Clin Med II Infectious Disease

Clin Med II Infectious DiseaseLecture IIViral Diseases, part 3/3Measles MeaslesAcute systemic paramyxovirus Inhalation of infective dropletsMajor worldwide cause of morbidity and mortality750,000 deaths in 2000 197,000 deaths in 2007 Rising rates of intentional undervaccinationsporadic outbreaksHighly contagious

MeaslesFever (40-40.6 C or 104-105 F)Malaise, coryza, cough, conjunctivitisKoplik spotsRash appears about 4 days after oonset Pinhead-sized papules brick-red, irregular, blochy maculopapular rash may become uniform erythemaFace and behind ears trunk extremities Erythematous pharynx with yellowish tonsillar exudateCoated tongueGeneralized lymphadenopathySplenomegalyMeasles

Measles

MeaslesLabsLeukopenia, thrombodytopenia, proteinuriaCan culture virus from nasopharyngeal washings and bloodIgM measles bodies or 4x rise in serum hemagglutination inhibition, fluorescent antibody staining of respiratory or urinary epithelial cellsComplicationsCNSpostinfectious encephalomyelitismultiple formsread in text Bronchopneumonia, bronchiolitis, bronchiectasisSecondary bacterial infectionsImmune reactivityGastroenteritisConjunctivitis, keratitis, otosclerosisMeaslesTreatment Generalisolation until week following rash onset; bed rest until afebrileAntipyretics and fluidsHigh dose vitamin Amaintains GI and respiratory mucosaTreatment of secondary bacterial infectionsEncephalitissymptomatic treatment only

MeaslesPreventionimmunization (12-15 mo, 4-6 yrs)Do not give in pregnancy or immunosuppressionReport all cases to public health. Refer in cases of HIV and pregnancyAdmit:Meningitis, encephalitis, myelitisSevere pneumoniaDiarrhea that compromises fluid balance

Mumps MumpsSpread by respiratory dropletsChildren are most commonly affectedIncidence highest in springIncubation 14-21 daysUp to 1/3 of infection--asymptomatic

MumpsParotid tenderness, swellingTrismusGlands usually normal within 1 wkFever and malaiseMeningitisOrchitismost common extrasalivary site in adultsPancreatitismost common cause of pancreatitis in children

MumpsLabsmild leukopenia, amylasemia (from salivary glands), mild kidney function abnormalitiesCSFpleiocytosis, hypoglorrhachiaDiagnosisusually characteristic clinical pictureIsolate of virus from swab of the duct of the parotid or other affected salivary glandCan isolate virus from CSF early in aseptic meningitisNucleic acid amplificationmore sensitive than viral culture but limited availabilityElevated IgM--diagnosticMumpsTreatmentisolate till swelling subsides, bed rest till afebrile; symptomatic relief Topical compressesIVIGcan try for complicated disease but no consensusMeningitissymptomatic; manage cerebral edema, airway, vital functionsEpididymoorchitisscrotal support, ice bags, pain reliefPancreatitissymptomatic, hydrationUsually lasts no longer than 2 weeksPreventionlive virus vaccine; routine immunizationOften in combination with measles, rubella and VZVRubella RubellaSystemic disasetogavirus transmitted by inhalation of infective dropletsOne attack usually confers permanent immunityDifficult to distinguish from mono, measles, other viral illnessesarthritis is more prominent in rubellaPrincipal importancedevastating effects on fetus in utero

RubellaFetaldevastatingPostnatally acquiredinnocuousup to 50% asymptomaticFever, malaise, tender suboccipital adenitis, coryzaArthritisfingers, wrists, kneesEarly posterior cervical and postauricular lymphadenopathyErythema of palate and throatFine pink maculopapular rash on face, trunk and extremities in rapid progression (2-3 days) and fades quickly1 day in each areaRubella

RubellaLabsleukopeniaDiagnosiselevated IgM antibody, isolation of virus, 4x or greater rise in IgGFalse positive IgMEpstein-Barr, CMV, parvovirus, RF

Exposure during pregnancyimmediate hemagglutination-binding rubella antibody levelInfection during 1st trimestercongenital rubella in 80%Evaluate immunizationtiters fall to seronegativity in 10% of patients after about 12 yrs

RubellaCongenital rubellausually have wide variety of manifestationseye disease, microphthatlmia, hearing deficits, psychomotor retardation, heart defects, organomegaly, maculopapular rashYounger fetus at infectionmore severe illnessSecond trimesterdeafnessSpecific test for IgM rubella antibody

