This document provides an overview of diseases that can affect the cardiovascular and lymphatic systems. It discusses several types of infections including sepsis, bacterial infections of the heart, tularemia, brucellosis, anthrax, gangrene, diseases caused by animal bites/scratches, plague, and relapsing fever. For each disease, it describes the causative pathogen, transmission, signs and symptoms, pathogenesis, diagnosis, and treatment.

1. Chapter 23: Diseases of the CV and Lymphatic Systems 1. Cardiovascular system = heart, blood, and blood vessels 2. Lymphatic system = lymph, lymph vessels, lymph nodes, lymphatic organs = tonsils, appendix, spleen, thymus 3. Blood and lymph carry nutrients and O2 to body tissues and carry away wastes a) they can also spread pathogens that have entered their circulation b) many of the body’s innate defensive systems are found in blood and lymph ex. Circulating phagocytic cells

2. Chapter 23: Diseases of the CV and Lymphatic Systems 4. Blood is a mixture of formed elements (cells) and plasma (liquid) a. some blood plasma leaves the blood capillaries and goes into the interstitial spaces as interstitial fluid b. this interstitial fluid is then picked up by lymph capillaries and now the interstitial fluid is referred to as lymph 5. Lymph capillaries are very permeable and also pick up microbes or their products

3. Chapter 23: Diseases of the CV and Lymphatic Systems 6. Lymph is transported to larger lymph vessels called lymphatics a. lymphatics contain valves to keep the lymph moving towards the heart b. lymph is returned to the blood before the blood enters the heart via a vein c. the lymphatic system is a one way system from interstitial fluid to the cardiovascular system

4. Chapter 23: Diseases of the CV and Lymphatic Systems 7. Lymph nodes are oval shaped structures throughout the lymphatic system a. contains fixed macrophages to remove microbes b. can become infected and swollen = buboes c. contain 2 types of lymphocytes 1) B cells – Abs 2) T cells – cell mediated immunity

5. Sepsis Sepsis = toxic, inflammatory condition arising from the spread of bacteria or bacterial toxins often accompanied by lymphangitis which is inflamed lymph vessels visible as red streaks under the skin Sx = fever, chills, accelerated breathing and heart rate If it is accompanied by a drop in blood pressure and organ dysfunction (can be just 1 organ), it is considered to be severe sepsis Septicemia = growth of bacterial pathogens in the bloodstream 1) can cause septic shock which is low BP that can’t be controlled by addition of fluids 2) usually a result of endotoxins (G- bacteria)

6. Sepsis 2. Gram negative sepsis = endotoxic shock a. lysis of cell causes release of endotoxins that cause a drop in BP 3. Gram positive sepsis – usually caused by Staphylococcus and Streptococcus – produce exotoxins a. Enterococci is one of the leading causes of nosocomial infections – they have a natural resistance to penicillin and an acquired resistance to vancomycin b. group B streptococci is a common cause of neonatal sepsis

7. Sepsis 4. Puerperal sepsis aka puerperal fever aka childbirth fever a. it is a nosocomial infection of the uterus that can lead to peritonitis (infection of the abdominal cavity) and septicemia b. caused by a group A beta hemolytic Streptococcus 1) most common is Streptococcus pyogenes

8. Bacterial infections of the heart Endocardium = innermost layer surrounding the heart a. Inflammation of endocardium = endocarditis b. Subacute (meaning it develops slowly) bacterial endocarditis usually is caused by an alpha hemolytic streptococci c. Acute bacterial endocarditis is usually caused by Staphylococcus aureus and develops much more rapidly and progressively 1) it can affect the heart valves and is often fatal

9. Bacterial infections of the heart 2. Pericarditis = inflammation of the sac around the heart (pericardium), usually caused by streptococci 3. Rheumatic fever is considered an autoimmune rx by the body to repeated infections by Streptococcus pyogenes a. inflammations cause arthritis and damage to heart valves b. some people develop Sydenham’s chorea aka St. Vitus dance which is characterized by involuntary movements which resolve in several months

