Presentation on theme: "Microbial Diseases of the Cardiovascular and Lymphatic Systems"— Presentation transcript:
1Microbial Diseases of the Cardiovascular and Lymphatic Systems Chapter 23Microbial Diseases of the Cardiovascular and Lymphatic Systems
2Q&AAlthough the emerging hemorrhagic fevers are almost entirely limited to tropical Africa, they have attracted much attention because of their mortality rate and devastating symptoms. What are these symptoms?
3Cardiovascular & Lymphatic Systems Learning Objective23-1 Identify the role of the cardiovascular and lymphatic systems in spreading and eliminating infections.
4Cardiovascular & Lymphatic Systems Plasma leaves blood to become interstitial fluidLymph capillaries: Transport interstitial fluid to bloodLymph nodes contain:Fixed macrophagesB cellsT cells
6Why is the lymphatic system so valuable for the working of the immune system? 23-1
7Bacterial Diseases Learning Objectives 23-2 List the signs and symptoms of sepsis, and explain the importance of infections that develop into septic shock.23-3 Differentiate gram-negative sepsis, gram-positive sepsis, and puerperal sepsis.23-4 Describe the epidemiologies of endocarditis and rheumatic fever.23-5 Discuss the epidemiology of tularemia.
8Bacterial Diseases Learning Objectives 23-6 Discuss the epidemiology of brucellosis.23-7 Discuss the epidemiology of anthrax.23-8 Discuss the epidemiology of gas gangrene.23-9 List three pathogens that are transmitted by animal bites and scratches.
9Sepsis and Septic Shock SepticemiaPersistent pathogens or their toxins in bloodSepsisSystemic inflammatory responseSevere sepsisSepsis + decreased blood pressureSeptic shockSepsis + uncontrollable decreased blood pressure
10Sepsis and Septic Shock LymphangitisInflamed lymph vessels accompanying septicemia and septic shockFigure 23.3
11Gram-Negative Sepsis Endotoxin shock Endotoxins cause blood pressure to decreaseAntibiotics can worsen condition by killing bacteriaPossible treatmentHuman activated protein C, an anticoagulant
12Gram-Positive Sepsis Nosocomial infections Staphylococcus aureus Streptococcus pyogenesGroup B streptococcus, S. agalactiaeEnterococcus faecium and E. faecalis
13Puerperal Sepsis Childbirth fever Streptococcus pyogenes Transmitted to mother during childbirth by attending physicians and midwives
14Diseases in Focus: Infections from Human Reservoirs A 27-year-old woman had a fever and cough for 5 days. Despite aggressive treatment with fluids and massive doses of antibiotics, she died 5 hours later. Catalase-negative, gram-positive cocci were isolated from her blood.What infections could cause these symptoms?
15What are two of the conditions that define the systemic inflammatory response syndrome of sepsis? 23-2Are the endotoxins that cause sepsis from gram-positive or gram-negative bacteria?