Postinfectious encephalopathymortality rate 20%RubellaTreatmentsymptomatic (acetaminophen)Prognosismildrarely lasts more than 3-4 daysCongenitalhigh mortality rate and permanent defectsPreventionlive attenuated rubella virus vaccineoften in combination with measles, mumps, and varicellaTry to immunize girls prior to menarcheDo not give immunization during pregnancy In US80% of 20-year-old women are immune to rubellaRoseola RoseolaHuman herpesvirus 6principal cause of exanthema subitumPrimary HHV6children under 2 years; major cause of infantile febrile seizuresMay also see encephalitis and acute liver failureHHV6 encephalitishippocampus, amygdala, limbusSymptomatic HHV6 is rare in immunocompetent adultsmono-like illness (primary) or encephalitis (reactivated)Can see infection during pregnancy / congenital transmissionReactivated diseasemainly in immunocompromised adultsassociated with graft rejection, graft-versus-host disease May cause fulminant hepatic failure and acute decompensation of chronic liver disease in children

Roseola

Influenza InfluenzaHighly contagiousrespiratory droplets3 types of virusesType A infects many mammals and birds, Types B and C infect humans almost exclusivelyType Asubtypes from hemagglutinin (H) and neuraminidase (N)Annual epidemics in fall and winter10-20% of global population each yearPandemicslonger intervals (decades)major genetic reassortment of virus or mutation of animal virusMain current virusesH1N1 and H3N2 subtypes and type B.InfluenzaTypes A and Bclinically indistinguishable infectionsType CminorAbrupt onsetFever, chills, malaise, myalgias, cough substernal soreness, headache, nasal stuffiness, nauseaElderlymay present with only lassitude, confusionMild pharyngeal infection, flushed face, conjunctival redness, cervical lymphadenopathyLabsleukopenia, may see leukocytosis; proteinuria; isolate virus from throat swasbs, nasal washings, cell culturesRapid assaysnasal or throat swabs60-80% sensitivity InfluenzaComplicationsnecrosis of respiratory epitheliumsecondary bacterial infectionsBacterial enzymes activate influenza virusesFrequent complicationssinusitis, otitis media, purulent bronchitis, pneumoniaYoung children, pregnant women, elderly, LTC facility patients, patients with comorbiditieshigher risk of complicationsReadReye Syndrome

InfluenzaTreatmentbed rest, analgesics, cough medicineTreat - suggestive clinical infection or laboratory confirmed influenza and high risk for complicationsNo proven benefit of antivirals after 48 hrs, but should consider if patient is hospitalizedNeuraminidase inhibitorsinhaled zanamivir or oral oseltamivirequally effective in treatmentreduce duration of symptoms and secondary complicationsdo not reduce hospitalizations or mortalityAdamantanesamantadine and rimantadinehigh levels of resistance and not recommended for treatmentPrognosisuncomplicated lasts 1-7 days; excellent prognosis in healthy, nonelderly adultsPreventionannual administration of influenza vaccineReadinformation on flu vaccine including contraindicationsHPV Human Papilloma VirusSkin Wartsflat (superficial) or plantar (deep growths)typically regress over timeHPV 1-4Benign Head and Neck Tumorssingle oral papillomaspedunculated with stalk and rough papillary appearanceLaryngeal papillomasmost often caused by HPV-11most common benign epithelial tumors of larynx; can cause airway obstruction in childrenCondyloma Acuminataalmost exclusively on squamous epithelium of external genitalia and perianal areas90% due to HPV 6 and HPV 11

Human Papilloma VirusSkin Warts

Human Papilloma VirusOral papilloma

Human Papilloma VirusCondyloma Acuminata

Human Papilloma VirusCondyloma Acuminata

Human Papilloma VirusCervical dysplasiakoilocyotic cellsHPV 16-18 (70%)Dysplasia40-70% of lesions spontaneously regressProgressive changes from mild (CIN I) to moderate (CIN II) to severe (CIN III) dysplasia, carcinoma in situ, or both

HPV Diagnosiswart can be confirmed microscopically by histologic appearancehyperplasia of prickle cells and excess keratinHPV infectionkoilocytoctic (vaculolated) squamous epithelia cells that are rounded and occur in clumpsHPV virions on electron microscopyMolecular probes for HPV DNAestablish in cervical swab and tissueHPV does not gro in cell culturesHPV antibodiesrarely usedHuman Papilloma VirusTreatmentspontaneous disappearance of warts is the rule; may take months to yearsCryotherapy, Electrocautery, ChemicalRecurrences are common See guidelines for follow-up on cervical dysplasia

PreventionHPV quadrivalent vaccine (Gardasil)Types 6,11,16,18 HIV HIVWhole chapter of its ownI suggest you read!

You should know:Major risk factors/Modes of transmissionPresenting symptoms (Hallmark of symptomatic HIV?) and major complicationsPrevention measuresHIV risk for health care professionalsMajor pathogens that need prophylaxisIndications for antiretroviral therapy Questions?