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
St. Louis Encephalitis
Flaviviridae: ssRNA, + sense, enveloped, icosahedral MC encephalitis in ELDERLY in USA. Fever, N/V, rash, acute flaccid paralysis. Transmitted via Culex mosquito
Japanese Encephaltis
Flaviviridae: ssRNA, + sense, enveloped, icosahedral Mild febrile illness, acute meningoencephalitis Transmitted via Culex mosquito
Rubella
Togaviridae: ssRNA, + sense, enveloped, icosahedral “German measles” MC presents as fever, maculopapular rash that begins on head and neck and move downward to trunk (“blueberry muffin rash”) and extremities in non nonvaccinated pts w/ POSTERIOR AURICULAR and OCCIPITAL LYMPHADENOPATHY –>presents as POLYARTHRALGIAS/POLYARTHRITIS in adults–>newborns can develop DEAFNESS, white pupils w/ CATARACTS, CARDIAC MALFORMATIONS (e.g. PDA) Transmitted via respiratory droplets. ***VACCINE: MMR (live, attenuated)
HIV
Retroviridae: ssRNA, +sense, enveloped, icosahedral *ONLY RNA virus that is DIPLOID Primary infection: mononucleosis-like syndrome. As dz progresses, virus infects and kills more CD4+ T cells which damage both humoral and cell-mediated immunity Transmitted via IV, sex, blood transfusions, birth process (vertical), breastmilk
HTLV-1 (Human T-cell Lymphotrophic virus type 1)
Retroviridae: ssRNA, +sense, enveloped, icosahedral Adult T cell leukemia and/or TSP (tropical spastic paraparesis). Can also lead to demyelination of the spinal cord pyramidal tract Transmitted via IV, sex, blood transfusions, birth process (vertical), breastmilk (same as HIV)
Coronavirus
Coronaviridae: ssRNA, +sense, enveloped, helical 2nd MCC of common cold. Can also cause gastroenteritis in infants Transmitted via respiratory droplets
HEV
Calciviridae: ssRNA, +sense, naked, icosahedral Enteric hepatitis. Usually self-limited, but can cause FULMINANT HEPATITIS IN PREGNANT WOMEN Transmitted via fecal-oral route
Norwalk virus (aka Norovirus=Norwalk agent)
Calciviridae: ssRNA, +sense, naked, icosahedral Adult gastroenteritis. VOMITING and diarrhea. ***CRUISE SHIPS Trasmitted via fecal-oral route
Sapovirus
Calciviridae: ssRNA, +sense, naked, icosahedral Pediatric gastroenteritis Transmitted via fecal-oral route
Poliovirus
Picornaviridae: ssRNA, +sense, naked, icosahedral Abortive poliomyelitis–>febrile syndrome Paralytic poliomyelitis–>damage to anterior horn motor neurons Postpolio syndrome–>muscle atrophy after resolution Aseptic meningitis (common cause of many picornaviruses) Transmitted via fecal-oral route ***VACCINE: Salk/IPV–>killed virus Sabin/OPV–>live attenuated virus (no longer available in US due to linkage to VAPP, vaccine-associated paralytic poliomyelitis, from reversion to wild-type virus)
HAV
Picornaviridae: ssRNA, +sense, naked, icosahedral “DAY CARES and DINERS” ACUTE viral hepatitis. Mostly asymptomatic, but if not will present as jaundice with watery diarrhea. Usually self-limited and NOT associated with chronic hepatitis or HCC Transmitted via fecal-oral route ***VACCINE:
Enterovirus
Picornaviridae: ssRNA, +sense, naked, icosahedral Mild febrile illness, aseptic meningitis, or conjunctivitis. Peak in summer-fall. Transmitted via fecal-oral route
Echovirus
Picornaviridae: ssRNA, +sense, naked, icosahedral Mild febrile illness, aseptic meningitis, or rash (Morbiliform/Roseoliform rash) Transmitted via viral invasion of nasopharyngeal mucosa. Peak in summer-fall.
Rhinovirus
Picornaviridae: ssRNA, +sense, naked, icosahedral MCC of common cold Transmitted via respiratory droplets, often through spread by self-inoculation of nose and throat
Coxsackievirus
Picornaviridae: ssRNA, +sense, naked, icosahedral Group A: herpangina (multiple small vesicles and erosions with erythematous halos on soft palate), hand-foot-mouth disease Group B: dilated cardiomyopathy (also, acute myocarditis and pericarditis can occur), aseptic meningitis, pleurodynia Transmitted via fecal-oral route
Astrovirus
Astroviridae: ssRNA, +sense, naked, icosahedral Gastroenteritis in neonates and pediatrics. Peaks in winter. (Similar to Rotavirus) Transmitted via fecal-oral route.
