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Micro Unit 4
Natalja Pathogen Charts: CNS Infections
99
Medical
Graduate
09/11/2012

Additional Medical Flashcards

 


 

Cards

Term
Streptococcus pneumoniae: Infection and Population Affected
Definition
Bacterial Meningitis

All ages
Especially <2 and elderly

Carriage of S.pneumo in the nasopharynx DECREAES with age
Term
Streptococcus pneumoniae: Virulence Factors
Definition
Adhesins: PspA and CpbA bind to choline on cell surfaces

IgA Protease

Pneumolysin: cytotoxin released when bacteria lyses (prevents Ab binding to bacteria)

Autolysin: causes bacteria to lyse and release contents (increases survival of those that do no lyse)

Capsule: over 90 serotypes

PG/TA: pro-inflammatory (tissue damage)
Term
Streptococcus pneumoniae: Etiology/Pathogenesis
Definition
Acquisition: aerosols or direct contact with oral secretions

Risk Factors:
-Immunosuppression
-Distant foci of infection
-Low levels of Ab to capsular polysaccharide

Symptoms:
-High fever
-Severe/persistent headach
-Stiff neck
-N/V
-Others requiring emergency treatment (confusion, sleepiness, difficulties waking up)

Symptoms in Infants:
-Irritability and tiredness
-Fever
-Poor feeding
Term
Streptococcus pneumoniae: Clinical ID
Definition
Shape: G(+) diplococcic

Biochemical:
-Catalase (-)
-Alpha hemolytic
-Optochin sensitive
-Bile sensitive
-Quelling reaction (+)
Term
Streptococcus pneumoniae: Vaccine?
Definition
Yes

23-Valent: capsular polysaccharides responsible for ~90% of infections; not conjugated so not for kids under 2

7/13-Valent: capsular polysaccharides that cause disease in kids, immunocompromised and elderly (100% effective for these serotypes); conjugated to diphtheria proteins
Term
Neisseria meningitidis: Infection and Population Affected
Definition
Bacterial Meningitis

Children and adolescents

Carriage of N.meningitidis in the nasopharynx INCREAES with age
Term
Neisseria meningitidis: Virulence Factors
Definition
IgA Protease

Pili: adherence to epithelium

LOS: pro-inflammatory (like LPS)

Capsule: A, B, C, Y, and W135
Term
Neisseria meningitidis: Etiology/Pathogenesis
Definition
Acquisitions: aerosols of direct contact with oral secretions

Risk Factor: close contact with infected people or areas of outbreak

Symptoms: same as S. pneumo
-Hemorrhagic rash with petechiae
-Eccymosis/necrosis of fingertips and toes in some cases
-Fulminating complications of rash possible (DIC, endotoxemia, shock, renal failure) in 1/3 of cases
Term
Neisseria meningitidis: Clinical ID
Definition
Shape: G(-) cocci (generally diplococcic)

Growth: fastidious (requires CAP- heme from lysed RBCs)

Biochemical:
-Oxidase (+)
-Ferments glucose AND maltose
Term
Neisseria meningitidis: Vaccine?
Definition
Yes

Basics:
-Protect against A, C, Y and W135
-Do NOT protect against B (which causes most disease), because it can cause autoimmunity due to sialic acid

MPSV4: polysaccharide vaccine for ages <10 and >55
MCV4: conjugate vaccine for ages 11-55
Term
Haemophlilus influenzae Type B: Infection and Population Affected
Definition
Bacterial Meningitis

Children under 5
Term
Haemophlilus influenzae Type B: Virulence Factors
Definition
IgA Protease

LPS: pro-inflammatory

Capsule: 6 serotypes (B responsible for meningitis)

Pili: adherence to epithelium

OMPs
Term
Haemophlilus influenzae Type B: Etiology/Pathogenesis
Definition
Acquisition: aerosols or direct contact with oral secretions

Risk Factors: close contact with infected people or areas of outbreak

Symptoms: same as S.pneumo
Term
Haemophlilus influenzae Type B: Clinical ID
Definition
Shape: G(-) pleiomorphic coccobacilli

Growth:
-Fastidious (requires factor V and X)
-Facultative anaerobe

Capsule:
-Encapsulated (typeable), OR non-encapsulated (non-typeable)
Term
Haemophlilus influenzae Type B: Vaccine?
Definition
Yes

