Marked increase in first-time HIV diagnoses in Ontario, 2002

Acknowledgements Public Health Laboratory staff, Ontario Ministry of Health and Long-Term Care Public Health Laboratory staff, Ontario Ministry of Health and Long-Term Care Keyi Wu, programming Keyi Wu, programming Mark Fisher, systems consulting and custom download Mark Fisher, systems consulting and custom download

Background In Ontario, HIV diagnostic testing is conducted at the HIV Laboratory and regional labs In Ontario, HIV diagnostic testing is conducted at the HIV Laboratory and regional labs Use HIV Laboratory data to monitor the HIV epidemics in Ontario Use HIV Laboratory data to monitor the HIV epidemics in Ontario In late 2002, observed a marked increase in first-time diagnoses in the first three quarters In late 2002, observed a marked increase in first-time diagnoses in the first three quarters

Study objectives 1. To characterize the increase in first-time HIV diagnoses at the Ontario HIV Laboratory in To better understand to what extent this increase was due to increased HIV testing or HIV incidence

Methods Examined first-time HIV-positive and total HIV tests from 1985 to 2002 Examined first-time HIV-positive and total HIV tests from 1985 to 2002 First-time HIV positive: confirmed positive with no link to a previous positive result in database and no other evidence of previous HIV-positive test in Ontario First-time HIV positive: confirmed positive with no link to a previous positive result in database and no other evidence of previous HIV-positive test in Ontario Based on the observed pattern, defined the period of increase as calendar year 2002 Based on the observed pattern, defined the period of increase as calendar year 2002 Compared HIV test results for 2002 to those in 2001 by sex, age, exposure category, reason for testing, health region and seroconverter or not Compared HIV test results for 2002 to those in 2001 by sex, age, exposure category, reason for testing, health region and seroconverter or not

RESULTS First-time HIV positives and HIV tests by year, Ontario, Year of testing First-time HIV postive tests All HIV tests First-time HIV positivesAll HIV tests

First-time HIV positives and HIV tests by quarter, Ontario, Q11999Q21999Q31999Q42000Q12000Q22000Q32000Q42001Q12001Q22001Q32001Q42002Q12002Q22002Q32002Q4 Year-Quarter Number of First-time HIV positive tests Number of all HIV tests First-time HIV positivesAll Tests

First-time HIV diagnoses by sex Ontario, 2002 versus 2001 Year Female Male Unknown Total , ,238 Relative rate (2002/2001) Excess tests ( )

First-time HIV diagnoses by health region Ontario, 2002 versus 2001 Year Northern Eastern Ottawa Central East Toronto South Central Other Other West West Relative rate (2002/2001) Excess tests ( ) Proportion of Excess0.80%6.90% 83.70% 8.60%

First-time HIV diagnoses by exposure category by year, Ontario, Year of testing Number of first-time positives UnknownMSMIDUEndemicHR HeteroLR Hetero

First-time HIV diagnoses by exposure category, Ontario, 2002 versus 2001 Year MSM IDU Endemic HR hetero LR hetero Unknown Relative rate (2002/2001) Excess tests ( ) Proportion of Excess42.7% 0.9% 4.0% 0.9% 3.6% 46.2%

First-time HIV diagnoses by reason for testing, Ontario, 2002 versus 2001 Year Donor of blood, tissue Diagnostic Follow-up Insurance Prenatal semen Visa (Known) Unknown Relative rate (2002/2001) Excess tests ( )

Is the the increase due to an increase in HIV testing?

Summary of increase in major categories

Proportion of seroconverters, linked and in progress, among first-time HIV diagnoses 2002 versus Relative rate Excess

Summary of observations Excess of 220 (+22%) first-time HIV diagnoses from 2001 to 2002 Excess of 220 (+22%) first-time HIV diagnoses from 2001 to 2002 Exposure category: MSM and persons from HIV-endemic regions (PHER) highest Exposure category: MSM and persons from HIV-endemic regions (PHER) highest Health region: Toronto and Central West highest Health region: Toronto and Central West highest Reason for test, visa applicants highest Reason for test, visa applicants highest Reasons for testing and exposure categories were mutually exclusive, e.g., no MSM among visa applicants Reasons for testing and exposure categories were mutually exclusive, e.g., no MSM among visa applicants Proportion of excess: MSM 43%, PHER 4%, visa 51% Proportion of excess: MSM 43%, PHER 4%, visa 51%

Conclusions Increase among visa applicants entirely due to increase in HIV testing Increase among visa applicants entirely due to increase in HIV testing Among MSM and PHER, increase in HIV diagnoses Among MSM and PHER, increase in HIV diagnoses not due to increased HIV testing not due to increased HIV testing Increases in these groups may be due to selective increased HIV testing in persons at high risk for HIV infection Increases in these groups may be due to selective increased HIV testing in persons at high risk for HIV infection Also, evidence of increased HIV incidence in MSM Also, evidence of increased HIV incidence in MSM Thus, both increased HIV testing and increased HIV incidence responsible for observed increase in HIV diagnoses Thus, both increased HIV testing and increased HIV incidence responsible for observed increase in HIV diagnoses Relative importance not clear; requires further study Relative importance not clear; requires further study