Transcript Infections of the Cardiovascular and Lymphatic Systems

Microbiology: A Systems
Approach, 2nd ed.
Chapter 20: Infectious Diseases
Affecting the Cardiovascular and
Lymphatic Symptoms
20.1 The Cardiovascular and
Lymphatic Systems and Their Defenses
• Cardiovascular System
– Blood vessels and heart
– Moves blood in a closed circuit
– Also known as the circulatory system
– Provides tissues with oxygen and nutrients and
carries away carbon dioxide and waste products
The Heart
• Divided into two halves, each half divided into an
upper and lower chamber
• Upper chambers: atria; lower chambers:
ventricles
• Covered by the pericardium
• Three layers to the wall of the heart (from outer
to inner)
– Epicardium
– Myocardium
– Endocardium
Figure 20.1
Figure 20.2
Lymphatic System
• One-way passage
• Returns fluids from the tissues to the
cardiovascular system
Figure 14.10
Defenses of the Cardiovascular and
Lymphatic Systems
• Cardiovascular system is highly protected,
however, if microbes do invade they gain access
to every part of the body
• Bloodstream infections are systemic infections;
often with the suffix –emia
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Viremia
Fungemia
Bacteremia
Septicemia (can lead to septic shock)
• Defenses in the bloodstream- leukocytes
20.2 Normal Biota of the
Cardiovascular and Lymphatic Systems
• None
• Some microorganisms may be present
transiently (filtering out of tissues) but they do
not colonize the systems in the healthy state
20.3 Cardiovascular and Lymphatic
System Diseases Caused by
Microorganisms
• Endocarditis
– Inflammation of the endocardium
– Usually refers to an infection of the valves of the heart
– Acute and subacute, with similar symptoms (in subacute
the symptoms develop more slowly and are less
pronounced)
– Fever, anemia, abnormal heartbeat
– Sometimes symptoms similar to heart attack
– Abdominal or side pain may be reported
– Petechiae over the upper half of the body and under the
fingernails may be present
– In subacute cases, may have enlarged spleen
Figure 20.3
Septicemias
• Occurs when organisms are actively multiplying in the
blood
• Many different bacteria and a few fungi can cause this
condition
• Fever- prominent symptom
• Patient appears very ill, may have an altered mental
state, shaking chills, and gastrointestinal symptoms
• Often exhibits increased breathing rate and respiratory
alkalosis
• Low blood pressure
Plague
• Three possible manifestations
– Pneumonic plague: respiratory disease
– Bubonic plague
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Bacterium injected through a flea bite
Enters the lymph and is filtered by a lymph node
Infection causes inflammation and necrosis of the node
Results in a swollen lesion called a bubo, usually in the groin
or axilla
• Incubation period: 2 to 8 days, ending with the onset of
fever, chills, headache, nausea, weakness, and tenderness of
the bubo
– Septicemic plague: when the case progresses to
massive bacterial growth in the blood
Figure 20.4
Figure 20.5
Figure 20.6
Tularemia
• Sometimes called rabbit fever, because it has been
associated with outbreaks of disease in wild rabbits
• Pathogen of concern on the lists of bioterrorism agents
• Tick bites: most frequent arthropod vector
• Incubation period of a few days to 3 weeks
• Symptoms: headache, backache, fever, chills, malaise,
and weakness
• Further symptoms tied to the portal of entry:
ulcerative skin lesions, swollen lymph glands,
conjunctival inflammation, sore throat, intestinal
disruption, pulmonary involvement
Lyme Disease
• Nonfatal
• Evolves into a slowly progressive syndrome
that mimics neuromuscular and rheumatoid
conditions
• Early symptom: rash a the site of a tick bite
• Other early symptoms: fever, headache, stiff
neck, and dizziness
• Second stage: cardiac and neurological
symptoms develop
Figure 20.7
Figure 20.8
Figure 20.9
Figure 20.10
Infectious Mononucleosis
• Majority caused by Epstein-Barr virus (EBV)
• Most of the remainder caused by
cytomegalovirus (CMV)
• Sore throat, high fever, and cervical
lymphadenopathy
• Long incubation period- 30 to 50 days
• Also may exhibit a gray-white exudates in the
throat, skin rash, and enlarged spleen and liver
• Sudden leukocytosis
• Fatigue
Figure 20.11
Hemorrhagic Fever Diseases
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Caused by viruses in one of four families:
Arenaviridae
Filoviridae
Flaviviridae
Bunyaviridae
Yellow Fever
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Capillary fragility
Disrupts the blood-clotting system
Begins with fever, headache, and muscle pain
