trends in hiv diagnoses in ontario, 20002004 robert s. remis, jane njihia, carol swantee, maraki...

instructional media centre, Laboratories Branch - 2000

Trends in HIV diagnoses Trends in HIV diagnoses in Ontario, 2000 2004in Ontario, 2000 2004

Robert S. Remis, Jane Njihia, Carol Swantee, Maraki Fikre MeridRobert S. Remis, Jane Njihia, Carol Swantee, Maraki Fikre Merid

Ontario HIV Epidemiologic Monitoring Unit, Public Health Sciences, Ontario HIV Epidemiologic Monitoring Unit, Public Health Sciences,

University of TorontoUniversity of Toronto; ; HIV Laboratory, Ontario Ministry of Health; HIV Laboratory, Ontario Ministry of Health;

Public Health Agency of CanadaPublic Health Agency of Canada

14th Annual Canadian Conference on HIV/AIDS 14th Annual Canadian Conference on HIV/AIDS Research Vancouver, BC, May 13, 2005Research Vancouver, BC, May 13, 2005


BackgroundBackground

• In Ontario, essentially all HIV diagnostic In Ontario, essentially all HIV diagnostic testing is conducted at the HIV Laboratory testing is conducted at the HIV Laboratory and regional labsand regional labs

• We use diagnostic test results to monitor the We use diagnostic test results to monitor the HIV epidemic on an ongoing basisHIV epidemic on an ongoing basis

• Since 2000, we observed a substantial Since 2000, we observed a substantial increase in the number of new HIV diagnosesincrease in the number of new HIV diagnoses

Dr. Robert S. RemisPublic Health Sciences, University of Toronto


Study objectivesStudy objectives

1. 1. To characterize trends in new HIV To characterize trends in new HIV diagnoses in Ontariodiagnoses in Ontario

2. To determine to what extent 2. To determine to what extent observed trends due to testing observed trends due to testing artefact artefact



MethodsMethods

• Examined first-time HIV-positive and total HIV Examined first-time HIV-positive and total HIV tests from 1985 to 2004, with particular tests from 1985 to 2004, with particular attention to years 2000 to 2004attention to years 2000 to 2004

• First-time HIV positive: confirmed positive with First-time HIV positive: confirmed positive with no previous positive result identified and no no previous positive result identified and no evidence of previous positive test in Ontarioevidence of previous positive test in Ontario

• Adjusted exposure category using data on risk Adjusted exposure category using data on risk factors from Laboratory Enhancement Studyfactors from Laboratory Enhancement Study



MethodsMethods

•Based on the observed pattern, Based on the observed pattern, defined the baseline year as 2000defined the baseline year as 2000

•Compared HIV test results for 2004 to Compared HIV test results for 2004 to those in earlier years by sex, exposure those in earlier years by sex, exposure category and reason for testingcategory and reason for testing



Number of HIV diagnoses by sex Number of HIV diagnoses by sex Ontario, 1985-2004Ontario, 1985-2004


-

500

1,000

1,500

2,000

2,500

Year of HIV test

Nu

mb

er

of H

IV d

iag

no

ses

Both sexesMalesFemales


Number of HIV diagnoses by sex Number of HIV diagnoses by sex Ontario, 2000-2004Ontario, 2000-2004


-

200

400

600

800

1,000

1,200

1,400

2000 2001 2002 2003 2004Year of HIV test

Nu

mb

er

of

HIV

dia

gn

os

es

Both sexesMalesFemales


Number of HIV diagnoses by Number of HIV diagnoses by exposure category, Ontario, 2000-exposure category, Ontario, 2000-20042004


0

100

200

300

400

500

600

700

2000 2001 2002 2003 2004

Year of HIV test

Nu

mb

er

of d

iag

no

ses

MSMIDUHIV-endemicHetero


Possible explanationsPossible explanations

•Artefact related to:Artefact related to:• Impact of immigration testing in 2002Impact of immigration testing in 2002• Impact of increased prenatal testingImpact of increased prenatal testing• General increase in HIV testingGeneral increase in HIV testing

•Real increase related to new HIV infectionReal increase related to new HIV infection



Impact of HIV diagnoses related to Impact of HIV diagnoses related to prenatal and immigration HIV testing, prenatal and immigration HIV testing, 2004 versus 20002004 versus 2000


