Viruses Flashcards

Question

Mumps

Answer 1

**Features:** "* -ssRNA * Enveloped" **Reservoir/Transmission:** "* Resp transmission * Replicates in parotid glands * Incubation period = 14-18 days * VF: Fusion protein, HA, NA" **Diseases:** "Replicates in parotid gland, testes, CNS, pancreas --> Viremia 12-25 days post-exposure * Parotitis: inflammation of parotid glands * Unilateral Orchitis: testicular atrophy & sterility can occur * Meningitis (virus replicates in CNS) * Pancreatitis" **Diagnosis:** **Treatment:** **Vaccines:** * MMR Vaccine: live attenuated vaccine (contraindicated in pregnancy); lifelong immunity | RNA Viruses (-) sense ## Footnote "PARAMYXOVIRUS (paranormal mixer)"

Answer 2

**Features:** "* -ssRNA * Enveloped" **Reservoir/Transmission:** "* Fusion protein * G protein: allows for attachment to resp endothelium * Humans are the ONLY source, can live on surfaces * Occurs in annual epidemics during winter/early spring * Incubation period = 2-8 days (viral shedding for 3-4 wks)" **Diseases:** "* Common in infants < 6 mo * Infants: #1 cause of pneuomnia & bronchiolitis in infants (lower resp infection) * infiltrates seen on CXR * Adults: severe lower resp infection esp in immunocompromised" **Diagnosis:** "* PCR (most sensitive) * Antigen detection assay * DFA/culture (rare)" **Treatment:** "* Ribavirin: Not commonly used in kids/pregnant women; used in adults only * Palivizumab: monoclonal ab against fusion protein; used for prevention of RSV in premature infants" **Vaccines:** | RNA Viruses (-) sense ## Footnote "PARAMYXOVIRUS (paranormal mixer)"

Answer 3

**Features:** "* -ssRNA * Enveloped" **Reservoir/Transmission:** * Fusion protein, HA, NA **Diseases:** "* Bronchiolitis & pneumonia in children < 1 yr (HPIV-3) * Croup/Laryngotracheobronchitis in 1-5 yo (HPIV1/2): inspiratory stridor & seal-bark cough * Refractory pneumonia in HSCT pts w 40% mortality * Bronchiolitis obliterans in lung transplant pts" **Diagnosis:** "* CXR: Steeple-sign (narrow trachae & subglottic region) indicates croup * Direct fluorescent ab, PCR or viral culture * Lung biopsy in immunocompromised or HSCT pts" **Treatment:** * Ribavirin: inhaled with IVIG for severe pneumonia **Vaccines:** | RNA Viruses (-) sense ## Footnote "PARAMYXOVIRUS (paranormal mixer)"

Answer 4

**Features:** **Reservoir/Transmission:** **Diseases:** **Diagnosis:** **Treatment:** **Vaccines:** | RNA Viruses (-) sense

Answer 5

**Features:** "* -ssRNA * Enveloped * Helical capsid * Bullet shaped * Negri bodies " **Reservoir/Transmission:** "* Carriers: bats (US), foxes, skunks, rodents, dogs (developing countries) * Transmitted via aerosol or bite * Binds nicotinic Ach receptors on post-synaptic motor end plate --> binds NCAMs entering neurons * Replicates in motor neurons/striated muscle cells * Retrograde movement along peripheral nerves to DRG" **Diseases:** "Rabies * Incubation period = weeks to months (depends on bite location) * Non-specific flu-like symptoms (malaise, headache, nausea, vomiting) --> Fever, encephalitis, foamy mouth (enters salivary glands) --> Acute neurologic syndrome including hydrophobia (fear of water), aerophobia (fear of breeze), photophobia * Pharyngeal muscle spasms--> dysphagia * Eosinophilic Negri bodies in cytoplasm of hippocampal pyramidal cells & cerebellar Purkinje cells (do not confuse w cowdry bodies which are nuclear inclusions w herpesvirus)" **Diagnosis:** **Treatment:** "* NOT effective once symptoms appear * Wound cleaning" **Vaccines:** "* Passive immunization post-exposure with preformed Abs * Killed vaccine (active immunization)" | RNA Viruses (-) sense ## Footnote Human Metapneumovirus