Hib Vaccine: against serotype B specifically

Note: protective Abs against Hib would develop naturally by age 5, but vaccine protects before this time
Term
Mycobacterium tuberculosis: Infection and Population Affected
Definition
Chronic Bacterial Meningitis

Rare
Usually people who are immunosuppressed
Term
Mycobacterium tuberculosis: Virulence Factors
Definition
Infection Process: -Enter host (droplet inhalation) and infect lung macrophages, forming a granuloma (primary lesion) -Disseminates to LNs, causes short bacteremia that can lead to CNS infection -Tubercle forms at meninges -> Meningitis -> CSF blockage -> Nerve/Blood vessel damage
Term
Mycobacterium tuberculosis: Etiology/Pathogenesis
Definition
Acquisition: aerosol spread or reactivation of latent disease

Risk Factors:
-Previous TB infection
-Immunosuppression
-Travel to endemic areas
Term
Mycobacterium tuberculosis: Clinical ID
Definition
--
Term
Mycobacterium tuberculosis: Vaccine?
Definition
Yes, but not regularly used in the US
Term
Streptococcus agalactiae (Group B Strep): Congenital(Fetal), Perinatal, and/or Postnatal Infection?
Definition
Neonatal Meningitis: Perinatal and Postnatal

Perinatal:
-Ascending route in utero through ruptured membranes
-Contamination during pass through birth canal
Early onset disease
-Occurs within 7 days after birth
-~60% fatal with long term sequelae

Postnatal:
-Acquired after birth, often due to poor hygiene in nursery
Late onset disease
-Occurs 1 week to 3 months after birth
-Lower mortality rate, but still significant
Term
Streptococcus agalactiae (Group B Strep): Virulence Factors
Definition
Adherence

Polysaccharide Capsule: most important
-Antiphagocytic

Invasion:
-Turn off capsule
-Invade respiratory epithelium and brain endothelium (BBB)

Beta-hemolysin: cytotoxin for lung epithelium and brain endothelium
Term
Streptococcus agalactiae (Group B Strep): Pathogenesis
Definition
Leading cause of bacterial neonatal meningitis

Perinatal:
-Inhalation of infected amniotic fluid or vaginal secretions
-Presents as bacteremia, pneumonia or meningitis

Post natal:
-Presents mostly as meningitis
-More insidious onset
Term
Streptococcus agalactiae (Group B Strep): Diagnosis and Treatment
Definition
G(+) diplococcic or short chains
Lab Tests:
-Catalase (-)
-Beta-hemolytic

Perinatal:
-Intrapartum antibiotic prophylaxis (usually penicillin) to mother

Post-natal:
-Good hygiene practices in nursery

TREAT INFECTED INFANT ON SUSPICION!!
Term
E.coli K1: Congenital(Fetal), Perinatal, and/or Postnatal Infection?
Definition
Bacterial Meningitis: Perinatal and Postnatal

Perinatal:
-Ruptured amniotic membranes
-During delivery through birth canal

High mortality rate: survivors have long term sequelae
Term
E.coli K1: Virulence Factors
Definition
K1 Polysialic Capsule:
-Resistant to PMN killing
-Not necessary for BBB invasion

Invasins (IbeA, IbeB):
-Help cross BBB

Type O Ag LPS:
-Establish infection

S.Fimbriae:
-Establish infection
Term
E.coli K1: Pathogenesis
Definition
Another common cause of meningitis in neonates

Presentation:
-Septicemia: at birth or within 2 days of birth
-Meningitis: in infants more than 2 days old

Variable symptoms:
-Can be subtle
Term
E.coli K1: Diagnosis and Treatment
Definition
G(-) rod

TREAT INFECTED INFANT ON SUSPICION!!
Term
Listeria monocytogenes: Congenital(Fetal), Perinatal, and/or Postnatal Infection?
Definition
Bacterial Meningitis: Congital(Fetal), Perinatal, and Postnatal

Perinatal:
-Listeriosis contracted during delivery usually localized to CNS (meningitis)
Term
Listeria monocytogenes: Virulence Factors
Definition
Intracellular: infects many cell types and evades immune system

