Viruses Flashcards
HBV
Hepadnaviridae: dsDNA, enveloped, circular (paritally ds w/ ssDNA gap) *INTRANUCLEAR (Cowdry A) inclusion bodies Viral replication also requires REVERSE TRANSCRIPTASE Infectious hepatitis. Hepatitis, cirrhosis, HCC Transmitted through blood products (IV, sex)
HSV-1 & 2
Herpesviridae: dsDNA, enveloped, icosahedral, linear *INTRANUCLEAR inclusion bodies *only viruses to use the host NUCLEAR membrane for envelope (all others use host PLASMA membrane) HSV-1=cold sores HSV-2=genital herpes Encephalitis (of temporal lobes) Multinucleated giant cells on TZANCK smear Grouped vesicles on an erthematous border Transmitted through contact, mucous membranes, breaks in skin, sex.
VZV
Herpesviridae: dsDNA, enveloped, icosahedral, linear *INTRANUCLEAR inclusion bodies *only viruses to use the host NUCLEAR membrane for envelope (all others use host PLASMA membrane) Chickenpox, shingles, pneumonia. “Dew drops on a rose petal” Transmitted via respiratory route
EBV
Herpesviridae: dsDNA, enveloped, icosahedral, linear *INTRANUCLEAR inclusion bodies *only viruses to use the host NUCLEAR membrane for envelope (all others use host PLASMA membrane) EBV binds to CD21 on B cells Fever, flu-like symptoms, pharyngitis, lymphadenopathy–>HETERONUCLEOPHILE/MONOSPOT-POSITIVE MONONUCLEOSIS. Encephalitis, BURKITT LYMPHOMA, NASOPHARYNGEAL CARCINOMA, ORAL HAIRY CELL LEUKOPLAKIA Transmitted via saliva and respiratory secretions (“kissing disease”, MC seen in teenagers and young adults)
CMV
Herpesviridae: dsDNA, enveloped, icosahedral, linear *INTRANUCLEAR inclusion bodies *only viruses to use the host NUCLEAR membrane for envelope (all others use host PLASMA membrane) Fever, flu-like symptoms, pharyngitis, lymphadenopathy–>HETERONUCLEOPHILE/MONOSPOT-NEGATIVE MONONUCLEOSIS *OWL’S EYE INCLUSION BODIES, purple intranuclear inclusion bodies surrounded by a halo Retinitis, pneumonia, esophagitis ***PERIVENTRICULAR BRAIN CALCIFICATIONS, DEAFNESS, BLINDNESS Transmitted via close contact (e.g. during birth via perinatal/venereal transmission)
HHV-6
Herpesviridae: dsDNA, enveloped, icosahedral, linear *INTRANUCLEAR inclusion bodies *only viruses to use the host NUCLEAR membrane for envelope (all others use host PLASMA membrane) “ROSEOLA” (aka Sixth Disease)–>fever, rash, adenopathy for 3-5 days w/ RASH APPEARING ONCE FEVER SUBSIDES–>rash consists of macules and papules on trunk initially (called Exanthem Subitum) that spreads to extremities–>can cause seizures, Transmitted via saliva
HHV-8
Herpesviridae: dsDNA, enveloped, icosahedral, linear *INTRANUCLEAR inclusion bodies *only viruses to use the host NUCLEAR membrane for envelope (all others use host PLASMA membrane) Kaposi Sarcoma in AIDS pts–>can affect any organ, but MC seen as purpuric, raised violaceous skin nodules containing extravasated RBCs Transmitted via sex/body fluids
Variola
Poxviridae: dsDNA, enveloped, complex, linear *ONLY viruses that make their OWN ENVELOPE (not from host membrane) *ONLY DNA viruses that replicate in the CYTOPLASM Smallpox. Lesions are ALL AT SAME STAGE OF DEVELOPMENT. Rash initially maculopapular, then vesicular, then pustules. Rash begins on face and extremities and spreads to the trunk, palms, and soles (centripetal) Transmitted via respiratory droplets or close contact
Vaccinia
