INFECTIOUS DISEASE AFFECTING THE CARDIOVASCULAR AND LYM

• Cardiovascular system


  Pumps blood in a closed system. Comprising the organs where the blood is being pumped.
• Heart


  The main role is to pump blood throughout the body
• Chambers of the heart

  • Right and left atria (receiving chambers)
  • Right and left ventricles (pumping chambers)
• Three layers/wall of the heart

  • Myocardium
  • Endocardium (common target of microbial infection)
  • Epicardium
• Blood vessels


  Carry blood to and from all regions of the body. Provide tissues with oxygen and nutrients. Carry away carbon dioxide and waste products.
• Types of blood vessels

  • Arteries (carry blood away from the heart)
  • Arterioles (smaller branches)
  • Veins (carry blood toward the heart)
  • Venules (smaller veins)
  • Capillaries (smallest blood vessels, connect venules and arterioles)
• Lymphatic system


  Major source of immune cells and fluids. Consists of lymphatic vessels, lymph nodes, and the spleen.
• Cardiovascular system defenses


  • Highly protected from microbial infection
  • Microbes that invade the system gain access to every part of the body and can affect every system causing systemic infections (bloodstream infections)
• Main role of the cardiovascular system

  To distribute blood throughout the different parts of the body
• Defenses in the bloodstream

  • 5000 to 10,000 WBCs per ml of blood
  • Lymphocytes (specific immunity)
  • Phagocytes (critical to specific and nonspecific responses)
• Medical conditions involving the blood

  • Viremia (viruses that cause meningitis)
  • Fungemia (fungi in the blood)
  • Bacteremia (presence of bacteria in the blood)
  • Septicemia (bacteria flourishing and growing in the bloodstream, can lead to decreased blood pressure and septic shock)
• The cardiovascular and lymphatic systems are "closed" and current science believes they possess no normal biota
• Defenses of the cardiovascular and lymphatic systems

  • Cardiovascular system: Blood-borne components of nonspecific and specific immunity, sparse, mostly in white blood cells including phagocytosis, specific immunity
  • Lymphatic system: Numerous immune defenses reside here
• Endocarditis


  Inflammation of the inner lining of the heart. Can be acute or subacute. Damage to heart valves or prosthetic heart valves predispose patients to endocarditis. Can also be caused by vascular trauma or circulating immune complexes.
• Symptoms of acute endocarditis


  • Fever, anemia, abnormal heartbeat, symptoms of heart attack, shortness of breath, chills, abdominal or side pain, Janeway lesions (painless red skin spots in the palm and the sole), Osler's nodes (small but painful nodes on the pads of fingers and toes)
• Symptoms of subacute endocarditis


  • Similar to acute endocarditis symptoms, develop more slowly and are less pronounced, enlarged spleen, clubbed fingers, and toes
• Sepsis (septicemia)


  Occurs when organisms are actively multiplying in the blood
• Signs and symptoms of sepsis


  • Fever, altered mental state, shaking chills, gastrointestinal symptoms, increased breathing rate, respiratory alkalosis, low blood pressure resulting in loss of fluid from the vasculature
• Endotoxic shock


  Result of gram-negative bacteria multiplying in the bloodstream and releasing endotoxin, stimulates a massive inflammatory response mediated by cytokines, leads to drastic loss of blood pressure. Gram-positive bacteria can instigate a similar series of events when fragments of the cell wall are released into the bloodstream.
• Manifestations of plague


  • Pneumonic plague (respiratory disease)
  • Bubonic plague (infection causes inflammation and necrosis of the lymph node, or a bubo, mortality rate 15% even with treatment)
  • Septicemic plague (results in disseminated intravascular coagulation, subcutaneous hemorrhage, and purpura that degenerate into necrosis and gangrene, 30% to 50% mortality with treatment, 100% mortality without treatment)
• Tularemia


  Zoonotic disease endemic throughout the Northern Hemisphere, symptoms include headache, backache, fever, chills, malaise, and weakness, signs include ulcerative skin lesions, swollen lymph glands, conjunctival inflammation, sore throat, intestinal disruption, pulmonary involvement, mortality rate 30% without proper treatment
• Tularemia causative agent and reservoirs


  Francisella tularensis: gram-negative, facultative intracellular parasite, infective dose 10 to 50 organisms, listed as a category a bioterrorism agent, rabbits and rodents are the chief reservoirs, skunks, beavers, opossums, foxes, and other wild animals are also reservoirs
• Lyme disease


  First discovered in Old Lyme, Connecticut in the 1970s, slow-acting, progressive syndrome with early symptom of characteristic bull's eye rash, fever, headache, stiff neck, and dizziness, progresses to cardiac and neurological symptoms, develops into crippling polyarthritis after several weeks to months
• Lyme disease causative agent

  Borrelia burgdorferi: relatively large spirochete with 3 to 10 irregularly spaced coils, evades the immune system by changing surface antigens, has multiple proteins for attachment to host cells
• Infectious mononucleosis


  Caused by Epstein-Barr virus, shares morphological and antigenic features with other herpesviruses, contains a circular form of DNA that is readily spliced into the host cell DNA, latency and ability to splice into host cell DNA allows it to evade the host immune response, more than 90% of the world's population has been infected with EBV
• Pericardium role?


  thin sac that surrounds the heart and protects it from infections and injury.