Bi-weeklyInfluenzaSituationUpdate30January2018

VirologicalSurveillanceSummaryThetotalnumberofspecimensandnumberofpositivespecimensreportedtoFluNetbytheWesternPacific Region countries and areas betweenweek 1 andweek 3 are presented in the table below. Inweek 3, 2018, both influenza A (H1N1)pdm09 and B(Yamagata lineage) circulated, with minorpredominanceofA(H1N1)pdm09.(Figure1).

Table1:CountriesandareasreportingdatatoFluNet,WesternPacificRegion,weeks1to3,2018

Figure1:Numberofspecimenspositiveforinfluenzabysubtype,WesternPacificRegion,

week52017toweek32018(Source:www.who.int/flunet)

Country(mostrecentweekofreport)Totalnumberof

specimensprocessed

Totalnumberofinfluenzapositive

specimensAustralia(week3) 544 39Cambodia(week2) 46 3China(week3) 43,939 17,274Japan(week2) NA 55LaoPeople'sDemocraticRepublic(week3) 112 19Mongolia(week3) 433 124NewCaledonia(week2) 34 5Philippines(week2) 66 5RepublicofKorea(week3) 925 580Singapore(week1) 83 45

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InfluenzasurveillancesummaryInfluenzasurveillanceintheWHOWesternPacificRegionisbasedonoutpatientandinpatientsentinelindicator based surveillance (IBS) systems as well as event-based surveillance. Case definitions,populations under surveillance and data formats differ among countries. This influenza surveillancesummaryincludescountries/areaswhereroutineIBSisconductedandinformationisavailable.

TheWHOsurveillancecasedefinitionfor ILI isanacuterespiratory infectionwithameasuredfeverof≥38oC and cough, with symptom onset within the last 10 days. For SARI, it is an acute respiratoryinfection(ARI)withahistoryoffeverormeasuredfeverof≥38oCandcough,withsymptomonsetwithinthelast10daysandrequireshospitalization.

CountriesinthetemperatezoneoftheNorthernHemisphereInmostcountrieswithin the temperatezoneof theNorthernHemisphere, ILI and influenzaactivity ishigherthanthecorrespondingperiodofpreviousyears.

OutpatientILISurveillance

China(North)Duringweek3,thepercentageofvisitsforILIatnationalsentinelhospitalsinnorthernChinawas5.2%,whichis lowerthanthepreviousweek(5.5%)buthigherthanthesameweekof2015,2016and2017(3.6%,3.5%and3.4%)(Figure2).

MongoliaILIactivityinMongoliaincreasedbetweenweek35andweek51of2017(Figure3).ILIactivityhassincedecreased.Mongoliapublishesweeklyreports,availablehere: http://www.flu.mn/eng/index.php?option=com_content&task=section&id=5&Itemid=51

China(North)

Mongolia

Figure2:PercentageofvisitsforILIatsentinelhospitalsinnorthChina,2014-2018(Source:ChinaNationalInfluenzaCenter)

Figure3:ProportionofoutpatientILIvisits(per10,000people),2015-2018(Source:MongoliaNationalInfluenzaCenter)

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RepublicofKoreaInweek1,therewere59.6ILIcasesper1,000outpatientvisits,whichwaslowerthanthepreviousweek(69.0)(Figure4).Koreapublishesaweeklyreport,availablehere:http://www.cdc.go.kr/CDC/info/CdcKrInfo0301.jsp?menuIds=HOME001-MNU1154-MNU0005-MNU0037-MNU1380

RepublicofKorea

Figure4:WeeklyILIincidencerateper1,000patients,2013-2017

(Source:KoreanCentreforDiseaseControlandPrevention)

Sentinelinfluenzasurveillance

JapanInweek2,influenzaactivityinJapanhasincreasedtohigherlevelsthanpreviousyears(Figure5).Moreinformation about historical trends are available here: https://www.niid.go.jp/niid/en/10/2096-weeklygraph/1644-01flu.html

Japan

Figure5:Numberofinfluenzacasesreportedweeklyperreportingsentinelhospitalsite,Japan2008-2018

(Source:JapanNationalInstituteofInfectiousDiseases)

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Countries/areasinthetropicalzoneCountries/areasinthetropicalzoneareobservinginfluenzaactivitythatisconsistentwithpreviousseasons.

Surveillance

HongKongSAR(China)–ILIandhospitalSurveillanceInweek3,theaverageconsultationrateforinfluenza-likeillness(ILI)amongsentinelgeneraloutpatientclinics (GOPCs)was12.4 ILIcasesper1,000consultations,whichwashigherthanthatrecorded inthepreviousweek(6.5)(Figure6).TheaverageconsultationrateforILIamongsentinelprivatedoctorswas70.0 ILI casesper1,000consultations,whichwashigher than the rate recorded in thepreviousweek(57.8) (Figure 7). Hong Kong SAR, China publishes a weekly report, available here:http://www.chp.gov.hk/en/guideline1_year/29/134/441/304.html

HongKong(China)-ILISurveillance

Figure6:ILIconsultationratesatsentinelgeneraloutpatientclinics,HongKong2014-2018(Source:HongKongCentreforHealthProtection)

Figure7:ILIconsultationratesatsentinelprivatedoctors,HongKong2014-2018(Source:HongKongCentreforHealthProtection)

China(South)-ILISurveillanceDuringweek3,thepercentageofoutpatientoremergencyvisitsforILIatnationalsentinelhospitalsinsouthernChinawas6.7%,whichishigherthanthelastweek(6.0%)aswellasthesameweekof2014,2015and2016(3.0%,3.3%and2.8%)(Figure6).

