Trends in HIV incidence in Ontario based on the detuned assay: Update to December 2002 Robert S....

Trends in HIV incidence in Trends in HIV incidence in Ontario based on the detuned Ontario based on the detuned assay: Update to December assay: Update to December 20022002

Robert S. Remis, Carol Major, Carol Swantee, Robert S. Remis, Carol Major, Carol Swantee, Margaret Fearon, Robert W. H. Palmer, Evelyn Margaret Fearon, Robert W. H. Palmer, Evelyn Wallace, Elaine Whittingham Wallace, Elaine Whittingham Department of Public Health Sciences, University of TorontoDepartment of Public Health Sciences, University of Toronto

HIV Laboratory, Laboratory Services, HIV Laboratory, Laboratory Services, Ontario Ministry of Health and Long-Term CareOntario Ministry of Health and Long-Term Care

Public Health Branch, Public Health Branch, Ontario Ministry of Health and Long-Term CareOntario Ministry of Health and Long-Term Care

Ontario HIV Treatment NetworkOntario HIV Treatment Network

5th Annual Research Day5th Annual Research Day

Toronto, Ontario, November 3-4, 2003Toronto, Ontario, November 3-4, 2003

MOHLTC, Laboratories Branch, IMC – 2001

IntroductionIntroduction

• Serodiagnostic data may be useful for Serodiagnostic data may be useful for surveillancesurveillance

• Testing of HIV-positive specimens using Testing of HIV-positive specimens using less sensitive (detuned” or STAHRS) assay less sensitive (detuned” or STAHRS) assay permits the identification of persons who permits the identification of persons who recently seroconverted (e.g.<4 months) recently seroconverted (e.g.<4 months)

• Allows the calculation of HIV incidence Allows the calculation of HIV incidence density, an important indicator usually density, an important indicator usually difficult to measuredifficult to measure


Study objectivesStudy objectives

• To estimate HIV incidence density among To estimate HIV incidence density among persons undergoing HIV testing according to persons undergoing HIV testing according to exposure category and region of testexposure category and region of test

• To monitor trends in HIV incidence density To monitor trends in HIV incidence density among specific populations particularly among specific populations particularly affected by the HIV epidemicaffected by the HIV epidemic


Data collection and managementData collection and management• Questionnaire sent with all HIV-positive Questionnaire sent with all HIV-positive

results results

and 1 in 200 sample of HIV-negative resultsand 1 in 200 sample of HIV-negative results• Data collected on risk factors for HIV infection Data collected on risk factors for HIV infection

and and HIV test historyHIV test history

• Questionnaire may be returned byQuestionnaire may be returned by• mailmail• faxfax• telephone interviewtelephone interview

• Data entered in Microsoft AccessData entered in Microsoft Access


Laboratory methodsLaboratory methods• Abbott 3A11 EIA kit modified as follows:Abbott 3A11 EIA kit modified as follows:

• serum diluted to 1:20,000serum diluted to 1:20,000• incubation period reduced to 30 minutesincubation period reduced to 30 minutes• cut-off value increasedcut-off value increased

• For specimens tested in October 2001 or For specimens tested in October 2001 or later, we used Organon-Teknika Vironostika later, we used Organon-Teknika Vironostika assay allowing for different “window period” assay allowing for different “window period” at different cut-off (70-336 days)at different cut-off (70-336 days)


Study questionnaires mailed Study questionnaires mailed and returned, and returned, October 1999 to December 2002October 1999 to December 2002

78%78%

78%78%

73%73%

73%73%

69%69%

71%71%

70%70%

3,1613,161

3,419 3,419

6,580 6,580

HIV-positiveHIV-positive

HIV-negativeHIV-negative

TotalTotal

8 mon.8 mon.4 mon.4 mon.ProportionProportionReturnedReturnedMailedMailed

Kaplan - Meier Kaplan - Meier returned byreturned byQuestionnairesQuestionnaires

2,1872,187

2,4402,440

4,6274,627


Exposure category classification according Exposure category classification according to to HIV test requisition, returned questionnaires HIV test requisition, returned questionnaires and modeled distribution, HIV-positives and modeled distribution, HIV-positives

HIV test HIV test requisitionrequisition

Returned Returned questionnaires questionnaires

among NIRamong NIR

Projected finalProjected finaldistributiondistribution

MSMMSM

MSM-IDUMSM-IDU

IDUIDU

EndemicEndemic

HR heteroHR hetero

LR heteroLR hetero

OtherOther

NIRNIR

780 780

26 26

143 143

108 108

95 95

271271

31 31

1,711 1,711

54%54%

2%2%

10%10%

7%7%

7%7%

19%19%

2%2%

413413

3535

7575

262262

4949

169169

4646

39%39%

3%3%

7%7%

25%25%

5%5%

16%16%

4%4%

1,454 1,454

83 83

265 265

535535

175 175

547547

106106

46%46%

3%3%

8%8%

17%17%

6%6%

17%17%

3%3%

TotalTotal 3,1653,165 1,0491,049 100%100% 3,1653,165 100%100%

%NIR%NIR 54%54%


HIV incidence (per 100 person-HIV incidence (per 100 person-years) for selected exposure years) for selected exposure categories by health regioncategories by health region