Answer 6

**Features:** "* -ssRNA * Enveloped * Helical capsid" **Reservoir/Transmission:** "* Monkey/bat * spread via bodily fluids (puts healthcare workers at risk) * Travel to Africa" **Diseases:** "Marburg & Ebola (can result in DIC) * Hemorrhagic fever & petechial rash * Hemorrhagic/hypovolemic shock --> End organ failure --> death" **Diagnosis:** * RT-PCR of blood/bodily fluids within 48 hr symptom onset **Treatment:** **Vaccines:** | RNA Viruses (-) sense ## Footnote Human Metapneumovirus

Answer 7

**Features:** "* -ssRNA * Enveloped (obtained from golgi bodis of host cells) * 3 circular segments (BOAR)" **Reservoir/Transmission:** "* Reservoir = deer mouse (arbovirus exception = robovirus - rodents) * Transmitted via rodent urine/feces" **Diseases:** "* Pulmonary capillary leak (radiographically similar to ARDS) --> hypotension, pre-renal azotemia & pulmonary edema * Cardiopulmonary syndrome (HCPS) * Hemorrhagic fever with renal syndrome (HFRS)" **Diagnosis:** **Treatment:** **Vaccines:** | RNA Viruses (-) sense ## Footnote "BUNYAVIRUS (paul bunyavirus)"

Answer 8

**Features:** "* -ssRNA * Enveloped (obtained from golgi bodis of host cells) * 3 circular segments (BOAR)" **Reservoir/Transmission:** * spread via Aedes mosquitoes (arbovirus) **Diseases:** "* Seizures * Encephalitis (all arboviruses cause encephalitis)" **Diagnosis:** **Treatment:** **Vaccines:** | RNA Viruses (-) sense ## Footnote "BUNYAVIRUS (paul bunyavirus)"

Answer 9

**Features:** "* -ssRNA * Ambisense (both +/- RNA) * Enveloped * Helical capsid * 2 circular segments (BOAR) * Grainy appearance w electron microscopy (host cell ribosomes)" **Reservoir/Transmission:** * transmitted by rodents **Diseases:** "* Lymphocytic Choriomeningitis Virus (LCV): fever & meningoencephalitis * Lassa Fever: Hemorrhagic fever & encephalitis (West Africa)" **Diagnosis:** **Treatment:** * Inactivated by heat and irradiation **Vaccines:** | RNA Viruses (-) sense

Answer 10

**Features:** "* dsRNA (replicates in cytoplasm) * Naked * 11 segments (BOAR) * Infection common in winter" **Reservoir/Transmission:** "* Entry through mouth, fecal oral * NSP4: enterotoxin that causes symptoms by increasing Cl- permeability --> Na & H2O leak out * Children @ risk" **Diseases:** "* #1 cause of severe diarrhea in young children * Watery diarrhea within 48 hrs infection that lasts 3-8 days (attacks villous cells of sm intestine) * Complications: dehydration, electrolyte imbalance, metabolic acidosis" **Diagnosis:** * Wheel-shaped **Treatment:** **Vaccines:** "* Live attenuated oral vaccine: first dose should be given when < 3 mo old due to side effect of intussesception (telescoping of bowel) - 2, 4, 6 mo" | RNA Viruses (-) sense ## Footnote "REOVIRUS (a race on the rio)"

Answer 11

**Features:** "* dsRNA (replicates in cytoplasm) * Naked * 11 segments (BOAR) * Infection common in winter" **Reservoir/Transmission:** **Diseases:** * Myalgia, fever, vomiting **Diagnosis:** **Treatment:** **Vaccines:** | RNA Viruses (-) sense ## Footnote "REOVIRUS (a race on the rio)"

