傳染病學(xué)英文版課件：Typhoid fever2

TyphoidfeverInfectiousDiseaseDefinitionAninfectiousfeverishdiseasecausedbythebacteriumSalmonellatyphi(SalmonellaentericaSerovarTyphi)andlesscommonlybySalmonellaparatyphi.Acutegeneralizedinfectionofthereticuloendothelialsystem,intestinallymphoidtissue,andthegallbladder.Theinfectionalwayscomesfromanotherhuman,eitheranillpersonorahealthycarrierofthebacterium.Thebacteriumispassedonwithwaterandfoodsandcanwithstandbothdryingandrefrigeration.History

AntoniusMusa,aRomanphysicianwhoachievedfamebytreatingtheEmperorAugustus2,000yearago,withcoldbathswhenhefellillwithtyphoid.

ThomasWilliswhoiscreditedwiththefirstdescriptionoftyphoidfeverin1659.

FrenchphysicianPierreCharlesAlexandreLouisfirstproposed

thename“typhoidfever”

WilliamWoodGerhardwhowasthefirsttodifferentiateclearlybetweentyphusfeverandtyphoidin1837.

CarlJosephEberthwhodiscoveredthetyphoidbacillusin1880.GeorgesWidalwhodescribedthe

‘Widalagglutinationreaction’ofthebloodin1896.

1.Thebestknowncarrierwas"TyphoidMary“;MaryMallonwasacookinOysterBay,NewYorkin1906whoisknowntohaveinfected53people,5ofwhomdied.2.Laterreturnedwithfalsenamebutdetainedandquarantinedafteranothertyphoidoutbreak.3.Shediedofpneumoniaafter26yearsinquarantine.

Causes

1.CausedbythebacteriumSalmonellaTyphi.

2.

Ingestionofcontaminatedfoodorwater.3.Contactwithanacutecaseoftyphoidfever.

4.Wateriscontaminatedwhereinadequateseweragesystemsandpoorsanitation.5.Contactwithachronicasymptomaticcarrier.

6.Eatingfoodordrinkingbeveragesthathandledbyapersoncarryingthebacteria.

7.SalmonellaenteriditisandSalmonellatyphimuriumareothersalmonellabacteria,causefoodpoisoninganddiarrhoea.

SalmonellaEntricaMemberofthegenusSalmonella.Rodshaped,flagellated,aerobic,Gramnegativebacterium.Largenumberoffimbrialandnon-fimbrialadhesins

arepresent,mediatebiofilmformationandcontacttohostcells.Secretedproteinsinvolvedinhostcellinvasionandintracellularproliferation.Infectscattle,poultry,domesticcats,hamsters,humansetc.Refrigerationandfreezingsubstantiallysloworhalttheirgrowth.Pasteurizingandfoodirradiation

killSalmonellaforcommercially-producedfoodstuffscontainingraweggssuchasicecream.Foodspreparedinthehomefromraweggscanspreadsalmonellaifnotproperlycookedbeforeconsumption.Howdoesthebacteriacausedisease?

Ingestionofcontaminatedfoodorwater

SalmonellabacteriaInvadesmallintestineandenterthebloodstreamCarriedbywhitebloodcellsintheliver,spleen,andbonemarrowMultiplyandreenterthebloodstream

Bacteriainvadethegallbladder,biliarysystem,andthelymphatictissueofthebowelandmultiplyinhighnumbersThenpassintotheintestinaltractandcanbeidentifiedfordiagnosisinculturesfromthestooltestedinthelaboratorySymptomsNosymptoms-ifonlyamildexposure;somepeoplebecome"carriers"oftyphoid.Poorappetite,Headaches,Generalizedachesandpains,Fever,Lethargy,Lethargy,Lethargy,Diarrhea,Haveasustainedfeverashighas103to104degreesFahrenheit(39to40degreesCelsius),Chestcongestiondevelopsinmanypatients,andabdominalpainanddiscomfortarecommon,Constipation,mildvomiting,slowheartbeat.

Rosespots

HighfeverDiarrhea

TyphoidMeningitis

AchesandpainsChestcongestion

TimeframeOccursgraduallyoverafewweeksafterexposuretothebacteria.Sometimeschildrensuddenlybecomesick.Theconditionmaylastforweeksorevenamonthorlongerwithouttreatment.