Internalins: cell evasion

Listeriolysin O: escape from host vacuoles

ActA: actin motility for cell-to-cell spread
Term
Listeria monocytogenes: Pathogenesis
Definition
Transmission to Mother: primarily food borne

Immunocompromised at risk: macrophage and T cell response to infection normally

Tropism for fetus and placenta: if born alive, septicemia begins within hours
Term
Listeria monocytogenes: Diagnosis and Treatment
Definition
G(+) rod

Growth: can grow in the refrigerator
Term
Toxoplasma gondii: Congenital(Fetal), Perinatal, and/or Postnatal Infection?
Definition
Both neonatal meningitis and encephalitis

Only Congenital (Fetal):
-Transplacental transmission
-Most are asymptomatic at birth

Infection is more severe if acquired earlier in pregnancy:
-Transmission less likely at this time (more likely later, which causes less severe disease)
Term
Toxoplasma gondii: Virulence Factors
Definition
Life cycle: environmentally resistant; can persist in host as tissue cysts

Actin-based motor: has its own actin ; used for invasion

Modification of host vacuole: release proteins that prevent fusion with lysosome
Term
Toxoplasma gondii: Pathogenesis
Definition
Ingest oocyst:
-Tachyzoite enters macrophages, which transport to all organ systems
Formation of tissue cysts: can last a lifetime

Can only occur if the mother is infected for the FIRST time during pregnancy: often asymptomatic
Term
Toxoplasma gondii: Diagnosis and Treatment
Definition
Obligate intracellular parasite (protozoan)

Prevention during pregnancy:
-Don’t change litter box
-Avoid uncooked meat
-Wash hands well after handling raw meat
-Spiramycin: may be given to reduce risk of fetal infection
Term
Campylobacteri jejuni: Virulence Factors
Definition
Low ID: ~800 organisms

Chemotaxis, motility, flagella: attachment and colonization of gut epithelium

Virulence Determinants (after colonization):
-Iron acquisition
-Host cell invasion
-Toxin production
-Epithelial disruption
Term
Campylobacteri jejuni: Etiology/Pathogenesis
Definition
Post-Infectious Syndrome

Acquisition: contaminated food (esp. chicken)

Symptoms:
-Food poisoning
-Acute paralysis (GBS)

Guillan Barre Syndrome:
-Demyelination of peripheral nerves
-Cross reactivity between microbial LPS and human gangliosides
Term
Campylobacteri jejuni: Clinical ID
Definition
Shape: G(-) curved rod

Growth:
-42 degrees C (chicken temperature)
-Microaerophilic

Motility: darting
Term
Polymicrobial Abscesses: Causative Agents
Definition
Most polymicrobial: often anaerobes

Gram(+):
-Streptococcus* (most common)
-Peptostreptococcus
-Staphylococcus
-Nocardia
-Actinomyces

Gram(-):
-Bacteroides
-Preveotella
-Fusobacterium
-E.coli
-Citrobacter koseri
-Proteus mirabilis

AIDS Patients:
-Toxoplasma gondii
-Cryptococcus
Term
Polymicrobial Abscesses: Etiology/Pathogenesis
Definition
Acquisition: usually normal flora, and usually a sequelae local or remote infections (do not arise de novo)

Risk Factors:
-Immunocompromise
-Head injury (skull fracture)
-Congenital heart disease in kids
-Distal infections (heart, lungs, kidneys etc.)
-Local infections (otitis media, dental abscesses, sinusitis)

Space occupying lesion that compresses normal structures:
-Headache
-Drowsiness
-Confusion
-Hemiparesis
-Seizures
-Speech difficulties
-Fever
-*NO STIFF NECK*
Term
Polymicrobial Abscesses: Clinical ID
Definition
CT scan: do this prior to lumbar puncture (faster, need to detect quickly due to risk of brain herniation)
-Fibrous capsule: can be seen around abscess on CT after 4-5 days
Term
Cryptococcus neoformans: Virulence Factors
Definition
Latent Infection: primary respiratory infection; usually asymptomatic; can lead to a latent infection (reactivated in immunocompromise  CNS)

Capsule: antiphagocytic, prevents complement and Ab deposition

Melanin: protects against oxidative defenses of MØ

Phopholipase B: degrades host phospholipids; aids in tissue destruction and cellular escape