Answer 12

**Features:** "Herpes Virus Family * dsDNA, linear * Enveloped * Cowdry bodies: Intranuclear eosinophilic inclusion bodies (also in CMV/VZV) * Tzank smear w multinucleated giant cells (same as VZV)" **Reservoir/Transmission:** **Diseases:** "Above the waist (1) symptoms vs below the waist (2) Herpetic whitlow: painful hand vesicle/wart; common in dentists Genital Herpes: * Most with HIV-2 have not been diagnosed with genital herpes, but shed virus in genital tract * HSV-1 increasing in first episodes of anogenital herpes (MSM, young women) Cervicitis: discharge, intermenstrual bleeding HIV --> Reactivation of HSV: esophagitis, recurrent mucocutaneous & genital ulcers" **Diagnosis:** "* PCR (gold standard) * Cell culture has low sensitivity that declines as healing occurs * Cowdry intranuclear inclusion bodies" **Treatment:** "* First episode: Acyclovir, Famcyclovir, or Valacyclovir (10 day course, extend if healing incomplete) * Recurrent: Higher doses of above antivirals for shorter courses * Suppressive therapy: reduces frequency of recurrence" **Vaccines:** | DNA Viruses

Answer 13

**Features:** "Herpes Virus Family * dsDNA, linear * Enveloped * Cowdry bodies: Intranuclear eosinophilic inclusion bodies (also in CMV/VZV) * Tzank smear w multinucleated giant cells (same as VZV)" **Reservoir/Transmission:** * Lies dormant in sacral ganglia **Diseases:** "* Aseptic meningitis in adolescents/adults * Painful inguinal lymphadeopathy * Vesicular genital lesions" **Diagnosis:** * Tzank smear w multinucleated giant cells (old test, now use PCR) **Treatment:** "* NO cure * Prevent with acyclovir or valcyclovir" * "* First episode: Acyclovir, Famcyclovir, or Valacyclovir (10 day course, extend if healing incomplete) * Recurrent: Higher doses of above antivirals for shorter courses * Suppressive therapy: reduces frequency of recurrence" **Vaccines:** | DNA Viruses

Answer 14

**Features:** "Herpes Virus Family * dsDNA, linear * Enveloped * Cowdry bodies: Intranuclear eosinophilic inclusion bodies (also in CMV/VZV) * Tzank smear w multinucleated giant cells (same as VZV)" **Reservoir/Transmission:** "* Vertical transmission (TORCHES) * Latent in trigeminal ganglia & reactivated by stress/immunosuppression" **Diseases:** "* First sign is gingivostomatitis (inflammed lips/tongue) * Rash: dew drops on rose petal appearancen on upper body * Erythema multiform: target-shaped rash w pink-red ring around pale center that appears 1-2 wk post-infection * Serpiginous/dendritic corneal ulcers seen on slit lamp exam of Keratoconjunctivitis (red eyes) * Temporal lobe encephalitis (#1 cause of sporadic encephalitis in US) --> hemorrhage/necrosis of tissue --> personality changes, hallucinations * Esophagitis with volcano-like ulcers (immunocompromised) * Herpes labialis (cold sores) result from reactivation of virus from stress" **Diagnosis:** "* PCR (gold standard) * Cell culture has low sensitivity that declines as healing occurs * Cowdry intranuclear inclusion bodies" **Treatment:** "* First episode: Acyclovir, Famcyclovir, or Valacyclovir (10 day course, extend if healing incomplete) * Recurrent: Higher doses of above antivirals for shorter courses * Suppressive therapy: reduces frequency of recurrence" **Vaccines:** | DNA Viruses

