Carol Major

Toronto street youth and HIV/AIDS: prevalence, demographics, and risks

PURPOSE The purposes of this study were: (a) to identify human immunodeficiency virus (HIV) prevalence in Toronto street youth through paired blood and saliva specimens; (b) to identify the HIV risk and prevention behaviors of street involved youth; and (c) to identify demographic or other factors that may contribute to the risk of street youth becoming infected with HIV/acquired immunodeficiency syndrome (AIDS) in the future. METHODS This was a cross-sectional convenience study of street-involved youth aged 14-25 years. The youth participated in interviews to identify HIV-related knowledge and personal risk and preventive behaviors. Following interviews, they were asked to provide a saliva sample, blood spot, or both. They could refuse one or both samples without jeopardizing their involvement or receiving an honorarium. Two males were the only participants who declined to provide a sample. RESULTS Fifteen of 695 (2.2%) youth tested positive for HIV infection. All were male, ranging in age from 18 to 25 years. Same and opposite sex, intravenous (IV) drug use, prostitution, and incarceration were risk factors associated with positive HIV test results. The rate of HIV infection was seven times greater for the group 20 years of age and older (20-25) compared to the younger group aged 14-9 years. The proportion testing positive for HIV from small cities, towns, and rural communities in Ontario was 40%; yet, they represented 21% of the study population. Most (57%) youth had been on their own for no more than 3 years and had moved frequently. Nearly two thirds (60%) had stayed in hostels or homeless shelters in the previous 6 months. CONCLUSION Street youth in Canada are at high risk of HIV infection with their risk increasing with age. Unprotected (same and opposite) sex, IV drug use, prostitution and incarceration were linked to their HIV infections. The high level of mobility identified by street youth challenges governments, communities, and public health officials to develop appropriate prevention strategies and to carefully monitor the spread of HIV infection in this vulnerable population.

Increases in HIV incidence among men who have sex with men undergoing repeat diagnostic HIV testing in Ontario, Canada.

ObjectiveTo estimate HIV incidence density for different exposure categories among people undergoing repeat testing in Ontario, Canada. MethodsPersons using voluntary, diagnostic HIV testing at least twice were identified by computerized and manual record linkage. In the 1992–2000 period, 980 seroconverters and 340 994 repeat negative testers contributed 936 145 person years (PY) of observation. Incidence density (ID) was calculated according to Kitayaporn et al.. Poisson regression was used to evaluate differences in incidence. ResultsAmong men who have sex with men (MSM), ID declined between 1992–1996, from 1.23 per 100 PY in 1992 to 0.79 per 100 PY in 1996 [relative risk (RR), 0.86 per year; 95% confidence interval (CI), 0.77–0.96]. Subsequently, ID increased to 1.39 per 100 PY in 1999 (RR, 1.18 per year; 95% CI, 1.05–1.34). In 2000, ID was 1.16 per 100 PY but this decrease was not statistically significantly different from 1999. MSM in their twenties had the highest ID in 1992–1996, but in 1996–2000 MSM in their thirties had the highest risk of infection. Among injecting drug users (IDU), ID decreased from 0.64 per 100 PY in 1992 to 0.14 per 100 PY in 2000 (RR, 0.87 per year; 95% CI, 0.80–0.94). Among heterosexuals, annual incidence remained constant at about 0.03 per 100 PY in 1992–2000. ConclusionsIncreases in ID were identified among MSM from 1996 to 1999. These findings are consistent with other research. Continued vigilance and improved surveillance are needed to better understand and control the epidemic.

Estimating the size of hard-to-reach populations: a novel method using HIV testing data compared to other methods.

Objective: To estimate population size of hard-to-reach groups such as injecting drug users and men who have sex with men. Design: Several different methods were used to estimate the size of these populations in Canadas three largest cities (Toronto, Montreal and Vancouver). Methods: A novel method (referred to as the indirect method) was developed for use in Toronto and Vancouver that combines HIV serodiagnostic information with data on HIV testing behavior. Population size estimates were obtained by dividing the number of injecting drug users or men who have sex with men recorded in HIV serodiagnostic databases in a given year by the proportion of the corresponding group that reported being tested in a 1-year period. Results of this method were compared with four other methods: (1) population surveys; (2) capture-recapture (for injecting drug users only); (3) a modified Delphi technique; and (4) a method based on the proportion of never-married men aged 45 and over (for men who have sex with men only). Only these other methods were used in Montreal. Results: The survey method gave the lowest estimates which are best viewed as minimum estimates given the relative inability of surveys to access these populations and the reluctance of participants to admit to sensitive behaviors. The indirect method produced results more closely comparable with those obtained by other methods, but they are probably slight overestimates, at least for injecting drug users, due to possible underestimation of the proportion tested for HIV. Point estimates using the indirect method were 17 700 and 17 500 for injecting drug users in Toronto and Vancouver, respectively, and 39 100 and 15 900 for men who have sex with men. In Toronto, results for the other methods ranged from 12 300-13 360 for injecting drug users and 18 800-35 000 for men who have sex with men. For Vancouver, these ranges were 6400-11 670 and 7000-26 500, respectively. In Montreal, ranges were 4300-12 500 for injecting drug users and 18 500-40 000 for men who have sex with men. Conclusions: This novel method provides estimates of population size of hard-to-reach groups such as injecting drug users and men who have sex with men that are comparable with results derived by other methods. These estimates may be useful for the purposes of planning, implementing and evaluating prevention and care services, especially when they are combined with the results of other estimation methods to improve the degree of confidence in the resulting estimates.

