Chapter23.

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Chapter23.

  1. 1. Chapter 23: Diseases of the CV and Lymphatic Systems <ul><li>1. Cardiovascular system = heart, blood, and blood vessels </li></ul><ul><li>2. Lymphatic system = lymph, lymph vessels, lymph nodes, lymphatic organs = tonsils, appendix, spleen, thymus </li></ul><ul><li>3. Blood and lymph carry nutrients and O2 to body tissues and carry away wastes </li></ul><ul><li>a) they can also spread pathogens that have entered their circulation </li></ul><ul><li>b) many of the body’s innate defensive systems are found in blood and lymph ex. Circulating phagocytic cells </li></ul>
  2. 2. Chapter 23: Diseases of the CV and Lymphatic Systems <ul><li>4. Blood is a mixture of formed elements (cells) and plasma (liquid) </li></ul><ul><li>a. some blood plasma leaves the blood capillaries and goes into the interstitial spaces as interstitial fluid </li></ul><ul><li>b. this interstitial fluid is then picked up by lymph capillaries and now the interstitial fluid is referred to as lymph </li></ul><ul><li>5. Lymph capillaries are very permeable and also pick up microbes or their products </li></ul>
  3. 3. Chapter 23: Diseases of the CV and Lymphatic Systems <ul><li>6. Lymph is transported to larger lymph vessels called lymphatics </li></ul><ul><li>a. lymphatics contain valves to keep the lymph moving towards the heart </li></ul><ul><li>b. lymph is returned to the blood before the blood enters the heart via a vein </li></ul><ul><li>c. the lymphatic system is a one way system from interstitial fluid to the cardiovascular system </li></ul>
  4. 4. Chapter 23: Diseases of the CV and Lymphatic Systems <ul><li>7. Lymph nodes are oval shaped structures throughout the lymphatic system </li></ul><ul><li>a. contains fixed macrophages to remove microbes </li></ul><ul><li>b. can become infected and swollen = buboes </li></ul><ul><li>c. contain 2 types of lymphocytes </li></ul><ul><li>1) B cells – Abs </li></ul><ul><li>2) T cells – cell mediated immunity </li></ul>
  5. 5. Sepsis <ul><li>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 </li></ul><ul><ul><li>Sx = fever, chills, accelerated breathing and heart rate </li></ul></ul><ul><ul><li>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 </li></ul></ul><ul><ul><li>Septicemia = growth of bacterial pathogens in the bloodstream </li></ul></ul><ul><ul><ul><li>1) can cause septic shock which is low BP that can’t be controlled by addition of fluids </li></ul></ul></ul><ul><ul><ul><li>2) usually a result of endotoxins (G- bacteria) </li></ul></ul></ul>
  6. 6. Sepsis <ul><li>2. Gram negative sepsis = endotoxic shock </li></ul><ul><li>a. lysis of cell causes release of endotoxins that cause a drop in BP </li></ul><ul><li>3. Gram positive sepsis – usually caused by Staphylococcus and Streptococcus – produce exotoxins </li></ul><ul><li>a. Enterococci is one of the leading causes of nosocomial infections – they have a natural resistance to penicillin and an acquired resistance to vancomycin </li></ul><ul><li>b. group B streptococci is a common cause of neonatal sepsis </li></ul>
  7. 7. Sepsis <ul><li>4. Puerperal sepsis aka puerperal fever aka childbirth fever </li></ul><ul><li>a. it is a nosocomial infection of the uterus that can lead to peritonitis (infection of the abdominal cavity) and septicemia </li></ul><ul><li>b. caused by a group A beta hemolytic Streptococcus </li></ul><ul><li>1) most common is Streptococcus pyogenes </li></ul>