Measles (aka Rubeola)
Paramyxoviridae: ssRNA, -sense, enveloped, helical 3 C’s: Cough, Coryza, Conjunctivitis. Rash that begins at head and moves down to trunk (much like Rubella/German measles). Blue-white (Koplik) spots on buccal mucosa Can also present as: croup, pneumonia, diarrhea, keratitis with scarring and blindness, encephalitis, hemorrhagic rashes Transmitted via respiratory droplets ***VACCINE: MMR (live attenuated)
Mumps
Paramyxoviridae: ssRNA, -sense, enveloped, helical Orchitis, parotitis Complications: aseptic meningitis, meningoencephalitis, unilateral nerve deafness, pancreatitis Transmitted via respiratory droplets ***VACCINE: MMR (live attenuated)
Parainfluenza
Paramyxoviridae: ssRNA, -sense, enveloped, helical Primarily infects kids <8 yoa. Common cold with fever, croup, bronchiolitis, pneumonia. Usually self-limiting. Transmitted via respiratory droplets
RSV
Paramyxoviridae: ssRNA, -sense, enveloped, helical Common cold, bronchiolitis, and pneumonia. Can be fatal. ***Palivizumab [Synagis]=monoclonal Ab to F (fusion) glycoprotein
Influenza
Orthomyxoviridae: ssRNA, -sense, enveloped, helical, segmented *ONLY virus besides Rotaviruses to have SEGMENTED GENOMES–>capable of genetic shifts through reassortment Fever, myalgia, malaise, headache, pharygitis Can also get: N/V/D (esp. in kids), cough, coryza (runny nose) Complication: PNEUMONIA (esp. in young children, elderly, alcoholics or immunocompromised pts. Key proteins: HA=Hemagglutinin–>viral attachment/entry into host cell NA=Neuraminidase–>viral release from host cell M2=Membrane protein–>ion channel that alters pH necessary for viral uncoating and assembly Tx: NA inhibitors–>Oseltamivir [Tamiflu] and Zanamivir–>MOST EFFECTIVE THERAPY. Can be used for both influenza type A and B M2 inhibitors–>Amantadine and Rimantidine–>not as effective. Only used for influenza type A
Ebola & Marburg viruses
Filoviridae: ssRNA, -sense, enveloped, helical Viral hemorrhagic fevers, with flu-like symptoms and death in ~90% of pts Transmitted via contact w/ body fluids
Rabies
Rhabdoviridae: ssRNA, -sense, enveloped, bullet Fever, malaise, headache, nausea, pain at bite site (initial flu-like syndrome)–>hydrophobia, hyper salivation, seizures, hallucinations, delirium –>paralysis, respiratory failure, coma. After animal bite, virus progresses to PNS to CNS via retrograde axonal transport. Transmitted via animal bite and virus lives in salivary glands (MC in US=skunk, raccoon, bat bites) ***VACCINE: after suspected bite, pt is administered HUMAN RABIES IMMUNOGLOBULIN and the RABIES VACCINE (killed virus)
LCMV (Lymphocytic choriomeningitis virus)
Arenaviridae: ssRNA, AMBISENSE AND NEGATIVE SENSE, enveloped, helical MC asymptomatic to mild febrile illness. But, could be aseptic meningitis/encephalitis Transmitted via rodents. No human to human transmission except mother to fetus
Lassa Fever
Arenaviridae: ssRNA, AMBISENSE AND NEGATIVE SENSE, enveloped, helical to circular Hemorrhagic fever, encephalitis, facial swelling, deafness Tranmission via rat
Hantavirus
Bunyaviridae: ssRNA, AMBISENSE AND NEGATIVE SENSE, enveloped, helical to circular HVRD: Hantavirus renal disease HVCPS: Hantavirus cardiopulmonary syndrome Transmitted via inhalation of rodent feces
La Crosse virus
Bunyaviridae: ssRNA, AMBISENSE AND NEGATIVE SENSE, enveloped, helical to circular Viral encephalitis Transmitted via mosquito
California encephalitis
Bunyaviridae: ssRNA, AMBISENSE AND NEGATIVE SENSE, enveloped, helical to circular Viral encephalitis Transmitted via mosquito
Crimean-Congo hemorrhagic fever
Bunyaviridae: ssRNA, AMBISENSE AND NEGATIVE SENSE, enveloped, helical to circular Viral encephalitis Transmitted via mosquito
Rift Valley fever virus
Bunyaviridae: ssRNA, AMBISENSE AND NEGATIVE SENSE, enveloped, helical to circular Acute febrile illness (saddle-back fever), myalgias, low back pain, HA, anorexia, retroorbital pain Transmitted via ticks
