www.jped.com.br
ORIGINAL
ARTICLE
Hospitalizations
and
deaths
due
to
pertussis
in
children
from
1996
to
2013
夽
Janayne
F.
Manc
¸aneira,
Juliana
R.
Benedetti,
Linjie
Zhang
∗MedicalSchool,UniversidadeFederaldoRioGrande(FURG),RioGrande,RS,Brazil
Received26November2014;accepted24March2015
Availableonline30July2015
KEYWORDS Pertussis; Hospitalization; Death;
Ecologicalstudy
Abstract
Objectives: ToassesstemporaltrendsofhospitalizationsanddeathsfrompertussisinBrazilian childrenintheperiodof1996---2013.
Methods: Thiswasadescriptiveecological studyoftemporaltrends,basedontheDATASUS database.Thenumberofhospitalizationsanddeathsfrompertussisinchildrenupto19years ofagefromJanuary1996toDecember2013wasobtained.Descriptivestatisticswereapplied fordataanalysis.
Results: Duringthestudy period,atotal of19,047hospital admissionsfrompertussis were recorded,ofwhich88.2%occurred ininfantsyoungerthan1year.Intheperiod1996---2010, themeanannualnumberofadmissionswas755,rangingfromamaximumof1179in2004toa minimumof400in2010.Therewasanincreaseofadmissionsinthelastthreeconsecutiveyears (2011,2012,and2013) with1177,2954and3589hospitalizations,respectively. Therewere 498deathsfrompertussisthroughoutthestudyperiod,ofwhich96.8% occurredinchildren youngerthanoneyear.Therewasanincreaseinthenumberofdeathsfrompertussisinchildren intheyears 2011, 2012,and 2013,with 40,93, and87 recordeddeaths, respectively. The increaseinhospitalizationsanddeathsfrompertussisinchildrenoccurredinallregionsofthe country,withthehighestincreaseobservedintheSoutheast,NorthandNortheastregions.
Conclusions: Therewasasubstantialincreaseinhospitalizationsanddeathsfrompertussisin childrenforthreeconsecutiveyears(2011,2012,and2013)inallBrazilianregions.Themost affectedagegroupwasthatofchildrenyoungerthanoneyear.
©2015SociedadeBrasileiradePediatria.PublishedbyElsevierEditoraLtda.Allrightsreserved.
夽
Pleasecitethisarticleas:Manc¸aneiraJF,BenedettiJR,ZhangL.Hospitalizationsanddeathsduetopertussisinchildrenfrom1996to 2013.JPediatr(RioJ).2016;92:40---5.
∗Correspondingauthor.
E-mail:[email protected](L.Zhang). http://dx.doi.org/10.1016/j.jped.2015.03.006
PALAVRAS-CHAVE Coqueluche; Internac¸ão; Óbito;
Estudoecológico
Internac¸õeseóbitosporcoquelucheemcrianc¸asnoperíodoentre1996e2013
Resumo
Objetivos: Avaliartendência temporalde internac¸ões eóbitos porcoqueluche em crianc¸as brasileirasnoperíodode1996a2013.
Métodos: Trata-sedeumestudoecológicodescritivodetendênciatemporal,baseadonobanco dedadosDATASUS.Foramextraídososnúmerosdeinternac¸õesedeóbitosporcoquelucheem crianc¸asaté19anosdeidadenoperíododejaneirosde1996adezembrode2013.Aestatística descritivafoiaplicadaparaanálisededados.
Resultados: Noperíodoestudado foramregistradas19.047 internac¸õespor coqueluche,das quais88,2%foramlactentesmenoresdeumano.Noperíodode1996a2010,onúmeromédio anualdeinternac¸õesfoide755,oscilandoentreomáximode1179em2004eomínimode 400em2010. Houveumacréscimodeinternac¸õesnosúltimostrêsanosconsecutivos(2011, 2012e2013),com1177,2954e3589registros,respectivamente.Ocorreram498óbitospor coquelucheem todooperíodo estudado,dos quais96,8% erammenores deum ano.Houve acréscimononúmerodeóbitosporcoquelucheemcrianc¸asnosanos2011,2012e2013,com 40,93e87registrados,respectivamente.Oaumentodeinternac¸õeseóbitosporcoqueluche emcrianc¸asocorreuemtodasasregiõesdopaís,havendomaioracréscimonasregiõesSudeste eNorte-Nordeste.