  8. 8. Bacterial infections of the heart <ul><li>Endocardium = innermost layer surrounding the heart </li></ul><ul><ul><li>a. Inflammation of endocardium = endocarditis </li></ul></ul><ul><ul><li>b. Subacute (meaning it develops slowly) bacterial endocarditis usually is caused by an alpha hemolytic streptococci </li></ul></ul><ul><ul><li>c. Acute bacterial endocarditis is usually caused by Staphylococcus aureus and develops much more rapidly and progressively </li></ul></ul><ul><ul><li>1) it can affect the heart valves and is often fatal </li></ul></ul>
  9. 9. Bacterial infections of the heart <ul><li>2. Pericarditis = inflammation of the sac around the heart (pericardium), usually caused by streptococci </li></ul><ul><li>3. Rheumatic fever is considered an autoimmune rx by the body to repeated infections by Streptococcus pyogenes </li></ul><ul><li>a. inflammations cause arthritis and damage to heart valves </li></ul><ul><li>b. some people develop Sydenham’s chorea aka St. Vitus dance which is characterized by involuntary movements which resolve in several months </li></ul>
  10. 10. Tularemia aka rabbit fever <ul><li>Tularemia – a zoonotic disease of the lymph nodes caused by Francisella tularensis (Gram neg rod) </li></ul><ul><li>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 </li></ul>
  11. 11. Tularemia aka rabbit fever <ul><li>3. Infection results in a small ulcer at the infection site and later lymph node involvement </li></ul><ul><li>4. Virulence factor = microbes grow intracellular in phagocytes which protect it from chemotherapy </li></ul><ul><li>5. Sxs = a. acute =HA, backache, fever, chills, malaise, weakness </li></ul><ul><li>b. associated with portal of entry </li></ul>
  12. 12. Brucellosis <ul><li>Aka Undulant fever- undulant means wavelike, periodic spiking of fever </li></ul><ul><li>Pathogen </li></ul><ul><ul><li>Brucella abortus – common in cattle </li></ul></ul><ul><ul><li>Brucella suis – in pigs, most common mode in US, both can infect humans </li></ul></ul><ul><li>Transmission </li></ul><ul><ul><li>Occupational hazard of animal handlers – vets, ranchers, slaughterhouse </li></ul></ul><ul><ul><li>Transmitted through direct contact with infected animals and eating raw cheese and milk </li></ul></ul>
  13. 13. Brucellosis <ul><li>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 </li></ul><ul><li>a. they live and reproduce within the macrophages making them resistant to Abs </li></ul>
  14. 14. Anthrax – common soil bacteria <ul><li>Pathogen – Bacillus anthracis </li></ul><ul><ul><li>aerobic, G+, lg rods, forms endospores </li></ul></ul><ul><ul><li>Multiplies in large #s in the blood and septicemic anthrax is possible for all 3 forms of anthrax </li></ul></ul><ul><li>Cutaneous anthrax - most common form </li></ul><ul><ul><li>Transmitted by contact with infected hides, wool, animal products esp. from the Middle East </li></ul></ul><ul><ul><li>endospores enter through minor skin lesion, next papules appear and then vesicles appear that form a depressed, ulcer covered by a black scab (pg679) </li></ul></ul>
  15. 15. Anthrax <ul><li>2. Cutaneous anthrax </li></ul><ul><ul><li>c. sxs= low grade fever, malaise, usually doesn’t enter the blood stream </li></ul></ul><ul><ul><li>d. Mortality rate w/o tx = 20%, with tx <1% </li></ul></ul><ul><li>3. Gastrointestinal anthrax – rare form </li></ul><ul><li>a. acquired through the ingestion of contaminated foods </li></ul><ul><li>b. sxs = nausea, abdominal pain, bloody diarrhea </li></ul><ul><li>c. ulcerative lesions to GI tract (mouth to intestines) </li></ul><ul><li>d. mortality rate > 50% </li></ul>
