Chapter 21 Infectious Diseases Affecting the Cardiovascular and Lymphatic Systems

Defenses Cardiovascular system Lymphatic system Protection

Cardiovascular system Blood vessels Arteries, capillaries, and veins Heart Atria and ventricles Casing and wall are prone to infection Provides tissues with oxygen and nutrients Carries away carbon dioxide and waste products

The heart pumps blood to and from all regions of the body. Fig. 20.1 The heart

Lymphatic system Lymph vessels Lymph nodes Parallel the blood vessels Lymph nodes Collects and filters impurities and infectious agents Returns fluids to the cardiovascular system Major source of immune cells and fluids

The cardiovascular system covers most the body, as does the lymphatic system. Fig. 20.2 The anatomy of the cardiovascular system.

Protection Cardiovascular and lymphatic systems Leukocytes (white blood cells) Normal flora

Leukocytes Granulocytes Agranulocytes Basophils Eosinophils Neutraphils Agranulocytes Lymphatics T cells B cells Monocytes Macrophages

Normal flora Absent Closed system Transiently present

Diseases Types Cardiovascular Lymphatic

Types Endocarditis Septicemia Plague Tularemia Infectious mononucleosis Lyme disease

Types continued Hemorrhagic fever Nonhemorrhagic fever Malaria Anthrax HIV Leukemia

Endocarditis Bacterial infection Inflammation of the endocardium (inner lining of the heart) Patients with prosthetic valves are at risk Acute – large blood stream challenge Subacute – damage to heart valves

Features of endocarditis. Checkpoint 20.1 Endocarditis

Septicemia Bacterial infection Fungal infection Organisms actively multiply in the blood (septic)

Bacterial Cardiovascular and Systemic Diseases Septicemia, Bacteremia, and Toxemia Septicemia Any microbial infection of the blood that produces illness Bacteremia Bacterial septicemia that is often harmless Toxemia Release of bacterial toxins into the blood Lymphangitis Infection and inflammation of the lymphatic vessels © 2012 Pearson Education Inc.

Figure 21.3 Petechiae, a sign of bacteremia

Features of septicemia. Checkpoint 20.2 Septicemia

Plague Bacterial infection Pneumonic Bubonic Respiratory Bubonic Enters lymph Septicemic plague can result from pneumonic and bubonic plague

Bubonic plague can cause inflammation of the nodes called bubo. Fig. 20.3 A classic inguinal bubo of bubonic plague.

Yersinia pestis has a unique “safety pin” appearance, and is the causative agent of plague. Fig. 20.4 Yersinia pestis

The infection cycle of the bacterium Yersinia pestis, the causative agent of plague. Fig. 20.5 The infection cycle of Yersinia pestis.

Features of plague. Checkpoint 20.3 Plague

Tularemia Bacterial infection Zoonotic Affects lymph nodes and lungs Intracellular infection macrophages

Features of tularemia. Checkpoint 20.4 Tularemia

Infectious mononucleosis Mostly a viral infection Epstein-Barr virus Cytomegalovirus Bacterial infection Viral latency Infects B and T cells

Viral Cardiovascular and Systemic Diseases Infectious Mononucleosis Pathogenesis and epidemiology Transmission occurs via saliva EBV infects B lymphocytes Majority of adults have antibodies against EBV Diagnosis, treatment, and prevention Diagnosed by presence of large, lobed B lymphocytes and neutropenia Treatment focuses on relieving symptoms Prevention is difficult since EBV occurrence is widespread © 2012 Pearson Education Inc.

Lymphocytes in the lymphatic and cardiovascular systems can be infected by the Epstein-Barr virus. Fig. 20.6 Evidence of Epstein-Barr infection in the blood Smear of a patient with infectious mononucleosis.

Features of infectious mononucleosis. Checkpoint 20.5 Infectious Mononucleosis.

Lyme disease Bacterial infection Erythema migrans (bull’s eye lesion) Second stage of infection affects the cardiovascular and nervous systems, severe arthritis

The characteristic bull’s eye lesion associated with Lyme disease. Fig. 20.7 Lesions of Lyme disease on the lower leg.

Borrelia burgdorferi, the causative agent of Lyme disease, is morphologically different from other pathogenic spirochetes. Fig. 20.8 Spirochetes

Figure 21.8 Borrelia burgdorferi Red blood cell

In the Northeast, the cycle of Lyme disease is a complex 2 –year cycle that involves two principle hosts. Fig. 20.9 The cycle of Lyme disease in the northeastern U.S.

Bacterial Cardiovascular and Systemic Diseases Lyme Disease Epidemiology One of the most reported vector-borne diseases in U.S. Two events contributed to an increase in Lyme disease Movement of human populations into woodland areas Protection of the deer population © 2012 Pearson Education Inc.

Figure 21.10 The occurrence of Lyme disease in the United States-overview

Features of Lyme disease. Checkpoint 20.6 Lyme Disease

Hemorrhagic fever Viral infection Capillary fragility Yellow fever Dengue fever Ebola and Marburg Lassa fever Capillary fragility Disrupts blood clotting system http://www.digitaljournal.com/article/266455

Viral Cardiovascular and Systemic Diseases African Viral Hemorrhagic Fever Signs and symptoms Fever and fatigue Minor petechiae progress to severe internal hemorrhaging Pathogens and virulence factors Caused by Ebolavirus or Marburgvirus Pathogenesis and epidemiology Occurs primarily in Africa Transmitted via contact with bodily fluids of infected individual © 2012 Pearson Education Inc.