First-StageTyphoidFeverThebeginningstageischaracterizedbyhighfever,fatigue,weakness,headache,sorethroat,diarrhea,constipation,stomachpainandaskinrashonthechestandabdominalarea.AccordingtotheMayoClinic,adultsaremostlikelytoexperienceconstipation,whilechildrenusuallyexperiencediarrhea.

SecondstageSecond-stage

typhoidfeverischaracterizedbyweightloss,highfever,severediarrheaandsevereconstipation.Also,theabdominalregionmayappearseverelydistended.TyphoidState

Whentyphoidfevercontinuesuntreatedformorethantwoorthreeweeks,theeffectedindividualmaybedeliriousorunabletostandandmove,andtheeyesmaybepartiallyopenduringthistime.Atthispointfatalcomplicationsmayemerge.Diagnosis

DiagnosisoftyphoidfeverismadebyBlood,bonemarrow,orstoolculturestestWidaltestSlideagglutinationAntimicrobialsusceptibilitytesting

Widaltest

"Atestinvolvingagglutinationoftyphoidbacilliwhentheyaremixedwithserumcontainingtyphoidantibodiesfromanindividualhavingtyphoidfever;usedtodetectthepresenceofSalmonellatyphiandS.paratyphi."StandardtesttubemethodTakefoursetsof8testtubesandlabelthem1to8forO,H,AHandBHantibodydetection.

PipetteintothetubeNo.1ofallsets1.9mlofisotonicsaline.Toeachoftheremainingtubes(2to8)add1.0mlofisotonicsaline.TothetubeNo.1tubeineachrowadd0.1mloftheserumsampletobetestedandmixwell.Transfer1mlofthedilutedserumfromtubeno.1totubeno.2andmixwell.Discardthe1mlofthedilutedserumfromtubeno.7ofeachset.Tubeno.8inallsets,servesasasalinecontrol.Nowthedilutionoftheserumsampleachievedineachsetisasfollows:Tubeno.12345678(control)Dilutions1:201:401:801:1601:3201:6401:1280–Toalltubes(1to8)ofeachsetaddonedropoftherespectiveWIDALTESTantigensuspension(O,H,AH,BH)fromreagentvialsandmixwell.Coverthetubesandincubateat37Covernight(approx.18hrs).Dislodgethesedimentedbuttongentlyandobserve.

HowdoyoureadWidaltestresultsfortyphoidfever?

Thehighestdilutionofthepatientsseruminwhichagglutinationsoccursisnoted,ex.ifthedilutionis1in160thenthetiteris169.Agglutinationindilutionupto<1:60isseeninnormalindividuals.Agglutinationindilution1:160issuggestiveofSalmonellainfection.Agglutinationindilutionofandmorethan1:320isconfirmatoryofEntericfever.

PreventionAndTreatmentPrevention

Twomaintyphoidfeverpreventionstrategies:

1.VaccinationFirsttypeofvaccine:ContainskilledSalmonellatyphibacteria.Administeredbyashot.

Secondtypeofvaccine:ContainsalivebutweakenedstrainoftheSalmonellabacteriathatcausestyphoidfever.Takenbymouth.

Bevaccinatedagainsttyphoidwhiletravelingtoacountrywheretyphoidiscommon.Needtocompleteyourvaccinationatleastoneweekbeforetravel.Typhoidvaccineslosetheireffectivenessafterseveralyearssocheckwithyourdoctortoseeifitistimeforaboostervaccination.

2.AvoidriskyfoodanddrinksBuybottleddrinkingwaterorbringittoarollingboilforoneminutebeforedrinkingit.Askfordrinkswithoutice,unlesstheiceismadefrombottledorboiledwater.AvoidPopsiclesandflavoredices.Eatfoodthathavebeenthoroughlycookedandthatarestillhotandsteaming.Avoidrawvegetablesandfoodthatcannotbepeeledlikelettuce.Wheneatrawfruitandvegetablesthatcanbepeeled,peelyourself.Don’teatthepeelings.Avoidfoodsandbeveragesfromstreetvendors.Treatment

ConsultationsAninfectiousdiseasespecialistorsurgeonshouldbeconsulted.