  16. 16. Anthrax <ul><li>4. Inhalational or pulmonary anthrax – most dangerous form </li></ul><ul><li>a. endospores are inhaled into the lungs and eventually enter the bloodstream </li></ul><ul><li>b. initial sxs = mild fever, coughing, chest pain </li></ul><ul><li>1) can be treated with Abs if suspect Anthrax </li></ul><ul><li>c. if bacteria enter the blood and proliferate – septic shock that kills the px within 24 – 36 hrs </li></ul><ul><li>1) mortality rate almost 100% </li></ul>
  17. 17. Anthrax <ul><li>5. pathogenesis/virulence factors </li></ul><ul><li>a. endospores are ingested by macrophages where they germinate into vegetative cells, multiply and kill macrophages (< body defense) </li></ul><ul><li>b. exotoxin complex composed of 3 separate proteins </li></ul><ul><li>1) protective antigen – binds toxins to target cells and permits them to enter the cells </li></ul><ul><li>2) edema toxin – causes local edema and interferes with phagocytosis of macrophages </li></ul><ul><li>3) lethal toxin – targets and kills macrophages </li></ul>
  18. 18. Anthrax <ul><li>6. Dx = presumptive dx – culture on blood agar and gram stain, test to differentiate B. anthracis from B. sp. </li></ul><ul><li>a. ex. B. anthracis is non motile </li></ul><ul><li>b. confirmatory test done at CDC </li></ul><ul><li>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 </li></ul>
  19. 19. Gangrene <ul><li>Pathogen = Clostridium perfringens an anaerobic, G+ , endospores – found in the soil </li></ul><ul><li>If a wound interrupts the blood supply to the tissue it causes a condition known as ischemia and the wound becomes anaerobic </li></ul><ul><li>Ischemia leads to necrosis (death of tissue) which results in gangrene </li></ul>
  20. 20. Gangrene <ul><li>4. Gas gangrene </li></ul><ul><li>a. as bacteria grow they ferment ms CH2Os and produce the gases CO2, H2 </li></ul><ul><li>b. bacteria produce toxins that can destroy ms tissue </li></ul><ul><li>c. if toxins and bacteria reach the bloodstream can cause systemic illness – w/o tx condition is fatal </li></ul><ul><li>5. Tx = surgical removal of necrotic tissue, amputation </li></ul><ul><li>a. if in abdominal cavity- tx w/ pressurized O2 rich environment – hyperbaric chamber, and penicillin </li></ul>
  21. 21. Systemic diseases caused by bites and scratches <ul><li>Cat scratch disease </li></ul><ul><ul><li>Pathogen = Bartonella henselae can live in cat’s RBCs causing bacteremia in cats </li></ul></ul><ul><ul><li>Transmission = usually by bite or scratch </li></ul></ul><ul><ul><li>Signs and sxs = initial sign is a papule followed lymph node swelling, malaise, fever </li></ul></ul><ul><ul><li>Tx = usually self limiting, Abs may help </li></ul></ul>
  22. 22. Systemic diseases caused by bites and scratches <ul><li>Rat bite fever </li></ul><ul><li>Streptobacillary rat bite fever </li></ul><ul><ul><li>Pathogen = Streptobacillus moniliformis </li></ul></ul><ul><ul><li>Transmission is by bite of urban rats </li></ul></ul><ul><ul><li>Sxs = fever, HA, ms ache, inflammation around the lesion </li></ul></ul><ul><ul><ul><li>1) If it spreads to the bloodstream – swollen lymph nodes, rash, occasionally endocarditis </li></ul></ul></ul><ul><li>2. Spirillar fever </li></ul><ul><li>a. pathogen = Spirillum minor </li></ul><ul><li>b. transmission is bite from wild rodents </li></ul><ul><li>c. sxs are similar to streptobacillary rat bite fever </li></ul><ul><li>d. tx = penicillin for both forms </li></ul>