16Bacterial Infections of the Heart EndocarditisInflammation of the endocardiumSubacute bacterial endocarditisAlpha-hemolytic streptococci from mouthAcute bacterial endocarditisStaphylococcus aureus from mouthPericarditisStreptococci
18Rheumatic Fever Inflammation of heart valves Autoimmune complication of Streptococcus pyogenes infectionsFigure 23.5
19What medical procedures are usually the cause of endocarditis? 23-4
20Tularemia Francisella tularensis Zoonosis Gram-negative rodZoonosisTransmitted from rabbits and deer by deer fliesBacteria reproduce in phagocytesFigure 23.6
21Brucellosis (Undulant Fever) Brucella spp.Gram-negative rods that grow in phagocytesB. abortus (elk, bison, cows)B. suis (swine)B. melitensis (goats, sheep, camels)Undulating fever spikes to 40°C each eveningTransmitted via milk from infected animals or contact with infected animals
22Clinical Focus: A Sick Child A child underwent excisional biopsy of the left axillary lymph node when intermittent fever and enlarged lymph node persisted for 49 days. The excised tissue was cultured; a Gram stain of the bacteria that grew is shown.Clinical Focus, p. 644
23Clinical Focus: A Sick Child What is the cause of the infection?PathogenAntibody titerBartonellaEhrlichiaFrancisella4096CMVT. gondii
24Anthrax Bacillus anthracis Found in soil Cattle routinely vaccinated Gram-positive, endospore-forming aerobic rodFound in soilCattle routinely vaccinatedTreated with ciprofloxacin or doxycycline
25Anthrax Cutaneous anthrax Endospores enter through minor cut 20% mortalityFigure 23.7
26Anthrax Gastrointestinal anthrax Inhalational (pulmonary) anthrax Ingestion of undercooked, contaminated food50% mortalityInhalational (pulmonary) anthraxInhalation of endospores100% mortality
27Biological Weapons1346: Plague-ridden bodies used by Tartar army against Kaffa1937: Plague-carrying flea bombs used in the Sino-Japanese War1979: Explosion of B. anthracis weapons plant in the Soviet Union1984: S. enterica used against the people of The Dalles1996: S. dysenteriae used to contaminate food2001: B. anthracis distributed in the United States
29Gangrene Ischemia: Loss of blood supply to tissue Necrosis: Death of tissueGangrene: Death of soft tissueGas gangreneClostridium perfringens, gram-positive, endospore-forming anaerobic rod, grows in necrotic tissueTreatment includes surgical removal of necrotic tissue and/or use of hyperbaric chamber
32Diseases in Focus: Infections Transmitted by Soil or Water A 65-year-old man with poor circulation in his legs developed an infection following injury to a toe. Dead tissue further reduced circulation, requiring amputation of two toes.What infection could cause these symptoms?
33Diseases in Focus: Infections from Animal Reservoirs A 10-year-old girl was admitted to a local hospital after having fever (40°C) for 12 days and back pain for 8 days. Bacteria could not be cultured from tissues. She had a recent history of dog and cat scratches. She recovered without treatment.What infections could cause these symptoms?
34What animals are the most common reservoir for tularemia? 23-5 What ethnic group in the United States is most commonly affected by brucellosis, and why? 23-6How do animals such as cattle become victims of anthrax? 23-7Why are hyperbaric chambers effective in treating gas gangrene? 23-8Bartonella henselae, the pathogen of cat-scratch disease, is capable of growth in what insect? 23-9
35Vector-Transmitted Bacterial Diseases Learning Objectives23-10 Compare and contrast the causative agents, vectors, reservoirs, symptoms, treatments, and preventive measures for plague, Lyme disease, and Rocky Mountain spotted fever.23-11 Identify the vector, etiology, and symptoms of five diseases transmitted by ticks.23-12 Describe the epidemiologies of epidemic typhus, endemic murine typhus, and spotted fevers.
36Plague Causative agent: Yersinia pestis, gram-negative rod Reservoir: Rats, ground squirrels, and prairie dogsVector: Xenopsylla cheopisBubonic plague: Bacterial growth in blood and lymphSepticemia plague: Septic shockPneumonic plague: Bacteria in the lungs
51Why is the plague-infected flea so eager to feed on a mammal? 23-10 What animal does the infecting tick feed on just before it transmits Lyme disease to a human?Which disease is tickborne: epidemic typhus, endemic typhus, or Rocky Mountain spotted fever? 23-12
52Viral Diseases Learning Objectives 23-13 Describe the epidemiologies of Burkitt’s lymphoma, infectious mononucleosis, and CMV inclusion disease.23-14 Compare and contrast the causative agents, vectors, reservoirs, and symptoms of yellow fever, dengue, dengue hemorrhagic fever, and chikungunya fever.23-15 Compare and contrast the causative agents, reservoirs, and symptoms of Ebola hemorrhagic fever and Hantavirus pulmonary syndrome.
