Rheumatic Fever to Gangrene

Rheumatic Fever

Caused by Streptococcus pyogenes (has M proteins)

Considered an autoimmune disease

Affects children between the ages between 4-18yo, average being 10yo

What is the leading cause of death in children?

Rheumatic fever, leads the cause of death in children in developing countries (at one time the US as well)

M proteins

Which are antigens

Found in strep and helps strep resist the immune response and stick to tissue

Also help resist phagocytes (white blood cells from eating it)

What causes substances to be released and breakdown tissue?

When M proteins attach the strep to a tissue such as the throat

Arachidonic Acid

A substance released by the tissue

Later converted into prostaglandins and leukotrienes which will signal WBC’s such as neutrophils and macrophages to come to an area

Neutrophils

Break down the M proteins and strep and turn the into antigens

Macrophages

break the M proteins and strep and put a piece on its cell membrane

What do the white blood cells do?

Brings the antigens to a lymph node

The B-cells make antibodies to the M cell

Then the antibodies attack and kill M cells and the person is cured

Why does the body attack healthy proteins in Rheumatic fever?

Rheumatic fever causes the body to confuse the healthy proteins in the body w/ M proteins and attacks them.

The reason why Rheumatic fever is considered an autoimmune disease

What do the skin antibodies think keratin is?

They think it is M proteins so they attack

Which then causes a rash

Collagen buildup

Causes subcutaneous nodules on the exterior surface on the limbs

Polyarthritis/Polyarthralgia

The antibodies attack the joint tissues causing painful inflammation of several joints which is called_____ or _____

Sydenham’s Chorea or St. Virtus’ dance

Antibodies attack proteins on the basal ganglia. Causes excessive flailing of the limbs while a person is awake.

Occurs a few months after rheumatic fever. Goes away on it’s own and usually affects females.

How can someone get SBE?

When the antibodies attack proteins on the endothelial cells on the heart valve. Leads to damage valve that can kill.

Which can cause SBE

Subacute Bacterial Endocarditis (SBE)

Caused by strep, staph or enterococci

Affects people with damaged hearts

When a person gets an oral procedure, such as tooth extraction, the strep enters into the bloodstream.

What are the other ways strep comes from? How can people get strep in blood?

Rheumatic Fever, congenital birth defects or long term syphilis

From body piercing such as tongue or nipple

How does death occur in SBE and when does it take affect?

When the strep goes to the endothelial lining on the valves and then goes into lesions then forms clots. A piece of the clot eventually breaks off and enters the bloodstream and gets caught in a blood vessel or kidney.

Death occurs within weeks to months

Acute Bacterial Endocarditis (ABE)

More rapidly progressive condition

Caused by staph

How does staph cause ABE?

The staph goes from the site of infection to the valve of the heart in the endothelium. Causes an immune response which destroys the valves and therefore the heart no longer works and destroys the person dies (with no treatment)

How long does it take for ABE to kill?

Within days to weeks

Pericarditis

When the three layers of the heart; Endocardium, myocardium and epicardium, the lining becomes inflamed

Brucellosis

Rare in US, common in Middle East

Found in slaughterhouse and chicken coops. Rare and not fatal, a person get its by breathing it in.

Symptoms are everything except it has an undulating fever (high, low etc)

What are the two types of Brucellosis and what animals are they found in?

Brucellosis abortus: Cows, camel and bison

Brucellosis melitness: Goats and sheep (most common)

Anthrax

Caused Bacillus Anthracis

Rare in humans, common is grazing animals

Can survive up to 60 years in soil and in a spore

How do humans get anthrax and what happens?

Get its from undercooked meat

It is phagocytized by a macrophage, but anthrax multiplies in the macrophage.

Eventually burst out of macrophage, enters the bloodstream and release lethal toxin and edema toxin

What are the two toxins release from anthrax and what do they do?

Lethal toxin targets and kills macrophages

Edema toxin causes swelling

How do lethal and edema toxins kill people?

The toxins have protein binding antigens that bind to cell membrane and allows toxin to enter

Eventually there is so much bacteria, which releases so much toxin that it kills

What are the three types of anthrax?

Cutaneous, Gastrointestinal, and Respiratory

Cutaneous Anthrax

Enters through a wound. Forms a papule (bump) which becomes a vesicle (blister)

The vesicle then bursts opens and forms an ulcer (hole in skin). Ulcer gets cover in black scab (eschar)

Toxin does not enter into the bloodstream therefore not deadly

Gastrointestinal Anthrax

Transferred by eating undercooked meat and ulcers form in the intestines

Causes diarrhea , nausea and vomiting. 50% death rate

Respiratory Anthrax

Received by breathing it in. Symptoms are mild such as low grade fever and cough.

Bacteria is multiplying. Becomes a respiratory problem

Death rate 100% of the time

Gangrene

Death of body tissue due to lack of blood or bacterial infection

Can be caused by abortion because 5% of women have clostridium perfringes in urinary tract

Ischemia

A wound cuts off the blood supply to an area

When ischemia causes necrosis, gangrene can occur

Necrosis

Death of a tissue

Caused by ischemia, trauma, infections, or toxin

What happens when a tissue dies?

Substances are released that some bacteria uses for survival

Clostridium Perfringes

Most common bacteria to use substance

Breaks down carbohydrate into CO2 and H

Moves along muscles ligaments and tendons breaking them with a toxin to remove the substances it survives on

When it enters the bloodstream causes death by severe sepsis

Gas Gangrene

CO2 and H

Caused by necrosis especially when muscles are broken down

Treatment of Gangrene

Removal of tissue or amputation

If it occurs in abdominal region the patient is put into a hyperbaric chamber and oxygen is blown onto the area