Pathogenic Viruses Flashcards
Polio virus
Picornavirus Enterovirus Non-Envelope (+) SS-RNA Fecal-Oral transmission Vaccine available IPV and OPV GI colonization and transcytosis to nerve cells Bulbar poliomyelitis - paralyzes respiratory muscles
Coxsackie A virus
Picornavirus Enterovirus Non-Envelope (+) SS-RNA Fecal-Oral very stable Highly infectious w high shed Hand Foot and Mouth Disease Aseptic Meningitis Herpangina (mouth blisters)
Coxsackie B virus
Coxsackie B virus
Stable
Infectious w/ high shed
Myocarditis
Pleurodynia/”Bornholm Disease”
Unilateral Chest pain targets intercostals
Possible role in Juvenile DM and Chronic Fatigue
No vaccine
No Anti-Viral
diagnosis by Ab titers and RNA PCR for CSF
ECHO virus
Picornavirus Enterovirus Non-Envelope (+) SS-RNA 32 serotypes Causes Rashes Leading cause of aseptic meningitis No Vaccine No Antivirals
Rotavirus
Reoviridae non-envelope DS-RNA x10 RDRP dependent Very stable Fecal oral, High shed Main cause 0-18 mo gastroE Seasonal winter peak 2 day incubation treat symptomatically Vaccine available "Rotarix" live-attenuated oral
Norwalk Virus
Caliciviridae Norovirus (+) SS-RNA Non-Envelope Gastroenteritis
Enterovirus EV70
Picornavirus Enterovirus Non-Envelope (+) SS-RNA Acute Hemorrhagic Conjunctivitis
EV 71
Picornavirus Enterovirus Non-Envelope (+) SS-RNA Hand Foot Mouth Disease
EV72 / Hepatitis A
Picornavirus Enterovirus Non-Envelope (+) SS-RNA Hepatitis A
Rhinovirus
Picornavirus Enterovirus Non-Envelope (+) SS-RNA common cause of Common cold Not enteric pathway (Respiratory tract) pH 3 killed cold growth (33C) Aerosol droplet
Adenoviruses
Adenoviridae Non-Envelope DS-DNA Fecal-Oral, aerosol, direct infection of eyes remains in adenoids/tonsils -respiratory diseases -epidemic keratoconjunctivitis (pink eyes) - Gastroenteritis Winter and shoulder seasons Sarcoma in mice No vaccine No treatment
Astroviruses
Astroviridae Non-Enveloped Cubic Capsids (+)SS-RNA Gastroenteritis Fever, Nausea, vomiting, Malaise
Influenza
Orthomyxoviridae
3-Types (A,B,C)
(-) SS-RNA x 8 w/ separate nucleocapsids
Envelope
Aerosol droplet transmission
Glycoprotein antigens Hemagglutinin and Neuraminidase
destruction of ciliated epithelium of resp tract
Hemagglutinate RBCs
Fevers, Chills, Aches
young and old most susceptible;
not viremic dependent
Vaccine available - trivalent(2A,1B) killed or live-attenuated
treatment - neuraminadase inhibitors oseltamivir(Tamaflu) and zanamivir(Relenza)
Respiratory Syncytial Virus (RSV)
Paramyxoviradae (-) SS-RNA x1 Enveloped No vaccine No long term IgA immunity passive IVIg mAb for high risk infants (palivizumab) most common infant LRI; also in elderly aerosolized ribivirin; uncertain effacacy no vaccine
SARS
Coronaviridae Enveloped helical neucleocapsid (+) SS-RNA aerosol droplet transmission Lower Resp infection w/ subsequent pneumonia
MERS
Coronaviridae Enveloped helical neucleocapsid (+) SS-RNA aerosol droplet transmission Fever, cough, dyspnea Lower Resp infection w/ subsequent pneumonia 50% case-fatality ratio
Parvovirus
Non-Envelope
Icosahedral
SS-DNA; Linear
ex. B19 virus
Polyomavirus
Non-Envelope
Icosahedral
DS-DNA; Circular; Supercoiled
ex. JC Virus, BK virus
Papillomavirus
Non-Envelope
Icosahedral
DS-DNA; Circular; Supercoiled
ex. HPV
Adenovirus
Non-Envelope
Icosahedral
DS-DNA; Linear
ex. Adenovirus
Hepadnavirus
Envelope
Icosahedral
DS-DNA incomplete circular
ex. Hepatitis B
Herpesvirus
Envelope
Icosahedral
DS-DNA, Linear
ex. Herpes Simplex, varicella-zoster, cytomegalovirus, Epstein-Barr
Poxvirus
Envelope
Complex protein coat
DS-DNA; linear
ex, smallpox, molluscum contagiosum virus
Picornavirus
Non-Envelope
Icosahedral
(+)SS-RNA; nonsegmented
ex. poliovirus, rhinovirus, hepatitis A
Hepevirus
Non-Envelope
Icosahedral
(+)SS-RNA; non-segmented
Hepatitis E