Conclusões: Houve um aumento substancial deinternac¸ões e de óbitosporcoqueluche em crianc¸asportrêsanosconsecutivos(2011,2012e2013)emtodasasregiõesbrasileiras.Afaixa etária maisatingidafoiademenoresdeumano.
©2015SociedadeBrasileiradePediatria.PublicadoporElsevierEditoraLtda.Todososdireitos reservados.
Introduction
Pertussisisahighlyinfectiousandcontagioushuman respi-ratory disease caused by the coccobacillus Bordetella pertussis.Althoughitisavaccine-preventabledisease, per-tussis remains an important cause of child morbidity and mortalityworldwide,andasourceofpublichealthconcern, even in countries where vaccination coverage is high.1---3
According totheWorld HealthOrganization (WHO), there
wereapproximately16millioncasesofpertussisintheworld
in2008,with95%occurringindevelopingcountries,causing
about200,000infantdeaths.1
Inmanydevelopedcountrieswithhighvaccination
cov-erage,pertussishasre-emergedinthelasttwodecadeswith
increasingincidence,especiallyamongyounginfantsnotyet
fully immunized,as well asadolescentsand young adults
whoarepotentiallycapableoftransmittingthediseaseto
youngerchildren.2---5Somehypotheseshavebeenconsidered
fortheresurgenceofthedisease,suchaslossofacquired
immunityduring thetimeafter vaccination,reduced
vac-cineeffectiveness,useofnewdiagnosticmethods,improved
epidemiologicalsurveillancesystems,andgeneticchanges
inbacteria.2,5,6
In Brazil, data from the Ministry of Health’s
epidemi-ological surveillance show an increase in the incidence
of pertussis since2011, after over a decade of stability.7
Approximately 70% of cases were children younger than
1year,withmostyoungerthan3months.
Duetothedifficultiesintheclinical diagnosisandlack
of availability of sensitive and specific laboratory tests,
pertussis remains an underdiagnosed and underreported
disease.6,8,9 Accurate data on the incidence rate of this
disease are difficult to obtain, particularly in developing
countries. Therefore, studies on hospital morbidity and
mortalityfrompertussis can provide important additional
informationinassessingthecurrentnational
epidemiologi-calsituationofthedisease.
This studyaimed todescribe temporaltrendsin
hospi-taladmissionsthroughtheBrazilian UnifiedHealthSystem
(SistemaÚnicodeSaúde[SUS])anddeathsfrompertussisin
Brazilianchildrenupto19yearsofage,from1996to2013.
The direct costs of hospitalizationfrom pertussis through
SUSin2013werealsocalculated.
Methods
Thiswasadescriptiveecologicalstudyoftemporaltrends, basedonthedatabaseoftheBrazilianUnifiedHealth Sys-temInformaticsDepartment(DATASUS).Thisstudyinvolved onlypublic-domaindatathatdonotidentifytheparticipants and,therefore, did not require approval by theResearch Ethics Committee.10 The numbers of hospitalizations and
number of deaths from pertussis, as well as the number
of hospitalizations fromall causes in children aged up to
19 years were obtained from January 1996 to December
2013.Thechoiceofthestudiedperiod,1996---2013,is
justi-fiedastheTenthRevisionoftheInternationalClassification
ofDiseases(ICD-10)wasimplementedinBrazilin1996.Data
onthe totalamount paidbySUSfor hospitalizations from
pertussisin2013,themeanamountpaidperadmission,and
thelengthofhospitalization(indays)forthisdiseasewere
4000
A
B
3500 3000 2500 2000 1000 1500 500Number of hospital admissions from per
tussis
T
otal number of hospitalizations
Year 0 199 6 199 7 199 8 199 9 200 0 200 1 200 2 200 3 200 4 200 5 200 6 200 7 200 8 200 9 201 0 201 1 201 2 201 3 Year 199 6 199 7 199 8 199 9 200 0 200 1 200 2 200 3 200 4 200 5 200 6 200 7 200 8 200 9 201 0 201 1 201 2 201 3 2000000 3000000 4000000 3500000 2500000
Figure1 (A)NumberofhospitaladmissionsfrompertussisinBrazilianchildren,1996---2013.(B)Totalnumberofhospitalizations inBrazilianchildren,1996---2013.
