1. Complex

2. Enveloped

3. Naked

Nucleic Acid: DNA or RNA

Capsid-outer coat (capsomere)

Spikes (not all)

ex: polio

nothing around the virus

Nucleic Acid: DNA or RNA

capsomere

Spikes (not all)

phospholipid membrane

(lysol targets phosp. and will dissolve)

used for attachment..

Hemagglutinin: RBC attachment

Neuraminidase: cells

1. attach to host cell: to gain entry

receptor mediator endocytosis

2. Deliver NA

fuse then split in RNA or DNA

endocytose whole virus

3. Duplicate/synthesis all parts

make more

4. Assemble all parts

spikes insert unto cell membrane for envelope and pull together

5. Exit host cell

RNA: occurs in cytoplasm

easier to make drugs for RNA bc DNA has to cross 2 membranes

DNA: occurs in nucleus but passes thru cytoplasm

Bacteriophage is only in DNA viruses

Retrovirus: Starts as RNA and works back to DNA.

RNA virus.

Targets THelper Cell: wont activate immune response if TH cells dont work.

Different:

ds RNA, enzyme: reverse transcriptase

glycoprotein spikes--attachment: gp120 and 50

1. Attach to host cell: THelper cell

spikes attach to CD4 receptor

2. release NA in cytoplasm

3. Reverse transcriptase makes 1 RNA and 1 DNA strand of viral, then makes 2 DNA strands

4. crosses into nucleus: viral DNA finds DNA ligase, cuts and inserts into chrom. (provirus)

Moves to a different chrom every time in each cell.

5. viral DNA --> viral RNA

6. Makes parts in cytoplasm

7. Assembles

8. Buds off host cell: has host cell membrane around it so immune system will recognize it as normal.

HIV

signs, symptoms

Signs: what you measure

• fever
• septicemia
• microbes in tissue fluid
• chest sounds
• skin eruptions
• leukocytosis
• leukopenia
• swollen lympth nodes
• abscesses
• Tachycardia (high <3 rate)
• Ab in serum

Symptoms: what you feel

• Chills
• pain, aches, sore, irritation
• nausea
• malaise, fatigue
• chest tightness
• itching
• headache
• abdominal cramps
• anorexia
• sore throat

HIV

Diagnostics

1. signs and symptoms

2. Ab-Ag rxn: very reliable

• Ouchterlony: run 5 tests at one time, precipitate line
• Flourescent Ab Test: FA ag-ab rxn, uses flourescent marker (direct test-1 layer of Ab; indirect-2 layers), time consuming, expensive
• ELISA: screening for HIV/large amount of screening, yellow= positive (96 well plate), can test many samples at one time, automated
• Hemaggulination test: used for flu virus, RBC & spike from flu (96 wells), looks for hemagglutination

3. grow cells in tissue culture, CPA, some viruses destroy cells of cell layer, cervical cancer-1st, eggs are used to grow viruses (chicken/turkey), used for vaccines as well.

4.  Electron microscopy: last resort, very expensive, WSU has 10 EM

5.  Gel electrophoresis: look for spikes and Abs, DNA sequence of virus, RNA or DNA

Awareness/education

prevention

transmission

vaccination -if there is one

Epidemiology...

who, what, where, when, why

1. low level of adverse side effects/toxicity

2. protect against exposure to natural, wild forms of pathogen

3. stimulate Anitbody (BCell) response and Cytotoxic (TCell) reponse

4. have longer term, lasting effects (produce memory cells)

5. should NOT require numerous doeses/boosters

6. should be inexpensive, have a relatively long shelf life, and be easy to administer

1. Latent Infection: (hide out) virus replicates in non ifectious state. Produces new disease symptoms.

ex: Rabies, chicken pox--> shingles

2. Chronic Infection: (over time) virus released from host without symptoms

hits liver (from food, blood transfusions, oral-fecal), food borne illness

ex: hepatitis B, C

3. Slow infection: (not right away) slowly developing disease. Multiply-agents

ex: HIV-->AIDS

virus:hepatitis

parasites: giardia

Bacteria: e.coli, listeria, salmonella

Mold: alfatoxins

Fungi: death angel-mushroom

Algae: Red tide

Infects GI tract-->stomach

Transmission:

Mode--Fecal, oral, vectors, water, food

Reservoirs--soil, water, animal/human

Microbe--bacteria, virus, parasite, algae, molds

Food Borne Illness

Groups at Risk

elderly

young, pregnant, children, Chronic ill:HIV or Cancer

Food Borne Illness

Agencies

WHO: World Health Organization

Public Health: Local and State

CDC: Center for Disease Control

USDA: US Department of Agriculture--meat and plants, port of entry, anything with diseases, they inspect everything, to ensure safe products

Food Borne Illness

Controls

Heat/Cooled

Filter

UV-radiation

Inspection

Common Sense

Animal/Plant control

Food Borne Illness

Why do we still have Problems?

1.  mishandling of food and food products
2. Centralization of food production
3. Antibiotics in feed
4. foreign trade
5. Environmental Contamination

Symptoms: blurred or double vision, weakness, nausea, vomiting, diarrhea, generalized paralysis, respiratory insuffieciency

Incubation: 12-36 hours

Causative agent: Clostridium botulinum-gram+, spore forming, rod shaped

Pathogenesis: release neurotoxins, survives stomach acid, absorbed into small intestine and carried to blood stream, blocks nerve signals

Epidemiology: ingestion of contaminated (home canned) food that was not heated enough to kill spores.

Prevention/treatment: Education, heating food to boiling for 15 mins prior to serving. Enemas and stomach washing, cleaning infected wounds

Symptoms: Diarrhea and vomiting, fever, headache, stomach pain, shock, abscesses

Incubation: 6-72 hours, can be 1-3 weeks in typhoin fever

Causative agent: Salmonella enterica, motile, gram -, enterobacteria

Pathogenesis: invasion of lining cells of lower small and large intestine, inflammatory response causes increased fluid secretion

Epidemiology: ingestion of food contam. by animal feces (poultry). Human fecal source in typhoid fever-like symptoms, raw eggs, chicken, peanuts.

Prevention/treatment: Adequate cooking and handling for food, vaccine against typhoid fever

symptoms: cold followed by headache, fever, pain, stiff neck and back, vomiting

Incubation: 1-7 days

Causatuve agent: Neisseria meningitidis, gram-

Pathogenesis: colonize upper respiritory system, enter bloodstream, carried to spinal fluid, causes pressure and impairs brain function and motor nerves

epidemiology: close contact with a case or carrier, inhale infectious droplets

prevention/treatment: polysaccharide vaccine against types A, C, W135, and Y.

Penicillin and ceftriaxone (treat)

Symptoms: fever, muscle aches, GI symptoms, headache and neck stiffness

Incubation period: few days to 2-3 months, 1-4 weeks in newborns

Causative agent: listeria monocytogenes, non spore, gram+ rod

Pathogenesis: ingested and gets into bloodstream

epidemiology: soft cheeses, nonpasteurizated milk, coleslaw, hotdogs, pregnant women--infected fetus, people with diabetes

Prevention/treatment: Care in handling, cooking of raw meats, washing vegetables, reheated of cold cuts, hot dogs, leftovers

penicillin

symptoms: vomiting and diarrhea

incubation period: 2 hours to 6 days

Causative agent: e coli, certain strains

pathogenesis: attachment to small intestinal cells, some produce enterotoxins, shigellas, invade large intestine

Epidemiology: common in travellers, foodborne or waterborne, fecal-oral route transmission, animal source

prevention/treatment: handwashing, pasteurization of drinks, cooking of meats, replacement of fluid loss, antibiotics and bismuth compounds (treat)

(creates toxin, targets certain areas, botulism)

Staph aureas: custards, cream filled, ham, dressing

very common, diarrhea, not fatal

Clostridium Bot.: home canned, water, honey

vacuum packed foods, can be fatal, neurotoxin-> respiratory

Clostridium perfringens: inadequately cooked meats

vegetative cells produce toxin within the intestine

Bacillus cereus: Reheated rice, potatoes, puddings, custards

Mimics staph enteritis, usuallys self limited

(ingesting organism, cross contamination)

Campylobacter jejuni: Transmitter via water, raw milk, raw chicken, shellfish, meats

common, diarrhea, neurological, animals are carriers of others, scuba divers: raw sewage, anchors in intestinal tract

Salmonella: poultry, eggs, dairy, meats

severe and life-threatening, neurotoxin produced.