Male Female Total

Excess HIV 212 155 368

Excess #Visa 74 43 117Prenatal 26 26Total 74 69 143

Excess %Visa 35% 28% 32%Prenatal 17% 7%Total 35% 45% 39%


HIV tests versus HIV diagnosesHIV tests versus HIV diagnosesMSM, Ontario 2000-2004MSM, Ontario 2000-2004


Tests Increase HIV diag Increase

2000 18,987 Referent 446 Referent

2001 20,320 7% 448 0%2002 24,348 28% 570 28%2003 25,075 32% 557 25%2004 27,378 44% 634 42%


HIV tests versus HIV diagnoses HIV tests versus HIV diagnoses HIV-endemic, Ontario, 2000-2004HIV-endemic, Ontario, 2000-2004




2001 7,308 8% 224 24%2002 9,706 43% 281 56%2003 10,631 57% 252 40%2004 11,355 67% 240 33%


HIV tests versus HIV diagnoses HIV tests versus HIV diagnoses heterosexual, Ontario, 2000-2004heterosexual, Ontario, 2000-2004




2001 196,517 7% 179 23%2002 248,143 35% 209 43%2003 256,537 39% 231 58%2004 277,153 51% 242 66%


Summary of findingsSummary of findings

•From 2000 to 2004, marked increase in HIV From 2000 to 2004, marked increase in HIV diagnoses, especially in heterosexual (+66%), diagnoses, especially in heterosexual (+66%), MSM (+42%) and endemic (+33%) exposure MSM (+42%) and endemic (+33%) exposure categoriescategories

• Increases partly related to increases in testing for Increases partly related to increases in testing for prenatal and immigration, especially in women prenatal and immigration, especially in women and persons from endemic countriesand persons from endemic countries

•Testing increased in all three exposure categoriesTesting increased in all three exposure categories•Endemic: Endemic: testing >> testing >> HIV diagnosesHIV diagnoses•MSM: MSM: testing testing HIV diagnosesHIV diagnoses•Heterosexual: Heterosexual: testing << testing << HIV diagnosesHIV diagnoses



Study limitationsStudy limitations

•Data on reason for testing indicating visa may be Data on reason for testing indicating visa may be incompleteincomplete

•Data on HIV diagnoses and testing based on Data on HIV diagnoses and testing based on adjustments using weights from LES; subject to adjustments using weights from LES; subject to uncertaintyuncertainty

•Limit data on characteristics of subpopulations Limit data on characteristics of subpopulations who present for HIV testing, who are “new” and who present for HIV testing, who are “new” and who are more frequent testerswho are more frequent testers



ConclusionsConclusions

•Among persons from HIV-endemic countries, increase Among persons from HIV-endemic countries, increase likely related immigration testing policy begun in Jan likely related immigration testing policy begun in Jan 20022002

•MSM: Testing and diagnoses increased about the MSM: Testing and diagnoses increased about the same, but not necessarily reassuring same, but not necessarily reassuring •Increased testing frequency should not increase Increased testing frequency should not increase number of diagnosesnumber of diagnoses

•If epidemic controlled, new persons testing yields few If epidemic controlled, new persons testing yields few additional diagnoses (“exhaust the prevalent cases”)additional diagnoses (“exhaust the prevalent cases”)



ConclusionsConclusions

•Heterosexual: Increased diagnoses >> increased Heterosexual: Increased diagnoses >> increased tests suggests substantial continued HIV tests suggests substantial continued HIV transmissiontransmission

•Study in Toronto and Ottawa to better understand Study in Toronto and Ottawa to better understand apparent increase in HIV infection among persons apparent increase in HIV infection among persons infected heterosexuallyinfected heterosexually

•HIV epidemic in Ontario still unstable and evolvingHIV epidemic in Ontario still unstable and evolving



AcknowledgementsAcknowledgements

•Frank McGee, AIDS Bureau, Frank McGee, AIDS Bureau, Ontario Ministry of Ontario Ministry of Health and Long Term Care (MOHLTC)Health and Long Term Care (MOHLTC)

•Carol Major, formerly of HIV Laboratory, MOHLTC Carol Major, formerly of HIV Laboratory, MOHLTC •OHTN (1999-2000) and Centre for Infectious OHTN (1999-2000) and Centre for Infectious Disease Prevention and Control, Public Health Disease Prevention and Control, Public Health Agency of Canada (2000-2006) for funding LESAgency of Canada (2000-2006) for funding LES

trends in hiv diagnoses in ontario, 20002004 robert s. remis, jane njihia, carol swantee, maraki...

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