  23. 23. Vector transmitted disease <ul><li>Plague – Yersinia pestis – G neg, rod </li></ul><ul><li>Normally a disease of rats, now cats are a new reservoir </li></ul><ul><li>Transmitted from one rat to another by the rat flea Xenopsylla cheopis </li></ul><ul><ul><li>If the host dies the fleas seek a new host including humans </li></ul></ul><ul><ul><li>Fleas not always necessary, can contact by skinning infected animals and by bites, scratches, licks from a cat </li></ul></ul><ul><li>After a flea bite bacteria enters the bloodstream and proliferate in lymph and blood </li></ul><ul><ul><li>Lymph nodes enlarge in the groin and armpit </li></ul></ul><ul><ul><ul><li>1) Swellings are called buboes for bubonic plague </li></ul></ul></ul><ul><ul><li>Mortality rate untreated 50 – 75% < a wk after sxs appear </li></ul></ul>
  24. 24. Vector transmitted disease <ul><li>Plague </li></ul><ul><li>4. From the buboes the bacteria spread to the bloodstream causing septicemic plague which can cause septic shock </li></ul><ul><li>5. Pneumonic plague is caused when bacteria are carried by the blood to the lungs </li></ul><ul><li>a. mortality rate is nearly 100% w/in 3 days </li></ul><ul><li>b. spread by airborne droplets from humans or animals </li></ul>
  25. 25. Vector transmitted disease <ul><li>Plague </li></ul><ul><li>6. Dx = culture and gram stain of blood or bubo aspirate, rapid diagnostic test can detect capsular antigens of Yersinia pestis </li></ul><ul><li>7. Tx = antibiotics Streptomycin and tetracycline </li></ul>
  26. 26. Vector transmitted disease <ul><li>Relapsing fever </li></ul><ul><li>All species of the genus Borrelia (a spirochete) cause relapsing fever except for Borrelia burgdorferi which causes Lyme’s disease </li></ul><ul><li>Transmission is by soft ticks and lice </li></ul><ul><li>Incidence increases during summer months when rodent and arthropod activity increases </li></ul>
  27. 27. Vector transmitted disease <ul><li>Relapsing fever </li></ul><ul><li>4. Sxs = high fever (>105 F), shaking chills, jaundice, rose colored rash </li></ul><ul><li>a. after 3 to 5 days the fever subsides but returns (relapses) each time for a shorter period and less severe </li></ul><ul><li>5. Dx = microscopic observations of bacteria in px blood </li></ul><ul><li>6. Tx = tetracycline </li></ul>
  28. 28. Vector transmitted disease <ul><li>Typhus – caused by rickettsias – obligate intracellular parasites of eukaryotes </li></ul><ul><li>Spread by arthropods the bacteria infect endothelial cells of the vascular system </li></ul><ul><li>The resulting inflammation causes blockage and rupture of the small blood vessels </li></ul><ul><li>Historically – a prolific killer of man, helped decimate the Aztec population in 1500s and helped the Russians defeat Napoleon's army </li></ul>
  29. 29. Typhus <ul><li>Epidemic typhus (louseborne typhus) </li></ul><ul><li>1. Pathogen – Rickettsia prowazekii is carried in the GI tract of the body louse Pediculus humanus corporis (vector) </li></ul><ul><li>2. Transmission – through louse feces when host scratches bite </li></ul><ul><li>3. Found in crowded unsanitary conditions where lice can move from one host to another easily </li></ul>
  30. 30. Typhus <ul><li>Epidemic typhus </li></ul><ul><li>4. Sxs = prolonged fever, stupor, rash of small red spots caused by subcutaneous hemorrhaging </li></ul><ul><li>5. Tx = tetracycline, chloramphenicol, eliminate conditions </li></ul><ul><li>6. Vaccines are available for military </li></ul>