Singapore–AcuteRespiratoryInfectionSurveillanceThe average daily number of patients seeking treatment in polyclinics for acute respiratory infectionincreased from3,632perworkingday inweek2, to4,234perworkingday inweek3 (Figure9). Theproportion of patients with ILI among polyclinic attendances for ARI remained at 2.2%. Singaporepublishesaweeklyreport,availablehere: http://www.moh.gov.sg/content/moh_web/home/statistics/infectiousDiseasesStatistics/weekly_infectiousdiseasesbulletin.html

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China(South)-ILISurveillance

Singapore–ARISurveillance

LaoPDRInweek3,influenzaactivityincreasedcomparedtothepreviousweek.Inweek3thenumberofcasesishigherthanreportedinthesameweekbetween2013and2016butlowerthanthatreportedinweek3in2017(seeFigure10).

Figure10:WeeklynumberofILIpresentationsatsentinelsites,2013toweek32018,LaoPDR

(Source:LaoNationalCenterforLaboratoryandEpidemiology)

Figure8:PercentageofvisitsduetoILIatnationalsentinelhospitalsinSouthChina,2014-2018(Source:ChinaNationalInfluenzaCenter)

Figure 9: Average daily polyclinic attendances for ARI inSingapore,2017-2018(Source:SingaporeMinistryofHealth)

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CountriesinthetemperatezoneofthesouthernhemisphereInthetemperatezoneofthesouthernhemisphere,influenzaactivityfollowedseasonaltrends.

Australia–Laboratory-confirmedinfluenza(noupdate)Thenumberoflaboratoryconfirmedinfluenzacaseshasdecreasedfromapeakreachedinweek33.Asof27October2017(week42),atotalof229,579notificationsof laboratoryconfirmed influenzawerereported to the National Notifiable Diseases Surveillance System (Figure 11). Sixty-three percent ofnotifications were influenza A (57% A(unsubtyped), 4% influenza A(H3N2) and 1% influenzaA(H1N1pdm09)),37%wereinfluenzaBandlessthan1%wereinfluenzaA&Bco-infectionsoruntyped.Australia publishes influenza surveillance reports on a fortnightly basis during the influenza season,typicallybetweenMayandOctober.Formoreinformation:http://www.health.gov.au/internet/main/publishing.nsf/content/cda-surveil-ozflu-flucurr.htm#current

Figure11:Australiannotificationsoflaboratoryconfirmedinfluenza

(Source:NationalNotifiableDiseasesSurveillanceSystem,AustralianDepartmentofHealth)

NewZealand–InfluenzalikeIllness(noupdate)Duringweek39,80patientswithinfluenza-likeillnessconsultedsentinelgeneralpracticesin20districthealth boards (DHBs). The weekly ILI incidence was 19.5 per 100 000 patient population. Of the 36laboratory tested ILIcases,eightwerepositive for influenzaviruses.Thisgivesan ILI related influenzaincidence (adjusted) of 4.3 per 100 000 patient population. New Zealand publishes a weekly report,availablehere:https://surv.esr.cri.nz/virology/influenza_weekly_update.php

Figure12:WeeklyresidentILIandinfluenzaincidencesinceWeek1of2017inNewZealand(Source:InstituteofEnvironmentalScienceandResearchLtd(ESR),NewZealand)

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PacificIslandCountriesandAreas(PICs)-ILISurveillanceInthePacificIslandCountriesandAreas,inweek3,thenumberofILIcasesreportedcomparedtopreviousweeksincreasedinKiribati(Figure13).ThePICssubmitareportonaweeklybasis,formoreinformation:http://www.wpro.who.int/southpacific/programmes/communicable_diseases/disease_surveillance_response/page/en/index2.html

Figure13:Reportedcasesofinfluenza-likeillnessinPacificIslandCountries,2018

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GlobalinfluenzasituationupdatesEpidemiologicalupdatehttp://www.who.int/influenza/surveillance_monitoring/updates/latest_update_GIP_surveillance/en/

Virologicalupdate:http://www.who.int/influenza/gisrs_laboratory/updates/summaryreport/en/

Globalupdate:http://www.who.int/influenza/surveillance_monitoring/updates/latest_update_GIP_surveillance/

Others:Recommendedcompositionofinfluenzavirusvaccinesforuseinthe2017southernhemisphereinfluenzaseasonhttp://www.who.int/influenza/vaccines/virus/recommendations/2017_south/en/

Recommendedcompositionof influenzavirusvaccines foruse in the2017-2018northernhemisphereinfluenzaseasonhttp://www.who.int/influenza/vaccines/virus/recommendations/201703_recommendation.pdf?ua=1

Antigenicandgeneticcharacteristicsofzoonoticinfluenzavirusesandcandidatevaccinevirusesdevelopedforpotentialuseinhumanvaccineshttp://www.who.int/influenza/vaccines/virus/characteristics_virus_vaccines/en/

4thWHOInformalConsultationonImprovingInfluenzaVaccineVirusSelectionhttp://www.who.int/influenza/vaccines/virus/4thmtg_improve_vaccine_virus_selection/en/

VideooninfluenzaonWHO'sYouTubeChannel Arabic:https://www.youtube.com/watch?v=PxW6Pg1AnwI Chinese:https://www.youtube.com/watch?v=xW9gDKEPitQ English:https://www.youtube.com/watch?v=yhhJfT86Bgg French:https://www.youtube.com/watch?v=8mo8rWWJZkc Russian:https://www.youtube.com/watch?v=XQO6nbkKUWQ Spanish:https://www.youtube.com/watch?v=qXr75cKxwTY