Shigella: unsanitary cooked foods, fish, shrimp, potatoes, salads

Carriers and flies contaminate, in dog feces

Vibrio enteritis: raw or poorly cooked seafoods, water

microbes lives naturally on marine animals

Literia: Birth defects, poorly pastuerized milk, cheeses, hot dogs, lunch meats

most severe in fetuses, newborns and immunodeficient

E. Coli: Contaminated raw vegetables, cheese, raw or rare beef, water

various strains, travellers diarrhea (sometimes bloody--0157:H7)

Acquired immunity:

natural and artificial

Natural: acquired through the normal life experiences of a human and is not induced through medical means

Artificial: produced purposefully through medical procedures

Active: Ag-Ab

Ig

developing own immune response to microbe

Passive: IgG, mother's milk

receiving a performed immunity made by another person

Vaccinations

Active: Vaccines

developing own immune response to a microbe

Passive: Ig after being exposed to Ag, immunoglobin shot (jump start IR)

receiving a performed immunity made by another person

symptoms: fever, muscle aches, lack of energy, headache, sor throat, cough, nasal conjestion,

Incubation period: 1-2 days

Causative agent: influenza virus

Pathogenesis: respiratory infection, cells destroyed and virus released to infect other cells.

Epidemiology: antigenic drift and antigenic shift thwart immunity

Prevention/treatment: Vaccines usually 80% to 90% effective.

Symptoms: mild fever, cold symptoms, rash beginning on forehead and face, swollen lymph nodes

Incubation period: 14-21 days

Causative agent: rubella virus, and RNA virus

pathogenesis: respiratory tract, virus goes to all parts of body and crosses the placenta, surviving fetuses may have abnormalities.

Epidemiology: Virus present in nose, throat from 1 week before rash to 1 week after.

Prevention/treatment: Attunuated rubella virus vaccine (children 12-16 months)

Symptoms: Rash, fever, weepy eyes, cough, nasal discharge

Incubation period: 10-12 days

Causative agent: rubeola virus, ss RNA virus

Pathogenesis: virus multiplies in respiratory tract, spreads to lymphnoid tissue then to all parts of body, damage to respiratory tract

Epidemiology: acquired by respiratory route, highly contagious

Prevention/treatment: virus vaccine after age 12 months, second does entering elementary school.

symptoms: itchy bumps, fever, latent infection

Incubation period: 10-21 days

causative agent: varicella-zoster virus, enveloped ds DNA

Pathogenesis: upper respiratory virus multiplication, goes through bloodstream to the skin

epidemiology: highly infectious, aquired by respiratory route

Prevention/treatment: attenuated vaccine

Symptoms: fever, throat pain, ulcerations in mouth and throat, itchy tingling pain, blisters that break leaving painful sores

Incubation period: 2-20 days

Causative agent: herpes simplex virus, usually type 1

pathogenesis: virus multiplies, cell destruction and blisters, immune response quickly limits the infection, stress activates breakouts

Epidemiology: widespread virus, transmitted by close physical contact

Prevention/Treatment: acyclovir, penciclovir, medications that inhibit HSV DNA polymerase

HIV disease

symptoms, etc

symptoms: fever, sore throat, head and muscle aches, rash, enlarged lymph nodes. malignant tumors, pneumonia, diarrhea

Incubation period: 6 days-6 weeks, 10 years for fully developed

Causative agents: Human immunodeficiency virus, type 1 (HIV1) many subtypes and strains. HIV2 mainly in west africa

Pathogenesis: infect various body cells, CD4 T and Antibody presenting cells (THelper), immune response no longer resist infections

epidemiology: 3 main routes: intimate sexual contact, blood transfer, mother to child during birth, breast milk and oral genital contact

Prevention/treatment: no vaccine yet. medications and vaccines can prevent many of the infections that can complicate HIV.  Preventative measures: education, needle exchange programs, use of condoms.

HAART therapy, anti HIV medication

2 forms:

attenuated bacteria (taken orally)

purified polysaccharide

Viral Uncoating/virus entry

NA Synthesis

Assembly and Release of Viral articles