Voluntary HIV testing among inmates: sociodemographic, behavioral risk, and attitudinal correlates.

We sought to determine the prevalence and correlates of self-reported HIV testing among inmates in correctional centers in Ontario, Canada. A cross-sectional survey was conducted with a stratified random sample of 597 male and female adult inmates. The participation rate was 89%. Descriptive statistics and multiple logistic regression were used to analyze HIV testing. Fifty-eight percent had ever been tested, and 21% had voluntarily tested while incarcerated in the past year. Having ever been tested was more common among those at risk for HIV through injection drug use (IDU) or sexual behavior. Testing while incarcerated in the past year was independently associated with being single (OR = 2.6), frequent IDU (OR = 4.0), not having casual sex partners prior to incarceration (OR = 0.53), a history of hepatitis (OR = 2.4), previous HIV testing (OR = 3.7), a close relationship with an HIV-positive person in the outside community (OR = 1.7), knowing an HIV-positive person inside (OR = 2.7), a perceived chance of being infected during incarceration (OR = 2.2), and support of mandatory testing (OR = 2.0). The predominant motivations for testing while incarcerated were IDU or fears of infection inside, possibly through contact with blood, during fights, or even by casual contact. Voluntary HIV testing in prison should be encouraged, and inmates should receive appropriate counseling and information to allow realistic assessment of risk.

The Benefits of HIV Antibody Testing of Saliva in Field Research

Much of the data that has been collected as part of the evaluation of the City of Toronto’s prevention programme comes from the interviews undertaken with Injection Drug Users (IDUs) at various locations around the city1. From these, we are able to describe the self-reported sexual and injecting behaviours of our participants. However, our respondents may answer in a fashion which they consider is expected of them rather than according to their actual behaviour. Therefore, the success of prevention programmes which are attributed to results obtained from interview data solely may be questioned on this basis. In contrast, if one can demonstrate a change in HIV infection rates amongst those utilizing compared to those not utilizing the programme or service, then policy makers may be more inclined to accept the validity of the findings. Therefore, in tandem with the analysis of results from our interviews we wished to look at HIV antibody test results in those who attended our needle exchange programme compared to those who did not.

Factors that affect HIV testing and counseling services among heterosexuals in Canada and the United Kingdom: An integrated review

OBJECTIVE To examine factors that affect the utilization of HIV testing and counseling (HTC) services among heterosexual populations in Canada and the U.K. METHODS We conducted an integrated review of published and unpublished literature (1996-September 2010) using Scopus, OVID-EMBASE, CSA illumina, CINHAL, PROQuest, Web of Science, and Google. RESULTS Twenty-seven studies met the inclusion criteria. We identified and categorized the key factors into three broad categories depending on their source. Personal-related factors included socio-demographic characteristics, risk perception, illness, HIV-related stigma, level of HIV and testing knowledge, and culture. Provider-related factors included provider-recommended HIV testing, provision of culturally and linguistically appropriate services, and doctor-patient relationship. System-related factors included integrating HIV testing with other health care services, anonymity of testing services, suitability of testing venues, technical aspects of HIV testing, and funding for immigrant health services. CONCLUSION The findings from our review indicate that HTC behaviors of heterosexuals in the Canada and the U.K. are likely influenced by several unchangeable (socio-demographic characteristics) and amenable factors. There is need to step-up research to confirm whether these associations are causal using stronger research designs. PRACTICAL IMPLICATION: We have made several recommendations that could be used to improve existing services in Canada.

Characteristics of HIV-infected pregnant women in the Bahamas

The Commonwealth of the Bahamas has one of the highest rates of acquired immunodeficiency syndrome (AIDS) in the English-speaking Caribbean. A seroprevalence study of pregnant women attending antenatal clinics in New Providence in 1990-91 showed that of 3,914 pregnant women tested, 2.9% were human immunodeficiency virus (HIV) infected. Women born in the Bahamas constituted 79.2% of the women tested; 17.7% were born in Haiti. The rate of HIV infection was 2.5% in the Bahamian women as compared with 4.5% in those born in Haiti. The highest incidence was in women aged 25-34 years and in women who had multiple pregnancies. There was a significant association with a history of crack cocaine use by the Bahamian women. There was also a significant association between a lack of education and HIV infection in this group. There was a lower rate of condom use among women with less education and also among women in common-law relationships, but the association of lack of condom use and HIV infection did not reach statistical significance.

