

general term for a wide range of conditions that result in inflammation of the lungs and difficulty breathing

- characterized by chronic cough, chest pains, chills, high fever, fluid accumulation, and eventual respiratory failure

E. Coli

- cause severe illness or death

- get it from eating undercooked ground beef, unpasteurized milk or juice, or sewage contaminated water

Tuberculosis

bacterial disease that is second to only HIV/AIDS as a global infectious agent killer

Viruses

- smallest of the known pathogens

- consist of protein structures containing either RNA or DNA

- cannot reproduce outside living cells

- some have incubation periods that last for years, which delay diagnosis

Types of Viruses

- common cold

- influenza

- infectious mononucleosis

- hepatitis

- mumps

- herpes

- measles, shingles, and rubella

- rabies

Common Cold

- endemic; they are always present

- can "catch" it from the airborne droplets of another's sneeze or from contact

- cannot get it from a chill

- rhinovirus is the main virus to cause it

Influenza

- some 5% to 20% of Americans get the flu each year

- contracting one form of it does not provide resistance to other forms

- those who should be vaccinated include seniors, pregnant women, and people with certain diseases, such as those affecting the heart and lungs

- three major varieties of this virus exist

Hepatitis A (HAV)

contracted through the fecal-oral route, such as ingesting selfish taken from contaminated water (transmitted through food, stays for about a month)

Hepatitis B (HBV)

spread through bodily fluids, unprotected sex, or by contact with the blood of an infected person (stays for your whole life)

- puts the person at risk for chronic liver disease or liver cancer

Hepatitis C (HCV)

spread primarily through blood or bodily fluids of an infected person.

- often manifest itself for many years after exposure, and resistant forms of this strain are emerging

Herpes

infections in the virus stays dormant and is reactivated periodically

- cold sore

- herpes simplex virus

- recurrent viral infection on the face (cold sore) or friction areas during sports Herpes gladiatorum

- in the genitals (very dangerous for the newborn baby)

Herpes Zoster Varicella Virus (HVZV)

- causes chickenpox and shingles

- shingles is a reoccurring zoster virus that is more serious than chickenpox (most sufferers are over the age of 60)

- herpes gladiatorum is prevalent among those who engage in contact sports such as wrestling

Fungi

pathogens that can cause disease in humans (ex: candidiasis, ringworm, and jock itch)

Zika and West Nile Virus (WNV)

diseases spread by the bite of an infected mosquito and infect the nervous system