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29 Cards in this Set
- Front
- Back
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live vaccines vs. killed vs. recombinant
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LIVE-ATTENUATED vaccines
- induce humoral and cell-mediated immunity - have reverted to virulence on rare occasions - measles, mumps, rubella, Sabin polio, VZV, yellow fever, smallpox KILLED vaccines - induce only humoral immunity but are stable - Rabies, Influenza, Salk Polio (salK Killed), HAV RECOMBINANT vaccines - HBV NOTE: It's dangerous to give vaccines to the immunocompromised or their close contacts |
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Recombination
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exchange of genes b/t 2 chromosomes by CROSSING OVER within regions of significant base sequence homology
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Reassortment
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when viruses with segmented genomes (eg - influenza virus) exchange segments
- high frequency recombination - cause worldwide influenza pandemics |
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complementation
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when 1 of 2 viruses that infect the cell has a mutation that results in a nonfunctional protein
- nonmutated virus "complements" the mutated one by making a functional protein that serves both viruses |
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phenotypic mixing
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occurs with simultaneous infection of a cell with 2 viruses
- genome of virus A can be partially or completely coated (forming pseudovirus) with the surface proteins of virus B - type B protein coat determines the infectivity of the phenotypically mixed virus - however, the progeny from this infection have type A coat that is encoaded by its type A genetic material |
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Negative stranded viruses
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- must transcribe negative strand to positive strand using RNA POLYMERASE
"Always Bring Polymerase Or Fail Replication Horribly" - Arenaviruses - Bunyaviruses - Paramyxoviruses - Orthomyxoviruses - Filoviruses - Rhabdoviruses - Hepatitis delta virus |
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Segmented viruses
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- all are RNA viruses
- Bunyaviruses - Orthomyxoviruses (influenza) - Arenaviruses - Reoviruses (like Rotavirus) Influenza virus - 8 segments of negatively-stranded RNA - these segments can undergo reassortment, causing antigenic shifts that lead to worldwide pandemics of the flu |
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HSV-1
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gingivostomatitis
keratoconjunctivitis temporal lobe encephalitis herpes labialis transmitted via respiratory secretions and saliva |
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HSV-2
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herpes genitalis
neonatal herpes transmitted by sexual contact, perinatal |
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VZV
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varicella-zoster (shingles)
encephalitis pneumonia transmitted by respiratory secretions |
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EBV
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infectious mononucleosis (positive Monospot)
Burkitt's lymphoma transmitted via respiratory secretions, saliva |
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CMV
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congenital infection
mononucleosis (negative Monospot) pneumonia infected cells have characteristic "owl's eye" appearance transmission congenital, transfusion, sexual contact, saliva, urine, transplant |
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HHV-8
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Kaposi's sarcoma (HIV pt)
sexual contact |
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identifying HSV infection
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Tzank Test
- a smear of an opened skin vesicle to detect multinucleated giant cells - used to assay for HSV-1, HSV-2, VZV infected cells also have intranuclear COWDRY A INCLUSIONS "Tzank heavens I don't have Herpes" |
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EBV
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- a herpesvirus
- can cause mono - infects B cells - characterized by fever hepatosplenomegaly pharyngitis lymphadenopathy (esp. in post auricular nodes) peak incidence age 15-20 + heterophile Ab test abnormal circulating cytotoxic T cells Associated with development of Hodgkin's lymphoma and endemic Burkitt's lymphoma also nasopharyngeal carcinoma Monospot test - heterophil Abs are detected by agglutination of sheep RBCs |
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Picornavirus
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PECoRNA
- Poliovirus - Echovirus - Coxsackievirus - Rhinovirus - NOTHING - HAV RNA is translated into 1 large polypeptide that is cleaved by proteases into functional viral proteins - can cause aseptic (viral) meningitis) |
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Rhinovirus
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a picornavirus
- non-enveloped RNA virus - most common cause of COMMON COLD - >100 serotypes |
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yellow fever virus
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a flavivirus
- (also an orbovirus) - transmitted by Aedes mosquitos - virus has a monkey or human reservoir Sx's: - high fever - black vomitus - jaundice - Councilman bodies (acidophilic inclusions) may be seen in liver Flavi - yellow |
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Rubella virus
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a TOGAVIRUS
- causes German (3-day) measles - Fever, lymphadenopathy, arthralgies, fine truncal rash - causes mild disease in children but serous congenital disease (a TORCH infection!) |
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Rotavirus
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THE MOST IMPORTANT GLOBAL CAUSE OF INFANTILE GASTROENTERITIS
- a segmented dsRNA virus (a reovirus) - major cause of acute diarrhea in US during winter - villous destruction with atrophy leads to decreased absorption of Na+ and water |
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Influenza viruses
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orthomyxoviruses
- enveloped, single stranded - RNA viruses with segmented genome - contains HEMAGLUTTININ (H) antigen - contains NEURAMINIDASE (N) antigen - responsible for fatal bacterial superinfection - rapid genetic changes - killed viral vaccine is major mode of protection - reformulated vaccine offered each fall to elderly, healthcare workers, etc. |
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genetic shift
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pandemic
reassortment of viral genome - such as when human flu A virus recombines with swine flu A virus Sudden Shift is more deadly than graDual Drift!!! |
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genetic drift
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epidemic
minor (antigenic drift) changes based on random mutation |
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treatment of influenza
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Amantadine and rimantadine
- for Influenza A - hight level of resistance to these drugs, no longer used Zanamivir and oseltamivir (neuraminidase inhibitors) - useful for influenza A and B |
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Parmyxoviruses
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disease in chidren
- parainfluenza (croup) - mumps - measles - RSV - which cuases respiratory tract infection (bronchilitis, pneumonia) in infants |
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Rubeola (measles) virus
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a paramyxovirus that causes measles
- Koplik spots (red spots with blue-white center on buccal mucosa) are diagnostic - SSPE (years later) - encephalitis - giant cell pneumonia - rash spreads head to toe 3 C's of measles - coryza - cough - conjunctivitis - K(c) oplik spots |
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Mumps
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a paramyxovirus
sx's: - parotitis - orchitis (inflammation of testes) - aseptic Meningitis - can cause sterility (especially after puberty) Mumps makes your parotid glands and testes as big as POM-poms |
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Rabies virus
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- Negri bodies - characteristic cytoplasmic inclusions in neurons infected by rabies virus
- bullet-shaped capsid - long incubation period (weeks-months) - causes fatal encephalitis with seizures, hydrophobia, hypersalivation and pharyngeal spasm - most commonly from bat, racoon, and skunk bites - moreso than dog bites in US - travels to CNS by migrating in retrograde fashion up nerve axons |
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Arbovruses
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- transmitted by arthropods (mosquitos, ticks)
- classic examples are dengue fever (aka break-bone fever) - yellow fever - variant of dengue fever in SE asia is hemorrhagic shock syndrome - arthropod-borne virus, including some members of Flavivirus, Togavirus, Bunyavirus Fever Transmitted by Bites |
