Is the HIV epidemic stable among MSM in Mexico? HIV prevalence and risk behavior results from a nationally representative survey among men who have sex with men

Implementation and Operational Research: Effect of Universal Access to Antiretroviral Therapy on HIV/AIDS Mortality in Mexico 1990-2011

INTRODUCTION

Universal coverage of highly active antiretroviral therapy (HAART) for HIV/AIDS in Mexico was achieved in a staggered fashion. First, HAART was made available in 1997 for employees in the formal sector and subsequently, in 2003, for informal sector workers and the unemployed population. We evaluated the impact of this free universal HAART program on HIV/AIDS mortality in the Mexican population aged 15 years or older.

METHODS

Time-series cross-sectional data analysis of standardized HIV/AIDS mortality rates (1990-2011) using marginal linear models with inflection points at 1994, 1997, and 2003.

RESULTS

Men employed in the formal sector experienced the greatest effect of access to HAART, with a 32% reduction in mortality from 1997 to 2011 (P < 0.01). For men in this sector, mortality increased from 1990 to 2003, then stabilizing at 7 deaths per 100,000. For women in the informal sector, mortality increased from 1990 to 2011. We found large between-state variability: mortality decreased by 59% in Mexico City while it increased by 245% in Tabasco during the study period. Six of 32 states achieved statistically significant reductions in mortality while 5 states continued to experience increasing mortality rates despite universal HAART.

CONCLUSIONS

Access to universal HAART has had relative success in Mexico. The heterogeneity of HIV/AIDS mortality by employment status, gender, and state of residence highlight urgent needs to improve health equity with pro-poor and gender-responsive programs and a call for country-specific operational research in HIV/AIDS prevention and treatment. Our results may apply to other countries seeking to implement universal access to antiretroviral therapy.

Preventing HIV Transmission Among Partners of HIV-Positive Male Sex Workers in Mexico City: A Modeling Study

Mexico has a concentrated HIV epidemic, with male sex workers constituting a key affected population. We estimated annual HIV cumulative incidence among male sex workers' partners, and then compared incidence under three hypothetical intervention scenarios: improving condom use; and scaling up HIV treatment as prevention, considering current viral suppression rates (CVS, 60.7 %) or full viral suppression among those treated (FVS, 100 %). Clinical and behavioral data to inform model parameterization were derived from a sample (n = 79) of male sex workers recruited from street locations and Clínica Condesa, an HIV clinic in Mexico City. We estimated annual HIV incidence among male sex workers' partners to be 8.0 % (95 % CI: 7.3-8.7). Simulation models demonstrated that increasing condom use by 10 %, and scaling up HIV treatment initiation by 50 % (from baseline values) would decrease the male sex workers-attributable annual incidence to 5.2, 4.4 % (CVS) and 3.2 % (FVS), respectively. Scaling up the number of male sex workers on ART and implementing interventions to ensure adherence is urgently required to decrease HIV incidence among male sex workers' partners in Mexico City.

Estimating the Impact of Earlier ART Initiation and Increased Testing Coverage on HIV Transmission among Men Who Have Sex with Men in Mexico using a Mathematical Model

Objective

To estimate the impact of late ART initiation on HIV transmission among men who have sex with men (MSM) in Mexico.

Methods

An HIV transmission model was built to estimate the number of infections transmitted by HIV-infected men who have sex with men (MSM-HIV+) MSM-HIV+ in the short and long term. Sexual risk behavior data were estimated from a nationwide study of MSM. CD4⁺ counts at ART initiation from a representative national cohort were used to estimate time since infection. Number of MSM-HIV+ on treatment and suppressed were estimated from surveillance and government reports. Status quo scenario (SQ), and scenarios of early ART initiation and increased HIV testing were modeled.

Results

We estimated 14239 new HIV infections per year from MSM-HIV+ in Mexico. In SQ, MSM take an average 7.4 years since infection to initiate treatment with a median CD4⁺ count of 148 cells/mm³(25^th-75^th percentiles 52–266). In SQ, 68% of MSM-HIV+ are not aware of their HIV status and transmit 78% of new infections. Increasing the CD4⁺ count at ART initiation to 350 cells/mm³ shortened the time since infection to 2.8 years. Increasing HIV testing to cover 80% of undiagnosed MSM resulted in a reduction of 70% in new infections in 20 years. Initiating ART at 500 cells/mm³ and increasing HIV testing the reduction would be of 75% in 20 years.

Conclusion

A substantial number of new HIV infections in Mexico are transmitted by undiagnosed and untreated MSM-HIV+. An aggressive increase in HIV testing coverage and initiating ART at a CD4 count of 500 cells/mm³ in this population would significantly benefit individuals and decrease the number of new HIV infections in Mexico.

A Cross-Sectional Study of Prisoners in Mexico City Comparing Prevalence of Transmissible Infections and Chronic Diseases with That in the General Population

OBJECTIVES

To describe patterns of transmissible infections, chronic illnesses, socio-demographic characteristics and risk behaviors in Mexico City prisons, including in comparison to the general population, to identify those currently needing healthcare and inform policy.