  31. 31. Typhus <ul><li>Endemic typhus – occurs sporadically rather than in epidemics </li></ul><ul><li>Murine is Latin for mouse, rodents such as rats, squirrels are hosts for this type of typhus </li></ul><ul><li>Pathogen = Rickettsia typhi which is transmitted by the rat flea Xenopsylla cheopis </li></ul><ul><li>Clinically endemic and epidemic typhus are the same but endemic typhus is less severe </li></ul><ul><li>Tx = tetracycline, </li></ul><ul><li>Prevention = rat control </li></ul>
  32. 32. Typhus <ul><li>Tickborne typhus = Rocky Mt. Spotted Fever </li></ul><ul><li>Pathogen = Rickettsia rickettsia which is a parasite of ticks </li></ul><ul><ul><li>In west - deer tick Dermacentor andersoni </li></ul></ul><ul><ul><li>In the east - deer tick Dermacentor variabilis </li></ul></ul><ul><li>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 </li></ul>
  33. 33. Typhus <ul><li>3. Dx = fluorescent antibody, PCR </li></ul><ul><li>4. Prevention – avoid ticks </li></ul><ul><li>5. Tx = tetracycline, chloramphenicol, doxycycline, no vaccine available </li></ul><ul><li>6. Without tx 20% mortality rate </li></ul><ul><li>7. Distinguishing characteristics – m.c. in east and SE US </li></ul>
  34. 34. Viral hemorrhagic fevers <ul><li>Hemorrhagic fevers are Certain viral fevers accompanied by severe hemorrhagic lesions of the tissues, most are zoonotic </li></ul><ul><li>Classic = they have been around for a long time </li></ul><ul><li>Emerging = they are fairly new </li></ul>
  35. 35. Viral hemorrhagic fevers Classic <ul><li>Yellow fever </li></ul><ul><li>Is caused by an arbovirus transmitted by the bite of the mosquito Aedes aegypti </li></ul><ul><li>Early sx = fever, chills, HA, followed by nausea and vomiting </li></ul><ul><li>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 </li></ul>
  36. 36. Viral hemorrhagic fevers Classic <ul><li>Yellow fever </li></ul><ul><li>4. Endemic to Africa, central and south America </li></ul><ul><li>5. Monkeys are the natural reservoirs but human to human transmission can occur </li></ul><ul><li>6. No specific tx, vaccine is live, attenuated, mortality rate – 20% </li></ul>
  37. 37. Viral hemorrhagic fevers Classic <ul><li>Dengue fever – aka breakbone fever, milder disease than yellow fever </li></ul><ul><li>RNA virus that is also transmitted by Aedes aegypti </li></ul><ul><li>Endemic to the Caribbean and tropical areas </li></ul><ul><li>Sx= fever, severe ms and joint pain, rash </li></ul><ul><li>no animal reservoir </li></ul>
  38. 38. Viral hemorrhagic fevers Classic <ul><li>5. Dx = rise in IgM titers </li></ul><ul><li>6. Prevention = a live, attenuated vaccine is being tested </li></ul><ul><li>7. Dengue hemorrhagic fever is a severe form caused when Abs from a previous infection combine with the virus </li></ul><ul><li>a. it can induce shock in a victim (usually a child) and kill in a few hours </li></ul><ul><li>b. one of the leading causes of death among SE Asian children </li></ul>
  39. 39. Viral hemorrhagic fevers Emerging <ul><li>Hantavirus pulmonary syndrome - 1993 </li></ul><ul><li>Pathogen – Sin Nombre virus is a Bunyavirus found mostly in western states </li></ul><ul><li>Transmission = by inhalation of airborne viruses from dried urine or feces of infected small rodents </li></ul><ul><li>Causes a frequently fatal pulmonary infection where the lungs fill with fluids </li></ul>
  40. 40. Viral hemorrhagic fevers Emerging <ul><li>Hantavirus </li></ul><ul><li>4. Dx = serology – IgM, PCR, id Ag in tissue </li></ul><ul><li>5. Prevention = avoid mouse habitats and droppings </li></ul><ul><li>6. Tx = supportive </li></ul><ul><li>7. Distinctive features = rapid onset, high mortality rate </li></ul>