10. Tularemia aka rabbit fever Tularemia – a zoonotic disease of the lymph nodes caused by Francisella tularensis (Gram neg rod) Transmission – hunters in contact with small animals (rabbits –mc, ground squirrels) infected by arthropod bites (ticks, deer fly), direct contact with body fluids of infected animals, airborne

11. Tularemia aka rabbit fever 3. Infection results in a small ulcer at the infection site and later lymph node involvement 4. Virulence factor = microbes grow intracellular in phagocytes which protect it from chemotherapy 5. Sxs = a. acute =HA, backache, fever, chills, malaise, weakness b. associated with portal of entry

12. Brucellosis Aka Undulant fever- undulant means wavelike, periodic spiking of fever Pathogen Brucella abortus – common in cattle Brucella suis – in pigs, most common mode in US, both can infect humans Transmission Occupational hazard of animal handlers – vets, ranchers, slaughterhouse Transmitted through direct contact with infected animals and eating raw cheese and milk

13. Brucellosis 4. Once the bacteria are in the body they are ingested by macrophages which transport them via the lymphatic system to the liver, spleen, bone marrow a. they live and reproduce within the macrophages making them resistant to Abs

14. Anthrax – common soil bacteria Pathogen – Bacillus anthracis aerobic, G+, lg rods, forms endospores Multiplies in large #s in the blood and septicemic anthrax is possible for all 3 forms of anthrax Cutaneous anthrax - most common form Transmitted by contact with infected hides, wool, animal products esp. from the Middle East endospores enter through minor skin lesion, next papules appear and then vesicles appear that form a depressed, ulcer covered by a black scab (pg679)

15. Anthrax 2. Cutaneous anthrax c. sxs= low grade fever, malaise, usually doesn’t enter the blood stream d. Mortality rate w/o tx = 20%, with tx <1% 3. Gastrointestinal anthrax – rare form a. acquired through the ingestion of contaminated foods b. sxs = nausea, abdominal pain, bloody diarrhea c. ulcerative lesions to GI tract (mouth to intestines) d. mortality rate > 50%

16. Anthrax 4. Inhalational or pulmonary anthrax – most dangerous form a. endospores are inhaled into the lungs and eventually enter the bloodstream b. initial sxs = mild fever, coughing, chest pain 1) can be treated with Abs if suspect Anthrax c. if bacteria enter the blood and proliferate – septic shock that kills the px within 24 – 36 hrs 1) mortality rate almost 100%

17. Anthrax 5. pathogenesis/virulence factors a. endospores are ingested by macrophages where they germinate into vegetative cells, multiply and kill macrophages (< body defense) b. exotoxin complex composed of 3 separate proteins 1) protective antigen – binds toxins to target cells and permits them to enter the cells 2) edema toxin – causes local edema and interferes with phagocytosis of macrophages 3) lethal toxin – targets and kills macrophages

18. Anthrax 6. Dx = presumptive dx – culture on blood agar and gram stain, test to differentiate B. anthracis from B. sp. a. ex. B. anthracis is non motile b. confirmatory test done at CDC 7. Vaccination is a live, attenuated vaccine for animals, for humans it is an inactivated form of toxins consisting of 6 injections over a 18 month period plus yearly boosters

19. Gangrene Pathogen = Clostridium perfringens an anaerobic, G+ , endospores – found in the soil If a wound interrupts the blood supply to the tissue it causes a condition known as ischemia and the wound becomes anaerobic Ischemia leads to necrosis (death of tissue) which results in gangrene

20. Gangrene 4. Gas gangrene a. as bacteria grow they ferment ms CH2Os and produce the gases CO2, H2 b. bacteria produce toxins that can destroy ms tissue c. if toxins and bacteria reach the bloodstream can cause systemic illness – w/o tx condition is fatal 5. Tx = surgical removal of necrotic tissue, amputation a. if in abdominal cavity- tx w/ pressurized O2 rich environment – hyperbaric chamber, and penicillin

