Trichomoniasis is the most common curable sexually transmitted disease in the U.S., affecting approximately 3.7 million people, often without noticeable symptoms. The infection primarily affects women and can lead to increased risks of preterm birth and HIV transmission, while men typically experience mild symptoms or none at all. Treatment options include metronidazole and tinidazole, with emphasis on testing and treating sexual partners to prevent reinfection.

1. Overview
Maybe youhaven’theardof thisinfection.Itisthe stepchildof sexuallytransmitteddiseases—one
that ishard to pronounce,letalone findinformationaboutwhyitisimportant.
Ironically,trichomoniasis(trick-o-mon-i-a-sisor“trich”) is the mostcommoncurable sexually
transmitteddisease(STD).Inrecentyears,diagnosingandtreatingthisdisease hasreceivedmore
attentionasnewresearchhasshownthat it isnot as harmlessaswas once thought.
About3.7 millionpeoplehave trichomoniasis,accordingtothe U.S.CentersforDisease Control and
Prevention(CDC).Mostmeninfectedwiththe parasiteTrichomonashave nosymptoms.When
symptomsoccur,menmay experience irritationinsidethe penis,discharge orslightburningafter
urinationorejaculation.Mostwomenare alsoasymptomatic.Some womenwiththe infection
experience afrothy,yellow-greenvaginaldischarge withastrongodor, discomfortduring
intercourse,painduringurination,itchinginthe genital areaorspottingbetween periods.Inrare
cases,painin the lowerabdomencanoccur. WomeninfectedwithTrichomonasare more atriskof
acquiringhumanimmunodeficiencyvirus(HIV)andotherSTDs.
Because trichomoniasisissocommonandcauses significantriskstowomen’shealth,youwould
expecttosee more interestinitsprevention.There are several reasonswhythisSTDhasreceivedso
little attention.First,itssymptoms—primarilydischarge andirritationof the vaginaandurethra—
are mildandhave beenseenastroubling butlessseriousthanthe side effectsof otherSTDs.
Second,the mostcommontreatments—metronidazoleandtinidazole—arehighlyeffective inmost
women,thoughsome difficultiescanarise,suchas drugallergiesorintoleranceorTrichomonas
becomingresistanttothisclassof drugs.No otherclassof drugsis veryeffective fortreatment.
The organismsthat cause trichomoniasisare protozoans(the simplest,single-cell organisminthe
animal kingdom).Theseprotozoans,calledtrichomonads,caninfectotherareasof the body,but
Trichomonasvaginalisisresponsible forgenital infectionandvaginitis.Thisparasite residesprimarily
inthe vaginaand/orbladder,where bodytemperature,low oxygenenvironmentandmoisture allow
it to growand multiply.
Trichomoniasisisone of the three mostcommontypesof vaginitis.The othertypesarebacterial
vaginosis(BV),whichisanovergrowthof anaerobicbacteriafoundinthe vagina,andvulvovaginal
candidiasis,more commonlyknownasyeastinfection.

2. As withBV,some researchsuggeststhattrichomoniasisisassociatedwithpretermbirth.Women
infectedwithTrichomonasduringpregnancyare more likelytohave low birthweightbabies(less
than 5.5 pounds).
Studiesalsolinktrichomoniasiswithanincreasedrisk of HIV transmission(HIV isthe virusthatleads
to AIDS).StudiesshowthatwomeninfectedwiththisSTDare at higherriskof acquiringand
transmittingHIV.
Trichomoniasisistransmittedthroughsexual intercourse.Itismostcommonin people whoare at
theirpeakof sexual activity(teensand20s),but itis foundinhigherratesamongolderwomenthan
otherSTDs. Havingmultiple sexpartnersandinfectionwithotherSTDsare primaryfactorsthat
increase awoman’sriskof infection.
In veryrare cases,trichomoniasismaybe transmittedbyapregnantwomanto herbaby during
childbirth.Pregnantwomenwithtrichomoniasisare more likelytodeliverearlyandtogive birthto a
lowbirth-weightbaby(lessthan5.5 pounds).Theirbabiesare alsomore likelytohave conjunctivitis.
In the UnitedStates,about3 percentof womenare infected.Amongwomeninfectedwithother
STDs, suchas gonorrhea,the rate of trichomoniasisishigher.Forreasonsnotentirelyclear,African
Americanwomenare 5 to 10 timesmore likelyhave trichomoniasisthanHispanicorCaucasian
women.
Diagnosis
A significantnumberof womeninfectedwithtrichomoniasishave nonoticeable symptoms.If
symptomsdevelop,theyusuallyoccurwithinfive to28 days afterexposure toaninfectedpartner.
However,insome cases,the symptomsmaybe delayedforlonger.The mostcommonsymptomsare
vaginal discharge,irritation,itchingandburningduringurination.
Trichomoniasismostoftenpresentsasayellowish-greenvaginaldischarge with astrongodor.
Itchingand sorenessof the vaginaandvulvaare common.Some womenexperience vague
abdominal pain.Trichomoniasiscanoccur withotherinfections,particularlypelvicinflammatory
disease andbacterial vaginosis.