Urease
Term
Cryptococcus neoformans: Etiology/Pathogenesis
Definition
Fungal Infections: Chronic Meningoencephalitis

Acquisition: inhalation

Source: pigeon excreta and rotting wood

Risk Factors: Immunosuppression

Can cause meningitis and/or encephalitis: see symptoms
Term
Cryptococcus neoformans: Clinical ID
Definition
Staining:
-G(+) yeast
-India ink (+): capsule
-Calcofluor white (+): fungus

Biochemical:
-Urease (+)

Detection of capsular Ag:
-CSF or serum
Term
Coccidiodes imitis (Valley Fever): Etiology/Pathogenesis
Definition
Fungal Infections: Chronic Meningoencephalitis

Acquisition: inhalation

Source: endemic to SW US; no person to person spread

Risk Factors: dispersion of athroconidia
-Dust storms
-Earthquakes
-Earth excavations

Pathogenesis:
-Formation of spherules in the lungs
- Usually an acute respiratory infection that resolves rapidly (flu-like symptoms)
-Can cause chronic infection and dissemination to bones, meninges, joints, subcutaneous and cutaneous tissues (1% of cases disseminate to CNS)
Term
Coccidiodes imitis (Valley Fever): Clinical ID
Definition
Dimorphic:
-Mold at 25 degrees
-Spherules at 37 degrees

Endospores: seen in tissues
Term
Histoplasma capsulatum (Histoplasmosis): Etiology/Pathogenesis
Definition
Fungal Infections: Chronic Meningoencephalitis


Acquisition: inhalation of macroconidia from soil

Source: bird and bat guano (central and southern US)

Risk Factors:
-Immunosuppression
-Age (<2, elderly)
-Exposure to large inoculum

Pathogenesis: usually subclinical infection in normal hosts
-Can disseminate in immunocompromise
-Cause of both chronic meningitis or encephalitis (both can be fatal)
Term
Trypanosoma cruzi (Chagas Disease): Etiology/Pathogenesis
Definition
Parasitic Infections: Acute Encephalitis

Acquisition: infected Triatome bug bite

Distribution: southern US to southern Argentina

Risk Factors:
-Infants
-Travel to endemic areas

Symptoms:
-Initial sore where bite occurred
-Fever
-Acute encephalitis
-Chronic disease possible (affecting heart, colon or CNS)
Term
Plasmodium falciparum (Malaria): Etiology/Pathogenesis
Definition
Parasitic Infections: Cerebral Malaria

Acquisition: bite from infected female Anopheles mosquito (spreads from human to human)

Site of Infection: liver and RBCs
-Infects liver first (multiplies here the leaves)
-Infects RBCs second (lyse, release merozoites that infect other RBCs and continue cycle)

Risk Factors:
-Age (<10)
-Exposure to endemic areas

Symptoms of Cerebral Malaria (CM):
-Widespread disease of the brain
-Recurrent episodes of malarial fever (fever, chills, anemia)
-If not treated, fatal quickly (24-72 hours)
Term
Plasmodium falciparum (Malaria): Virulence Factors
Definition
Life Cycle:
-Mosquitos pick up gametocytes when they bite infected humans (not affected by diseae)
-Sporozoites form in salivary glands of mosquito, and they can transfer to the next human they bite
-Sporozoites injected by mosquito, and multiply in liver and then RBCs
Term
Toxoplasma gondii: Etiology/Pathogenesis
Definition
Parasitic Infections: Encephalitis

Primary Infection: flu-like symptoms

Progression:
-Encephalitis
-Psychotic symptoms (similar to schizophrenia)
Term
Poliovirus (Enterovirus): Disease Caused and Viral Family Characteristics
Definition
Poliomyelitis

Picornaviridae

Genome: +ssRNA
Structure: unenveloped icosahedral
Replication: cytoplasm
Single polypeptide: divided into 3 regions (P1, P2, P3)
Mature virion release: lysis

Important Functions:
Shuts off host cell genes without affecting synthesis of their own proteins (cleave cellular eIF-4G)
Term
Poliovirus (Enterovirus): Etiology/Pathogenesis
Definition
Most cases caused by Type 1 Poliovirus: only 1% of infections progress to poliomyelitis

