Viruses Flashcards
Positive-stranded RNA viruses
I went to a RETRO TOGA party, where I drank FLAVored CORONA and ate HIPPY CALIfornia PICO de giyo. Retrovirus Togavirus Flavivirus Hepevirus Calicivirus Picornnavirus
Naked (nonenveloped) viruses
Naked CPR H and PAPP smears (DNA = PAPP, RNA = CPR)
Calicivirus, Picornavirus, Reovirus, Hepevirus
Parvovirus, Adenovirus, Papilloma, Polyoma
General DNA Virus rules
- HHAPPPPy viruses (Hepadna, Herpes, Adeno, Pox, Parvo, Papilloma, Polyoma)
- Double Stranded (except parvo)
- Linear (except papilloma, polyoma, hepadna)
- Icosahedral (except pox)
- Replicated in nucleus (except pox)
Herpesviruses
Enveloped, linear dsDNA virus
HSV-1, HSV-2, VZV (HHV-3), EBV (HHV-4), CMV (HHV-5), HHV-6, HHV-7, HHV-8
HSV-1
Respiratory secretions, Saliva
Gingivostomatitis, keratoconjunctivits, temporal lobe encephalitis (sporadic), Herpes labialis.
Latent in trigeminal ganglia
HSV-2
Sexual Contact, pernatal
Herpes genitalis, neonatal herpes.
Latent in sacral ganglia
Tzanck test
VZV (HHV-3)
Respiratory secretions
Varicella-zoster (chicken pox, shingles), encephalitis, pneumonia
Latent in dorsal root or trigeminal ganglia
EBV (HHV-4)
Respiratory secretions, Saliva
Infectious mononucleosis - fever, hepatosplenomegaly, pharyngitis, and lymphadenopathy (esp posterior cervical nodes) - peak 15-20 yo, + Monospot test - heterophile Abs detected by agglutination of sheep or horse RBCs
Burkitt’s Lymphoma, nasopharyngeal carcinoma.
Latent in B cells
CMV (HHV-5)
Congenital, Transfusion, Sex, Saliva, Urine, Transplant
Mononucleosis (negative monospot), pneumonia, retinitis
Infected cells have Owl’s Eye inclusions
Latent in mononuclear cells
HHV-6
Roseola - high fever for several days -> seizures and diffuse macular rash
HHV-8
Sexual contact
Kaposi’s sarcoma in HIV patients
Hepadnavirus
Enveloped partial circular dsDNA virus
HBV - acute or chronic hepatitis
Vaccine available with HBV surface antigen
Not a retrovirus but has reverse transcriptase
Adenovirus
Naked linear dsDNA virus Febrile pharyngitis - sore throat, acute hemorrhagic cystitis Pneumonia Conjunctivitis - pink eye Watery Diarrhea
Parvovirus
Naked linear ssDNA (-) Virus (smallest)
B19 virus - aplastic crisis in sickle cell dz, “slapped cheeks” rash in children - erythema infectiosum (fifth dz), RBC destruction in fetus leads to hydrops fetalis and death, pure RB aplasia and rheumatoid arthritis-like symptoms in adults
Papillomarvirus
Naked circular dsDNA virus
HPV 1,2,6,11 - Warts
HPV 16,18 - CIN, Cervical Cancer
Vaccine available
Polyomavirus
Naked circular dsDNA virus
JC - progessive multifocal leukoencephalopathy (PML) in HIV
BK virus - transplant patients, commonly targets kidney
(JC: Junky Cerebrum; BK: Bad Kidney)
Poxvirus
Enveloped linear dsDNA virus (largest- not icosahedral and carries own DNA-dependent RNA polymerase)
Smallpox
Vaccinia - cowpox (milkmaid’s blisters)
Molluscum contagiosum - flesh-colored dome lesions with central dimple
Tzanck Test
a smear of an opened skin vesicle to detect multinucleated giant cells (test for HSV-1,2, VZV) - infected cells also have intranuclear Cowdry A inclusions
Reovirus
Naked linear Icosahedral dsRNA virus (10-12 segments)
Coltivirus - Colorado tick fever
Rotavirus - #1 cause of fatal diarrhea in children, especially during winter in day-cares, kindergartens. Villous destruction with atrophy leads to decr absorption of Na+ and water
ROTA = Right Out The Anus
Picornavirus
Naked linear Icosahedral ssRNA virus
Poliovrus - polio-Salk/Sabin vaccines - IPV/OPV
Echovirus - aseptic meningtits
Rhinovirus - common cold, >100 serologic types. Acid Labile - destroyed by stomach acid so does not infect GI tract (like others)
Coxsackievirus - aseptic meningitis, herpangina - febrile pharyngitis, hand, foot, and mouth disease, myocarditis
