crossmark Human Infections with Sarcocystis Species RonaldFayer,aDouglasH.Esposito,bJitenderP.Dubeya U.S.DepartmentofAgriculture,AgriculturalResearchService,Beltsville,Maryland,USAa;DivisionofGlobalMigrationandQuarantine,NationalCenterforEmergingand ZoonoticInfectiousDiseases,CentersforDiseaseControlandPrevention,Atlanta,Georgia,USAb SUMMARY..................................................................................................................................................295 INTRODUCTION............................................................................................................................................295 LifeCycleStages..........................................................................................................................................296 SpeciesInfectingAnimals................................................................................................................................297 SpeciesInfectingHumans................................................................................................................................297 SourcesofIntestinalandMuscularSarcocystosis.........................................................................................................300 PREVALENCE,SYMPTOMS,ANDDIAGNOSISOFINFECTIONINHUMANS ...............................................................................301 D IntestinalSarcocystosisSpeciesandSymptoms..........................................................................................................301 o w IntestinalSarcocystosisinEurope........................................................................................................................301 n IntestinalSarcocystosisinAsia............................................................................................................................304 lo IntestinalSarcocystosisinAustralia.......................................................................................................................305 a IntestinalSarcocystosisinNorthandSouthAmerica.....................................................................................................305 d DiagnosisofIntestinalSarcocystosis.....................................................................................................................305 e d ExtraintestinalSarcocystosis..............................................................................................................................305 f OutbreaksandCaseDescriptions........................................................................................................................306 r o SarcocystosisandCardiomyopathy......................................................................................................................307 m SarcocystosisandGlomerulonephritis...................................................................................................................307 h SarcocystosisandMalignancy............................................................................................................................307 t IMMUNITY,PROPHYLAXIS,ANDTREATMENT ............................................................................................................307 tp IntestinalSarcocystosis...................................................................................................................................307 :/ / MuscularSarcocystosis...................................................................................................................................308 c m PREVENTION................................................................................................................................................308 CONCLUSIONS.............................................................................................................................................309 r. a REFERENCES................................................................................................................................................309 s AUTHORBIOS..............................................................................................................................................311 m . o r g / SUMMARY INTRODUCTION o n Recurrentoutbreaksofmuscularsarcocystosisamongtourists SarcocystisisclassifiedinthephylumApicomplexa,alongwith A visiting islands in Malaysia have focused international atten- speciesofEimeria that cause coccidiosis in poultry and live- p r tion on sarcocystosis, a disease once considered rare in hu- stock;Toxoplasmagondii,whichinfectsvirtuallyallwarm-blooded il 3 mans.Sarcocystisspeciesrequiretwohosts,definitiveandinter- vertebrates;andspeciesofCystoisosporathatinfecthumansanda , mediate, to complete their life cycle. Humans can serve as varietyofanimals.Sarcocystisspeciesareubiquitousinnatureand 2 0 definitive hosts, with intestinal sarcocystosis