21. Systemic diseases caused by bites and scratches Cat scratch disease Pathogen = Bartonella henselae can live in cat’s RBCs causing bacteremia in cats Transmission = usually by bite or scratch Signs and sxs = initial sign is a papule followed lymph node swelling, malaise, fever Tx = usually self limiting, Abs may help

22. Systemic diseases caused by bites and scratches Rat bite fever Streptobacillary rat bite fever Pathogen = Streptobacillus moniliformis Transmission is by bite of urban rats Sxs = fever, HA, ms ache, inflammation around the lesion 1) If it spreads to the bloodstream – swollen lymph nodes, rash, occasionally endocarditis 2. Spirillar fever a. pathogen = Spirillum minor b. transmission is bite from wild rodents c. sxs are similar to streptobacillary rat bite fever d. tx = penicillin for both forms

23. Vector transmitted disease Plague – Yersinia pestis – G neg, rod Normally a disease of rats, now cats are a new reservoir Transmitted from one rat to another by the rat flea Xenopsylla cheopis If the host dies the fleas seek a new host including humans Fleas not always necessary, can contact by skinning infected animals and by bites, scratches, licks from a cat After a flea bite bacteria enters the bloodstream and proliferate in lymph and blood Lymph nodes enlarge in the groin and armpit 1) Swellings are called buboes for bubonic plague Mortality rate untreated 50 – 75% < a wk after sxs appear

24. Vector transmitted disease Plague 4. From the buboes the bacteria spread to the bloodstream causing septicemic plague which can cause septic shock 5. Pneumonic plague is caused when bacteria are carried by the blood to the lungs a. mortality rate is nearly 100% w/in 3 days b. spread by airborne droplets from humans or animals

25. Vector transmitted disease Plague 6. Dx = culture and gram stain of blood or bubo aspirate, rapid diagnostic test can detect capsular antigens of Yersinia pestis 7. Tx = antibiotics Streptomycin and tetracycline

26. Vector transmitted disease Relapsing fever All species of the genus Borrelia (a spirochete) cause relapsing fever except for Borrelia burgdorferi which causes Lyme’s disease Transmission is by soft ticks and lice Incidence increases during summer months when rodent and arthropod activity increases

27. Vector transmitted disease Relapsing fever 4. Sxs = high fever (>105 F), shaking chills, jaundice, rose colored rash a. after 3 to 5 days the fever subsides but returns (relapses) each time for a shorter period and less severe 5. Dx = microscopic observations of bacteria in px blood 6. Tx = tetracycline

28. Vector transmitted disease Typhus – caused by rickettsias – obligate intracellular parasites of eukaryotes Spread by arthropods the bacteria infect endothelial cells of the vascular system The resulting inflammation causes blockage and rupture of the small blood vessels Historically – a prolific killer of man, helped decimate the Aztec population in 1500s and helped the Russians defeat Napoleon's army

29. Typhus Epidemic typhus (louseborne typhus) 1. Pathogen – Rickettsia prowazekii is carried in the GI tract of the body louse Pediculus humanus corporis (vector) 2. Transmission – through louse feces when host scratches bite 3. Found in crowded unsanitary conditions where lice can move from one host to another easily

30. Typhus Epidemic typhus 4. Sxs = prolonged fever, stupor, rash of small red spots caused by subcutaneous hemorrhaging 5. Tx = tetracycline, chloramphenicol, eliminate conditions 6. Vaccines are available for military

31. Typhus Endemic typhus – occurs sporadically rather than in epidemics Murine is Latin for mouse, rodents such as rats, squirrels are hosts for this type of typhus Pathogen = Rickettsia typhi which is transmitted by the rat flea Xenopsylla cheopis Clinically endemic and epidemic typhus are the same but endemic typhus is less severe Tx = tetracycline, Prevention = rat control

32. Typhus Tickborne typhus = Rocky Mt. Spotted Fever Pathogen = Rickettsia rickettsia which is a parasite of ticks In west - deer tick Dermacentor andersoni In the east - deer tick Dermacentor variabilis 2. One week after the tick bite – macular rash develops which may be mistaken for measles except the rash can be on the palms and soles which does not occur with viral rashes

