Ch. 23 Microbial diseases of the cardio & lymph systems Flashcards
Cardiovascular system (microbiota?)
Closed systems so no microbiota. Blood isn’t as sterile as we think…some microbes can cross gut wall and enter bloodstream
Septicemia
bacteria stays in blood long-term
Sepsis
- Serious inflammatory response syndrome.
- Seen through lymphangitis (inflamed blood vessels)
- Severe sepsis: failure of at least one organ
Gram-negative sepsis
- LPS (endotoxin)
Gram-positive sepsis
- Staphylococci & Streptococci (Exotoxins)
- Streptococcus Agalactiae
- GBS, group B streptococci
- Neonates sepsis
Pureeral sepsis (childbed fever)
- Infection of uterine lining
- S. Pyogenes
- Ignatz Semmelweis & oliver wendell holmes introduced handwashing before childbirth
Infection of heart
- Subacute bacterial endocarditis
- a-hemolytic streptococci)
- predisposing factor: defective heart valve
- Acute bacterial endocarditis
- S. Aureus
- Prophylactic antibiotics
Rheumatic fever
- autoimmune effect of S. pyogenes infection
- Damages heart valves
- Sydenham’s chorea
Anthrax is caused by…
Bacillus anthracis (can make endospores)
Three major forms of Anthrax…
1) cutaneous (direct contact transmission)
- black lesion
- not as serious as the other two; more serious if it enters the bloodstream (bloodstream mortality >20%)
- mortality rate w antibiotic <1%
2) gastrointestinal anthrax (digestion of endosopres)
- mortality rate over 50%
3) pulmonary anthrax (inhalation of endospores)
- mortality rate is basically 100% even with treatment
gangrene (aka gas gangrene) is caused by…
caused by Clostridium perfringens
(obligate anaerobe)
grows in areas where blood supply has been cut off (ischemia - predisposing factor)
occurs mostly in extremities
treatment for gangrene = prevention of spread
- Debridement (removal of dead tissue)
- larval debridement (consume only dead tissue
- hyperbaric O2 = infuse tissue with higher levels of oxygen
- amputation
vector-transmitted diseases
- plague
- lyme disease
- rocky mountain spotted fever
plague/bubonic plague caused by…
Yersinia pestis (gram-negative bacterium)
transmission of plague
reservoir:
- rodents (usually)
vector:
- rat flea (Xenopsylla cheopsis) – biological transmission
signs and symptoms of plague
- buboes (axillary lymph nodes, groin)
- bruising
forms of plague
Septicemic plague (organisms in blood stream, causing septic shock) Pneumonic plague (in lungs; only way to transmit person to person)
treatment for plague
- antbiotics effective if started 12-15 hr after onset of fever
- vaccine for those who are likely to be exposed
Lyme Disease caused by…
Borrellia burgdorferi is the causative agent (spirochete)
zoonosis (animal –> human)
vector - tick
reservoir = deer
signs and symptoms of lyme disease
First phase: bull’s eye rash (quite susceptible to antibiotic therapy), will go away on its own if not treated but can cause more problems
Second phase (2-8 wks after)more severe symptoms: irregular heartbeat, neurological symptoms, encephalitis, pain when moving eyes, cognitive defects, fatigue, headaches, fainting,
Third phase (6mo - several years): arthritis (where the disease likes to hang out), very difficult to get rid of (basiclaly latent)
Rocky Mountain spotted fever is caused by…
Ricketsia rickettsii
Vector: tick
Rocky Mountain diagnosis and treatment
harder to diagnose (may be mistaken for measles etc), but rash will occur on palms and soles of feet w this one and not measles
responsive to antibiotic, but 20% mortality without
difficult to diagnose in those with darker skin
fever, rash are symptoms
Viral diseases
- Burkitt’s Lymphoma
- infectious mononucleosis (mono)
- Evola Hemorrhagic Fever
Burkitt’s Lymphoma is ….
most common childhood cancer in Africa
in US, occurs in immunocompromised people (such as HIV+)
jaw cancer
