Acase-controlstudyofhouseholdairpollutionandtuberculosisinwomenandyoungchildreninurbanIndia

JessicaElf,PhDMPHPostdoctoralFellow

JohnsHopkinsSchoolofMedicineSchroederInstituteatTruthInitiative

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© 2014, Johns Hopkins University. All rights reserved.

© 2014, Johns Hopkins University. All rights reserved.

©2015, Johns Hopkins University. All rights reserved.

- 9.6millionincidentcases,1.5milliondeaths

• 88%ofnewcasesand73%ofTBdeathswereinHIV-uninfected

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Background

Lonnroth_Soc Sci Med_2009WHO_Global TBReport_2015

DiseaseofPoverty

- Mostprevalentamongthoseinpoorsocialandeconomicconditions

- Socialdeterminantsincreasingriskforinfectionà disease

ü Undernutrition

ü TobaccoSmoking

ü Crowding

ü AlcoholAbuse

??HouseholdAirPollution

© 2014, Johns Hopkins University. All rights reserved.

© 2014, Johns Hopkins University. All rights reserved.

©2015, Johns Hopkins University. All rights reserved.

HouseholdAirPollution(HAP)- Complexmixofby-productsfromhousehold-basedcombustion

• Somemajorcontributors:Cooking/heatingfuel,SHS,mosquitocoils

- Associatedwithotherrespiratorydiseases:ALRI,COPD,asthma,lungcancer

à NotdefinitivelyassociatedwithTB• Meta-analysis:OR1.6(95%CI:0.7-3.6)whenrestrictedto

females

• Lakshmi2012(India):3.14(95%CI:1.15– 8.56)

• Pohkrel 2010(Nepal):OR1.21(95%CI:0.48– 3.05)o KeroseneStove:OR3.36(95%CI:1.01-11.22)

Gordon_Lancet_2014Sussan_2014

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© 2014, Johns Hopkins University. All rights reserved.

© 2014, Johns Hopkins University. All rights reserved.

©2015, Johns Hopkins University. All rights reserved.

StudyLocationIndia

- 2.2millionincidentcases(23%ofglobalburden)

- 220,000deaths

- TBepidemicnotdrivenbyHIV

- 64%ofIndianhouseholdsusebiomassfuels(Rural:81%;Urban:26%)

PuneDistrict

- LargedistrictlocatedinstateofMaharastra

- 5.7millionurban,3.7millionrural

- AnnualTBIncidence:185/100,000

- Byramjee JeejeebhoyMedicalCollegeandSassoonGeneralHospital(BJMC/SGH)– largetertiarypublichospital

†Graham_JID_2012IndiaRNTCP

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© 2014, Johns Hopkins University. All rights reserved.

© 2014, Johns Hopkins University. All rights reserved.

©2015, Johns Hopkins University. All rights reserved.

MethodsMatchedcase-controlstudy- Cases

Inclusion:<5yearsofageoradultwomenpresentingatBJMC/SGHanddiagnosedwithTBExclusion:HIVinfection,diabetes

- ControlsInclusion:Randomlyselectedfromsameneighborhood,age(± 12monthsforchildren,± 5yearsforadults)andsexmatchedExclusion:HIVinfection,diabetes,positiveforTBsymptomscreen

StatisticalMethods- Conditionallogisticregressionformatcheddata

- Outcomeà TB- 1° Exposureà Log-transformed24-hourPM2.5

- Predictorvariablesofinterest:p<0.20inunivariateanalysisorapriori

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© 2014, Johns Hopkins University. All rights reserved.

©2015, Johns Hopkins University. All rights reserved.

ExposureAssessment

QuestionnairesandReportedMeasures- Socio-demographic- Fuelusepatterns- Secondhandtobaccosmoke

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EnvironmentalExposureAssessment:PM2.5

- 24-hourPM2.5 (PM<2.5micronsdiameter)• Importantproductofcombustion• Highlyregulatedandmonitored

- 1x1meterawayfromprimarycookstove

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© 2014, Johns Hopkins University. All rights reserved.

©2015, Johns Hopkins University. All rights reserved.

ReportedExposuretoPollutants:CookingFueln=156

PrimaryCookingFuel,n(%)LPGorElectricityKeroseneWood

134(86)17(11)5(3)

SecondaryCookingFuel,n(%)NoneElectricity/LPGKeroseneWood

83(53)18(12)19(12)36(23)

Composite CookingFuel,n(%)LPG/ElectricityOnlyKerosene(butnowood)AnyWood

87(56)28(18)41(26)

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© 2014, Johns Hopkins University. All rights reserved.

©2015, Johns Hopkins University. All rights reserved.

24-hourTime-weightedAveragePM2.5

WorldHealthOrganizationPM2.5 24-hourGuidelines:25μg/m3

InterimTarget:75μg/m3

ControlsvsCasesCompositeCookingFuels

OverallMedianConcentration:182μg/m3 (IQR:114- 318)

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© 2014, Johns Hopkins University. All rights reserved.

© 2014, Johns Hopkins University. All rights reserved.

©2015, Johns Hopkins University. All rights reserved.

StudyLimitationsandStrengthsLimitations

- SinglemeasureofhouseholdPM2.5

- Ubiquitouslyhighlevelsofexposure

- Unmeasuredconfounders

Strengths

- Objectivemeasuresforexposureclassification:PM2.5

- Contributionofavarietyofsourcesofexposure

- Vulnerable,hardtoreachpopulation

- Inclusionofchildren

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© 2014, Johns Hopkins University. All rights reserved.

© 2014, Johns Hopkins University. All rights reserved.

©2015, Johns Hopkins University. All rights reserved.

Discussion- HigherconcentrationsofPM2.5 tendedtobeassociatedwithTB- Highermagnitudeofeffectwithreporteduseofkerosene

• Cookinglocation• Needforadditionalstudiesduetocontributiontoparticulate

massmeasurements- FirststudyassessingassociationbetweenTBandobjectivemarkersof

combustioninhome

ImportanceofSocioeconomicDeterminants- Prevention(37%ofestimatednewcasesundiagnosed/notreported)- Usefulforidentifyingthoseatgreatestrisk

• Screeningstrategies• Activecase-finding• Targetsforpreventivetherapy

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© 2014, Johns Hopkins University. All rights reserved.

© 2014, Johns Hopkins University. All rights reserved.

©2015, Johns Hopkins University. All rights reserved.

StudyAcknowledgements

JohnsHopkinsUniversityJonathanGolubAmita GuptaPatrickBreysse (andlab)Vidya MaveNikhilGupteNishiSuryavanshi

BJMC/SGH,Pune,IndiaAnju KagalSandhya KhadseAarti KinikarTilak DhamgayePriyanka KulkarniPune OfficeatBJMCSunita PatekarVaishali Kulkarni

FundingFogartyGlobalHealthFellowTrainingProgramUjala FoundationGileadFoundationInstituteforGlobalTobaccoControl(JHU)

Studyparticipantsandtheirfamilies

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