test 2 diseases

Describe the organisms which cause GAS

Streptococcus pyogenes

Gram-positive, nonmotile chains of spherical cells or diplococcus

Typically, capsulated

Facultative anaerobic

Positive for beta-hemolysis

List and describe the mild illnesses associated with GAS.

No illness- 5 to 15% have bacteria.

Mild illness- strep throat, impetigo

Severe illness- scarlet fever. Necrotizing fasciitis (invasive GAS), streptococcal toxic shock syndrome (invasive GAS)

 

List and describe the severe illnesses associated with GAS.

Mild

Strep throat:

• Sore scratchy throat

• Postulates

• Swollen lymph glands

• Severe complications: heart valve damage

Impetigo signs

• One of the most common skin infections

• Common in children

• Bacterium enters in cuts and bites

• Normally around the mouth

 

Severe

Scarlet fever:

• After or with strep

• Rash- strain makes erythrogenic toxin

• Throat and tongue covered by postulates strawberry tongue

• Complication: rheumatic fever

Necrotizing Fasciitis

• Flesh-eating disease

• Destroys muscle, fat, and skin tissue

• 40% of patients die

• Makes exotoxin A

Streptococcal toxin shock syndrome

• STSS

• Cascade of steps leads to rapid drop of blood pressure and organ failure (liver, kidneys)

• 50% of patients die

 

Treatment:

Penicillin and clindamycin

Amputations for necrotizing fasciitis

 

Why a STI? 

Sexually transmitted infection

Long periods with no signs and symptoms

Describe the derivation of the slang term for gonorrhea

French word clapper meaning brothel

Keeper of a brothel named mother clap (Margaret Clap)

Painful sting in male urethra feels like a clap

A clap was a traditional treatment to clear the blockage

 

Describe the organism which causes gonorrhea.

Neisseria gonorrhoeae

Gram-negative bacterium

Lots of fimbriae and opacity proteins (Opa Proteins)

diplococci

What are some symptoms in men and women which have gonorrhea?

Men:

• Some can be asymptomatic for several months

• Burning sensation when urinating

• White, yellow, green discharge from the penis

• If untreated, it can cause epididymitis, a painful condition of the testicles- lead to infertility

Women

• Often mild; most women have no symptoms

• Painful or burning sensation when urinating

• Increased vaginal discharge or bleeding between cycles

• If untreated- pelvic inflammatory disease

  • Not always signs/symptoms

  • Abdominal pain/fever

  • Internal abscesses

Damaged fallopian tubes- infertility

What is a major problem for women which have gonorrhea? 

Gonococcal conjunctivitis.

What is a problem associated with this disease and newborns

Pregnant women infect their babies as it passes through the birth canal during delivery

Causes blindness, joint infections blood infections.

What is the prevention for gonorrhea?

Abstain from sexual intercourse,

long-term monogamous relationship

Latex condoms with the correct use

 

Describe the three “schools” of thought for the origin of syphilis?

Pre Columbus

• Present in Hippocrates writing

• Some bible passages

Columbian theory

• New world disease brought back by Columbus

• First well-recorded outbreak of what we know as syphilis in Naples in 1494

Bot sides wrong-combination

• Similar disease-yaws existed in Europe

• Form of yaws that had evolved in the new world and was brought back to the old

Describe and list the causative agent of syphilis

Bacterium- treponema pallidum

Spiral shaped bacterium called spirochete

Axial filament- internal flagella- moves the whole organism “twist”

Does not survive well outside of host

Gram negative

Describe the four stages of the disease.

Primary stage

• Marked by the appearance of a single sore called a chancre (can be multiple)

• Chancre lasts 3-6 weeks, and it heals without treatment

• No treatment then progresses

Secondary stage

• Skin and mucous membrane rash with lesions

  • Rough red or reddish-brown spots mainly visible on palms and soles

• Swollen lymph glands

• Sore throat

• Person most contagious in the secondary stage

Latent (hidden stage)

• Secondary symptoms and signs disappear

• Infection remains in the body- only mother-to-fetus transmission

• Most cases end here (25% progress after years)

Tertiary stage

• Tumor-like growth on skin-rubbing lesions

• Neurological problems

• Cardiovascular problems

• Blindness

 

How is the disease important in medical ethics?