Transmission: fecal-oral

Host Attachment: attaches to Pvr

Pathogenesis: flaccid paralysis (destruction of motor neurons in anterior horn of spinal cord)
Term
Poliovirus (Enterovirus): Treatment/Prevention/Other
Definition
Vaccine:
-IPV/Salk: inactivated with less GI immunity
-Sabin/OPV: live attenuated with risk of reversion

Eradication should be possible:
-Vaccination
-Humans only reservoirs
Term
Coxsackie Virus A/B (Enterovirus): Disease Caused and Viral Family Characteristics
Definition
Herpangina, Aseptic Meningitis: Hand, Foot and Mouth Disease

Picornaviridae

Genome: +ssRNA
Structure: unenveloped icosahedral
Replication: cytoplasm
Single polypeptide: divided into 3 regions (P1, P2, P3)
Mature virion release: lysis

Important Functions:
Shuts off host cell genes without affecting synthesis of their own proteins (cleave cellular eIF-4G)
Term
Coxsackie Virus A/B (Enterovirus): Etiology/Pathogenesis
Definition
At risk population: children

Transmission: fecal-oral

Host Attachment: may require co-receptor

Group A:
-Aseptic meningitis (headache, stiff neck, fever)
-Herpangina (ulcers on tonsils and palate)
-Hand-foot-mouth disease (A16)

Group B:
-Aseptic meningitis (headache, stiff neck, fever)
Term
HIV-1: Disease Caused and Viral Family
Definition
General Neurological Complications of AIDS: (HIV Associated Dementia)

Retroviridae
Term
HIV-1: Etiology/Pathogenesis
Definition
Cell Tropism:
-T cell tropic
-MØ tropic
-Neurotropic (still unclear)
Term
HIV-1: Treatment/Prevention/Other
Definition
HAART: highly active retroviral treatment; does not provide full protection against neurological damage in AIDS (BBB only partially permeable to anti-retroviral drugs)
Term
HTLV-1 (Oncoviridae): Disease Caused and Viral Family
Definition
Adult T cell Leukemia
Tropical Spastic Parapresis (Neurological Disease)

Retroviridae
Term
HTLV-1 (Oncoviridae): Etiology/Pathogenesis
Definition
Prevalent Areas: SW Japan, Carribean, S. America, Central and West Africa

Transmission: breast-feeding, sex, blood transfusion, IV drug use
Term
HTLV-1 (Oncoviridae): Treatment/Prevention/Other
Definition
No specific /effective Tx:
-IFN-alpha + Zidovudine
-Chemotherapy
-Zidovudine + Danazol + Vit. C (temporary relief from TSP)
Term
West Nile Virus: Viral Family Characteristics
Definition
Flaviridae (Arbovirus)
Flavivirus
5’ methylated cap
No 3’ tail


Genome: linear +ssRNA
Structure: enveloped icosahedral
Replication: cytoplasm
Mature virion release: exocytosis
Term
West Nile Virus: Etiology/Pathogenesis
Definition
Reservoir: bids
Vector: mosquitoes, ticks
Infects: humans, horses, bats, squirrels, domestic rabbits

Human Pathogenesis: abrupt onset flu-like illness
-Moderate to high fever
-Headache
-Sore throat
-Back ache and myalgias
-Fatigue
-Rash
-Lymphadenopathy
-Acute aseptic meningitis OR encephalitis
Term
West Nile Virus: Treatment/Prevention/Other
Definition
Vaccine: no

Treatment: Ribavirin

Prevention: mosquito control
Term
Yellow Fever: Viral Family Characteristics
Definition
Flaviridae (Arbovirus)
Flavivirus
5’ methylated cap
No 3’ tail


Genome: linear +ssRNA
Structure: enveloped icosahedral
Replication: cytoplasm
Mature virion release: exocytosis
Term
Yellow Fever: Etiology/Pathogenesis
Definition
Symptoms:
-High fever and chills
-Headache
-Vomiting
-Jaundice
-Hemorrhagic complications
-Renal failure
Term
Yellow Fever: Treatment/Prevention/Other
Definition
Vaccine: yes

Prevention: mosquito control
Term
Dengue Hemorrhagic Fever (DHF)
Dengue Shock Syndrome (DSS): Viral Family Characteristics
Definition
Flaviridae (Arbovirus)
Flavivirus
5’ methylated cap
No 3’ tail


