Medical Microbiology

host,theybindhostcomponentstotheirsurface(IgM,complement,erythro-

cytereceptor)and,thusequipped,coupletomacrophagereceptors.Theyare

thenphagocytosedandenclosedinaphagolysosome,wheretheyarepro-

tectedfromtheeffectsoflysosomalenzymesinteraliabysubstancesintheir

cellmembrane.Thepromastigotesquickly(within 12 – 14 hours)transform

intoamastigotestages,whicharefinallysurroundedbyaparasitophorous

vacuolewithinthephagolysosomeandreproducebybinaryfission.The

amastigoteformsarethenreleasedinaprocessresemblingexocytosisand

caninfectnewcells.

Clinicalmanifestationsandimmunology.Themostimportanthumanforms

ofleishmaniosesaresummarizedinTable9. 4 .Itisimportanttonotethatin

CLandMCLtheparasitesgenerallyremainrestrictedtotheskinorskinand

mucosa.CLlesionsmaypersistforlongperiods,buttendtohealsponta-

neously,whereasagreatertendencytodestructivechangesisseeninMCL

infections.Bycontrast,inVLtheleishmaniaorganismscaninvadetheentire

496 9 Protozoa

Table9. 4 Continued:SelectedFormsofLeishmaniosesinHumans

&L.(L.)aethiopica: Ethiopia,Kenya.Cutaneousleishmaniosis.Reservoirhosts:

rockhyraxandbushhyrax.Vectors:Phlebotomusspecies.

Americancutaneousandmucocutaneousleishmanioses

Mainlocalization: Skin,mucosa.

Primarysymptoms: Skinchangessimilartoorientalsore.Someformstendto

spreadtomucosaandcauseseveretissuedestruction.

&L.(L.)mexicana-

complex:

SouthernUS(Texas),partsofCentralAmericaandnorthern

SouthAmerica.VariousLeishmaniasubspecies.Destructive

cutaneousform.Reservoirhosts:woodlandrodents.

Vectors:Lutzomyiaspecies.

&L.(V.)braziliensis

complex:

PartsofCentralandSouthAmerica.VariousLeishmania

subspecies.Mucocutaneousform(“espundia”).Reservoir

hosts:woodlandrodents,sloth,opossum.Vectors:

Lutzomyiaspecies.

&L.(V.)peruviana: Peru(Andes).Cutaneousform(“uta”).Reservoirhosts:dogs.

Vectors:Lutzomyia

(^1) Kala(Hindi)azar(Persian)=blackdisease(duetohyperpigmentationofskincaused
bytheinfection)isthenamegiveninIndiatotheinfectioncausedbyL.(L.)donovani.
(^2) Reservoirhosts:Epidemiologicallysignificanthostsfromwhichvectorscantransmit
parasitestohumans.Inparentheseswithquestionmark:significancequestionable.
(^3) L.chagasiandL.infantumhavemanysimilarities.ItisthereforeassumedthatL.in-
fantumwasimportedtoSouthAmericaindogsfromEurope.
9
Kayser, Medical Microbiology © 2005 Thieme