  41. 41. Viral hemorrhagic fevers Emerging <ul><li>Ebola </li></ul><ul><li>Caused by a filovirus which is threadlike RNA virus, endemic to Africa </li></ul><ul><li>transmission is by direct contact with body fluid of infected person or animal </li></ul><ul><li>Virulence = disruption of clotting factors resulting in massive hemorrhage from all orifices, mucous membranes, internal organs </li></ul><ul><li>Dx = PCR, viral culture conducted at the CDC </li></ul>
  42. 42. Burkitt’s Lymphoma <ul><li>A fast growing tumor of the jaw in African children </li></ul><ul><li>Pathogen is the Epstein-Barr virus </li></ul><ul><ul><li>a. Official name is human herpesvirus 4 </li></ul></ul><ul><li>Associated with children who have had malaria which impairs their immune response to the EB virus </li></ul>
  43. 43. Protozoan Disease of the CV and Lymphatic Systems <ul><li>Chagas Disease = American trypanosomiasis </li></ul><ul><li>Pathogen = Trypanosoma cruzi – a flagellated protozoan </li></ul><ul><li>Occurs in Texas, Mexico, Central America, parts, of South America (infects 40-50% or rural populations in SA) </li></ul><ul><li>Reservoir for T. cruzi is wild animals –ex. Rodents, possums, armadillos </li></ul>
  44. 44. Protozoan Disease of the CV and Lymphatic Systems <ul><li>Chagas Disease </li></ul><ul><li>4. Arthropod vector = Reduviid bug aka the kissing bug because it bites near the lips </li></ul><ul><li>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 </li></ul><ul><li>a. blood transfusions are another way of transmission </li></ul>
  45. 45. Protozoan Disease of the CV and Lymphatic Systems <ul><li>Chagas Disease </li></ul><ul><li>6. Most dangerous to children because of heart damage – 10% mortality </li></ul><ul><li>7. Can cause nerve damage controlling peristaltic action of the esophagus and colon </li></ul><ul><li>a. can result in grossly enlarged organs – megacolon, megaesophagus </li></ul><ul><li>b. now these organs can’t transport food </li></ul>
  46. 46. Protozoan Disease of the CV and Lymphatic Systems <ul><li>Toxoplasmosis </li></ul><ul><li>Pathogen = Toxoplasma gondii – a spore forming protozoan </li></ul><ul><li>Cats are the definitive host and the protozoan undergoes the sexual phase in their intestinal tract </li></ul><ul><ul><li>a. Oocysts are shed in cat’s feces and ingested by intermediate hosts – ex. Mouse, cow, pig, humans </li></ul></ul>
  47. 47. Protozoan Disease of the CV and Lymphatic Systems <ul><li>Toxoplasmosis </li></ul><ul><li>3. It is an asymptomatic infection in most persons, in a non-immune pregnant women it can lead to congenital toxoplasmosis </li></ul><ul><li>a. danger to fetus is stillbirth or child with severe brain damage or vision problems </li></ul><ul><li>b. pg women shouldn’t change litter box </li></ul><ul><li>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 </li></ul>
  48. 48. Protozoan Disease of the CV and Lymphatic Systems <ul><li>Malaria </li></ul><ul><li>Pathogen = Plasmodium , a protozoan parasite </li></ul><ul><li>Vector = female Anopheles mosquito </li></ul><ul><li>WW resurgence of malaria, 300 – 500 million affected ww, 2-4 million die annually </li></ul><ul><li>4 types of Plasmodium can cause malaria – P. vivax, P. ovale, P. malariae and P. falciparum (which is the most dangerous) </li></ul>
  49. 49. Malaria <ul><li>5. Virulence factor - multiple life stages </li></ul><ul><li>a. asexual sporozoites are in the saliva of feeding mosquitoes, when they bite a human the sporozoites enter a capillary </li></ul><ul><li>b. Sporozoites invade the liver cells and develop into large #s of merozoites through a process called schizogony = asexual division </li></ul>