Answer 15

**Features:** "* dsDNA (linear) * Enveloped * Atypical CTLs (Downey type II): basophilic, vacuolated cytoplasm & lobulated nucleus * Reed-Sternberg Cells: Hodgkin's lymphoma; binucleate w prominent nucleoli (owl eyes)" **Reservoir/Transmission:** "* Mainly saliva transmission * Virus envelope gp binds CD21 to infect B cells (CD21 is a receptor & binds gp350) --> spread to lymphoid system * Latent in B cells (episome) * Incubation period = 30-50 days * More common in adults/adolescents in developed countries & in kids in developing countries Compromised hosts include: * X-linked lymphoproliferative syndrome: genetic inability to mount normal immune response to EBV * Infection associated Hemophagocytic Syndrome: CTL/NK cells inability to regulate EBV proliferation; hypercytokinemia * Post transplant Lymphoproliferative Disorder: risk due to immunosuppression highest in first year after * HIV infection --> Primary CNS Lymphoma: Lethargy, confusion, seizures, constitutional symptoms (dx: imaging, EBV PCR on CSF if possible)" **Diseases:** "Heterophile-positive Mononucleosis (agglutinates with non-human RBCs) * 3-5 days of headache, malaise & fatigue; fevers (high as 40'C & last 7-14 days) * Generalized lymphadeopathy, fever, splenomegaly (T cell proliferation), pharyngitis (sore throat) & tonsilar exudate, periorbital edema * Confused w Strep (which is more common in kids); when given amox/ampicillin for suspected strep --> maculopapular rash Complications: * Neuro: meningitis, encephalitis, optic neuritis, cranial nerve palsy, myelitis, psychosis * Heme: hemolytic anemia, thrombocytopenia, aplastic anemia, leukopenia Associated Conditions: * Lymphocytic Interstitial Pneumonitis: pulmonary condition that causes chronic wheezing (very rare) * Non-Hodgkin's Lymphoma: VERY common * Oral Hairy Leukoplakia: seen in HIV pts; non-cancerous lesion usually on lateral tongue similar to candida/oral thrush (But CANNOT be scraped off) * Leiomyosarcoma: soft tissue tumors that can occur anywhere in body (common in those with AIDS) * Hodgkin's Lymphoma: Mediastinal mass/non-tender lymphadenopathy - Reed-Sternberg cell: binucleate B cells w nucleoli (owl eyes) - mixed cellularity & lymphocyte depleted subtypes * Endemic/African Burkitt Lymphoma: large jaw lesion & swelling (non-endemic/sporadic form presents w abd mass) * Nasopharyngeal Carcinoma: Asian ancestry" **Diagnosis:** "* Heterophile Ab: IgM Abs produced by B cells that are reactive against sheep, horse RBCs & do NOT react with specific EBV proteins (non-specific) - Monospot test POSITIVE * EBV Viral Capsid Antigen: - IgM peaks 2-6 wks, decline 2-3 mo - IgG Ab perists for life * Early Antigens (EA): IgG Ab that appears while symptomatic & indicates ACUTE infection * EBV Nuclear Antigen (EBNA): Abs that indicate LATENT infection (maintains virus in episome) " **Treatment:** * Supportive care, avoid contact sports (risk of splenic rupture) **Vaccines:** | DNA Viruses