Poxviridae: dsDNA, enveloped, complex, linear *ONLY viruses that make their OWN ENVELOPE (not from host membrane) *ONLY DNA viruses that replicate in the CYTOPLASM Used to make smallpox vaccine Cowpox “milkmaid’s blisters” Transmitted via contact
Molluscum contagiosum
Poxviridae: dsDNA, enveloped, complex, linear *ONLY viruses that make their OWN ENVELOPE (not from host membrane) *ONLY DNA viruses that replicate in the CYTOPLASM Small, spontaneously regressing, umbilicated, fles-colored lesions. Common among newborns, wrestlers, HIV pts Transmitted via contact
HPV
Papillomaviridae: dsDNA, naked, icosahedral, circular Cervical carcinoma and anogenital cancers–>HPV serotypes 16, 18, 31, 33, 45 (high risk) Condylomata/genital warts–>HPV serotypes 6 and 11 *E6 protein–>inhibits p53 E7 protein–>inhibits Rb Transmitted via sex and contact ***VACCINE=Guardasil, which helps protect against HPV serotypes 6, 11, 16, 18
JC virus
Polyomaviridae: dsDNA, naked, icosahedral, circular “jC–>Cerebrum, bK–>Kidneys” Reactivation of JC virus in immunocompromised pts results in PML (progressive multifocal leukoencephalopathy)–>demyelinating, rapidly progressive, fatal disease affecting oligodendrocytes producing deficits in speech, coordination, and memory. Transmitted via sex and contact
BK virus
Polyomaviridae: dsDNA, naked, icosahedral, circular “jC–>Cerebrum, bK–>Kidneys” Kidney disease, found especially in solid organ/kidney and bone marrow transplants. Hemorrhagic cystitis, ureteral stenosis, UTIs. Transmitted via sex and contact.
Adenovirus
Adenoviridae: dsDNA, naked, icosahedral, linear One of the MCC of common cold. Can also cause conjunctivitis (***RED EYES), pneumonia, gastroenteritis. MCC of acute hemorrhagic cystitis in children Transmitted via respiratory droplets, contact, or fecal-oral route
Parvovirus B19
Parvoviridae: ssDNA, naked, icosahedral, linear *ONLY ssDNA VIRUS Replicates in RBCs (particularly in the bone marrow) and destroys them Erythema infectiosum (“Fifth disease”)–>“slapped cheek” rash that can also cause arthralgias Aplastic anemia–>pts w/ thalassemia or sickle cell can develop a transient aplastic anemia Hydrops fetalis–>severe anemia in infants Transmitted via respiratory droplets, oral secretions, parenterally
Rotavirus
Reoviridae: dsRNA, naked, icosahedral, linear, segmented *ONLY dsRNA virus *ONLY virus besides Orthomyxoviruses to have SEGMENTED GENOMES–>capable of genetic shifts through reassortment MCC of INFANTILE DIARRHEA. Causes vili destruction leading to watery diarrhea, and malabsorption. Peaks in winter. “If the child is old enough to WALK, then it’s more likely that NorWALK virus is the cause. Otherwise, it’s Rotavirus” Vomiting, diarrhea, fever, dehydration Transmitted via fecal-oral route ***VACCINE: RotaTeq
HCV
Flaviviridae: ssRNA, + sense, enveloped, icosahedral Acute, usually subclinical hepatitis (~80% chronic). Cirrhosis, HCC Transmitted via IV, sex
Dengue Fever
Flaviviridae: ssRNA, + sense, enveloped, icosahedral Mild fever, HA, bone aches, hemorrhagic shock syndrome (in SE Asian variant) Transmitted via Aedes mosquito
West Nile Virus
Flaviviridae: ssRNA, + sense, enveloped, icosahedral Fever, N/V, rash, acute flaccid paralysis. Peaks in summer Transmitted via Culex mosquito
Yellow fever virus
Flaviviridae: ssRNA, + sense, enveloped, icosahedral Chills, fever, black vomit, HA. If liver is involved, pts have jaundice w/ Councilman bodies (acidophilic inclusions). Can have acute flaccid paralysis Transmitted via Aedes mosquito