Diseases of the Cardiovascular and Lymphatic Systems

1. Diseases of the Cardiovascular and Lymphatic Systems

2. Cardiovascular System

3. Lymphatic System

4. Lymph node • Found in various location throughout the body • “Inspect” lymph for foreign material such as bacteria, viruses, etc. • Swollen and tender nodes may indicate infection

5. Sepsis • Systemic inflammatory response syndrome(SIRS) caused by infection that releases mediators of inflammation into the blood • SIRS must exhibit two sets of conditions: • Fever,rapid heart or respiration • High WBC count • Often leads to lymphangitis, inflammation of the lymph vessels • Continued growth of bacteria leads to septic shock and death • Two major forms of sepsis • Gram – sepsis • Gram + sepsis

6. Gram Negative Sepsis • Outer LPS layer of Gram – bacteria is a powerful toxin that is released when the bacteria lyses • Symptoms include fever, chills, and severe drop in blood pressure • Rapidly fatal condition with little effective treatment • About 750,000 cases in the US every year, 225,000 are fatal!

7. Gram positive sepsis • Various species of Staphylococcus and Enterococcus are the cause • Release of exotoxin • Often nosocomial in origin • Results from invasive hospital procedure • Antibiotic resistant strains of Enterococcus have become a major problem • Gram positive bacteria are the leading cause of sepsis.

8. Heart structure

9. Subacute Bacterial Endocarditis • Infection of heart valves • Oral bacteria from dental procedures get into the blood • Lodge on damaged heart valves, causing further valve damage, impairs blood flow • Heart damage and death if not treated • Oral surgery and antibiotics

10. Bacterial endocarditis

11. Anthrax • Bacillus anthracis • G+ spore forming rod • Isolated by Robert Koch in 1877 • Zoonotic disease of grazing animals • Human are incidental hosts

12. Cutaneous anthrax • Most common form of anthrax in humans • 95% of human cases • Spores enter the skin via small cut and cause a cutaneous lesion • Low mortality • Resolved with antibiotic therapy

13. Gastrointestinal Ingest spores from under cooked meat Rare form of the disease Causes severe nausea, pain and diarrhea Mortality rate can be as high as 50% Pulmonary anthrax Most dangerous form of the disease Inhale the spores Systemic spread from the lungs Rapidly fatal Nearly 100% mortality Biological weapon Vaccine? Other forms of anthrax

14. Gangrene • Loss of blood supply, death of soft tissue • Ischemia - loss of blood supply • Necrosis - tissue death • Clostridium perfringens infection in the dead tissue • Bacterial toxin kills more tissue and gas is produced which causes swelling • Systemic infection when the bacteria and toxin enter the blood • Often fatal without treatment • Antibiotic therapy, amputation in severe cases • Hyperbaric chamber

15. Gangrene • Necrosis – tissue death • Gangrene in the toes can be a complication of diabetes • Anaerobic environment necessary for the infection

16. Vector transmitted diseases • Plague • Lyme disease • Typhus • Rocky Mountain Spotted fever

17. Plague (Black Death) • Yersinia pestis • Gram – rod • Disease of rats that spreads to humans by infected flea bite • Estimated 25,000,000 deaths in Europe in 5 years in the 14th century

18. Plague • Three forms of the disease • Bubonic plague, infection of lymphatic system • Septicemic plague, bacteria in the blood • Pneumonic plague, lung infection • Rat is the reservoir, flea is the vector

19. Bubonic plague • Lymphatic system • Buboes • Lymph nodes swell and hemorrhage, turn black, hence the name “black death” • Mortality rate of 50-75% • Death in a week

20. Systemic plague Bacteria in blood causing septic shock Rapidly fatal Pneumonic plague Flea bite is not necessary Inhalation transmission Very contagious Mortality nearly 100% Other form of plague

22. Lyme Disease • Borrelia burgdorferi • Spirochete • Reservoir is the field mouse • Vector is a tick of genus Ixodes • Spread to humans by the tick bite

23. Lyme Disease • Characteristic rash associated with the disease (bulls-eye) • Flu-like initial symptoms • Antibiotic treatment works well for initial symptoms • Some cases linger and become systemic causing meningitis, encephalitis, and arthritis

24. Distribution of Lyme disease in the US

25. Lyme Disease Risk Map

26. Rickettsia • Rickettsia are bacteria; small intracellular parasites • Discovered by Dr. Howard Ricketts as a pathogenic group • This group causes diseases such as typhus, and spotted fever • Dr. Ricketts died in Mexico in 1910 while investigating an outbreak of typhus

27. Epidemic typhus • Caused by the bite of the human body louse carrying the rickettsia • Rickettsia prowazeki • Louse bites and defecates; you scratch the bite and inoculate yourself • Crowded, unsanitary conditions • Prolonged fever, rash, can develop into fatal encephalitis or myocarditis • High mortality rate • Treated with tetracycline and chloramphenicol • Also prevented by better sanitation and control of lice

28. Rocky Mountain Spotted Fever • Rickettsial disease transmitted by tick bite • Characteristic rash • Fever, headache, chills rash. Systemic complications include renal failure, gastrointestinal complications • Mortality rate of about 20% if not treated • Chloramphenicol and tetracycline treatment • Disease found mostly in the southeastern US

29. Distribution of Rocky Mountain Spotted Fever

30. Toxoplasmosis • Protozoan disease that can be contracted by humans • Caused by Toxoplasma gondii • Humans get the disease from infected cats • Especially dangerous to pregnant women who are exposed from infected cat feces • Causes severe fetal damage

31. Toxoplasmosis life cycle

32. Malaria • Protozoan systemic disease of humans • Caused by various species of genus Plasmodium (P. falciparum) • Very wide spread disease • Effects 300-500 million people, killing 1-2 million people each year • Spread by the bite of the infected female Anopheles mosquito

33. Malaria • Complicated life cycle effecting RBC and causing anemia • Symptoms are fever, chills and severe headache alternating with no symptoms • Mosquitoes are the vectors, humans are the host • Treatment is mosquito control, sleeping under bed nets, and drugs such as chloroquine, mefloquine, and malarone

34. Malaria life cycle