Mpox: guidance on when to suspect a case of mpox

This guidance documentis providesfor guidancehealthcare professionals on when to suspect mpox, the disease caused by any clade of the virus called MPXV., Diseaseand causedhow byto cladedecide Iif MPXVa issuspected case needs to be managed as a highHigh consequenceConsequence infectiousInfectious diseaseDisease (HCID). Clade II mpox has been circulating in the UK.

WhenUK assessingand patientsglobally forsince mpox,2022 alwayspredominantly takein agay, travelbisexual history.or Thereother men who have sex with men, but remains uncommon. It is ano currentlonger outbreakclassified ofas an HCID.

Clade (cladeI I) mpox inis thecurrently Democraticclassified Republicas ofan theHCID. CongoIt (DRC)includes andclade otherIa, countriespresent in thecentral AfricanAfrica, region.and Furtherclade informationIb, oncurrently affectedcausing an outbreak in multiple countries can(see bethe foundaffected atcountry Operationallist). mpoxIt HCIDhas (cladenot I)been casedetected definition.in Bethe alertUK to date.

Consider the possibility of HCID mpox (cladewhen I)patients with exposure risk and which fit the clinical description in allthe patientssection withon suspectedWhen to suspect mpox. ifWhen theyassessing havepatients afor travelmpox, historyalways toconsider the affectedpossibility region.

Discussof anyHCID casesand oftake mpoxa thattravel mayhistory. beIf the patient fits the HCID (cladecase I)definition, withthey yourshould relevantbe localmanaged infectionas teampotential (infectiousHCID diseases,and microbiologydiscussed orwith virology)local infection team, who may adviserefer furtherto discussion with the importedImported feverFever serviceService (IFS).

SuspectedWhen to suspect mpox

TheConsider possibility of mpox should be considered:

1. where a case presents withwith:

1. a prodrome [note(fever, 1]chills, compatibleheadache, withexhaustion, mpoxmyalgia, infection,arthralgia, backache, lymphadenopathy), and where there is known prior contact with a confirmed or suspected case of mpox in the 21 days before symptom onset

orOr:

2. wherean ampox-compatible caserash presentsanywhere withon unexplainedthe lesionsskin (for(face, examplelimbs, vesicles,extremities, pustules,torso), nodulesmucosae (including oral, genital, anal), or ulcers)symptoms compatibleof withproctitis, mpoxand anywhereat onleast one of the body,following includingin butthe not21 limiteddays to:before symptom onset:

• anywhererecent onnew thesexual skinpartner
• contact (face,with limbs,known extremities,or torso)suspected case of mpox
• oral,a genitaltravel orhistory ano-genitalto lesionsa country where mpox is currently common
• proctitislink –to foran exampleinfected anorectalanimal pain,or bleedingmeat

andIf alsothe onerash oris morehighly ofclinically thesuggestive followingof apply:

• hasmpox, anbut epidemiologicalyou linkcannot toidentify a confirmedrisk orfactor, suspecteddiscuss casewith oflocal infection services whether to consider mpox intesting alongside the 21more dayscommon beforedifferential symptomdiagnosis.

  Consider onset

• hascommon ainfections travelsuch historyas tochickenpox specifiedor countriesshingles, whereherpes theresimplex mayvirus, beand aenterovirus riskin ofthe cladedifferential Idiagnosis; exposurethese withincirculate 21widely daysand ofare symptommore onsetcommon (seethan operationalmpox; exclude as appropriate.

  When to consider clade I mpox, a high consequence infectious disease (HCID operational case definition)

• identifiesdefinition)

  In as a gay,person bisexualwith orclinically othersuspected manmpox, whothey hasshould sexbe withmanaged menas (GBMSMHCID)

• has hadif 1they meet one or more newof sexualthe partnersfollowing incriteria:
  • has thea 21travel dayshistory beforeto symptomspecified onset
  • hascountries nonewhere ofthere themay abovebe a risk factors,of butclade hasI beenexposure discussedin withthe local21 infectiondays servicesbefore (infectioussymptom diseases,onset microbiology,(see affected virologycountry orlist)
  • has sexualan healthepidemiological aslink appropriate)to anda investigatedconfirmed locallyor forsuspected commoncase diagnosesof [noteclade 2]I withoutmpox ain causethe identified21 days before symptom onset
  • has a relevant zoonotic link, including contact with a wild or captive mammal that is an African endemicnative species (this includes contact with derived products, for example, game meat)

  Note

  Actions 1:for Prodromea consistssuspected case of fever,mpox

  For chills,all headache,suspected exhaustion,mpox musclecases

  Patients achesidentified (myalgia),as jointsuspected painmpox (arthralgia),cases backache,should andbe swollenmanaged lymphas nodesper (lymphadenopathy).

  Notethe 2:NHS Commonguidance diagnoseson include,Infection butprevention areand notcontrol limitedmeasures to:for chickenpoxclinically orsuspected varicellaand zosterconfirmed viruscases (VZV),of herpesmpox simplexin (HSV)healthcare and enterovirus.settings.

  Actions

  All forsuspected acases suspectedundergoing casetesting ofshould mpox

  be notified to the local health protection team by the clinician.

  For cases meeting the operational HCID mpox case definition

  The managing clinician should contact their relevant local infection team (infectious diseases, microbiology, or virology). LocalThe local infection team toshould then discuss with the the IFS (0844 (0844 778 8990) who will review risk assessment and advise on the next steps for investigation and and management including teh need for admission. If a decision is made to test, information on diagnostic testing for mpox is available. The managing clinician should contact the local health protection team.

  For cases that do not meet the operational HCID mpox case definition

  Test for for MPXV, the causative agent of mpox (using designated testing pathway). See also also Mpox diagnostic testing guidance.

  Undertake additional contemporaneous tests to rule out alternative diagnoses if clinically appropriate and if not done already.

  If admission of patient isrequires requiredadmission for clinical reasons, reasons, IPC measures measures should be undertaken as per the the NHS guidance on on IPC measures measures for clinically suspected and confirmed cases of mpox in healthcare settings and and the the national national IPC manual manual.

  If patient does not requiringrequire admission for clinical reasons: advise self-isolation at home (based on assessment by the clinician and following following UKHSA guidance guidance.

  ). If admissionthe of patient iscannot notself-isolate required for clinical reasons, but self-isolation at homehome, isthe not possible for social or medical reasons following clinician assessment, patient should be admitted pending test result, with with IPC measures measures undertaken as per the the NHS guidance on on IPC measures measures for clinically suspected and confirmed cases of mpox in healthcare settings and and the the national national IPC manual manual.

  Case definitions once test results are available

  Highly probable case

  A highly probable case is defined as a person with an orthopox virus PCR positive result where mpox remains the most likely diagnosis.

  Confirmed case

  A confirmed case is defined as a person with a laboratory-confirmed mpox infection (MPXV PCR positive).

  Actions for a confirmed or highly probable case

  All confirmed or highly probable cases should be assessed for the need for admission based on either clinical or self-isolation requirements. The NHS provides guidance on management of patients with confirmed mpox.

  All confirmed and highly probable cases, or suspected cases undergoing testing should be notified to the local health protection team by the clinician; there is a statutory obligation for clinicians to make a clinical notification to the health protection team if it is believed that the diagnosis is mpox.

  Further information

  Additional Additional mpox resources are are available on GOV.UK, including guidance on on vaccination and  and contact tracing.