Answer 16

**Features:** "* dsDNA * Owl's eye inclusion bodies * Icosahedral shape" **Reservoir/Transmission:** "* Binds cellular integrans (heparan sulfate) * Transmitted via sexual contact, organ transplant, vertically (placenta, TORCHES) - Primary infection to upper resp & GI tract mucosal surfaces - Spread during acute phase & in asymptomatic hosts for mo-yrs * Latent in bone marrow stem cells (B/T lymphocytes & macrophages) - Blocks MHC-I express --> inhibits CTLs - Reactivated with immunosuppression * OI: HIV w CD4 < 50 --> reactivation" **Diseases:** "Congenital: Greatest risk during 1st trimester * #1 cause of congenital infection (1-2% infected at birth, 10% infected during birth) * MR DICS - Microcephaly, Retardation, Deaf, Intracranial calcifications, Seizures * Other symptoms: Jaundice, hepatosplenomegaly, ventriculomegaly (head CT), anemia, pneumonitis * Hydrops fetalis: heart failure --> edema --> spont abortion * Blueberry muffin rash: thrombocytopenia, petechial rash (similar to rubella) Immunocompetent hosts: Mononucleosis w sore throat, lymphadenopathy, fatigue (mono spot test = neg, differs from EBV mono) Immunocompromised hosts: Organ transplant & AIDS pt (CD4 count < 50) * Interstitial pneumonia: HSCT complication within first 120 days; rapid onset resp symptoms that last < 2 wk, fever, non-productive cough, dyspnea that can progress to hypoxia * Retinitis: full thickness necrotizing infection that has pizza pie appearance & cotton wool spots on fundoscopy (retinal lesions with intraretinal hemorrhages) * Esophagitis: Singular/deep linear ulcers (differs from HSV which has multiple shallow ones) * Colitis w ulcerated walls (diarrhea, abdominal pain, fever) * CNS manifestations: dementia, ventriculoencephalitis, radiculopathy" **Diagnosis:** "* Buffy Coat Culture: Tests transplant pts for lg cells w prominent owl's eye inclusions * Fundoscopy (retinitis) * Endoscopy with biopsy: (esophagitis & colitis) large cells w intracellular & intracytoplasmic inclusions Congenital * Viral isolation from urine/saliva sample during first 3 wk of life * PCR on serum, urine or CSF" **Treatment:** "* Ganciclovir (IV): Nucleoside analog that inhibits viral DNA Pol; initial phosphorylation step catalyzed by viral enzyme & final steps by host enzymes; half-life > 24 hr; myelosuppression * Valganciclovir (PO): Pro-drug of ganciclovir (same MOA & spectrum) but allows for oral dosing; myelosuppression * Foscarnit in those with resistance to ganciclovir due to mutated UL97 gene (phosphotransferase) & UL54 (viral DNA Pol) * Prevent interstitial pneumonia in HSCT pts using antivirals 90-120 days post-transplant * No PPX for HIV pts Congenital * Ganciclovir or oral valganciclovir" **Vaccines:** | DNA Viruses

Answer 17

**Features:** "Herpes Virus Family (all enveloped) * Multinucleated giant cells on Tzank smear (same as HSV)+C32" **Reservoir/Transmission:** "* Resp droplet transmission * Latent in DRG - Primary = sensory ganglia (4-6 days disseminates to other organs/here) - Secondary = viral infection of skin * Incubation period = 10-21 days" **Diseases:** "VZV/Chickenpox: * Vesicular dew drops on rose rash (HSV); chickenpox (superficial, mostly on trunk); lesions in different stages of healing (smallpox = same stage) * Fever, headache * Pneumina & encephalitis in adults/immunocompromised Congenital Varicella Syndrome: Infection during 1/2 trimester * Limb hypoplasia * Cutaneous scarring in dermatomal pattern * Blindness Herpes Zoster/Shingles: * Reactivated with stress, aging, immunosuppression * Same dew drop on rose appearance with dermatomal distribution (commonly lumbar & thoracic; disseminated if it crosses midline) * Opthalmicus: vision loss if trigeminal nerve VI affected * Post-herpetic neuralgia: pain after rash subsides * Ramsey Hunt Syndrome?" **Diagnosis:** * VZV: Tzank smear shows multinucleated giant cells (old test, now use PCR) **Treatment:** "Shingles: * Famciclovir: shingles tx VZV: * Acyclovir: kids > 12 yo, adults, immunocompromised * Valcyclovir" **Vaccines:** "* Shingles (Shingrex): killed vaccine for > 50 yo (2 doses); shingles & PHN * Varicella (Varivax): Live attenuated vaccine for kids > 12 mo * MMRV: 1-12 yo" | DNA Viruses

Answer 18

**Features:** "Herpes Virus Family * dsDNA" **Reservoir/Transmission:** "* Infects CD4 T cells * Remains latent in lymphocytes/monocytes" **Diseases:** "Roseola / Sixth Disease / Exanthum Subitum: 6-19 mo, usually self-limiting * High fever (> 104) for 4 days w abrupt onset --> Febrile seizures (bulging fontanelle) * After fever resolves, diffuse lacy rash that SPARES face (measles = fever DURING rash) * Cervical & occipital lymphadenopathy * GI or resp symptoms, inflammed tympanic membrane * Latent in WBCs & reactivation can occur --> rejection of transplants" **Diagnosis:** **Treatment:** Cooling/fluids **Vaccines:** | DNA Viruses