2.12.1

2.42.4

0.230.23

0.100.10

0.010.01

39,603 39,603

1,763 1,763

46,034 46,034

40,674 40,674

646,721 646,721

0.960.96

0.310.31

0.150.15

0.060.06

0.010.01

11,910 11,910

1,311 1,311

28,299 28,299

22,465 22,465

318,548 318,548

1.81.8

16.2316.23

0.700.70

0.090.09

0.020.02

5,157 5,157

82 82

3,883 3,883

3,8433,843

70,830 70,830

2.82.8

6.96.9

0.250.25

0.160.16

0.020.02

MSMMSM

MSM-IDUMSM-IDU

IDUIDU

HR heteroHR hetero

LR heteroLR hetero

IncidenceIncidenceTestedTestedIncidenceIncidenceTestedTestedIncidenceIncidenceTested Tested IncidenceIncidence

OverallOverallRest of OntarioRest of OntarioOttawaOttawaTorontoToronto

TestedTested

22,53522,535

370370

13,85313,853

14,36614,366

257,343257,343


MSM: HIV incidence by six-monthMSM: HIV incidence by six-monthperiod and region,Ontario, period and region,Ontario, October1999-December 10th October1999-December 10th 20022002

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

1999B 2000A 2000B 2001A 2001B 2002A 2002B

Period

HIV

inci

dence

(per

100 p

y) Toronto

OttawaRest of Ontario


IDU: HIV incidence by six-month IDU: HIV incidence by six-month

period and region,Ontario,period and region,Ontario,October1999- December 10th October1999- December 10th 2002 2002

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1999B 2000A 2000B 2001A 2001B 2002A 2002B

Period

HIV

inci

dence

(per

100 p

y)

Toronto

OttawaRest of Ontario


High risk heterosexuals: HIV High risk heterosexuals: HIV incidence by six-month period and incidence by six-month period and region, Ontario,October1999-region, Ontario,October1999-December 10th 2002December 10th 2002

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

1999B 2000A 2000B 2000A 2001B 2002A 2002B

Period

HIV

inci

dence

(per

100 p

y)

TorontoOttawa

Rest of Ontario


Low risk heterosexuals: HIV Low risk heterosexuals: HIV incidence by six-month period and incidence by six-month period and region, Ontario, October1999-region, Ontario, October1999-December 10th 2002December 10th 2002

0.00

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08

0.09

0.10

1999B 2000A 2000B 2001A 2001B 2000A 2002B

Period

HIV

inci

dence

(per

100 p

y)

TorontoOttawa

Rest of Ontario


Summary of findingsSummary of findings• Exposure category distribution among those Exposure category distribution among those

with risk factor data not representative with risk factor data not representative • Trends in HIV incidence Trends in HIV incidence

• MSM: highest in Toronto but decreasing; MSM: highest in Toronto but decreasing; intermediate and stable in Ottawa and intermediate and stable in Ottawa and elsewhere elsewhere

• IDU: high in Ottawa; lower elsewhere IDU: high in Ottawa; lower elsewhere appears to be decreasing in Ottawa and appears to be decreasing in Ottawa and TorontoToronto

• HR heterosexual: Incidence apparently HR heterosexual: Incidence apparently increasing in Ottawaincreasing in Ottawa


InterpretationInterpretation

• Number of discordant samples and HIV tests Number of discordant samples and HIV tests by exposure category modeled by exposure category modeled

• Since Since persons who test may not be persons who test may not be representative and data quality is representative and data quality is inconsistent, true HIV incidence and HIV inconsistent, true HIV incidence and HIV prevalence cannot be derived directly from prevalence cannot be derived directly from datadata

• Thus,interpretation of HIV incidence must Thus,interpretation of HIV incidence must incorporate knowledge of patterns in HIV test incorporate knowledge of patterns in HIV test seeking behaviours; measured HIV incidence seeking behaviours; measured HIV incidence likely higher than true incidencelikely higher than true incidence


ConclusionsConclusions

• HIV serodiagnostic program extremely useful HIV serodiagnostic program extremely useful for HIV surveillance for HIV surveillance

• Due to important problems in missing and Due to important problems in missing and unrepresentative data on risk factors and HIV unrepresentative data on risk factors and HIV test history, available data must be enhanced test history, available data must be enhanced through supplementary means on an ongoing through supplementary means on an ongoing basisbasis

• Detuned assay provides a critical indicator of Detuned assay provides a critical indicator of trends in the epidemic at low costtrends in the epidemic at low cost


AcknowledgementsAcknowledgements

• At the HIV LaboratoryAt the HIV Laboratory• Lisa Santangelo and Cindi Farina, data collectionLisa Santangelo and Cindi Farina, data collection• Lynda Healey, detuned assayLynda Healey, detuned assay• Elaine McFarlane, data entry screens Elaine McFarlane, data entry screens • Len Neglia, mail-out of questionnairesLen Neglia, mail-out of questionnaires

• Regional PHLs, mail-out of negative questionnairesRegional PHLs, mail-out of negative questionnaires• Physicians who prescribe HIV testing and provide Physicians who prescribe HIV testing and provide

supplementary datasupplementary data• Ontario HIV Treatment Network and the Centre for Ontario HIV Treatment Network and the Centre for

Infectious Disease Prevention and Control, Health Infectious Disease Prevention and Control, Health Canada for fundingCanada for funding

Trends in HIV incidence in Ontario based on the detuned assay: Update to December 2002 Robert S....

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