33. Typhus 3. Dx = fluorescent antibody, PCR 4. Prevention – avoid ticks 5. Tx = tetracycline, chloramphenicol, doxycycline, no vaccine available 6. Without tx 20% mortality rate 7. Distinguishing characteristics – m.c. in east and SE US

34. Viral hemorrhagic fevers Hemorrhagic fevers are Certain viral fevers accompanied by severe hemorrhagic lesions of the tissues, most are zoonotic Classic = they have been around for a long time Emerging = they are fairly new

35. Viral hemorrhagic fevers Classic Yellow fever Is caused by an arbovirus transmitted by the bite of the mosquito Aedes aegypti Early sx = fever, chills, HA, followed by nausea and vomiting Later sx = jaundice (yellowing of the skin and eyes) which reflects liver damage resulting in deposits of bile pigments in the skin, some px may hemorrhage from the nose and mouth

36. Viral hemorrhagic fevers Classic Yellow fever 4. Endemic to Africa, central and south America 5. Monkeys are the natural reservoirs but human to human transmission can occur 6. No specific tx, vaccine is live, attenuated, mortality rate – 20%

37. Viral hemorrhagic fevers Classic Dengue fever – aka breakbone fever, milder disease than yellow fever RNA virus that is also transmitted by Aedes aegypti Endemic to the Caribbean and tropical areas Sx= fever, severe ms and joint pain, rash no animal reservoir

38. Viral hemorrhagic fevers Classic 5. Dx = rise in IgM titers 6. Prevention = a live, attenuated vaccine is being tested 7. Dengue hemorrhagic fever is a severe form caused when Abs from a previous infection combine with the virus a. it can induce shock in a victim (usually a child) and kill in a few hours b. one of the leading causes of death among SE Asian children

39. Viral hemorrhagic fevers Emerging Hantavirus pulmonary syndrome - 1993 Pathogen – Sin Nombre virus is a Bunyavirus found mostly in western states Transmission = by inhalation of airborne viruses from dried urine or feces of infected small rodents Causes a frequently fatal pulmonary infection where the lungs fill with fluids

40. Viral hemorrhagic fevers Emerging Hantavirus 4. Dx = serology – IgM, PCR, id Ag in tissue 5. Prevention = avoid mouse habitats and droppings 6. Tx = supportive 7. Distinctive features = rapid onset, high mortality rate

41. Viral hemorrhagic fevers Emerging Ebola Caused by a filovirus which is threadlike RNA virus, endemic to Africa transmission is by direct contact with body fluid of infected person or animal Virulence = disruption of clotting factors resulting in massive hemorrhage from all orifices, mucous membranes, internal organs Dx = PCR, viral culture conducted at the CDC

42. Burkitt’s Lymphoma A fast growing tumor of the jaw in African children Pathogen is the Epstein-Barr virus a. Official name is human herpesvirus 4 Associated with children who have had malaria which impairs their immune response to the EB virus

43. Protozoan Disease of the CV and Lymphatic Systems Chagas Disease = American trypanosomiasis Pathogen = Trypanosoma cruzi – a flagellated protozoan Occurs in Texas, Mexico, Central America, parts, of South America (infects 40-50% or rural populations in SA) Reservoir for T. cruzi is wild animals –ex. Rodents, possums, armadillos

44. Protozoan Disease of the CV and Lymphatic Systems Chagas Disease 4. Arthropod vector = Reduviid bug aka the kissing bug because it bites near the lips 5. Trypanosomes grow in the gut of the bug and is passed to humans by infected bug feces being rubbed into the wound or eyes a. blood transfusions are another way of transmission

45. Protozoan Disease of the CV and Lymphatic Systems Chagas Disease 6. Most dangerous to children because of heart damage – 10% mortality 7. Can cause nerve damage controlling peristaltic action of the esophagus and colon a. can result in grossly enlarged organs – megacolon, megaesophagus b. now these organs can’t transport food