Rapid DNA fingerprinting to control for specimen errors in HIV testing by the polymerase chain reaction

Variable-number-tandem-repeats (VNTRs) are highly polymorphic and provide informative genetic markers for distinguishing between individuals. We have used PCR amplification of VNTR locus pMCT118 to identify mislabelled specimens submitted for HIV PCR testing. The method is rapid, can be applied to large numbers of samples and eliminates the need for radioactive probes. DNA samples (10 ng) are amplified for 25 cycles using fluorescence-labelled oligonucleotide primers (blue dye). An aliquot of the PCR product is then combined with an internal lane size standard (labelled with a red dye), electrophoresed through a 2% agarose gel on an automated fluorescence DNA fragment analyser and the size and quantity of the fragments determined automatically relative to the internal standard. Fifteen alleles, ranging in size from 398 tp 709 bp were readily identified in a random sampling of DNA from 63 unrelated HIV-infected patients. Fragment size was reproducible and corresponded to alleles containing from 16 to 35 repeats of a 16 bp unit. VNTR genotyping will prove useful for resolving discordant results due to specimen mix-up and ensuring that the correct samples have been analyzed.

Increase in transmitted HIV drug resistance among persons undergoing genotypic resistance testing in Ontario, Canada, 2002–09

OBJECTIVES To characterize persons undergoing HIV genotypic resistance testing (GRT) while treatment naive and to estimate the prevalence of transmitted HIV drug resistance (TDR) among HIV-positive outpatients in Ontario, Canada. METHODS We analysed data from a multi-site cohort of persons receiving HIV care. Data were obtained from medical chart abstractions, interviews and record linkage with the Public Health Laboratories, Public Health Ontario. The analysis was restricted to 626 treatment-naive persons diagnosed in 2002-09. TDR mutations were identified using the calibrated population resistance tool. We used descriptive statistics and regression methods to characterize treatment-naive GRT test uptake and patterns of TDR. RESULTS Overall, 53.2% (333/626) of participants had baseline GRT. The proportion increased with year of HIV diagnosis from 30.0% in 2002 to 82.6% in 2009 (P < 0.0001). Among those tested, 13.6% (CI 9.9-17.3%) had one or more drug resistance mutations, and 8.8% (CI 5.7-11.8%), 4.8% (CI 2.5-7.2%) and 2.7% (CI 1.0-4.5%) had mutations conferring resistance to nucleoside/tide reverse transcriptase inhibitors (NRTIs), non-nucleoside reverse transcriptase inhibitors (NNRTIs) and protease inhibitors (PIs), respectively. TDR prevalence increased from 2002-07 to 2008-09 (adjusted OR 3.7, 95% CI 1.7-8.2), driven by a higher proportion with NRTI (18.2% versus 5.9%, P = 0.0009) and NNRTI mutations (11.7% versus 2.8%, P = 0.004) in the later time period. PI TDR remained unchanged. CONCLUSIONS Baseline GRT increased dramatically since 2002, but remains below 100%. The prevalence of overall TDR tripled due to increases in NRTI and NNRTI mutations. These findings highlight the value of routine baseline GRT for TDR surveillance and patient care.

Nonfinancial factors associated with decreased plasma viral load testing in Ontario, Canada

Objective:To examine whether individual characteristics were associated with differential use of viral load testing when testing is available without charge to all HIV-positive patients with provincial health insurance. Methods:Individuals enrolled in the HIV Ontario Observational Database with complete medication records and health insurance numbers for linkage were studied. Generalized estimating equation regression models were used to examine the relationship between time-varying covariates such as plasma viral load levels, CD4 counts, and antiretroviral regimen characteristics and the number of days between viral load tests and the occurrence of an interval of ≥6 or 9 months between tests. Results:A total of 1032 individuals were included in the analysis with a median follow-up of 4.6 years and a median of 18 viral load tests. In multivariate analyses, clinically important gaps in viral load testing were more likely among injection drug users (odds ratio [OR] = 1.86, P < 0.0001), in more recent years (P < 0.01) and for individuals not using antiretrovirals (OR = 1.70, P < 0.0001) and less likely among individuals using >4 antiretrovirals (OR = 0.62, P < 0.0001). Results were similar when the outcome was the number of days between tests. Conclusions:Injection drug users, younger individuals, and residents of Toronto used fewer viral load tests than other individuals, even when financial barriers to testing were removed.