for two species arefoundworldwide.Twohostsarerequiredtomaintainthelife 1 9 acquired from eating undercooked meat: Sarcocystis hominis, cycle: an intermediate or prey host, in which cysts (sarcocysts) b from beef, and Sarcocystis suihominis, from pork. Symptoms containinginfectiouszoitesinfectthemuscles,andadefinitive, y such as nausea, stomachache, and diarrhea vary widely de- final,orpredatorhostthatingeststhecysts,becomesinfectedwith g u pendingonthenumberofcystsingestedbutappearmorese- intestinal-stageparasites,andexcretesoocystsorsporocystsinto e vere with pork than with beef. Humans serve as intermediate theenvironment.Forthe(cid:2)150speciesofSarcocystis,mostinter- st hostsforSarcocystisnesbitti,aspecieswithareptiliandefinitive mediatehostsincludeherbivorousmammalsandhumansandother primatesbutalsosomebirds,reptiles,andpossiblyfish.Definitive host, and possibly other unidentified species, acquired by in- hostsincludecarnivoresoromnivores,includinghumansandsome gestingsporocystsfromfeces-contaminatedfoodorwaterand reptilesandraptorialbirds(1).Althoughothersmayexist,onlySar- the environment; infections have an early phase of develop- cocystisnesbittihasbeenidentifiedinhumansandnonhumanprimates ment in vascular endothelium, with illness that is difficult to servingasintermediatehosts,withasnakepossiblyservingasthedefini- diagnose; clinical signs include fever, headache, and myalgia. Subsequent development of intramuscular cysts is character- izedbymyositis.Presumptivediagnosisbasedontravelhistory Published25February2015 totropicalregions,elevatedserumenzymelevels,andeosino- CitationFayerR,EspositoDH,DubeyJP.25February2015.Humaninfectionswith philiaisconfirmedbyfindingsarcocystsinmusclebiopsyspec- Sarcocystisspecies.ClinMicrobiolRevdoi:10.1128/CMR.00113-14. imens.Thereisnovaccineorconfirmedeffectiveantiparasitic AddresscorrespondencetoRonaldFayer,[email protected]. drugformuscularsarcocystosis,butanti-inflammatorydrugs Copyright©2015,AmericanSocietyforMicrobiology.AllRightsReserved. may reduce symptoms. Prevention strategies are also dis- doi:10.1128/CMR.00113-14 cussed. April2015 Volume28 Number2 ClinicalMicrobiologyReviews cmr.asm.org 295 Fayeretal. D o w n lo FIG1Humansasdefinitive(final)hostsforSarcocystisspecies. a d e d tivehost.However,thisidentificationisbasedonacomparisonofavail- riodestablishedtherequisiterelationshipofthetwo-host,prey- fr o ablecongenersthatmostcloselymatchedthoseofspeciesinwhichsnakes predator(intermediatehost-definitivehost)lifecycleforallspe- m werethefinalhostsandhasyettobeconfirmed.Twospecies,Sarcocystis ciesofSarcocystis. h hominisandS.suihominis,havebeenidentifiedinhumansandnon- tt p humanprimatesservingasdefinitivehosts(Fig.1). LifeCycleStages : / / Earlyknowledgeofinfectionsinhumansisscantbecausethe Inintermediatehosts,includinghumans,onlyasexual-stagepar- c m relationship between infection and symptoms was not under- asitesarefound(Fig.2).Theinitialstagesofasexualdevelopment r stood,tissuespecimenswererare,lightmicroscopy(LM)hadlim- areknownfromanimalstudiesbuthavenotbeenseeninhuman .a s itations, the life cycle was unknown, and other diagnostic tools tissues.ThefollowingdescriptionsarebasedonSarcocystiscruzi m werenotdeveloped.Thefirstrecordofwhatwouldbecomerec- development in cattle. Infection begins when oocysts or sporo- . o ognized as Sarcocystis was in 1843 by Meischer, who observed cystsinfecesfromafinalhostbecomeingestedbyasusceptible r g long,thin,whitecystsinmusclesofadeermouseinSwitzerland intermediatehost.Exposuretotrypsinandbilecausestheplates / o (1). For the following 2 decades, this parasite with no scientific that form the sporocyst wall to disunite, liberating four motile n name was called Meischer’s tubules. In 1865, a parasite with a sporozoites contained within. The sporozoites pass into or A similar appearance in muscles of a pig was then described by throughthegutwallandarefirstfoundwithinendothelialcells p r Kuhn,whoproposedthenameSynchytriummiescherianum(1). thatlinesmallarteriesinallpartsofthebody.Thisisthefirstof il 3 However,thenameSynchytriumwasalreadyinuseforanother approximatelyfourcyclesofasexualdevelopment,calledmer- , organism.Thus,in1899,LabbechangedthenametoSarcocystis ogony or schizogony, the number and timing of which may 2 0 meischeriana(1),anditbecamethetypespeciesofthegenus.In vary with the species. During each of the first three cycles, 1 9 the following decades, many species of Sarcocystis were named nucleardivisioneventuallygivesrisetomerozoites,whichare b basedonfindingintramuscularcystsinvariousanimals,andthese motile,crescent-shapedorganismswithastructuresimilarto y werereferredtoassarcocysts.InsomereferencestoSarcocystis,the that of sporozoites. Subsequent generations are found down- g u termsarcosporidiumwasused.Thispossiblyresultedfromstud- stream,inarterioles,andthenincapillariesandinveinsinall e