HAV - Fecal-oral transmission, Asymptomatic, Acute viral hepatitis
All are enteroviruses (fecal-oral) except rhinovirus
PERCH on a “peak”
Hepevirus
Naked linear Icosahedral ssRNA virus
HEV - fecal-oral transmission with short incubation time. High mortality in pregnant women (Enteric, Expectant mothers, Epidemic)
Calicivirus
Naked linear Icosahedral ssRNA
Norwalk virus - viral gastroenteritis (watery diarrhea)
Flavivirus
Enveloped linear Icosahedral ssRNA virus
HCV - Blood, IVDU, post-transfusion transmission, Long Incubation, can be a Carrier and lead to Chronic Hep, Cirrhosis, and Carcinoma
Yellow Fever - Aedes mosquito with monkey or human reservoir -> high fever, black vomitus, jaundice
Dengues
St. Louis encephalitis
West Nile virus
Togavirus
Enveloped linear Icosahedral ssRNA virus
Rubella (German Measles) - Fever, postauricular adenopathy, lymphadenopathy, arthralgia, fine truncal rash that starts at head and moves down (TORCH infxn)
Eastern equine encephalitis
Western equine encephalitis
Retrovirus
Enveloped linear ssRNA virus with Reverse Transcriptase
HIV - complex and conical -> AIDS
HTLV - Icosahedral -> T-cell leukemia
Coronavirus
Enveloped linear Helical ssRNA virus
Coronavirus - common cold and SARS
Orthomyxovirus
Enveloped linear Helical ssRNA virus (8 segments)
Influenza virus - contains hemagglutin (promotes viral entry) and nueraminidase (promots progeny virion release) antigens. Patients at risk for fatal bacterial superinfection.
Rapid genetic changes including
1. Genetic shift/antigenic shifts (pandemic) - high-frequency recombination -> deadly
2. Genetic drift (epidemic) - minor changes
Px - Killed viral vaccine
Paramyxovirus
Enveloped linear Helical ssRNA virus (-)
Parainfluenza - croup
RSV - bronchiolitis in babies, Rx - ribavirin
Rubeola (Measles) - Koplic spots on buccal mucosa and descending maculopapular rash
Mumps - Parotitis, Orchitis, aseptic Meningitis
All contain surface F (fusion) protein -> respiratory epithelial cells to fuse and form multinucleated cells.
Px - Palivixumab (premies)
Rhabdovirus
Enveloped linear Helical ssRNA virus (-)
Rabies - bullet-shaped capsid, Negri Bodies - cytoplasmic inclusions in neurons infected by rabies virus - commonly found in Purkinje cells of cerebellum.
Rabies has long incubation period before symptom onset, but prophylactic vaccination should occur immediately upon exposure
Fever, Malaise -> Agitation, Photophobia, Hydrophobia -> Paralysis, Coma -> Death
More commonly from bat, raccoon, and skunk bites in US
Filovirus
Enveloped linear Helical ssRNA virus (-)
Ebola/Marburg hemorrhagic fever - often fatal
Arenavirus
Enveloped circular Helical circular ssRNA virus (2 segments) (-)
LCMV - Lymphocytic choriomeningitis virus
Lassa fever encephalitis - spread by mice
Bunyavirus
Enveloped circular Helical ssRNA virus (3 segments) (-)
California encephalitis
Sandfly/Rift Valley Fevers
Crimean-Congo Hemorrhagic fever
Hantavirus - hemorrhagic fever, pneumonia
Deltavirus
Enveloped circular helical ssRNA (-)
HDV - Parenteral, sexual, maternal-fetal transmission, coninfection or superinfection with HBV (needs HbsAg as envelope)
Segemented viruses (all RNA viruses)
BOAR
Bunyavirus, Orthomyxovirus (influenza) Arenavirus, Reovirus
Negative stranded viruses
Always Bring Polymerase Or Fail Replication
(must bring RNA-dependent RNA polymerase)
Arenavirus, Bunyavirus, Paramyxovirus, Orthomyxovirus, Filovirus, Rhabdovirus
Measles (rubeola) virus
Paramyxovirus
Koplic spots, red spots with blu-white center on buccal mucose and descending maculopapular rash
SSPE, encephaltis, and giant cell phneumonia are sequelae
3 C’s of measles
Cough, Coryza, Conjunctivitis
Mumps virus
Paramyxovirus
Mumps makes your parotid glands and testes as big as POM-poms
Parotitis, Orchitis, asepctic Meningitis