Dataextractionwasperformedbyoneindividual,using astandardized form.The extracted datawereverifiedby anotherresearcher.The linegraphs wereusedtoplotthe temporaltrendsofhospitalizationsanddeathsfrom pertus-sisinthestudiedperiod,withabsolutenumbersplottedon thevertical axisand yearsof observationonthe horizon-talaxis.Descriptivestatisticswereappliedfordataanalysis usingtheprogramStata(StataCorp.2009.StataStatistical Software:Release11.CollegeStation,TX,USA).
Results
Duringthestudyperiod,atotalof19,047admissionsfrom pertussiswererecordedinchildrenyoungerthan19 years of age in Brazil. Of the total admissions, 88.2% (16,790 records)wereofchildrenyoungerthan1yearandonly1.2% (221records)wereadolescentsaged10---19years(Table1).
Fig.1Ashowsthetemporaltrendinthenumberof
hospi-talizationsfrompertussisinBrazilianchildren.Intheperiod
1996---2010,themeanannualnumberofadmissionswas755,
ranging from a maximum of 1179 in 2004 to a minimum
of 400 in 2010. There was an increase in the number of
admissionsinthelastthreeconsecutiveyears(2011,2012,
and2013),with1177,2954,and3589records,respectively.
Themeanannualnumberofhospitalizationsfrompertussis
in the period of 2011 to 2013 increased by 242% in
rela-tiontotheprevious period.Incontrast,thetotalnumber
of general admissions in children during the study period
decreasedeach year (Fig.1B). The increasein admissions
frompertussisin thelastthreeyearsoccurred in all
geo-graphicregionsofthecountry,butwasmoreevidentinthe
Southeast,North,Northeast,andSouthregions(Fig.2).
Inthe periodfrom1996to2013, 498deathsfrom
per-tussiswererecorded in childrenyounger than19 yearsin
Brazil, of which 96.8% (482 records)occurred in children
0
2010 2011 2012 2013
200 400 600 800 1000 1200 1400 1600 North-Northeast Southeast South Midwest
Number of hospital admissions
Year
Figure2 HospitalizationfrompertussisinBrazilianchildren ingeographicregions,2010---2013.
youngerthan1year.Agrowingtemporaltrendinthe num-ber of deaths from pertussis in Brazilian children can be observedinthelastthreeyears,with40,93,and87deaths recordedin2011,2012,and2013,respectively(Fig.3).This
trendoccurredinallregionsofthecountry,withthehighest
increasein theSoutheast,NorthandNortheastregions.In
Table1 NumberofhospitaladmissionsfrompertussisinBrazilianchildrenupto19yearsofage,1996---2013.