iesinwhichsarcocystsinculturemediaappearedtodevelophy- partsofthebodyuntilthelastgenerationdevelopsinskeletal, s t phaeandmyceliaresultingfromcontamination,andSarcocystis smooth,andcardiacmuscles,andsometimesinneuraltissue, thereforewasthoughttobeatypeoffungalorganism.In1967, wheresarcocystsareformed. electron micrographs clearly demonstrated that the organisms ForS.cruzi,thefirstgenerationisfound(cid:3)2weeksafteringes- containedwithinthesarcocystswerenotfungalsporesbutwere tionofsporocysts(Fig.3A),andthesecondgenerationisfoundas zoites morphologically similar to those of other apicomplexan singlesorpairsofmerozoiteswithinmononuclearcellsinperiph- protozoa(2),removinganyconsiderationthatSarcocystiswastax- eralbloodnearly4weeksafteringestionofsporocysts(Fig.3C).A onomicallyrelatedtofungi.Otherlifecyclestagesremainedun- fewdaystoaweeklater,thethirdgenerationisseenasimmature knownuntilthe1970s,whenzoitesfreedfromsarcocystsinthe multinucleateschizontsormatureschizontscontainingmerozo- muscles of grackles (Quiscalus quiscula) developed into sexual- itesinendothelialcellsofcapillariesthroughoutthebody,butthey stage parasites and oocysts in cultured mammalian cells (3, 4). areespeciallyprominentinrenalglomeruli(Fig.3B).Merozoites Additionally, sarcocysts from cattle were fed to cats, dogs, and fromtheseschizontsentermusclecells,wheretheybeginsarcocyst humans, establishing three distinct species, with the proposed formation, first differentiating into a single round cell, called a namesSarcocystisbovifelis,S.bovicanis,andS.bovihominis,com- metrocyteormothercell.Aseriesofdivisionsgivesrisetonumer- binations representing two hosts (5–7). Although these species ousmetrocytesasthesarcocystgrowswhile,concurrently,awall nameswerelaterchanged,thecumulativefindingsfromthispe- develops, isolating the sarcocyst from the surrounding muscle 296 cmr.asm.org ClinicalMicrobiologyReviews April2015 Volume28 Number2 SarcocystosisinHumans D o w n lo a FIG2HumansasaberrantintermediatehostsforSarcocystisspecies. d e d f r o (Fig. 3D). At the time when metrocytes develop into infectious foursporozoitesandaclusterofresidualgranules(Fig.3I).Sporo- m bradyzoites,alsoreferredtoascystozoitesorjustzoites,thesar- cystsofS.hominisandS.suihominishaveaveragesizesof9.3by h cocystisconsideredmature(Fig.3EandF).Thematurationtime 14.7and10.5by13.5(cid:4)m,respectively,andareimmediatelyin- tt p appearstodifferamongspeciesandcantake2monthsormoreto fectiouswhenexcreted(1). : / / complete,butthesarcocystcanthenpersistformonthsoryears. c m Dependingonthespecies,sarcocystsdifferinsizeandshapefrom SpeciesInfectingAnimals r microscopictomacroscopic.Theyrangefromafewmicrometers SomespeciesofSarcocystisthatinfectagriculturalandcompanion .a to several millimeters in length, range from narrow to wide in animals,suchascattle,sheep,andhorses,areofeconomicimpor- sm circumference, and have a great variety of wall structures that tancebecausetheycauseillnessthatresultsinfever,lethargy,poor . o differinthicknessandinpatternsofperipheralprotrusionscalled growth,poorfeeduse,reducedmilkproduction,lameness,wool r g cytophaneres.Sevenmorphologicallyuniquewallstructureswere andhairloss,abortion,carcasscondemnationatmeatinspection, / o describedinearlyreportsofsarcocystsfoundinhumanmuscles aswellasdeath.Informationobtainedfromsuchinfectionshas n (8)(Table1),butmostsubsequentreportsofintramuscularsar- been helpful in understanding aspects of clinical disease in hu- A cocystosis in humans did not identify wall morphology (9–31) mans. For example, data on hematology, serum enzyme level p r (Table2).Somesarcocystshaveinternalseptathatformcompart- changes,theinflammatoryresponse,histopathology,thelocation il 3 ments,whileinothers,noseptaareapparent.Theseptaandcyto- andtimingofdevelopmentalstages,thefebrileresponse,theneg- , phaneresmaybedifficulttodistinguishbylightmicroscopyand ativeimpactongrowth,abortion,andotherfactorshavebeenwell 2 0 arebestseenbyelectronmicroscopy.Sarcocystscanbefoundin documentedfromexperimentalandoutbreakstudiesofsarcocys- 1 9 the muscles of limbs, tongue, esophagus, diaphragm, and heart tosisinlivestockandhavebeenreviewed(1,32). b but also in neural tissue in the brain, spinal cord, and Purkinje y fibers. SpeciesInfectingHumans g u Sexualstagesoccurindefinitivehosts.Afterasusceptiblehost Humanscanbeeitherfinalorintermediatehosts(Fig.1and2). e haseatenmeatcontainingmaturesarcocysts,thewallofthesar- Humans can become final hosts after eating undercooked pork s t cocystbecomesdigestedorbroken.Bradyzoiteswithinthesarco- and beef harboring mature sarcocysts of S. suihominis and S. cystsarereleasedandcansoonbefoundintracellularlyinvilliof hominis,respectively.Tissuesofmanyspeciesofdomesticatedan- thesmallintestine.Eachbradyzoitetransformsintoeitherami- imals,wildmammals,birds,andreptilesthatareeatenformeat crogamont (male) or a macrogamont (female) stage (Fig. 3G). throughouttheworldcontainsarcocystscapableofinfectingun- Microgametocytes