SurgicalCareUsuallyindicatedincasesofintestinalperforation.Mostsurgeonsprefersimpleclosureoftheperforationwithdrainageoftheperitoneum.Small-bowelresectionisindicatedforpatientswithmultipleperforations.Ifantibiotictreatmentfailstoeradicatethehepatobiliarycarriage,thegallbladdershouldberesected.Cholecystectomyisnotalwayssuccessfulineradicatingthecarrierstatebecauseofpersistinghepaticinfection.

DietFluidsandelectrolytesshouldbemonitoredandreplaceddiligently.Oralnutritionwithasoftdigestibledietispreferableintheabsenceofabdominaldistensionorileus.

ActivityNospecificlimitationsonactivityareindicated.Restishelpful,butmobilityshouldbemaintainediftolerable.Thepatientshouldbeencouragedtostayhomefromworkuntilrecovery.Somecommonhomeremedies

TaketwograinsofUnnab,Munnakka4,Kuhbkalan3gm's.andMisri10gm's.grindallofthemandmixin100ml.ofwater,preferablyboiledandcooled.Strainthewaterandmakethepatientdrinkatfourhourlyinterval.Take4basilleaves,saffron7shreds,7grainsofblackpepper.Grindthemtoapastebyaddingwaterandformsmalltabletsoutofthewholelot.Takeeachtablettwiceorthriceeverydaywithlukewarmmilk.Thefeverwouldalsosubsideandthepatientwouldgetthedesiredrelief.1to2teaspoonsoffreshjuiceofcorianderleavesmixedin1cupbuttermilkandtaken2-3timesaday.Masharipebananaalongwith1tablespoonhoneyandeattwiceadayforafewdays.

Medication

AntibioticsAntibiotics,suchasampicillin,chloramphenicol,fluoroquinolonetrimethoprim-sulfamethoxazole,Amoxicillinandciprofloxacinetcusedtotreattyphoidfever.Prompttreatmentofthediseasewithantibioticsreducesthecase-fatalityratetoapproximately1%.

12FluoroquinolonesOptimalforthetreatmentoftyphoidfeverRelativelyinexpensive,welltoleratedandmorerapidlyandreliablyeffectivethantheformerfirst-linedrugs,viz.chloramphenicol,ampicillin,amoxicillinandtrimethoprim-sulfamethoxazole.Themajorityofisolatesarestillsensitive.Attainexcellenttissuepenetration,killS.typhiinitsintracellularstationarystageinmonocytes/macrophagesandachievehigheractivedruglevelsinthegallbladderthanotherdrugs.Rapidtherapeuticresponse,i.e.clearanceoffeverandsymptomsinthreetofivedays,andverylowratesofpost-treatmentcarriage.Bindsto50Sbacterial-ribosomalsubunitsandinhibitsbacterialgrowthbyinhibitingproteinsynthesis.Therecommendeddosageis50-75mgperkgperdayfor14daysdividedintofourdosesperday,orforatleastfivetosevendaysafterdefervescence.Oraladministrationgivesslightlygreaterbioavailabilitythanintramuscular(i.m.)orintravenous(i.v.)administrationofthesuccinatesalt.Thedisadvantagesofusingchloramphenicolincludearelativelyhighrateofrelapse(57%),longtreatmentcourses(14days)andthefrequentdevelopmentofacarrierstateinadults.ChloramphenicolCeftriaxone:50-75mgperkgperdayoneortwodosesCefotaxime:40-80mgperkgperdayintwoorthreedosesCefoperazone:50-100mgperkgperdayCephalosporinsAmoxicillin(Trimox,Amoxil,Biomox)

Interfereswithsynthesisofcellwallmucopeptidesduringactivemultiplication,resultinginbactericidalactivityagainstsusceptiblebacteria.Atleastaseffectiveaschloramphenicolinrapidityofdefervescenceandrelapserate.Convalescencecarriageoccurslesscommonlythanwithotheragentswhenorganismsarefullysusceptible.UsuallygivenPOwithadailydoseof75-100mg/kgtid(threetimesaday)for14d.Adult1gPOq8hPediatric20-50mg/kg/dPOdividedq8hfor14d

Trimethoprimandsulfamethoxazole

Inhibitsbacterialgrowthbyinhibitingsynthesisofdihydrofolicacid.AntibacterialactivityofTMP-SMZincludescommonurinarytractpathogens,exceptPseudomonasaeruginosa.Aseffectiveaschloramphenicolindefervescenceandrelapserate.Trimethoprimalonehasbeeneffectivei