Year <1year 1---4years 5---9years 10---14years 15---19years Total
1996 353 51 24 6 1 435
1997 577 48 26 11 1 663
1998 815 57 24 8 2 906
1999 551 69 25 9 0 654
2000 771 74 34 10 2 891
2001 661 60 10 6 0 737
2002 444 56 13 3 1 517
2003 725 65 23 6 0 819
2004 1067 75 20 12 2 1176
2005 910 69 17 7 1 1004
2006 680 54 13 5 2 754
2007 719 47 7 4 0 777
2008 836 60 17 7 3 923
2009 600 44 13 8 6 671
2010 352 27 15 4 2 400
2011 1061 86 20 7 3 1177
2012 2588 280 50 24 12 2954
2013 3080 369 94 38 8 3589
Total 16,790 1591 445 175 46 19,047
tenintheSoutheast,NorthandNortheastregions,andlower than five in the South and Midwest regions. This number increased to40, 26, 10 and 11 in 2013 in the Southeast, North,Northeast,South,andMidwestregions,respectively. In2013,approximatelyfivemillionreais(R$5,000,000) werepaidbySUSforhospitalizationsfrompertussisin chil-dren inBrazil. Those agedlessthan 1 yearaccounted for approximately90% of total costs withhospitaladmissions fromthisdisease.Moreover,thisistheagegroupthathad thehighestmeanhospitalstay(7.3days),resultinginhigher meanamountspaidperadmission(R$1365.26).
Number of deaths from per
tussis
Year
0 1818
23 24 27
1012 19
1921 2118 18 18 40
93
87
12
10 20 30 40 50 60 70 80 90 100
1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013
Figure 3 Deaths from pertussis in Brazilian children, 1996---2013.
Discussion
The present study disclosed a substantialincrease in the numbers of hospitalizations and deaths from pertussis in Brazilianchildrenin thelastthreeyears(2011,2012,and 2013).This increase occurred in all geographicregions of the country, although it was more evident in the South-east,NorthandNortheastregions.Childrenagedlessthan 1yearaccountedfor mostofthedeaths,hospitalizations, andrelatedcostsfrompertussis.
Theresultsofthisstudycorroboratedatafromthe Min-istryofHealthepidemiologicalsurveillance,whichshowan increaseinconfirmedcasesofpertussisinBrazilinthelast threeyears.7 Theincidenceratewas1.2,2.8,and3.1per
100,000inhabitantsin2011, 2012,and2013,respectively,
comparedwiththemeanof0.7per100,000inhabitantsfrom
1996to2010.Thehighestincreaseintheincidenceof
per-tussisoccurred in infants younger than 1 year, especially
thoseagedlessthan3months.Thisphenomenonhasalready
occurred in many developed countries over the past two
decades,promptingtheimplementationofnewvaccination
strategies against pertussis, such as the cocoon strategy,
vaccinationofpregnantwomen,vaccinationofadolescents
andadults,aswellasofhealthprofessionals.2,11---15
The cocoon strategy consistsin vaccinating all
individ-ualslivingwiththeinfant(parents,grandparents,siblings,
and caregivers), because in 75% of cases, the source of
diseasetransmission is a memberof the family, withthe
motherrepresentingthemainsourceofcontagion.2,11,14The
vaccinationofpregnantwomenaimstointroducethe
pro-ductionof high antibody titers againstpertussis, allowing
thetransplacentaltransferoftheseantibodiestothefetus,
resultinginindirect vaccineprotectioninthefirstmonths
oflife,whenthechildis notyet oldenough toreceive or
Due to the lack of convincing evidence on the
effi-cacy and cost-effectiveness of these strategies, either
alone or in combination, there is substantial variation
betweencountriesinEurope,NorthAmerica,andthePacific
regarding the implementation of these new vaccination
strategies.2 A booster dose using the acellular vaccine is
giventoadolescentsaged11---17 years inmost developed
countries, such as Germany, Australia, Austria, Belgium,
Canada,USA,France,Finland,Italy,andSwitzerland,except
for Great Britain, the Netherlands, and Poland.16---18 The
cocoon strategy has been implemented in Germany,
Aus-tralia, Belgium, USA, France, Finland, Great Britain, the
Netherlands, and Switzerland.16---18 In some countries,the
cocoonstrategyiscombinedwithvaccinationofadultsand
healthprofessionals.