Answer 19

**Features:** "Herpes Virus Family * dsDNA" **Reservoir/Transmission:** "* Higher incidence in Russian men & African populations * Associated w AIDS & immunosuppression (ART will alleviate lesions)" **Diseases:** "Kaposi's Sarcoma: * Most common cancer seen in AIDS pts * initial cutaneous disease (violaceous lesions on nose, extremities & mucous surfaces) - Most often on hard palate (arched ceiling of mouth) & GI tract - Inactivates Rb --> Dysregulation of VEGF --> Angiogenesis --> lesions * Lymphocytic infilitrate (Bacillary angiomatosis = neutrophilic bc bacteria) Primary Effusion Lymphoma: infection of B cells; type of B cell lymphoma (aka body cavity based lymphoma)" **Diagnosis:** **Treatment:** "* ART & chemo alleviate lesions * IFN-a: Kaposi sarcoma tx" **Vaccines:** | DNA Viruses

Answer 20

**Features:** "* circular dsDNA * Naked" **Reservoir/Transmission:** "* Ubiquitous in immunocompetent * Affects HIV pts w CD4 < 200 & immunocompromised * Resp transmission during childhood * seed kidney --> clinically latent infection" **Diseases:** "JC Virus (John-Cunningham): * Mostly immunocompromised * Progressive Multifocal Leukoencephalopathy (PML): demyelinating disease that kills oligodendrocytes (lethal, death within months) --> Non-enhancing multifocal brain lesions in white matter (toxoplasma causes ring-enhancing lesions) - Normal ICP - Increased risk w natalizumab/rituximab (tx of MS) BK Virus: * Nephropathy, esp in kidney/bone marrow transplant pts * Hemorrhagic cytitis --> Hematuria * Ureteral stenosis" **Diagnosis:** **Treatment:** **Vaccines:** | DNA Viruses

Answer 21

**Features:** "* dsDNA * Naked * circular genome * > 100 types (most important are 6, 11, 16, 18, 31, 33) * Predilection for stratified squamous epithelium" **Reservoir/Transmission:** "* Infects mucosal epithelium * Virus encodes proteins that target regulators of cell cycle G1 to S phase --> uncontrolled cell growth - E6 inhibits p53 - E7 inhibits Rb (tumor suppressor gene) * Immunosuppression & HIV are risk factors" **Diseases:** "* Most common STD * AIDS-definining illness: invasive cervical, anal or penile cancer * Clinical Manifestations: anogenital warts, recurrent resp papillomatosis (RRP), cervical cancer precursors (cervical intraepithelial neoplasia), cancer (cervical, anal, vaginal, vulvar, penile, head, neck) HPV 1, 4 * Verruca Vulgans: cutaneous common wart on hands/feet that is soft, flesh-colored, cauliflower-like papule; infection of keratinocytes - Transmitted via contact HPV 6, 11: * Recurrent resp papillomatosis: tumors present on kids airway (vocal cords) - Acquired during vaginal birth (NOT sexually transmitted) * Condyloma acuminata: Angiogenital warts & koilocytes - Sexually transmitted HPV 16, 18 + 31, 33 * Oncogenic or high risk infection are responsible for cervical, penile, vulvar, vaginal & oropharyngeal cancers + precancers * Cervical Intraepithelial Neoplasia (CIN): dysplastic pre-cancerous lesion of cervix that commonly manifests following loss of p53/Rb after infectio * Anogenital cancer of skin, anus, cervix - Squamous cell carcinoma = most common cervical cancer - Sexually transmitted" **Diagnosis:** "* Pap smear: cervical cancer screening; sample cervical cells from transformation zone where outer squamous cells meet inner columnar cells * Koilocytes: Large, dense, wrinkled nucleus w perinuclear halos" **Treatment:** * Cutaneous warts: salicylic acid/liquid nitrogen **Vaccines:** "* Gardasil Vaccine: inactivated subunit that treats HIV 6, 11, 16, 18 to prevent STDs by targetting capsid proteins (9-45 yo) - HPV L1: capsid protein; Ag used - 11-12 yo: 2 doses (6-12 mo) - 15+ yo: 3 doses" | DNA Viruses