Genome: linear +ssRNA
Structure: enveloped icosahedral
Replication: cytoplasm
Mature virion release: exocytosis
Term
Dengue Hemorrhagic Fever (DHF)
Dengue Shock Syndrome (DSS): Etiology/Pathogenesis
Definition
Most prevalent: low mortality rate

Transmission: person to person via mosquitoes

Four serotypes: can lead to Ab Dependent Enhancement of virus (ADE)

Symptoms:
-Fever
-Headache
-Lumbosacral pain
Term
Dengue Hemorrhagic Fever (DHF)
Dengue Shock Syndrome (DSS): Treatment/Prevention/Other
Definition
Prevention: mosquito control

ADE:
-Abs to one serotype are unable to neutralize other serotypes
-Virus + non-neutralizing Ab form infectious immune complex that is easily taken up into MØ
-Enhances viral infection
Term
St.Louis Encephalitis: Viral Family Characteristics
Definition
Flaviridae (Arbovirus)
Flavivirus
5’ methylated cap
No 3’ tail


Genome: linear +ssRNA
Structure: enveloped icosahedral
Replication: cytoplasm
Mature virion release: exocytosis
Term
St.Louis Encephalitis: Etiology/Pathogenesis
Definition
Reservoir: birds
Transmission: mosquito

Symptoms:
-Simple febrile headache  meningoencephalitis
-Mild in children
-Elderly at high risk for severe disease
Term
St.Louis Encephalitis: Treatment/Prevention/Other
Definition
One of the leading causes of flaviviral encephalitis in the US
Term
Hepatitis C: Viral Family Characteristics
Definition
Flaviridae (Arbovirus)
Hepacivirus
No 5’ cap (IRES)
No 3’ tail

Genome: linear +ssRNA
Structure: enveloped icosahedral
Replication: cytoplasm
Mature virion release: exocytosis
Term
Hepatitis C: Etiology/Pathogenesis
Definition
Inflammation of the liver: can lead to cirrhosis

Transmission: blood and secretions
Term
Hepatitis C: Treatment/Prevention/Other
Definition
IFN + Ribavirin
Term
Togavirus: Disease Caused and Viral Family Characteristics
Definition
Eastern Equine Encephalitis (EEE)

Togaviridae (Arbovirus)

Genome: linear +ssRNA
Structure: enveloped icosahedral
Replication: cytoplasm
Term
Togavirus: Etiology/Pathogenesis
Definition
Reservoir: marsh birds

Transmission: infected mosquito

Infects: humans, horses, birds, quail and ostriches
Symptoms:
-Fever
-Myalgias
-Severe headache
-Permanent brain damage
-Seizures
-Coma
Term
Togavirus: Treatment/Prevention/Other
Definition
Very rare but very fatal

Pathology: small hemorrhages in the brain and extensive neural damage
Term
Rhabdovirus: Disease Caused and Viral Family Characteristics
Definition
Rabies

Rhabdoviridae (Zoonotic)

Genome: -ssRNA (has RNA dependent viral RNA transcriptase)
Structure: bullet shaped (external glycoprotein coat and peripheral matrix protein)
Replication: cytoplasm
Term
Rhabdovirus: Etiology/Pathogenesis
Definition
Transmission: animal bite (infected saliva)
Incubation Period: up to 12 months
Spread: quickly advances to the PNS (submaxillary salivary glands) and the CNS

Early Symptoms:
-Non-specific flu like symptoms
-Headache
-Difficulty swallowing
-Hydrophobia
Late Symptoms:
-Cerebral dysfunction
-Anxiety and confusion
-Agitation
-Hallucinations
-Insomnia
Term
Rhabdovirus: Treatment/Prevention/Other
Definition
Pathology: cytoplasmic eosinophilic inclusion bodies (Negri bodies) in neuronal cells
-Pyramidal cells of hippocampus
-Neurons of cortex
-Outer regions of CNS (ie. spinal ganglia)

Diagnosis: no test to rule out with certainty
-Fluorescent Ab assay is standard

NO TREATMENT ONCE SYMPTOMS OF DISEASE APPEAR!!