Calcivirus
Non-Envelope
Icosahedral
(+)SS-RNA; non-segmented
ex. Norwalk viruses
Reovirus
Non-Envelope
Icosahedral
DS-RNA; Linear 10-11 segments
ex Rotavirus
Flavivirus
Envelope
Icosahedral
(+)SS-RNA; Linear
ex. yellow fever virus, dengue , West Nile virus, Hepatitis C
Togavirus
Envelope
Icosahedral
(+)SS-RNA; Linear
ex. Rubella virus
Retrovirus
Envelope
Icosahedral
(+)SS-RNA (2x identical strands)
ex. HIV, T-Cell leukemia virus
Orthomyxovirus
Enveloped
Helical Protein
(-)SS-RNA; x8 segments
ex. influenza virus
Paramyxovirus
Envelope Helical Protein (-) SS-RNA ex. Measles/ Mumps/Parainfluenza 1-4/RSV/ Croup Rx: Aerosol ribavirin
Rhabdovirus
Envelope
Helical
(-)SS-RNA
ex. rabies virus
Filovirus
Envelope
Helical
(-)SS-RNA
ex. ebola virus, marburg virus
Coronavirus
Enveloped
Helical
(-)SS-RNA
ex. Coronavirus, SARS, MERS
Arenavirus
Enveloped
Helical
(-)SS-RNA; 2x segments w/ cohesive ends
ex. lymphocytic choriomeningitis virus
Bunyvirus
Enveloped
Helical
(-)SS-RNA; 3x segemnts w cohesive ends
ex. hantavirus, California encephalitis virus
Deltavirus
Enveloped
Unknown Protein shape
(-)SS-RNA; circular
ex. Hepatitis Delta virus (Hep D)
Measles
Paramyxoviradae Enveloped 1x (-)SS-RNA Helical Nucleocapsid Hemagglutinate RBCs antigenically stable (1x RNA strand) 1 Serotype; Humans sole reservoir Most contagious disease known cyclic epidemics (every 3 years) Transmission by aerosol droplets infection via respiratory tract 14 days incubation Prodromal symptoms: - fever, runny nose, red eyes, - Koplik's Spots; red lesion w/ white center on buccal mucosa - Giant multinucleate cells maculopapular erythematous rash viremia essential for replication infection causes immun anergy for wks-mths Live attenuated w. MMR infection confers life long immunity (IgG)
Mumps
Paramyxoviradae Enveloped 1x (-)SS-RNA Helical Nucleocapsid 1 Serotype Antigenically related to parainfluenza antigenically stable (1x RNA strand) Incubation 18-21 days Transmitted by Aerosol droplets viremia essential for replication Hemagglutinate RBCs Parotid gland swelling (classic sign) Aseptic meningitis (common) Testicular, pancreatic, ovary swelling Live attenuated via MMR no antiviral therapy infection confers life long immunity (IgG)
Parainfluenza
Paramyxoviradae Enveloped 1x (-)SS-RNA Helical Nucleocapsid Local-non systemic infections Hemagglutinate RBCs Not viremic
JC Virus
Papovavirus Progressive Multifocal Leukoencephalopathy Only in immunocompromised quick progression blindness, dementia, coma, death
SSPE
Subacute Sclerosing Panencephalitis
helical nucleocapsid
prior measles infection
intelectual deteroration, psych disturb, slow decline, blindness, terminal paralysis
Hepatitis A Virus
Non-Enveloped (+)SS-RNA Icosahedral Picornavirus Fecal-Oral Spread Incubation 30days Sx: anorexia, nausea, fever, jaundice, elevated LFTs Killed Vaccination
Hepatitis B Virus
Hepadnavirus Circular DNA Icosahedral Enveloped Sexual/Blood product Tx perinatal infection RNA dependent RNA Polymerase Incubation 50-180 days (mean 70) HBeAG correlates strongly w/ infection Recombinant Subunit Vaccination Integrates into host genome
Hepatitis C Virus
Flavivirus (+)SS RNA Icosahedral Enveloped Sexual/Blood product transmission Incubation 60days 70-85% become chronic diagnosis by PCR Sx. Jaundice, cirrhosis, hepatocellular carcinoma Prodromal Sx: arthritis, rash No host genome integration
Hepatitis D
Enveloped (defective)
(-)SS-RNA
Requires HBV co-infection
Hepatitis E
Hepevirus Non-Envelope (+)SS-RNA Fecal-Oral Sx. acute fever, nausea, jaundice Developing nations
HSV-1 /HHV1
Alphaherpesvirinae
Large
Enveloped
Linear dsDNA
icosahedral
“Upstairs Herpes”, Cold sores, Herpetic Whitlow, Herpes gladitorium
Latent in Trigeminal Ganglia
Latent infections activated by fever, UV light, emotion etc.