Figure 21.17 Filamentous Ebolavirus

Figure 21.18 Sites in which locally acquired cases of Marburg and Ebola viruses have occurred

Features of hemorrhagic fever. Checkpoint 20.7 Hemorrhagic fevers

Nonhemorrhagic fever Bacterial infection Infects phagocytic cells Brucellosis Q fever Cat-scratch disease Trench fever Ehrlichioses Rocky Mountain Spotted fever Infects phagocytic cells

Bacterial Cardiovascular and Systemic Diseases Brucellosis Signs and symptoms Fluctuating fever that spikes every afternoon Pathogen and virulence factors Caused by Brucella melitensis strains Endotoxin causes some of the signs and symptoms Pathogenesis and epidemiology Consumption of contaminated dairy products Contact with animal blood, urine, or placentas Diagnosis, treatment, and prevention Usually requires no treatment Attenuated vaccine exists for animals © 2012 Pearson Education Inc.

A classic symptom of brucellosis is the undulating fever or fluctuating body temperature. Fig.20.10 The temperature cycle in classic brucellosis.

Endosporulation of Coxiella burnetii contributes toward the transmission and development of Q fever. Fig. 20.11 The agent of Q fever.

A primary nodule due to cat-scratch disease can form, which further lead to pus formation and lymph node swelling. Fig. 20.12 Cat-scratch disease

Rocky Mountain spotted fever occurs throughout the U. S Rocky Mountain spotted fever occurs throughout the U.S., and the number of cases the past few years have been increasing. Fig. 20.13 Trends in infection for Rocky Mountain spotted fever.

An example of late generalized rash of Rocky Mountain spotted fever. Fig. 20.14 Late generalized rash of Rocky Mountain Spotted fever.

Features of nonhemorrhagic fever diseases. Checkpoint 20.8 Nonhemorrhagic fever diseases.

Malaria Protozoan infection Rupturing of red blood cells Falciparum malaria- most common virulent type Cerebral malaria-obstruction of small blood vessels in the brain Rupturing of red blood cells Relapses can occur

Development of malaria consist of an asexual phase (carried out in the human) and a sexual phase (carried out in the mosquito). Fig. 20.15 The life and transmission of Plasmodium

Initial infection of rbc by Plasmodium is marked by a ring trophozoite. Fig. 20.16 The ring trophozoite stage in a Plasmodium

Prevention efforts for malaria involve the use of bed nets to prevent mosquito infestation. Fig. 20.17 A public demonstration of impregnating Bed nets with insecticide.

Features of malaria. Checkpoint 20.9 Malaria

Protozoan and Helminthic Cardiovascular and Systemic Diseases Toxoplasmosis Signs and symptoms Majority of cases have no symptoms Symptoms in individuals with poor immunity Fever, malaise, inflammation of the lungs, liver, and heart Symptoms in the fetus Stillbirth, epilepsy, mental retardation Pathogen and virulence factors Toxoplasma gondii is the causative agent Cats are the definitive host © 2012 Pearson Education Inc.

Protozoan and Helminthic Cardiovascular and Systemic Diseases Toxoplasmosis Pathogenesis and epidemiology Consumed in undercooked meat containing the parasite Transmission across the placenta can also occur Specific mechanism of disease is not yet known Diagnosis, treatment, and prevention Diagnosed mainly by detecting organisms in tissues Treatment needed only in AIDS patients, pregnant women, and newborns Prevention is difficult because T.gondii has numerous hosts © 2012 Pearson Education Inc.

Anthrax Bacterial infection Zoonotic Skin, lungs and CNS can be infected Tripartite Toxin (three proteins) Edema factor Protective antigen Lethal factor

Bacillus anthracis, the causative agent of anthrax, has a unique endospore and a streptobacillus cell arrangement. Fig. 20.18 Bacillus anthracis

Features of anthrax. Checkpoint 20.10 Anthrax

Human immunodeficiency virus (HIV) Viral infection Acquired immunodeficiency syndrome (AIDS) Infects helper T cells (CD4 receptor) Latency Therapy

There are four main stages of an HIV infection. Fig. 20.19 Dynamics of virus antigen, antibody, and T cells In circulation.

AIDS is a cluster of symptoms associated with the initial infection of HIV. Table 20.A AIDS-defining illnesses

HIV have specific glycoprotein receptors that bind to CD4 receptors of T cells. Fig. 20.20 The general structure of HIV.

HIV infects, undergoes latency, and eventually replicates and lyses the host T cell. Fig. 20.21 The general multiplication cycle of HIV.

Primary sources and possible routes of infection by HIV. Fig. 20.22 Primary sources and suggested routes of Infection by HIV.

HIV/AIDS is a serious infectious disease that is prevalent throughout the world. Table 20.1 Regional HIV/AIDS statistics and features

New HIV infections based on gender, risk group, and race. Fig. 20.23 New HIV infections each year in the U.S.

Nucleoside analogs, protease inhibitors, and integrase inhibitors are effective therapies used to treat HIV infections. Fig. 20.24 Mechanisms of action of anti-HIV drugs.

Features of HIV infections and AIDS. Checkpoint 20.11 HIV infections and AIDS

Leukemia Virus infection Anemia Platelet deficiency T-cell Hairy-cell Anemia Platelet deficiency Complications - tumors

Features of Adult T-cell leukemia and Hairy-cell leukemia. Checkpoint 20.12 Adult T-cell leukemia and hairy cell Leukemia.

Summary of the diseases of the cardiovascular and lymphatic systems. Taxonomic organization of microorganisms

Infectious Diseases Affecting the Cardiovascular and Lymphatic Systems. Fig. 20.p648