become multinucleate, and a sperm-like mi- identified final hosts, possibly including humans and with un- crogamete forms around each nucleus. A single flagellated mi- knownhealthconsequences.Therefore,theremaybeadditional crogametefindsandfuseswithamacrogamont.Theirnucleicom- undocumentedspeciesforwhichhumanscanserveasadefinitive bine,andthefertilizedmacrogamontdevelopsintoanoocystthat host.AlthoughsporocystsinthefecesarediagnosticforSarcocystis sporulatesinsitu,formingtwosporocyststhateachcontainfour infectionsofdefinitivehosts,theyaresomorphologicallysimilar sporozoites(Fig.3H).Althoughoocystsareimmobile,theyreach thatspeciescannotbedifferentiatedsimplybythesizeandshape thelumenoftheintestineandareexcretedwithfeces,sometimes ofsporocysts. intactwithabarelyvisiblewall,appearingasapairofsporocysts, WithintheSarcocystislifecycle,humanswhoareinfectedwith ormoreoften,thefragilewallbreaks,andindividualsporocysts muscular sarcocystosis are considered aberrant intermediate arereleased.Sporocystsofvirtuallyallspeciesareindistinguish- hostsbecausetheyaccidentlysubstituteforthenaturalhoststhat ablefromoneanother,measuring(cid:3)10by15(cid:4)mandcontaining routinelyserveaspreyforadefinitivepredatorhost.Thenum- April2015 Volume28 Number2 ClinicalMicrobiologyReviews cmr.asm.org 297 Fayeretal. D o w n lo a d e d f r o m h t t p : / / c m r . a s m . o r g / o n A p r il 3 , 2 0 1 FIG3Sarcocystisstagesintissuesofintermediatehosts(AtoF)anddefinitivehosts(GtoI).PanelsAtoGshowhematoxylin-stainedimages.Allimagesareof 9 S.cruzi,exceptpanelE,whichisanimageofS.hominis.(A)Arterywithafirst-generationmultinucleateschizont(arrow)inanendothelialcell.(B)Kidney b glomeruluswithimmature(arrowhead)andmature(arrow)second-generationschizonts.(C)Bloodsmearwithamerozoiteinamononuclearcell.(D)Heart y withanimmaturesarcocystcontainingglobularmetrocytes.(E)Skeletalmusclewithacrosssectionofamaturesarcocystwithathickstriatedwallsurrounded g byamononuclearcellinfiltrate.(F)Skeletalmusclewithlongitudinalandcrosssectionsofsarcocysts.Thewasnoinflammatoryresponse.(G)Laminapropria u e ofsmallintestinewithamacrogametocyte(arrow).(H)Smallintestinewithsporulatedsporocysts(arrow)(Whipf’spolychromestain).(I)Phase-contrast s microscopyoftwosporocystsinafecalfloat. t berofspeciesforwhichhumanscanserveasanintermediate cocystis nesbitti (26–28) based on 18S ribosomal DNA (rDNA) hostisunknown,buttheremaybesevenormorespeciesbased sequencedata.Sarcocystisnesbitti,describedbyMandourin1969, on differences in sarcocyst wall morphology observed in hu- wasoriginallydetectedinmusclesfromarhesusmonkeybasedon mantissuespecimens(8).Sarcocystwallmorphologyhasalso LM,butitstaxonomicvalidityisquestionable,andtherearenei- been used to differentiate species in animals (1). The use of ther transmission electron microscopy (TEM) morphological sarcocystwallmorphologytodistinguishspecieshasbeencon- datanorLMphotographicsupportfortheoriginaldescription. troversial because morphology can be difficult to discern by Nevertheless,thefirstreportofSarcocystisinnonhumanprimates lightmicroscopy,canbeaffectedduringtheprocessingoftis- (Macacafascicularis)inChina,whichwassupportedbyLMand sues,andcanchangewiththeageofthesarcocysts.Molecular TEMstudies(33),wasbasedontheperceivedresemblancetoS. methods have been used but have been extremely limited. nesbitti,sothoseauthorsnamedtheorganismsthattheyfoundin Greater use will extend and confirm species identity and im- M.fascicularismusclesS.nesbitti.Morphologicalsimilaritiessug- provediagnosisofinfections. gestedthatonespeciesofSarcocystismightinfectMacacafascicu- HumanshavebeenidentifiedasanintermediatehostforSar- laris,Macacamulatta,Papiopapionis,Cercocebusatys,aswellas 298 cmr.asm.org ClinicalMicrobiologyReviews April2015 Volume28 Number2 SarcocystosisinHumans TABLE1Summarizationofearlyreportsofhumanswithsarcocystsc Patientage(yr), Countryorregion gender Sarcocystlocation(s) Biopsyorautopsy Sarcocysttypeb Originalauthor(s),yra Sudan 36,M Abdomen A 2 Kartuli,1893 France Adult,M Larynx A 1 BarbaranandSt.Remy,1894 France Adult,unknown Skeletalmuscle A 1 Vuillemin,1902 Malaysia 30,M Tongue A 4 Darling,1919 UK Unknown Heart A 6 Manifold,1924 India 55,M Chest B 2 Vasudevan,1927 USAviaWestIndies 32,F Heart A 7 Lambert,1927 Indonesia 20,M Cheek B 4 BonneandSoewandi,1929 China Adult,M Leg B 1 Feng,1932 UK Adult,F Heart A 5 Hewett,1933 Panama 11,F Heart A 7 Gilmoreetal.,1942 Panama 48,F Heart A 7 KeanandGrocott,1943 Brazil 32,F Heart A 7 DeFreitas,1946 D USAviaGermany 31,M Heart A 7 Arai,1949 o w USAviaPuertoRico 34,M Heart A 7 Arai,1949 n India 37,M Leg B 2 DasturandIyer,1955 lo India 20,M Leg B DasturandIyer,1955 a Sudan 45,M Foot B 3 McKinnonandAbbott,1955 d e UKviaIndia 60,M Pectoral B 2 McGillandGoodbody,1957 d Brazil 40,F Heart A 6 Koberle,1958 f r Italy 17,F Heart A 5 D’ArrigoandSquillaci,1962 o m Indonesia 51,M Pectoral B 4 VanThielandVandenBerg,1964 