590 10 Helminths&Chronicsymptomaticinfection:chronicobstructivechangesinthelym-
phaticsystem!hindranceorblockageoftheflowoflymphanddilatationof
thelymphaticvessels(“lymphaticvarices”)!induratedswellingscausedby
connectivetissueproliferationinlymphnodes,extremities(especiallythe
legs,“elephantiasis”),thescrotum,etc.,thickenedskin(Fig. 1 0. 16 ).Lymph-
uria,chyluria,chyloceleetc.whenlymphvesselsrupture.Thisclinicalpicture
developsgraduallyinindigenousinhabitantsoveraperiodof 10 – 15 years
aftertheacutephase,inimmigrantsusuallyfaster.
&Tropical,pulmonaryeosinophilia:syndromewithcoughing,asthmatic
pulmonarysymptoms,high-levelbloodeosinophilia,lymphnodeswelling
andhighconcentrationsofserumantibodies(includingIgE)tofilarialanti-
gens.Nomicrofilariaearedetectableinblood,butsometimesinthelymph
nodesandlungs.Thisisanallergicreactiontofilarialantigens.
Diagnosis.Adiagnosiscanbebasedonclinicalsymptoms(frequenteosino-
philia!)andfindingofmicrofilariaeinblood(bloodsamplingatnightfornoc-
turnalperiodicspecies!).Microfilariaeofthevariousspeciescanbedifferen-
tiatedmorphologicallyinstainedbloodsmears(Table 1 0. 4 ,Fig. 1 0. 17 )andby
DNAanalysis.Conglomerationsofadultwormsaredetectablebyultrasono-
graphy,particularlyinthemalescrotalarea.Detectionofserumantibodies
(group-specificantibodies,specificIgEandIgGsubclasses)andcirculating
antigensarefurtherdiagnostictools(Table 11. 5 ,p.625).Therecentdevelop-
mentofaspecificELISAandasimplequicktest(theICTfilariosiscardtest)
representsagenuinediagnosticprogressduetothehighlevelsofsensitivity
andspecificitywithwhichcirculatingfilarialantigenscannowbedetected,
evenin“occult”infectionsinwhichmicrofilariaearenotfoundintheblood.
Therapy.Bothalbendazoleanddiethylcarbamazinehavebeenshowntobeat
leastpartiallyeffectiveagainstadultfilarialstages.However,optimaltreat-
mentregimensstillneedtobedefined.Adjunctivemeasuresagainstbacterial
andfungalsuperinfectioncansignificantlyreducepathologyandsuffering.
Controlandprevention.In 1997 ,theWHOinitiatedaprogramtoeradicate
lymphaticfilariosis.Themainstaycontrolmeasureismasstreatmentofpop-
ulationsinendemicareaswithmicrofilaricides.Concurrentsingledosesof
twoactivesubstances(albendazolewitheitherdiethylcarbamazineoriver-Fig. 1 0. 16 aInfectionwithWuchereriabancrofti:elephantiasis;binfectionwith
Loaloa:eyelidswelling;conchocercosis:cutaneousnodulescausedbyOnchocerca
volvulus;dblindnesscausedbyO.volvulus;eTrichinellaspiralis;larvaeinrat
musculature;flarvamigransexterna.(Imagesa,b,d:TropeninstitutTu ̈bingen,
c:TropeninstitutAmsterdam; f:DermatologischeKlinikderUniversita ̈tZu ̈rich.) "10
Kayser, Medical Microbiology © 2005 Thieme