Answer 22

**Features:** "* ssDNA * Smallest DNA virus * Naked" **Reservoir/Transmission:** "* Resp, blood products & vertical transmission (TORCHES) * Preferentially infects erythroid progenitors (requires P blood group antigen receptor/globoside to enter cell)" **Diseases:** "Fifth Disease / Erythema infectiosum / Slapped Cheek Fever: * Fever for 1 wk (clears BEFORE rash begins) * Slapped cheek rash: red lacy rash that starts on face & moves down; can relapse with sunlight, stress, exercise but does NOT indicate relapse of infection * IgM appears in serum * Aplastic anemia w SCD: depletion of bone marrow causes adipocytes to pack into cob webs; normally transient condition Adults: Polyarthropathy syndrome * Papular-purpuric gloves & socks syndrome (adults/adolescents, painful, resolves in 1-3 wks) * Hydrops fetalis: if infected during 1/2 trimester; edema & death" **Diagnosis:** **Treatment:** * Immunocompromised: IVIG & RBC transfusion **Vaccines:** | DNA Viruses

Answer 23

**Features:** "* Naked * dsDNA * 54 serotypes" **Reservoir/Transmission:** "* Risk factors: military recruits, children, public swimming pools, organ transplant * Fecal-oral, contact (fomites) AND resp transmission * Enters/lysis mucosal cells by binding w hemagglutinin" **Diseases:** "* #1 cause of infection in adenoids & tonsils (tonsilitis) * Resp infections: OM, pharyngitis, exudative tonsilitis, cervical adenopathy, croup, bronchitis, pertussis-like syndrome, bronchiolitis, pneumonia (+/- pleural effusions) and necrotizing pneumonia w resp failure * Pharyngoconjunctival Fever: Keratoconjunctivitis, gastroenteritis, acute hemorrhagic cystitis (hematuria), acute myocarditis * Organ transplant --> reactivation" **Diagnosis:** " * Histopathology (tissue) * Culture * PCR (used for organ transplant) * Liver biopsy: necrosis, intracellular inclusion bodies" **Treatment:** * Self limiting **Vaccines:** * Live attenuated vaccine for military recruits only | DNA Viruses

Answer 24

**Features:** "* Linear dsDNA (largest DNA virus) * contains DNA-dep RNA Pol (replicates in cytoplasm) * Makes its own envelope * Dumbbell shaped core (only DNA virus W/O icosahedral symmetry) * Guarnieri bodies (type B1): intracytoplasmic inclusion bodies that are sites of replication" **Reservoir/Transmission:** * Sexual transmission in adults **Diseases:** "Molluscum Contagiosum: Causes flesh colored, dome shaped, umbilicated (dimple center) skin lesions (similar to snail shell) * Most common in children, present on trunk (not palms/soles) * Adults: ususally a single lesion - Diffuse infection suggests HIV infection * Sexually transmitted Smallpox / Variolla: Raised blisters on skin/mucosal surfaces that are all of the same stage & deep; mostly affect face/palms (chickenpox is of various stages & superficial) Cowpox: Transmitted by contact with infected cow uterus; led to eradication of smallpox" **Diagnosis:** **Treatment:** **Vaccines:** "* Smallpox has been eradicated * Vaccinia: Live attenuated vaccine " | DNA Viruses