In Brazil, although the Brazilian Society of Pediatrics
andtheBrazilianSociety ofImmunizationrecommendthe
vaccination of adolescents against pertussis, this vaccine
has not yet been included in the SUS Basic
Immuniza-tion Calendar for this population.19,20 In November 2014,
the Ministry of Health introduced the adsorbed
diphthe-ria,tetanus, andacellular pertussisvaccine (DTaP) inthe
SUSNationalVaccinationCalendarforpregnantwomenand
healthprofessionalswhotreatnewbornsinmaternitywards
andneonatalintensivecareunits.21Theimpactofthis
vac-cinestrategyonchildmorbimortalityfrompertussisandthe
cost-effectivenessofvaccinationshouldbeassessedatthe
nationallevel.
In addition to increased morbimortality frompertussis
inyounginfants,thesepatientsmaypresent withatypical
disease symptoms, which complicates and delays
diagno-sisandtreatment.6,22,23Therefore,specialattentionshould
bepaidtothis population,which requires greater
aware-nessofthemedicalteamabouttheriskofdiseaseandthe
useofdiagnostictests.Pertussisshouldalsobeincludedin
thedifferentialdiagnosisofprolongedcoughinadultsand
adolescents,especiallyinnon-atopic patients.23 As
impor-tantasthediagnosisistheearlytreatmentofpatientsand
antimicrobialprophylaxisfor contacts,preventingthe
dis-seminationofthediseasetosusceptibleindividuals.24
In 2013,approximately fivemillion reais(R$5,000,000)
werepaidbySUSforhospitalizationsfrompertussisin
chil-dreninBrazil.Thisamountrepresentsasignificantfinancial
burdenonthehealthsystemofthecountry.Outpatientand
emergencycare costsassociatedwitholderchildren,
ado-lescents,andadults,aswellasindirectcostsrelatedtothe
disease,shouldbeevenhigher.
Somelimitationsshouldbeconsideredwheninterpreting
theresultsof thisstudy.AccordingtotheEpidemiological
Surveillance Guide of the Ministry of Health,25 diagnostic
confirmationofpertussismustbemadebylaboratory
test-ing, through the culture of Bordetella pertussis bacteria
or by isolation through polymerase chain reaction (PCR).
Confirmationcanalsobeattainedusingclinicalor
clinical-epidemiologicalcriteria.
Therefore, the diagnosis of pertussis depends on the
technicaland operational conditions of the
epidemiologi-calsurveillancesystemineachgeographicalareatodetect,
report, investigate, and confirm cases. When the
confir-mation depends only on clinical data, diagnostic errors
may occur because pertussis may be misdiagnosed as
other conditions caused by other agents that produce
pertussissyndrome.6,9,26Thesesituationscanleadto
over-or underreporting of cases. Due to the relatively small
numberof deaths andhospitalizationsfrom pertussis,the
present study used the absolute number of occurrences
ratherthan mortality andhospitalization incidencerates.
However,theabsolutenumberofdiseaseoccurrencecanbe
influencedbythevariationinthepopulationovertime.The
simple increase in the population could have contributed
to the higher number of hospitalizations and deaths.
However, the significant increase in absolute numbers of
hospitalizations and deaths from pertussis that occurred
in the last three years does not support this hypothesis.
Additionally,proportionalmortalityandhospitalizationfrom
pertussiswerenotincludedbecausetheconstantreduction
inmortalityandthenumberofoverallhospitaladmissions
in Brazilianchildren overthe recentdecadescouldaffect
thesemeasures. Anotherlimitationis relatedtothe
inca-pacity tomake inferencesabout the causesof the trends
foundbythestudy.
Even considering the above limitations, it can be
concludedthat there wasa substantialincrease in
hospi-talizationsanddeaths frompertussis inchildren forthree
consecutive years (2011, 2012, and 2013) in the country
asawholeandin allBrazilianregions. Themost affected
age group was that of children younger than one year.
Theseresultsemphasizetheimportanceofepidemiological
surveillanceandimplementationofnewvaccination
strate-giesagainstpertussisinBrazil.Greaterattentionshouldbe
giventotheSoutheast,North,andNortheastregions,which
haveshownahigherincreaseinthenumbersof
hospitaliza-tionsanddeathsduetopertussisinrecentyears.
Conflicts
of
interest
Theauthorsdeclarenoconflictsofinterest.
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