Leptospira(Leptospirosis,WeilDisease) 329
damagemainlytheendothelialcellsofthecapillaries,leadingtogreaterper-
meabilityandhemorrhageandinterruptingtheO 2 supplytothetissues.
Jaundiceiscausedbyanonnecrotichepatocellulardysfunction.Disturbances
ofrenalfunctionresultfromhypoxictubulardamage.Aclinicaldistinctionis
drawnbetweenanictericleptospirosis,whichhasamildercourse,andthe
severeclinicalpictureofictericleptospirosis(Weildisease).Inprinciple,any
oftheserovarscouldpotentiallycauseeitherofthesetwoclinicalcourses.In
practice,however,theserogroupicterohemorrhagiaeisisolatedmorefre-
quentlyinWeildisease.
Bothtypesofleptospirosisarecharacterizedbyfeverwithchills,head-
ache,andmyalgiasthatsetinafteranincubationperiodofsevento 12
days.Thisinitialsepticstageofthediseaselaststhreetosevendaysand
isthenfollowedbythesecond,so-calledimmunestage,whichlastsfrom
fourto 30 days.Themostimportantclinicalmanifestationofstagetwoan-
ictericleptospirosisisamild,asepticmeningitis.ThesecondstageofWeil
diseaseischaracterizedbyhepaticandrenaldysfunctions,extensivehemor-
rhaging,cardiovascularsymptoms,andcloudingofthestateofconscious-
ness.Theimmunityconferredbysurvivaloftheinfectionisreliable,but
onlyprotectsagainsttheonespecificserovar.
Diagnosis.Detectionandidentificationofleptospiraeareaccomplishedby
growingtheorganismsincultures.Blood,cerebrospinalfluid,urine,ororgan
biopsies,whichmustnotbecontaminatedwithotherbacteria,areincubated
inspecialmediumsat 27 – 308 Cforthreetofourweeks.Amicroscopecheck
(darkfield)iscarriedouteveryweektoseeifanyleptospiraeareproliferating.
TheLeptospiraearetypedserologicallyinalysis-agglutinationreactionwith
specifictestsera.
Themethodofchoiceforalaboratorydiagnosisisanantibodyassay.
Theantibodiesproducedafterthefirstweekoftheinfectionaredetected
Leptospirainterrogans
Fig.4. 26 Serogroup
icterohemorrhagiae.
Culturepreparation.
Darkfieldmicroscopy.
4
Kayser, Medical Microbiology © 2005 Thieme