Sometimes progresses to oral hemorrhage,
nosebleed, vomiting, jaundice, and liver and
kidney damage
Dengue Fever
• Usually mild
• Sometimes it can progress to dengue
hemorrhagic shock syndrome
• Causes severe pain in muscles and joints
Ebola and Marburg
• Related viruses, cause similar symptoms
• Extreme manifestations of of hemorrhagic
events with extensive capillary fragility and
disruption of clotting
• Patients bleed from their orifices, mucous
membranes, and experience massive internal
and external hemorrhage
• Often manifest a rash on the trunk in early
stages
Lassa Fever
• Most cases asymptomatic
• In 20% of the cases a severe hemorrhagic
syndrome develops
• Chest pain, hemorrhaging, sore throat, back
pain, vomiting, diarrhea, and sometimes
encephalitis
• Patients who recover often suffer from
deafness
Nonhemorrhagic Fever Diseases
• Brucellosis
– On the CDC list of possible bioterror agents
– Bacteria is carried into the bloodstream by
phagocytic cells, creating focal lesions in the liver,
spleen, bone marrow, and kidney
– Fluctuating pattern of fever accompanied by chills,
profuse sweating, headache, muscle pain and
weakness, and weight loss
Figure 20.12
Q Fever
• Abrupt onset of fever, chills, head and muscle
ache, and occasionally a rash
• Sometimes complicated by pneumonitis,
hepatitis, and endocarditis
Figure 20.13
Cat-Scratch Disease
• Symptoms start after 1 to 2 weeks
• Cluster of small papules at the site of
inoculation
• In a few weeks, lymph nodes swell and can
become pus-filled
• Only about 1/3 of patients experience high
fever
Figure 20.14
Trench Fever
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Highly variable symptoms
5- to 6-day fever
Leg pains, especially in the tibial region
Headache, chills, and muscle aches
Macular rash can occur
Endocarditis can develop
HGA and HME
• Similar signs and symptoms
• Acute febrile state
• Headache, muscle pain, and rigors
Rocky Mountain Spotted Fever (RMSF)
• 2 to 4 days incubation
• First symptoms: sustained fever, chills, headache,
and muscular pain
• Distinctive spotted rash within 2 to 4 days after
the prodrome
• In most severe untreated cases, enlarged lesions
merge and become necrotic
• Other manifestations: cardiovascular disruption;
conditions of restlessness, delirium, convulsions,
tremor, and coma
Figure 20.15
Figure 20.16
Malaria
• The world’s dominant protozoan disease
• 10- to 16-day incubation period
• First symptoms: malaise, fatigue, vague aches,
and nausea with or without diarrhea
• Next symptoms: bouts of chills, fever, and
sweating
• Symptoms occur at 48- or 72-hour intervals
• The interval, length, and regularity of symptoms
reflect the type of malaria
Figure 20.17
Figure 20.18
Figure 20.19
Anthrax
• Can exhibit its primary sumptoms in various
locations of the body
– Cutaneous anthrax
– Pulmonary anthrax
– Gastrointestinal tract
– Anthrax meningitis
• Cutaneous and pulmonary forms most
common
Figure 20.20
HIV Infection and AIDS
• Retrovirus: human immunodeficiency virus
(HIV)
– Hybrid virus- genetic sequences from two separate
monkey SIVs
• The disease: acquired immunodeficiency
syndrome (AIDS)
• Spectrum of clinical disease associated with HIV
infection
• Symptoms directly tied to two things: the level of
virus in the blood and the level of T cells in the
blood
Symptoms
• Initial infection: vague, mononucleosis-like symptoms
that soon disappear (initial high levels of virus)
– Within days, about 50% of the T helper cells with memory
for the virus are destroyed
• Period of asymptomatic infection that varies in length
from 2 to 15 years
– During this period the number of T cells in the blood is
steadily decreasing
– Once T cells reach low enough levels, symptoms of AIDS
ensue
• Initial symptoms of AIDS: fatigue, diarrhea, weight
loss, and neurological changes
Other Symptoms as the Disease
Progresses
• Opportunistic infections or neoplasms
• Severe immune deregulation, hormone
imbalances, metabolic disturbances
• Pronounced wasting of body mass
• Protracted fever, fatigue, sore throat, and
night sweats
• Lesions in the brain, meninges, spinal column,
and peripheral nerves
Figure 20.21
Figure 20.22
Figure 20.23
Figure 20.24
Figure 20.25
Adult T-Cell Leukemia and Hairy-Cell
Leukemia
• Leukemia: general name for at least four
different malignant diseases of the WBC forming
elements originating in the bone marrow
• Some acute, others chronic
• Many causes- two of which are thought to be
viral
– Adult T-cell leukemia by HTLV-I
– Hairy-cell leukemia by HTLV-II
• Signs and symptoms include easy bruising or
bleeding, paleness, fatigue, and recurring minor
infections