UKviaSoutheastAsia 51,M Leg B 4 Mandour,1965 h t Angola 30,F Chest B 2 LiuandRoberts,1965 tp India 22,F Leg,arm B 2 Guptaetal.,1973 :/ / SoutheastAsia 21,M Leg B 3 Jeffrey,1974 c m UKviaMalaysia 34,M Pectoral B 4 Jeffrey,1974 r Malaysia 34,M Larynx B 4 KuttyandDissanaike,1975 .a Malaysia 12,F Pharynx A 4 Kuttyetal.,1975 s m India 56,M Arm B 3 Agarwaletal.,1976 . India 54,F Leg B 3 Thomas,1976 o r Malaysia 20,M Foot B 4 PrathapandDissanaike,1976 g / Malaysia 23,M Neck A 4 PrathapandDissanaike,1978 o Unknown Unknown Skeletalmuscle A 4 Frenkel,1976 n USAviaAsia 40,M Arm B 4 McLeodetal.,1979 A p Uganda 50,M Leg B 1 Beaver,1979 r India 50,M Arm B 3 Beaver,1979 il 3 Singapore Unknown Skeletalmuscle B 4 Beaver,1979 , Singapore Unknown Skeletalmuscle B 4 Beaver,1979 2 0 CostaRica 9,M Heart A 6 Beaver,1979 1 9 aOriginalauthorsandyearscanbefoundinreference8,andnotalloftheseareincludedinthelistofreferencesinthisstudy. bThesetypes,describedbyBeaveretal.(8),differfromthosedescribedbyDubeyetal.(1)andaredefinedasfollows:type1,thick,radiallystriatedwall,largezoitesoftensparsein b y thecenter,andmetrocytes;type2,generallylargesarcocysts,thinandsmoothwall,mediumzoites,andsepta;type3,smallandmediumsarcocysts,thinwall,mediumzoites,and g septa;type4,longandmediumsarcocysts,thinwall,smallzoites,andseptaevidentincenter;type5,smallsarcocysts,thinwall,mediumzoites,andinmyocardium;type6,smallto u mediumsarcocysts,thinwall,largezoites,andinmyocardium;type7,smallsarcocysts,thinwall,smallzoites,andinmyocardium. e cDatawerecompiledfromreference8.Abbreviations:A,autopsy;B,biopsy;F,female;M,male. st humans(34).SarcocystsinmusclesfromM.fascicularisidentified TEM (26). The 18S rDNA sequences of Sarcocystis from these asS.nesbittibyYangetal.(33)werelaterexaminedbymolecular patientsvaried1%fromeachother,andaBLASTanalysisfound methods(34),and18SrDNAsequencedatafromtwosarcocysts thattheyshared99%homologywithS.nesbittifromthemuscleof placedthisspeciesinaclusterwithS.atheridisandS.singaporensis, M.fascicularis(26).Anotherreportalsoidentifiedapatientwith specieswithrodentintermediatehostsandsnakedefinitivehosts. sarcocystsinthetemporalismuscleandanotherwithsarcocystsin This suggested that a final host for S. nesbitti might be a snake. alegmuscle,forwhichDNAsequencesmatched100%ofthosefor PCRevidenceofSarcocystiswasfoundinfecesfromacobra(26); S.nesbittiinthecladewithS.atheridis(25).Stillanotherstudy(27) the18SrDNAsequenceclusteredwithSarcocystissequencesfrom reportedthesame18SrDNAfindingsasthosereportedbyAbu- othersnakesandwiththetwoS.nesbittisequencesobtainedfrom Bakaretal.(25)andTianetal.(34).The18SrDNAsequencefrom M.fascicularisbyTianetal.(34).ThreereportsfromthePangkor themusclebiopsyspecimenofapatientwhohadvisitedTioman IslandoutbreakinMalaysiareportedsimilarfindings.Musclebi- IslandinMalaysiaalsoshowed100%homologywiththeS.nesbitti opsyspecimensfromtheswollenjawofonepatientandthelegof gene sequence reported under GenBank accession number another showed intramuscular sarcocysts identified by LM and HF544323(28). April2015 Volume28 Number2 ClinicalMicrobiologyReviews cmr.asm.org 299 Fayeretal. TABLE2SummaryofreportsofmuscularsarcocystosisinhumansnotincludedinthereviewbyBeaveretal.andpresentedinchronologicalorder ofpublication Descriptionofhumansubject(s)or Reference,yrof Countryorregion specimen(s) Sarcocystlocation Biopsyorautopsyc publication Malaysia 58-yr-oldMa Tongue B 9,1981 India 2persons Leg B 10,1983 Gluteus B Denmark? 4of112specimensb Muscle A? 11,1985 Malaysia 45-yr-oldMa Nasopharynx B 12,1987 53-yr-oldMa Nasopharynx B Malaysia 1person Skeletalmuscle B 13,1988 D AustraliaviaThailand 31-yr-oldM Skeletalmuscle B 14,1990 o w Egypt 1person Skeletalmuscle B 15,1990 n lo Malaysia 45-yr-oldMa Tongue B 16,1992 a d 67-yr-oldFa Tongue B e 32-yr-oldFa Pectoralmuscle B d f r o Malaysia 21personsaged16to57yr Tongue A 17,1992 m BelgiumviaBrazil,Kenya, 31-yr-oldM Thigh B 18,1995 h t andTanzania tp : / / India 40-yr-oldM Thigh B 19,1996 c m 14-yr-oldF Arm B r 52-yr-oldF Thigh B .a 23-yr-oldF Arm B s m . Malaysia 44-yr-oldFa Thigh B 20,1998 o r 19-yr-oldF Calf B g / o Malaysia 7adults,M 1muscle B 21,1999 n A Thailand 66-yr-oldMa Larynx B 22,2011 p r il India 20-yr-oldM Arm B 23,2012 3 , 2 India 50-yr-oldM Neck B 0 1 9 India 47-yr-oldM Leg B 24,2013 b y PangkorIsland,Malaysia 89people Leg B 25,2013 g 26,2014 u e 27,2014 s t TiomanIsland,Malaysia 39Fand29Msubjects,aged4to72yr Skeletalmusclefrom15patients;1 B 28,2014 PCRpositive 29,2014 TiomanIsland,Malaysia 3Fand3Msubjects Febrilemyositissyndrome NTE 30,2014 TiomanIsland,Malaysia 26casesinGermanyreportedpreviously Symptomaticchanges;skeletalmuscle B 31,2014 aCancerpatients. bTissuesexaminedbytrichinoscopy. cNTE,notissueexamined. SourcesofIntestinalandMuscularSarcocystosis animalsofmanyspecies.Althoughonlytwospeciesareknownto The only source of intestinal sarcocystosis is ingestion of meat infect humans as definitive hosts, S. hominis from beef and S. containingmaturesarcocysts.Therangeofmeatsandmeatprod- suihominis from pork, many others may exist throughout the uctsconsumedbyhumansworldwideincludesdomesticandwild worldbutareasyetundefined. 