80% seroprevalence in adults
Can cause encephalitis, periocular herpes, (Herpetic stromal keratitis, acute retinal necrosis, dendritic ulcer)
Rx w/ acyclovir
HSV-2 /HHV2
Alphaherpesvirinae Genital Herpes Herpes Simplex Virus-2 Large Enveloped Linear dsDNA icosahedral "Downstairs Herpes", Genital herpes Latent in Sensory Ganglia Latent infections activated by fever, UV light, emotion etc. 20% seroprevalence in adults Rx w/ acyclovir perinatal infections generally systemic and fatal
Varicella-Zoster /HHV3
Alphaherpesvirinae Chickenpox & Shingles/Zoster alpha herpes virus Large Enveloped Linear dsDNA icosahedral Latent in Sensory Ganglia
Cytomegalovirus
/HHV5
Betaherpesvirinae
Enveloped
Linear dsDNA
icosahedral
- Tx by close contact
- 3-12 wk incubation
- Sx. normally asymptomatic, Mononucleosis like syndrome but w/ negative heterophile test. Owl eye inclusion, large multinuclear cells, pneumoniapharyo-esophagitis and retinitis
- Cytomegalovirus TORCH infection, microcephalic, retardation, neuro-sensory deafness, jaundice, hepato/splenomegaly, anemia
Latent in monocytes
- no vaccine
Rx; ganciclovir - high toxicity, Vitravene - ocular use
Epstein-Barr Virus
/HHV8
Gammaherpesvirinae Enveloped Linear dsDNA icosahedral Latent in Lymphocytes Infectious Mononucleosis Tx by saliva Sx. fever, sore throat, lymphadenopathy incubation 4-6 wks Abnormal lymphocytes CTLs to attack infected B-Cells Dx. Heterophile test vs sheep RBCs Transforms lymphocytes -Burkits lymphoma and Hodgkins Lymphoma - Nasopharyngeal carcinoma
Herpes Simplex Virus Encephalitis
HSE
High mortality w/ severe neuro sequelae
Sx. High fever, confusion, lymphocytes in CSF (PCR)
MRI w/ unilateral temporal lobe lesion(s)
RX. acyclovir on suspicion
Herpes Simplex Keratitis
Keratoconjuctivitis
SX. keratitis of bulbar and palpebral conjunctiva +- cornea, unilateral red eye, photophobia
RX. acyclovir/topical trifluridine
Chickenpox
HHV3 Varicella/Zoster
incubation 2-3 weeks
prodromal malaise
SX. fever, rash of small itchy vesicles
Rx calamine lotion w/ acyclovir for severe cases or immunocompromised
Varivax live-attenuated for 1-12 years, Oka strain
Zoster/Shingles
HHV3 - Varicella Zoster
latent infection reactivated
prodromal dermatomal pain
Sx painful, unilateral , dermatomal lesions
Post herpatic neuralgia after symptom resolution
Rx acyclovir w/in 1-2 days reduces risk or PHN
Zostavax live-attenuated 60+ population
HHV-8
Kaposi’s Sarcoma Herpes Virus
Opportunistic pathogen of the immunosuppressed
flat red vascular lesions
HHV-6
exanthum subitum (roseola infantum)
mild rash OR high fever no rash
rare encephalitis