3. The majorityof men infectedwithTrichomonasdonothave symptoms.The mostcommonsymptom
isdischarge fromthe penisor burningwithurination.Whenmenhave symptoms,theyoftensubside
withouttreatmentafteraweekormore.
For bothmenand women,adiagnosisbasedon symptomsisinadequatebecause manyof these
symptomsare sharedwithotherinflammatoryconditionsof the vaginaandcervix,suchas bacterial
vaginosisandyeastinfections.
For women,the mostcommonwayto diagnose trichomoniasisisbyphysical examinationof the
pelvicareabya healthcare professionalandbylookingata sample of vaginal fluidundera
microscope (called“wetmounts”) forthe presence of protozoa.A pelvicexaminationcanreveal
small redulcerationsonthe vaginal wall orcervix.The wetmounttechnique,however,isaccurate
onlyabout60 percentto 70 percentof the time,as protozoamay be hard to findor mistakenfor
normal cells.Itcan alsoyieldfalse positives.There alsoare severalrapid-diagnostickitsavailable
that can diagnose infectionin10 to 45 minutes.These testsalsocome withthe riskof false positives.
More reliable testshave beendeveloped,suchasthe polymerase chainreaction(PCR) test,atype of
nucleicacidtestthat usesenzymestobetterdetectthe virusinthe culture.Itisveryeffectivein
identifyingT.vaginalisinwomenandisbecomingmore readilyavailable.
Treatment
The standard drugsusedfor treatingtrichomoniasisare metronidazole (Flagyl) andtinidazole
(Tindamax).Inmostcases,Trichomonasinfectioniscuredinwomenwithasingle oral dose of two
grams of eitherdrug.Both of these prescriptiondrugsare inthe nitroimidazole class.Metronidazole
has beenfoundtobe safe inpregnancy.
All sexual partnersof aninfectedpersonshouldbe treated.Aninfectedpersonshouldabstainfrom
sex duringtreatmentanduntil all symptomsgoaway,approximatelyaweekortwoaftertreatment.
Because of the highrate of reinfection(upto17 percentwithinthree months),sexuallyactive
womenmay wantto considergettingrescreenedthree monthsaftertreatment.Thisisespecially
importantforHIV-infectedwomenwhoalsohave trichomoniasis,because theyhave anevenhigher
rate of recurrence.
For those whofail treatment,longercoursesof metronidazoleortinidazoleare recommendedby
the CentersforDisease Control andPrevention(CDC).Patientswhocontinue tohave aninfection