Answer 25

**Features:** "Hepdnavirus Family * Partially ds circular DNA * Enveloped * Uses RT (does not integrate into host DNA/not a retrovirus like HIV) * Replicates both in nucleus & cytoplasm; viral DNA Pol completes partial dsDNA upon entry into nucleus; HOST RNA Pol transcribes mRNA from dsDNA" **Reservoir/Transmission:** "* Transmitted via sex & blood products: HBsAg-positive fluids from person with acute or chronic infection * Transmitted during delivery (too large to cross placenta, TORCHES) * Humans are the ONLY host" **Diseases:** "* Causes chronic hepatitis, cirrhosis & hepatocellular carcinoma * Similar to serum sickness (fever, rash, arthralgias) - Purpuric rash with non-blanching dark macules * Polyarthritis nodosa: systemic vasculitis that affects sm/med vessels --> small aneurysms w beads on string appearance --> HTN & decreased GFR (renal dysfunction) * Membranous glomerulonephritis: thickened glomerular membrane --> Membranous proliferative glomerulonephritis: deposits in mesangium Perinatal Transmission: * Newborns infected have a 90% chance of developing chronic infection (older pts are less likely) * Mother who is HBsAg (chronic infection) AND HBeAg (highly infectious) positive is MORE likely to infect NB than if just HBsAg positive" **Diagnosis:** "LFTs: * Alcoholic hepatitis: AST > ALT * Viral hepatitis: ALT > AST * Neonatal hepatitis: Normal ALT in early infection Biomarkers: * HbsAg: first marker of infection (surface ag); required for HDV infection * HbeAg: high levels indicate highly infectious - BOTH in early symptomatic ifection * Anti-HBc: positive during window period; indicates recovery * Anti-HBe: present during low infectivity * Anti-HBs: indicates recovery; checked with vaccination to ensure immunity from vaccine" **Treatment:** "* Acute cases are self-limiting/supportive care * Chronic cases/pregnant women should receive tx: - Lamivudine, IFN-a (Hep C tx), NRTIs (HIV tx) - does NOT eradicate disease, prevents replication * Newborns: anti-Hep B Ig & Hep B vaccine (active & passive immunity) " **Vaccines:** "* Recombinant HBsAg: lasts 20 yrs, 3 doses, booster not routinely recommended; used in: - ALL infants - High risk: MSM, many partners, IVDU" | DNA Viruses

Answer 26

**Features:** "Deltavirus Family * Circular -ssRNA virus * Enveloped (received from HBsAg)" **Reservoir/Transmission:** **Diseases:** "* Requires HBsAg from Hep B to be infectious * Coinfection with simultaneous transmission of Hep B & D * Superinfection with Hep D transmission AFTER Hep B --> worse outcome * Similar presentation to Hep B" **Diagnosis:** **Treatment:** **Vaccines:** | DNA Viruses

Answer 27

**Features:** * Complication with COVID-19 infection **Reservoir/Transmission:** **Diseases:** "* Diagnosis: < 21 yo with fever inflammation, multisystem organ involvement (CV, renal, heme, GI, neuro, derm) - AND no alternative dx - AND recent SARS-CoV-2 infection * Fever > 38'C for > 24 hr * Elevated CRP, ESR, fibrinogen, procalcitonin, d-dimer, ferritin, LDH, IL6, neutrophils; low lymphocytes/albumin * Skin manifestations" **Diagnosis:** **Treatment:** **Vaccines:** | DNA Viruses

Answer 28

**Features:** * < 5 yo, highest rates in Asian ancestry **Reservoir/Transmission:** **Diseases:** "* Febrile exanthematous multisystem med vessel vasculitis * STARTS w fever & irritabillity * Rash: fiery red, confined to groin, demarcated stocking/glove distribution of erythema, digital cyanosis/gangrene * Dx with 5 days of fever + 4/5 of the following: bilateral bulbar conjunctival injection w/o exudate, erythematous mouth/pharynx w strawberry tongue & cracked red lips, polymorphous generalized erythematous rash (NOT vesicular), changes in peripheral extremities, later periungal desquamation, acute unilateral cervical lymphadenitis * CV consequences including aneurysm" **Diagnosis:** **Treatment:** * high dose IVIG + oral aspirin **Vaccines:** | DNA Viruses

Viruses Flashcards

(52 cards)