Microbio Ch 23 Cardiovascular Diseases

Subacute Bacterial Endocarditis (Bacterial Diseases)

• Fever, weakness, heart murmur

• Usually α‑hemolytic streptococci

• Often from oral infections (teeth/tonsils)

• Bacteria lodge in heart lesions → clot growth

• Can be fatal if untreated

Acute Bacterial Endocarditis (Bacterial Diseases)

• Staphylococcus aureus

• Rapid valve destruction

• Fatal in days–weeks if untreated

Pericarditis (Bacterial Diseases)

• Often caused by streptococci

• Inflammation of pericardium

Rheumatic Fever (Bacterial Diseases)

• Group A Streptococcus

• After strep throat (ages 4–18)

Arthritis, fever, subcutaneous nodules

• Immune reaction to M protein → heart inflammation

• Damages heart valves

Gangrene (Bacterial Diseases)

• Ischemia → anaerobic environment → necrosis

• Often Clostridium perfringens

• Black tissue, poor circulation

• Common in diabetes

Gas Gangrene (Bacterial Diseases)

• C. perfringens ferments carbs → gas, swelling

Toxins spread along muscle bundles

• Fatal without treatment

Can follow traumatic wounds or unsafe abortions

Pasteurella multocida Infection (Bacterial Diseases)

• From dog/cat bites

• Causes sepsis, pneumonia, severe swelling

• Treat with penicillin or tetracycline

Plague (Bubonic Plague) (Bacterial Diseases)

• Yersinia pestis • Transmitted by rat flea

• Flea gut blocked → regurgitates infected blood

• Buboes in groin/armpit

• Historically killed 25% of Europe

• Treatable with antibiotics

Lyme Disease (Bacterial Diseases

• Borrelia burgdorferi

• Transmitted by Ixodes ticks

• Bull’s‑eye rash, flu‑like symptoms

Untreated → heart arrhythmias, neuro issues, arthritis

Typhus Fever (Bacterial Diseases

• Rickettsia prowazekii

• Spread by body louse

• Louse feces rubbed into bite wound

• Causes vessel blockage/rupture

Rocky Mountain Spotted Fever (Bacterial Diseases

• Rickettsia rickettsii

• Tick‑borne

• Macular rash on palms/soles

• Fever, headache

• 3% fatality rate

Mononucleosis (Viral Diseases)

• HHV‑4 (Epstein–Barr virus)

• Spread by saliva (“kissing disease”)

• Long incubation (4–7 weeks)

• Fever, weakness

• Symptoms from T‑cell response

Dengue Fever (Viral Diseases)

• Aedes aegypti mosquito

• Endemic in Caribbean/tropics

• 400 million cases worldwide

• Severe dengue → bleeding, organ impairment

• Cases increasing in Florida/Hawaii

Ebola (Viral Hemorrhagic Fever) (Viral Diseases)

• Damages blood vessel walls → bleeding

~90% mortality

• Reservoir likely fruit bats

Spread via blood/body fluids

• Burial practices increase spread

Hantavirus Pulmonary Syndrome (Viral Diseases)

• Sin Nombre virus •

Western U.S.

• Lungs fill with fluid

• Spread via inhaled rodent urine/feces

• Treatment: mechanical ventilation, ribavirin

Chagas Disease (Protist Diseases)

• Trypanosoma cruzi

• Transmitted by reduviid (“kissing bug”)

• Bug defecates while feeding → infection

• Acute: fever, swollen glands

• Chronic: nerve damage to esophagus/colon

Toxoplasmosis (Protist Diseases)

• Toxoplasma gondii

• 22.5% of U.S. infected

From undercooked meat or cat feces

• Congenital infection → stillbirth, brain/vision damage

• Affects blood & lymphatic vessels

• Cat litter contamination affects sea otters

Malaria (Protist Diseases)

• Plasmodium falciparum

• Anopheles mosquito

• Chills, fever, headache

• RBCs stick to capillaries → organ damage

• Affects kidneys, liver, brain

• Prevention: chloroquine

• Treatment: ACT (artemisinin combo)

• Diagnosis: blood smear (gold standard)

Schistosomiasis (Helminthic Disease)

• Caused by fluke (Schistosoma)

• Female lives in groove of male

Eggs lodge in tissues → granulomas

• Fluke mimics human tissue to evade immunity