300 cmr.asm.org ClinicalMicrobiologyReviews April2015 Volume28 Number2 SarcocystosisinHumans Thesourceofmuscularsarcocystosisisingestionofsporocysts, quantityofmeatconsumed,thespeciesandnumberofsarcocysts mostlikelythroughcontaminatedwaterorfreshproduceorpos- consumed,andwhetherapatientingestedrawmeatonceormul- siblythroughexposuretoacontaminatedenvironment.Itisdif- tipletimes.Thelongestperiodofcontinuoussporocystexcretion ficulttopredictforunnamedspeciesofSarcocystishowspecific (I.hominis)was21monthsormoreforapatientinTheNether- eithertheintermediateorthefinalhostspeciesmustbe,butthere lands, while other patients excreted sporocysts for at least 6 aresomegeneralizedpatterns.Dogs,coyotes,andfoxes,butnot months(35).ApatientinPolandexcretedsporocystsforatleast humansorcats,arefinalhostsforS.cruzi,withintermediatehosts 12months(36).However,themostreliableinformationonthe beingrestrictedtocattleandbison,butnotsheep,monkeys,pigs, prepatentandpatentperiodsisfromhumanvolunteerstudies.In orrats.IntermediatehostsofS.odocoileocanisincludewhite-tailed Germany,diaphragmsfromcattleandpigswereobtainedfroman deer,sheep,andcattle.Thereareotherexamplesinwhichclusters abattoir,groundinameatgrinder,andfoundtocontainzoitesof ofrelatedhostspeciesserveaseitherintermediateorfinalhosts. Sarcocystis.Thisgroundmeatwasthenfedtovolunteerswhowere BasedonthelikelihoodthatonespeciesofSarcocystiscaninfect notexcretingoocystsorsporocystsintheirstools(6).Inthefirst multiple closely related host species, some species of Sarcocystis experiment,twovolunteersate500gofrawbeefdiaphragmwith thatinfectnonhumanprimatesmightalsobeexpectedtobeable onions and spices and began excreting sporocysts 9 days later, to infect humans. This is true for S. nesbitti, a species found in continuingfor40daysorlonger.Inthesecondexperiment,four D musclesofmacaquesandrecentlyinhumans;snakesandpossibly volunteersateseasonedrawporkdiaphragmandbeganexcreting o otherreptilesmayserveasdefinitivehosts(33,34).Becausemost sporocysts 9, 13, and 17 days later; the fourth person remained w n casesofhumanmuscularsarcocystosishavebeenfoundintropi- uninfected.Thepatentperiodforthethreevolunteerswasatleast lo calareasinhabitedbymanyspeciesofnonhumanprimatesand 30 days. For a volunteer in China who ingested S. suihominis- a d reptiles,andbecausesomelocationscouldbesubjecttocontam- infected pork, the prepatent period was12 days, and the patent e inationfromreptilianfeces,thecombinationofthesefactorsap- period was (cid:2)120 days (50). Another volunteer excreted sporo- d pearsconducivetohumaninfection. cystsfromdays8to40aftereatingbeef(51).Twoothervolunteers fr o inChinawhoatebeefandthreewhoatewaterbuffalohadprepat- m PREVALENCE,SYMPTOMS,ANDDIAGNOSISOFINFECTION entperiodsof10to12daysandpatentperiodsof11to29days h INHUMANS (57). Another volunteer in China excreted sporocysts of S. ttp suihominisforanestimated91daysbeginning10daysaftereating : / IntestinalSarcocystosisSpeciesandSymptoms pork(62).OfsevenvolunteersinBrazilwhoaterawkibbe(beef), /c m Humanswithintestinalsarcocystosis(Fig.1)havebeenidentified sixbegantoexcreteS.hominisoocysts/sporocysts10to14days r worldwide,withtheexceptionofAfricaandtheMiddleEast,al- laterandexcretedthemfor5to12days(58). .a s thoughsuchinfectionslikelyoccurtheregivencustomsofeating m raworundercookedmeatinthoseareas.Locationswherecasesof IntestinalSarcocystosisinEurope . o intestinalsarcocystosishavebeenreportedarelistedinTable3, InTheNetherlands,oocystsandsporocystswereidentifiedasI. r g includinginfectionsthatresultedaftervolunteersingestednatu- hominisinstoolsamplesof17of72persons,somewithoutillness / o rallyinfectedorexperimentallyinfectedmeat(6,7,35–68).Early andotherssuspectedofsufferingfromchronicamoebiasis;addi- n investigators,withnoknowledgeoftheSarcocystislifecycle,ob- tionally,in5of17subjects,intestinalmucosascrapingstakenat A servedtwoparasiteswithcharacteristicsofapicomplexanoocysts autopsy contained sporocysts of I. hominis (35). Also, in The p r instoolsamplesofinfectedpersonsandnamedoneIsosporabelli, Netherlands and in various other countries between 1960 and il 3 whichwasexcretedasadistinctiveunsporulated(internallyun- 1970,severalsurveyswereconducted,inwhichstoolsamplesfrom , differentiated) oocyst, unique in size and shape and unlike any humans were examined (69). Ten percent to (cid:2)50% of persons 2 0 other apicomplexan parasite. The other coccidian parasite, ex- excretingsporocystswereincountrieswhererawmeatwasusually 1 9 cretedasasporulatedoocyst(containingsporocystswithsporo- consumed. In a subsequent survey in The Netherlands, babies b zoites) or as individual sporocysts, was named Isospora hominis borntomotherswhoexcretedsporocystsbeganexcretingsporo- y (35,37,39,44)andrepresentedwhatisnowrecognizedasmulti- cystsat9to10monthsofage,correlatingwiththembeingfedraw g u plespeciesofSarcocystis,twoofwhichareknowntobeS.hominis or partially cooked, minced beef (69). In Poland, a 29-year-old e (6,40,41,46–48,51,53,54,58,59)andS.suihominis(6,40,50,53, womanworkinginanorphanagehadsingleanddoublesporo- s t 62).However,otherspeciesmayhavebeenpresentbecausethe cystsinherfecesfor12months(36),whichcouldhaveresulted oocystsandsporocystsofSarcocystisspeciesaremorphologically fromrepeatedreinfection.Neitherherfamilynorhercoworkers indistinguishable.MostreportsciteinfectionsinpersonsinEuro- werefoundtobepositive,butlater,7personsattheorphanage pean countries, including The Netherlands, Germany, Poland, werefoundtobeinfected,andatotherlocationsinSzczecinProv- Slovakia, France, and Spain (Table 3). In Asia, infections have ince,92additionalpersonswerefoundtobeinfected. been reported in China, Tibet, Laos, and Thailand (Table 3). In Germany, of 150 stool samples examined, I. hominis was OthercaseshavebeenreportedinAustralia,Argentina,andBrazil detectedin12personswhohadeatenrawbeeforpork(38).Sixof (Table3). the12personshaddifferentgastricorintestinalsymptoms,and6 Asdefinitivehosts,humanscanexperiencenausea,vomiting, wereasymptomatic.AlsoinGermany,avolunteerconsumed100 acute and severe enteritis, or chronic enteritis, but many infec- to 200 g of raw beef naturally infected with S. hominis or meat tionsappeartobemildorasymptomatic.Differencesdependon fromcattleexperimentallyinfectedwithS.hominisfor1to3days thenumber,andperhapsthespecies,ofsarcocystsingested.Few onfourseparateoccasionsatintervalsofseveralmonths(40).The accurate data are available on the duration of infection or the volunteerhadlow-gradeclinicalsymptomsofstomachache,nau- numbers of oocysts and sporocysts excreted. Most case studies sea, and diarrhea beginning 3 to 6 h after meat consumption; sufferfromnotknowingthetimeofonsetofinfection,thetypeor symptomslasted24to36h.Diarrheaandstomachachewereagain April2015 Volume28 Number2 ClinicalMicrobiologyReviews cmr.asm.org 301 Fayeretal. e c n e er Ref 35 6 36 37 7 38 39 40 41 42 43 44 45 46 47 48 d Clinicalsign(s) NI 1of6personshadsevereinfluenza-likesymptomsanmilddiarrhea Symptomsveryscant NI None;noinfectionresultedfromingestionofmacroscopiccystsfromsheep 6personshadgastricandintestinalproblems 10of22personshadgastricandintestinalproblems;12personshadnogastrointestinalsigns DiarrheaandstomachacheBloating,inappetence,nausea,vomiting,diarrhea NaturalinfectiontransmittedtocalfNI Intermittententeritiswithdiarrheaorrheumaticphenomenaorasymptomatic NI Asymptomatic Notinfectious,asymptomatic NaturalinfectionExperimentallyinfectedwith15,000sarcocysts NI All6subjectshadacutefeverandacuteabdominalpain,and5hadleukocytosis;bacterialinfectionmayhavecontributedtoseverityofillnesses Downloade d cysts fro o m c k sar por h bections Sourceof NI Beef Pork NI NI Sheep Beefand NI BeefPork NIBeef NI NI NI Beef BeefBeef Beef BeefBeef ttp://cm nf ali r.a nt s me m eri .o attemptedexp Species aI.hominis S.hominis S.suihominis Sarcocystissp.Sarcocystissp.Sarcocystissp. aI.hominis S.tenella Sarcocystissp. aI.hominis S.hominisS.suihominis S.hominisS.hominis NI NI aI.hominis S.cruzi S.hominisS.hominis S.hominis S.hominis S.hominisS.hominis on Aprg/ d r inhumansan Naturalorexperimentalinfection N E N N E N N E NE N N N NE N N NN il 3, 2019 allyacquiredintestinalsarcocystosis Descriptionofhumansubject(s)and/orsamples 12of72persons5of17autopsyspecimens 2volunteers 4volunteers 29-yr-oldF7subjects(assumedtobechildren)92unidentifiedsubjects 200persons 1volunteer 12of150persons 22of300persons 1volunteer3volunteers 1child3volunteers 8of506persons 13of125children7to18yrold 12-yr-oldF 2persons 5persons1person 2%of3,500samples 30-yr-oldM 3-yr-oldF60-yr-oldF by guest r u nat as of are TABLE3Reports Country Netherlands Germany Poland Poland Germany Germany Germany Germany Netherlands Germany Poland Slovakia UnitedStates Netherlands Franceviatropical Thailand 302 cmr.asm.org ClinicalMicrobiologyReviews April2015 Volume28 Number2 SarcocystosisinHumans ge) a p g n 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 owi oll f Abdominaldistension,pain,diarrhea,constipation,stomachache,dyspneaNoinformation Asymptomatichumanwhoateporkexcretedsporocystsinfectiousforpigs;sarcocystsinpigmuscledidnotinfectmonkeys NI None AsymptomaticAsymptomatic NI Asymptomatic NI Allhadclinicalsymptomsincludingabdominalpain,distension,waterydiarrhea,andeosinophilia Diarrhea Abdominaldiscomfort,loosestools 8haddiarrheaandabdominalpain;1hadonlyabdominalpain NI Distension,diarrhea,fever,pain NINI Diarrhea Becameillbutdidnotexcretesporocysts (Continuedon Downloade d pork fro or o m BeefBeefBeef Pork Unknown Pork Beef Unknown BeefPork NI Possiblybeef NI Cattle Waterbuffal Beefkibbe Beef Pork(raw) Pork(raw) Pork NINI NI Buffalo http://c m cysts r.a