  50. 50. Malaria <ul><li>c. Merozoites are released into the circulation and enter RBCs </li></ul><ul><li>1) initial infection is marked by a ring trophozoite pg. 697 for pix. </li></ul><ul><li>d. Schizogony inside the RBC produces more merozoites that cause the RBC to burst and releases them to infect more RBCs </li></ul><ul><li>1) when merozoites are released so are toxic compounds which cause the characteristic fever and chills of malaria </li></ul>
  51. 51. Malaria <ul><li>e. Gametocytes develop in certain infected RBCs and are ingested by another mosquito </li></ul><ul><li>f. the sexual phase of fertilization and sporozoite formation occur in the mosquito </li></ul><ul><li>6. The original drug for malaria was quinine and today they use it and its derivatives </li></ul>
  52. 52. Leishmaniasis <ul><li>A protozoan disease that affects the internal organs or skin and mucous membranes </li></ul><ul><li>Transmission is by the bite of the female sandfly (vector) </li></ul><ul><li>Leishmania donovani causes visceral leishmaniasis </li></ul><ul><ul><li>a. Occurs in much of the tropical world, in India is called kala azar </li></ul></ul>
  53. 53. Leishmaniasis <ul><li>3. b. sxs = chills and sweating like malaria </li></ul><ul><li>1) sxs may take a year to appear after infection </li></ul><ul><li>c. protozoa proliferate in the liver and spleen causing enlargement, eventually the kidney is invaded and function is lost </li></ul><ul><li>d. if untreated – death in a year or 2 </li></ul><ul><li>e. tx – injected drugs that contain the toxic metal antimony, new oral drugs but can cause birth defects </li></ul>
  54. 54. Leishmaniasis <ul><li>4. Leishmania tropical aka oriental sore – cutaneous form </li></ul><ul><li>a. papule appears at bite site several weeks after the bite </li></ul><ul><li>b. papule ulcerates, heals, leaves a scar </li></ul><ul><li>5. Leishmania braziliensis – mucocutaneous leishmaniasis aka American leishmaniasis </li></ul><ul><li>a. destruction of the nose, mouth, and upper throat tissue </li></ul><ul><li>b. found in the Yucatan and the rain forests of Central and South America </li></ul>
  55. 55. Leishmaniasis <ul><li>6. Virulence factor – protozoa multiplies within macrophages </li></ul><ul><li>7. Dx = examine blood and look for parasite in WBCs, dx of cutaneous form by clinical appearance and microscopic scrapings </li></ul>
  56. 56. Schistosomiasis <ul><li>A helminth disease caused by a small fluke </li></ul><ul><li>Adult worms coat themselves with a layer that mimics the hosts tissue to avoid body defenses </li></ul><ul><li>The female lives in a groove of the body of the male – schistosome = split body </li></ul><ul><ul><li>a. Have a continuous supply of eggs </li></ul></ul>
  57. 57. Schistosomiasis <ul><li>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 </li></ul><ul><li>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 </li></ul><ul><li>1) the US doesn’t have the right kind of snails for an intermediate host </li></ul>
  58. 58. Schistosomiasis <ul><li>5. three primary types of schistosomiasis </li></ul><ul><li>a. Schistosoma haematobium – inflammation of the urinary bladder wall </li></ul><ul><li>1) Africa, Middle East, esp. Egypt </li></ul><ul><li>b. Schistosoma japonicum – intestinal inflammation </li></ul><ul><li>1) East Asia </li></ul><ul><li>c. Schistosoma mansoni – intestinal inflammation </li></ul><ul><li>1) South America, Caribbean, Puerto Rico </li></ul>

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