Tuskegee syphilis experiment

• 1932 and 1972- US public health service conducted an experiment on 399 black men in the late stages of syphilis

• Never told what disease they were suffering from

• Doctors had no intention of curing them

• 28 men died and others passed the disease on

• Start of IRB

 

 

Describe some features of the causative agent for TB.

Mycobacterium tuberculosis

Acid-fast bacterium (mycolic acid in the cell wall)

Rod-shaped

Obligate aerobe

List and describe the two forms of TB.

latent

active

latent tuberculosis infection

• People are carriers (no symptoms of active)

• Can’t spread bacteria

• Can develop active form

• Can be in this form for a lifetime

active tuberculosis infection

• Only 10% of infected people develop the infection (weakened immune system)

  • Bad cough (with or without blood/sputum

  • Chest pain

• Spread bacteria

• Without treatment, very few survive

 

how is TB diagnosed

Mantoux PPD skin test

Inject tuberculin under skin of the forearm

            Reacts with sensitive tcells

After 48-72 hours, measure welt

            15 mm or more positive

Confirm with chest x-ray

 

concepts of TB history

• Ancient disease- common in Greek (Hippocrates) and Egyptian writings

• Epidemic in Europe and North America from the 18^th and into the 20^th century

  • Known as the white plague or consumption

  • #1 killer of people during this time (20-30% of people)

  • Better ventilation in homes and at work sites and pasteurization of milk helped slow disease

• #1 single infectious disease killer (over time)

 

List some Emerging Infectious Disease information  (numbers) associated with TB

• Ranks 4^th in death due to infectious diseases worldwide (now)

• Estimated that 1.5 million die each year (worldwide)

• 1/3 of people with latent infections (worldwide)

What is the main problem associated with the disease?  Describe what happens. botulism

Flaccid paralysis

The botulism toxin interferes with nerve to muscle impulses

List and describe the three types of botulism.

1. Food borne

   1. Eating foods contaminated with botulism toxin

   2. Cause container lids to bulge and contents have an off odor

   3. Very dangerous-many people can get sick

2. Infant botulism

   1. Endospores of toxin growing in the intestinal tract of infants-releasing the toxin

   2. Infants don’t have established normal flora

   3. Dont feed infants under 1 honey

3. Wound botulism

   1. Wounds infected endospores

   2. Majority of cases in US linked with those who mainline or skin pop Mexican tar heroin

food borne botulism symptoms

1. Weaknesses of muscles, blurry vision, double vision, droopy eyelids, slurred speech, dry mouth, difficulty swallowing, nausea and vomiting

infant botulism

1. Weak poor muscle control, eat less, often become constipated, weak cry, nausea and vomiting

Describe the organism which causes botulism.

Clostridium botulinum

Rod shaped

Motile

Survive best in conditions where little oxygen is present

Gram positive

Noncontagious

Endospore former

What are some types of treatment for botulism?

Antitoxin

Vomiting or enemas

Wounds surgically cleaned

Breathing through ventilator

How can Botulism be prevented?

Boil home canned food for 10 minutes

            Can denature protein toxin

Use proper canning techniques.

Do not inject street drugs

 

List and describe the three forms of anthrax

1. Cutaneous

   1. Most common 95% of cases

   2. Endospores enter cut or abrasion on the skin-germinated in macrophages.

   3. Starts as raised itchy bump

   4. Vesicle and then a painless ulcer

   5. Black necrotic (dying) area in the center

   6. 20% of untreated cases=death

   7. Deaths are rare with appropriate antimicrobial therapy

2. Inhalation (better chance of bacteria reaching the bloodstream and proliferating)

   1. Person inhales microspores

   2. Like common cold

   3. Progresses to severe breathing problems and septic shock

   4. Usually fatal-close to 100%

3. Intestinal (rare)

   1. Consumption of contaminated/undercooked meat

   2. Nausea, loss of appetite, vomiting, fever are followed by abdominal pain, vomiting blood, and severe diarrhea

   3. Mortality- 50-60% of cases

 

 

What causes the disease (give some organism characteristics)?

Bacillus anthrax

Gram positive

Endospore forming

Soil bacteria

Obligate aerobe

Makes exotoxins

 

List vaccination and bioterrorism information.

 

Can be treated with antibiotics

Human vaccine available but only given to high risk individuals

Use a livestock vaccine in areas where there is a constant outbreaks called endemic

22 people infected in the US (2001)

Five died

Anthrax endospores were distributed via letter sent by US mail to media organizations and political offices

Need a better vaccine to prevent