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
|
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
|
|
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 |
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Term
| Varicella-Zoster Virus: Disease Caused and Viral Family Characteristics |
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Definition
Varies by infection
Herpesviridae
DNA Virus |
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Term
| Varicella-Zoster Virus: Etiology/Pathogenesis |
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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 |
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Term
| Cytomegalovirus: Disease Caused and Viral Family Characteristics |
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Definition
Congenital CMV
Herpesviridae
DNA Virus |
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Term
| Cytomegalovirus: Etiology/Pathogenesis |
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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 |
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Term
| John Cunningham Virus (JCV): Viral Family Characteristics |
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Definition
Human Polyomavirus
Papoviridae
Genome: circular dsDNA
Structure: undeveloped icosahedral
Replication: nucleus (highly dependent on cellular enzymes for DNA replication/gene expression) |
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Term
| John Cunningham Virus (JCV): Etiology/Pathogenesis |
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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** |
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Term
| John Cunningham Virus (JCV): Treatment/Prevention/Other |
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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) |
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Term
| BK Virus: Viral Family Characteristics |
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Definition
Human Polyomavirus
Papoviridae
Genome: circular dsDNA
Structure: undeveloped icosahedral
Replication: nucleus (highly dependent on cellular enzymes for DNA replication/gene expression) |
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Term
| BK Virus: Etiology/Pathogenesis |
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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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