Negative stranded RNA Flashcards
Lyssavirus (Rabies)
Bullet shaped
Bite or scratch
Symptoms appear -> 100% death
Replicates in muscle, NM junctions, replicates neuronally, CNS spread (symptoms appear)
Prodromal: malaise, fever, ha, myalgia, fatigue, emotional lability
Fulminate: hydrophobia, seizures, hallucinations, aggression/lucidity, spasms, excessive salvia, paralysis, death
Viral Ag in skin immunofluorescent detection, PCR
Human rabies immune globulin, immunization
Purified inactivated vaccine (5 injections)
Negative stranded RNA
ss
Helical capsid
Enveloped
Morbilli Virus
Measles
Non segmented
Spherical shape
F protein: fusion
HN protein: hemagglutinating/neurominidase
Resp droplets
Winter/spring
Highly contagious
Mucosal epithelium, to lymph nodes, primary viremia, asymptomatic
Lymphoid hyperplasia, multinucleated giant cells, secondary viremia
Most infectious at end of prodrome, rash starts
Prodrome of cough, coryza, conjunctivitis, fever, Koplik’s spots (bright red, blue/white peak)
Rash: macular, blotchy, starts around ears forehead and neck spreads
Encephalomyelitis: 3-4d after recovery seizure coma death
Subacute sclerosing panencephalitis: personality and gait changes, focal neuro deficits
Supportive care, post exposure immunization
Live attenuated vaccine
Parainfluenza/Paramyxovirus
Croup Non segmented Spherical shape F protein: fusion HN protein: hemagglutination/neurominidase Droplets, direct contact Resp infection in children PIV 1/2 causes croup Barking cough, stridor, wheezing, rhinitis No long lasting immunity Supportive care, cool mist therapy
Pneumovirus
RSV
Non segmented
No HN protein
Droplets, nosocomial spread, very contagious
Acute fatal resp tract infections in infants/2yo
Young get severe illness
Broncholitis: plugs small airways
PNA: most common cause in infants/children, labored breathing
Can later develop asthma, wheezing
Rubulavirus
Mumps Non segmented, spherical shape F and HN proteins Close contact, salvia Viremia, glandular/nervous tissue Infection of parotid gland Self limiting Orchitis: testicular inflammation, oophoritis Supportive care Live attenuated vaccine
Influenza A/B
Flu
Type, animal, place, strain, year
Antigenic shift and drift
H1N1, H2N2, H3N2
Epidemic indicator: excess death of elderly
Jan-March
Resp droplets
Abrupt onset of high fever, severe ha, myalgia, sore throat, non productive cough, NO coryza
4d incubation, no viremia, PNA common, otitis media (strep pneumo)
Reye’s syndrome: rare complication of B flu
Rapid Zsstat test, nasal/threat swab (NA activity)
Supportive care, no aspirin
Neurominidase inhibitors: Zanamivir, Oseltamivir (within 2d of sx onset)
Vaccines: trivalent inactivated (killed) 2 A and 1 B
LAIV: live attenuated, better immunity, some sx
Antigenic shift
differences in their HA molecules, also in NA molecules
Influenza A only
Antigenic drift
Changes in aa sequence over time
Hypervariable regions
Changes in antigenic sites causes outbreaks
Hemagglutination
Attachment/ enter cell
Neurominidase
Liquefies mucosa, allows hemagglutinatinin to initiate infection
Reassortment
Exchange of RNA segments between subtypes
Filoviridae
Ebola, Marburg, Reston Hook shape, filamentous Bush meat/monkeys/bats So lethal it eliminates population before spread Multiple organ failures Endothelial alterations -> bleeding Extensive necrosis Pro-inflammatory cytokine release -> shock-like sx -> high fluid release Platelets become dysfunctional Worse with Ab response Hemorrhagic fever 1d: abrupt fever, arthalgia, ha, myalgia 2-3d: sore throat, vomit 5d: profuse bleeding from mucosa 90% mortality Strict isolation, immunofluoresence Supportive care
Hantavirus
Segmented (3) Inhaled rodent feces (deer mouse) Hantavirus Pulmonary Syndrome: acute fever, myalgia, ha, cough -> rapid resp failure with pulmonary edema, hypotension and shock Not as dense on X-ray as PNA SW USA Supportive care
Hepatitis D Virus
RNA has its own ribozyme
Uses HBV envelope
Greatest risk in sex transmission and IV drug users
Acute is self limiting
Chronic is superinfection and changes to chronic active hepatitis
Anti-HDV IgM in acute infections
Vaccination with HBV vaccine