poro cted cted sm S.hominisS.hominisS.hominis Sarcocystissp. Sarcocystissp. S.suihominis-likes S.hominis Sarcocystissp. S.hominisS.suihominis S.hominis Sarcocystissp. Sarcocystissp. Sarcocystissp. Sarcocystissp. S.hominis Sarcocystissp. S.suihominissuspe S.suihominissuspe S.suihominis Sarcocystissp.Sarcocystissp. Sarcocystissp. S.sinensis on Ap.org/ r il 3 , 2 0 1 NNN N N N E EE N N N N N E E E N N N E NN N E 9 b y g 9-yr-oldM19-yr-oldM70-yr-oldM 48-yr-oldM AdultM AdultM(naturallyinfected) 4monkeys 1volunteer2monkeys 14of1,228workers 20.5%–22.9%of926persons0.6%–7%of926persons (cid:2)10%of1,008persons 23.2%of362persons 2of385persons 3volunteers 2volunteers 6of7volunteers 35-yr-oldM 27of501persons 32of489persons 1volunteer 4.6%of479specimens8%of1,124specimens 31-yr-oldHIVpatient 2volunteers uest m China China(YunnanProvince) China SlovakiaviaNorthVietna Tibet Laos Thailand Australia China Brazil Spain China(Guangxi) China(Guangxi) China ThailandUbonRatchathaniKhonKaen Argentina China April2015 Volume28 Number2 ClinicalMicrobiologyReviews cmr.asm.org 303 Fayeretal. e presentwhenmostsporocystswereexcreted14to18daysafterthe c en meat was consumed. Again in Germany, three volunteers who Refer 66 67 68 consumed 100 to 400 g of raw minced pork from pigs heavily infectedwithS.suihominisbecamesymptomaticbeginning6to 8hlater,withdiarrhea,dyspnea,vomiting,bloat,nausea,stom- achache,inappetence,andrapidpulse(40).Symptomscontinued upto48h.Well-cookedporkfromthesamepigscausednoclin- ng, icalsymptomsinnineothervolunteerswhoatethemeat.Basedon miti these observations, S. suihominis was considered either patho- o v genicortoxicforhumans.Othersconcludedthatsuchpatholog- ea, icaleffectswereduetotoxicity(69). us a IneasternSlovakia,a12-year-oldgirlhospitalizedfortubercu- n a, losiswasincidentallyfoundtobeexcretingoocystsandsporocysts e h Clinicalsign(s) NI Abdominalpain,diarrintermittentfever NI onegIInnxafatcsmITetr.reshehottsaeoiiennidmlwataesinlnopsdStriois,kanrseiroanicrlxcsoyhspcwyseytamrhsstoisptoetotfnoiosmoStimssalm3r(sic4ni(ogt45ocrA)2ya.7sst)tIe0i.inadsycfoeoeavrnrestraroaamflpeSaealgroneivowoadkfioti4ahf9,1aod8cfaum1yts,e2o,e2nwn8tihttVehsr,iien1ttio4-s Downloade andleukocytosisunderwentresectionsurgeryoftheileum(48). d cysts Thehistopathologicaldiagnosisindicatedsegmentaleosinophilic fro o a enteritisorsegmentalnecrotizingenteritis.Sexualstagesandde- m c m sar ar velopingoocystsresemblingthoseofSarcocystiswereobservedin h Sourceof NI Beefshaw NI wereknown. rGoBetorshsaeemcirntse-d.pdiBcoutesicssitasciuuvaesetetslbesfar,aocraicmnloldicowytnhseteerseppwaaoettbirieeesnneprttrsv,eeaasdtneednirntasipwntiosblrsooeuceceafylssimnatsmcaahrpnkilldeeistdnbfiurseohmemfeesfr,rfioothuvmees ttp://cm Species Sarcocystissp. S.hominis Sarcocystissp. opriabeforeSarcocystisspecies iSsRahStnoau.aoammrmthtKhccopaoaihomntcleareiyincsitsssnhtofwlPiiaarfssroanbtow(smhoi6vaPrar6iese1tnr)sro4rf.cpsoe0veO,opui,f8nnfonen3csmr4do.iet37braica%t9lnloehnesne2dfaotoa3con1fslr.oudt2,w1etl%dh1r2hsen0e4aodo2mimsTfnttmhhopsfetwaaolaoectillelstoetasirhlovpcneseoinedlamlclsc,mlai.aeam0gIctple.ntte4elrlesee%nsnd-s(2soh5ffwfrturr5rotoomeoh)mmr8.meea0Orn3nprKyfu6poeTh22rasaoah5riratlsn3aaisvUoisyKlsiefamttbaeanofoepogodSnne-rl., on Apr.asm.org/ Naturalorexperimentalinfection N N N stagesinlaminapr fiwisantrnoaeTdsoahilpnwasrgahielsmsaeearnpnendltdee,nis4no.tf6ter(cid:2)h%roiemc1ra0ssn1%a(dr,50c58o0o,%f8c6ysp6awse)tmeorsrsspueoilsgnepgissosefswseritnoteitrdmvheeeamepftoxeniarcroms.SroIatinnhrncseenord(cid:2)ecn,yig2saTth0nihbsdyao(ei6Srlaa3.irnn)hsg.dooTmLfihsaiaeonagssinees, ril 3, 2019 d n b subject(s) ystsinfecesamental. (afl5no4Idtn)a.tDTiouinbileomt,nesgttdhoeooqdlis,npagencdciomSu.enhntosiemfsrionwmiesrw9e2ae6sxdpaeemtresicnotenedsdfbirnoym2t0h.Le5inztoiznh2ci2,s.M9u%liflaiontef, y gues man orocperi the specimens in the three counties (53). S. suihominis was de- t Descriptionofhuand/orsamples 1of253persons 19-yr-oldM 1of269persons20-yr-oldF meusedtoidentifyspmale;N,natural;E,ex uawtennecIddrtneeiddsCucoilhsnuouibsn7ael.aled0l,y,sto0rpaf.eso6say,rttmooamnocpeyldtnsso0tptsm%.ewcaoitemifrctee,hnafeosnsuedpxneamdcmimoinisnetnesbpdse,efcrcraeiomsmmpeeenc1nts2ievfpgreaeolytrmisv(o5ent3was),fo.tsCeimrnasgaeelnnes naM, (49).Noinformationwasprovidedforoneman,buttheother,48 TABLE3(Continued) Country NortheastThailand(KhonKaen) Jordan Malaysia aIsosporahominiswasanearlybNI,notindicated;F,female; ydhtcpimniyeiraoagasaedntrtrssitr,seeohhanaownaentcft.aeedearnIsaogebnpnfreeoada,YAcrswhaucossucaouncpadsnymnroessiaartesthbnskidcepdawbPaaotnteelormsintorooweobvinnhtieeSnaaeba.cntlndehsedduao,1oiciws3vCshcteaieoheatnomphonintftfdsiieaAnotSd,6oins.sa5cmaasaswvduranaoiiaicdsthvlyhhuioaspnaonmlcaibuhtdhiieetninefres,oaierafswdare.ndesdcidHoteeihhtvnsdoii,eosayfwltolnsohetepraexpevnrlaaeesnesmdiprnsaa,oui.tdfnitromHinhoazrgee----- 304 cmr.asm.org ClinicalMicrobiologyReviews April2015 Volume28 Number2