53Infectious Mononucleosis Epstein-Barr virus (HHV–4)Childhood infections are asymptomaticTransmitted via salivaCharacterized by proliferation of monocytes
54Burkitt’s Lymphoma Epstein-Barr virus (HHV–4) Nasopharyngeal carcinoma Cancer in immunosuppressed individuals and in malaria and AIDS patientsFigure 23.19
55Cytomegalovirus Infections Cytomegalovirus (HHV-5)Infected cells swell (cyto-, mega-)Latent in white blood cellsMay be asymptomatic or mildTransmitted across the placenta; may cause mental retardationTransmitted sexually, by blood, or by transplanted tissue
56Typical U.S. Prevalence of Antibodies Figure 23.20
57Viral Hemorrhagic Fevers PathogenPortal of EntryReservoirMethod of TransmissionYellow feverArbovirusSkinMonkeysAedes aegyptiDengueHumansAedes aegypti;A. Albopictus
58Viral Hemorrhagic Fevers Marburg, Ebola, Lassa, Argentine and Bolivian hemorrhagic fevers, Whitewater ArroyoPathogenPortal of EntryReservoirMethod of TransmissionFilovirus, arenavirusMucous membranesProbably fruit bats; other mammalsContact with blood
59Viral Hemorrhagic Fevers PathogenPortal of EntryReservoirMethod of TransmissionHantavirus pulmonary syndromeBunyavirusRespiratorytractField miceInhalation
61Q&AAlthough the emerging hemorrhagic fevers are almost entirely limited to tropical Africa, they have attracted much attention because of their mortality rate and devastating symptoms. What are these symptoms?
62Diseases in Focus: Viral Hemorrhagic Fevers What microbe could cause rash and severe joint pain in a 20-year-old woman?
63Although not a disease with an insect vector, why is Burkitt’s lymphoma most commonly a disease found in malarial areas? 23-13Why is the mosquito Aedes albopictus a special concern to the populations of temperate climates? 23-14Which disease does Ebola hemorrhagic fever more closely resemble, Lassa fever or Hantavirus pulmonary syndrome? 23-15
64Protozoan Diseases Learning Objectives 23-16 Compare and contrast the causative agents, modes of transmission, reservoirs, symptoms, and treatments for Chagas’ disease, toxoplasmosis, malaria, leishmaniasis, and babesiosis.23-17 Discuss the worldwide effects of these diseases on human health.
65Chagas’ Disease Also called American trypanosomiasis Causative agent: Trypanosoma cruziReservoir: Rodents, opossums, armadillosVector: Reduviid bugFigures 23.22, 12.32d
66Toxoplasmosis Caused by Toxoplasma gondii Transmission: Ingesting undercooked meatContact with cat fecesCongenital infectionStillbirthNeurological damage
74Leishmaniasis Disease Visceral Leishmaniasis Cutaneous Leishmaniasis Mucocutaneous LeishmaniasisBabesiosisFatal if untreatedPapuleDisfiguringReplicates in RBCsCausative AgentLeishmania donovaniL. tropicaL. braziliensisBabesia microtiVectorSandfliesIxodes ticksReservoirSmall mammalsRodentsTreatmentAmphotericin B or miltefosineAntimony compoundsAtovaquone + azithromycinGeographic DistributionSouth Asia, Sudan, BrazilAsia, Africa, Mediterranean, Central America, South AmericaYucatan, South AmericaUnited States
75What tickborne disease in the United States is sometimes mistaken for malaria when blood smears are inspected? 23-16Eliminating which of these diseases, malaria or Chagas’ disease, would have the greater effect on the well-being of the population of Africa? 23-17
76Helminthic Diseases Learning Objective 23-18 Diagram the life cycle of Schistosoma, and show where the cycle can be interrupted to prevent human disease.
77SchistosomiasisTissue damage (granulomas) in response to eggs lodging in tissuesFigure 23.28
78Types of Schistosomiasis S. haematobiumGranulomas in urinary bladder wallAfrica, Middle EastS. japonicumGranulomas in intestinal wallEast AsiaS. mansoniAfrican, Middle East, South American, CaribbeanSwimmer’s itchCutaneous allergic reaction to cercariaeU.S. parasite of wildfowl
80What freshwater creature is essential to the life cycle of the pathogen causing schistosomiasis?
81Diseases in Focus: Infections Transmitted by Vectors A 22-year-old soldier returning from a tour of duty in Iraq had three painless skin ulcers. She reported being bitten by insects every night. Ovoid, protozoa-like bodies were observed within her macrophages by examination with a light microscope.What infections could cause these symptoms?