Vaccine: pre-exposure for high risk groups (ie. veterinarians)
Post-Exposure:
-Local wound tx (wash thoroughly)
-Passive immunization (HRIG)
-Vaccination (HDCV)

Prevention: vaccinate wild and domestic animals
Term
Herpes Simplex Virus: Disease Caused and Viral Family Characteristics
Definition
HSV Encephalitis

Herpesviridae
DNA Virus
Term
Herpes Simplex Virus: Etiology/Pathogenesis
Definition
Most common form of sporadic fatal encephalitis in adults: mortality is especially high if not treated

Pathogenesis: focal encephalopathy, most often affecting the temporal lobe

Symptoms:
-Fever
-Altered consciousness and behavior
-Severe headache
-Disordered thinking
-LOC
Term
Herpes Simplex Virus: Treatment/Prevention/Other
Definition
Treatment: acyclovir (and others)

Note: while treatment reduces mortality, many people still have long term sequelae
Term
Herpes B Virus (Monkey Virus): Disease Caused and Viral Family Characteristics
Definition
Fatal Encephalitis

Herpesviridae
DNA Virus
Term
Herpes B Virus (Monkey Virus): Etiology/Pathogenesis
Definition
Transmission: infected secretions from animal (bite or contact with mucous membranes)
Highly pathogenic in humans: frequently fatal
Term
Herpes B Virus (Monkey Virus): Treatment/Prevention/Other
Definition
Treatment: high dose acyclovir or ganciclovir
Long-term sequelae
Term
Varicella-Zoster Virus: Disease Caused and Viral Family Characteristics
Definition
Varies by infection

Herpesviridae
DNA Virus
Term
Varicella-Zoster Virus: Etiology/Pathogenesis
Definition
Varicella (Chickenpox):
-Encephalitis (most common, but still rare)
-Transient cerebella ataxia (usually self-limiting)
-Aseptic meningitis
-Transverse myelitis (infection of the spinal cord)

Zoster:
-Encephalitis

Congenital Varicella:
-Mental retardation
-Cerebral atrophy
-Other non-CNS abnormalities
Term
Cytomegalovirus: Disease Caused and Viral Family Characteristics
Definition
Congenital CMV

Herpesviridae
DNA Virus
Term
Cytomegalovirus: Etiology/Pathogenesis
Definition
Transmission: transplacental (during primary infection in mother)

If Symptomatic at Birth (~10%):
-Intrauterine growth retardation
-Hepatosplenomegaly
-Microcephaly (w/ long term neurological issues)
-Long term sequelae (MR, seizures, blindness, deafness)

Asymptomatic at Birth: still at risk for developing hearing, vision, and intellectual problems
Term
John Cunningham Virus (JCV): Viral Family Characteristics
Definition
Human Polyomavirus

Papoviridae

Genome: circular dsDNA
Structure: undeveloped icosahedral
Replication: nucleus (highly dependent on cellular enzymes for DNA replication/gene expression)
Term
John Cunningham Virus (JCV): Etiology/Pathogenesis
Definition
Usually asymptomatic: may cause mild URI

Progressive Multifocal Leukoencephalopathy: in immunocompromise
Pathogenesis: loss of myelin due to viral replication in oligodendroytes
-Cerebrum (subcortical regions- deep white matter)
-Cerebellum or brainstem (less common)
Initial Symptoms:
-Indicate focal cerebral involvement (personality changes, loss of motor skills, sensory loss)
-Less frequently, cerebellar or brainstem involvement (difficulty speaking, swallowing, ataxia)
Rapid Progression: death in 2-12 months
**Little to no inflammation**
Term
John Cunningham Virus (JCV): Treatment/Prevention/Other
Definition
Treatment: none
-Rare remission only if immunocompromise is corrected

Diagnosis:
-Suspect in immunocompromise with progressive neurological deficits
-CT/MRI (lesions)
-PCR (JCV in CSF)
-Brain biopsy (rule out other infections that imitate PML)
Term
BK Virus: Viral Family Characteristics
Definition
Human Polyomavirus

Papoviridae

Genome: circular dsDNA
Structure: undeveloped icosahedral
Replication: nucleus (highly dependent on cellular enzymes for DNA replication/gene expression)
Term
BK Virus: Etiology/Pathogenesis
Definition
Usually asymptomatic: may cause mild URI
Associated with a few diseases:
-Nephropathy in renal transplant patients
-Hemorrhagic cystitis in BM transplant patients
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