46. Protozoan Disease of the CV and Lymphatic Systems Toxoplasmosis Pathogen = Toxoplasma gondii – a spore forming protozoan Cats are the definitive host and the protozoan undergoes the sexual phase in their intestinal tract a. Oocysts are shed in cat’s feces and ingested by intermediate hosts – ex. Mouse, cow, pig, humans

47. Protozoan Disease of the CV and Lymphatic Systems Toxoplasmosis 3. It is an asymptomatic infection in most persons, in a non-immune pregnant women it can lead to congenital toxoplasmosis a. danger to fetus is stillbirth or child with severe brain damage or vision problems b. pg women shouldn’t change litter box 4. Calif. Fatal encephalitis of sea otters caused by T. gondii from ingestion of oocysts in waste water from flushing litter box contents down toilet

48. Protozoan Disease of the CV and Lymphatic Systems Malaria Pathogen = Plasmodium , a protozoan parasite Vector = female Anopheles mosquito WW resurgence of malaria, 300 – 500 million affected ww, 2-4 million die annually 4 types of Plasmodium can cause malaria – P. vivax, P. ovale, P. malariae and P. falciparum (which is the most dangerous)

49. Malaria 5. Virulence factor - multiple life stages a. asexual sporozoites are in the saliva of feeding mosquitoes, when they bite a human the sporozoites enter a capillary b. Sporozoites invade the liver cells and develop into large #s of merozoites through a process called schizogony = asexual division

50. Malaria c. Merozoites are released into the circulation and enter RBCs 1) initial infection is marked by a ring trophozoite pg. 697 for pix. d. Schizogony inside the RBC produces more merozoites that cause the RBC to burst and releases them to infect more RBCs 1) when merozoites are released so are toxic compounds which cause the characteristic fever and chills of malaria

51. Malaria e. Gametocytes develop in certain infected RBCs and are ingested by another mosquito f. the sexual phase of fertilization and sporozoite formation occur in the mosquito 6. The original drug for malaria was quinine and today they use it and its derivatives

52. Leishmaniasis A protozoan disease that affects the internal organs or skin and mucous membranes Transmission is by the bite of the female sandfly (vector) Leishmania donovani causes visceral leishmaniasis a. Occurs in much of the tropical world, in India is called kala azar

53. Leishmaniasis 3. b. sxs = chills and sweating like malaria 1) sxs may take a year to appear after infection c. protozoa proliferate in the liver and spleen causing enlargement, eventually the kidney is invaded and function is lost d. if untreated – death in a year or 2 e. tx – injected drugs that contain the toxic metal antimony, new oral drugs but can cause birth defects

54. Leishmaniasis 4. Leishmania tropical aka oriental sore – cutaneous form a. papule appears at bite site several weeks after the bite b. papule ulcerates, heals, leaves a scar 5. Leishmania braziliensis – mucocutaneous leishmaniasis aka American leishmaniasis a. destruction of the nose, mouth, and upper throat tissue b. found in the Yucatan and the rain forests of Central and South America

55. Leishmaniasis 6. Virulence factor – protozoa multiplies within macrophages 7. Dx = examine blood and look for parasite in WBCs, dx of cutaneous form by clinical appearance and microscopic scrapings

56. Schistosomiasis A helminth disease caused by a small fluke Adult worms coat themselves with a layer that mimics the hosts tissue to avoid body defenses The female lives in a groove of the body of the male – schistosome = split body a. Have a continuous supply of eggs

57. Schistosomiasis 4. Some eggs lodge themselves in tissue where the body forms granulomas to wall them off, others are excreted to find their way to a water supply and a new host a. a snail is the intermediate host that releases free swimming cercariae that will penetrate human skin to travel through the circulatory system to the intestinal BVs where they mature into adults 1) the US doesn’t have the right kind of snails for an intermediate host

58. Schistosomiasis 5. three primary types of schistosomiasis a. Schistosoma haematobium – inflammation of the urinary bladder wall 1) Africa, Middle East, esp. Egypt b. Schistosoma japonicum – intestinal inflammation 1) East Asia c. Schistosoma mansoni – intestinal inflammation 1) South America, Caribbean, Puerto Rico