4. aftera single dose of metronidazole shouldtake 500 milligramsof metronidazole orallytwice aday
for sevendays.If thissecondcourse of medicationfails,the CDCsaysto considertreatingwithtwo
grams dailyforfive daysof eithermetronidazoleortinidazole.If thesetherapiesfailtocure the
infection,furthertreatmentshouldbe discussedwithaspecialist.
You shouldtake metronidazole ortinidazolewithfoodandavoiddrinkingalcohol for24 to 72 hours
aftertakingthe drugs.
Prevention
Preventionof trichomoniasisissimilartothatfor othersexuallytransmitteddiseases(STDs).
Protective measuresinclude:
Use a latex condomeverytime youhave sex.
Limityournumberof sex partners.
Get testedif youthinkyouhave an STD and have yourpartnertested,too.
Facts to Know
Trichomoniasisisthe mostcommoncurable sexuallytransmitteddisease inthe UnitedStates.
Accordingto the CDC, about3.7 millionpeopleinthe UnitedStateshave trichomoniasis.
Trichomoniasisismore commonamongAfricanAmericanwomen.The reasonforthisisnotclear.
Lack of accessto medical care in economicallychallengedcommunitiesmayplayarole.
Trichomoniasisincreasesawoman’sriskof pretermbirthordeliveryof alow birthweightbaby.
It isimportantthat sexual partnersof infectedwomenbe treated.Althoughtrichomoniasisisoften
asymptomaticinmales,if left untreateditcancause urethral infections,particularlyurethritis,and
can leadto reinfectionof the woman.
Because a testfor vaginal infectionisnotnecessarilyapart of a routine pelvicexam, youcan’t
assume yourhealthcare professional will test youfortrichomoniasis.Youshouldrequest
trichomoniasisscreeningif youhave symptomsorif youhave beenincontact witha high-risksexual
partner.
You can have more than one type of vaginitisatthe same time.Itispossible tohave trichomoniasis
and bacterial vaginosistogether,eachof whichcan be treatedwithmetronidazole.
If you visityourhealthcare professionaltosee if youhave a vaginal infection,youshouldschedule
your examinationwhenyouare nothavingyourperiod.

5. It iseasyto misdiagnose trichomoniasisorbacterial vaginosisasayeastinfectionbecause yeast
infectionalsocausesanunpleasantdischarge.Treatmentforyeastinfectionsisdifferentthanfor
trichomoniasisorBV,soan accurate diagnosisisimportant.
KeyQ&A
How doI knowif I needtosee myhealthcare professional?Payattentiontoyourbody.Call your
healthcare professional if youexperience anyunusual symptoms,suchas:a change in the color,
odor or consistencyof vaginal fluid;vulvarirritation;itching; andburning,frequentorpainful
urination.
What if I am allergictothe 5-nitroimidazole drugs(metronidazole ortinidazole)oram not
respondingwell tothem?Upto10 percentof womendonot respondtostandard treatment.For
those whofail treatment,alongercourse of metronidazole isrecommendedbythe Centersfor
Disease Control andPrevention(CDC).If thissecondcourse of medicationfails,the CDC
recommendstwogramsdailyforfive daysof eithermetronidazoleortinidazole.If youdevelopa
rash inresponse tothe 5-nitroimidazole drugs,there are othermedicationsyoucantry, butthey
have poor cure rates.If youare allergictotinidazole andmetronidazole,yourprovidermaysuggest
desensitizingyoutothese medicationssoyoucanundergotreatment.
What are mychances of havingtrichomoniasisreoccur?Treatmentissuccessfulinmostwomen,and
once the organismsare killedtheydon’tcome backunlessyouare exposedagaintoan infected
partner.
What isthe relationshipbetweenvaginitisandexcessivedouching?The healthyvaginal ecosystem
requiresjustthe rightbalance of bacteriaflora.These bacteriamake natural acidsthatkeep
abnormal bacteriafrombecomingpredominant.Douchingmaydisruptthe pHbalance of the vagina
and leadtobacterial vaginosis,whichmayincrease awoman’sriskof acquiringtrichomoniasis.
What aboutdiagnosingandtreatingtrichomoniasisinmen?Theorganismsthatcause trichomoniasis
oftendon’tcause symptomsinmales.Consequently,mostmenneverseektreatmentbecause they
don’tknowtheyare infected.Diagnosisinmenisusuallymade withaurine culture specificallyfor
Trichomonas.If yoursexual partnersare nottreated,itis likelyyouwill becomereinfected.
What isconsiderednormal vaginal discharge?For uninfectedwomen,vaginal dischargeisusually
cloudywhite inappearance.Discharge oftenincreasesinthe middleof yourmenstrual cycle,and
duringovulationitchangesconsistency,appearingsimilartoeggwhites.Symptomaticwomenwith
trichomoniasis experience afrothy,yellow-greenvaginal dischargewithastrongodor,possibly
coupledwithdiscomfortduringintercourse,painful urinationorgenital itching.