MATERIALS AND METHODS

A cross-sectional study among 17,000 prisoners at 4 Mexico City prisons (June to December 2010). Participation was voluntary, confidential and based on informed consent. Participants were tested for HIV, Hepatitis B & C, syphilis, hypertension, obesity, and, if at risk, glucose and cholesterol. A subset completed a questionnaire on socio-demographic characteristics and risk behaviors. Positive results were delivered with counseling and treatment or referral.

RESULTS

76.8% (15,517/20,196) of men and 92.9% (1,779/1,914) of women participated. Complete data sets were available for 98.8%. The following prevalence data were established for transmissible infections: HIV 0.7%; syphilis: Anti-TP+/VDRL+ 2.0%; Hepatitis B: HBcAb 2.8%, HBsAg 0.15%; Anti-HCV 3.2%. Obesity: 9.5% men, 33.8% women. Compared with national age- and sex-matched data, the relative prevalence was greater for HIV and syphilis among women, HIV and Hepatitis C in men, and all infections in younger participants. Obesity prevalence was similar for women and lower among male participants. The prevalence of previously diagnosed diabetes and hypertension was lower. Questionnaire data (1,934 men, 520 women) demonstrated lower educational levels, increased smoking and substance use compared to national data. High levels of non-sterile tattooing, physical abuse and histories of sexual violence were found.

CONCLUSION

The study identified that health screening is acceptable to Mexico City prisoners and feasible on a large-scale. It demonstrated higher prevalence of HIV and other infections compared to national data, though low rates compared to international data. Individual participants benefited from earlier diagnosis, treatment and support. The data collected will also enable the formulation of improved policy for this vulnerable group.

Risk behaviours and prevalence of sexually transmitted infections and HIV in a group of Dominican gay men, other men who have sex with men and transgender women

OBJECTIVES

The objectives of this study were to estimate the point prevalence of sexually transmitted infection (STI) and to investigate the sexual practices and behaviours associated with STIs in a group of gay men, other men who have sex with men and transgender women (GMT) in the province of La Romana, Dominican Republic.

DESIGN

A cross-sectional study of a convenience sample of GMT persons.

SETTING

The study was conducted in the province of La Romana, Dominican Republic, in June-July 2013.

PARTICIPANTS

Out of 117 GMT persons screened, a total of 100 completed the study. Participants had to be at least 18 years of age, reside in La Romana and have had sex with another man in the preceding 12 months. All participants were interviewed and tested for STI.

PRIMARY OUTCOME MEASURE

The main outcome of interest was the detection of any STI (HIV, herpes simplex virus type 2 (HSV-2), syphilis, hepatitis B or C) by serology.

RESULTS

Among 100 participants, the median age was 22 years (range 18-65). One-third had consumed illicit drugs the preceding year and only 43% consistently used condoms. Prevalence was 38% for HSV-2, 5% for HIV and 13% for syphilis. There were no cases of hepatitis B or C. Factors associated with the odds of a STI were age >22 years (OR=11.1, 95% CI 3.6 to 34.5), receptive anal intercourse (OR=4.2, 95% CI 1.3 to 13.6) and having ≥2 male sexual partners during the preceding month (OR=4, 95% CI 1.3 to 12.5).

CONCLUSIONS

In this group of GMT persons, seroprevalence of STI was high, and a number of risk behaviours were associated with STI. These preliminary data will help inform policy and programmes to prevent HIV/STI in GMT persons in the region.

Prevalence and correlates of HIV among men who have sex with men in Tijuana, Mexico

Introduction

Men who have sex with men (MSM) in developing countries such as Mexico have received relatively little research attention. In Tijuana, Mexico, a border city experiencing a dynamic HIV epidemic, data on MSM are over a decade old. Our aims were to estimate the prevalence and examine correlates of HIV infection among MSM in this city.

Methods

We conducted a cross-sectional study of 191 MSM recruited through respondent-driven sampling (RDS) in 2012. Biological males over the age of 18 who resided in Tijuana and reported sex with a male in the past year were included. Participants underwent interviewer-administered surveys and rapid tests for HIV and syphilis with confirmation.

Results

A total of 33 MSM tested positive for HIV, yielding an RDS-adjusted estimated 20% prevalence. Of those who tested positive, 89% were previously unaware of their HIV status. An estimated 36% (95% CI: 26.4–46.5) had been tested for HIV in the past year, and 30% (95% CI: 19.0–40.0) were estimated to have ever used methamphetamine. Independent correlates of being infected with HIV were methamphetamine use (odds ratio [OR]=2.24, p=0.045, 95% CI: 1.02, 4.92) and active syphilis infection (OR=4.33, p=0.01, 95% CI: 1.42, 13.19).

Conclusions

Our data indicate that MSM are a key sub-population in Tijuana at higher risk for HIV. Tijuana would also appear to have the highest proportion among upper-middle-income countries of HIV-positive MSM who are unknowingly infected. More HIV prevention research on MSM is urgently needed in Tijuana.

The changing face of HIV in Latin America and the Caribbean

Latin America and the Caribbean (LAC) is a region with similarities and important disparities. In recent years LAC has witnessed achievements, with HIV prevalence rates relatively stable for LA and decreasing for the Caribbean. However average values hide differences. General population HIV prevalence in LAC is 0.4 % on average. In the Caribbean there are fewer new HIV infections but HIV prevalence among adults exceeds 1 % in several countries. It is estimated that 31 % of adults living with HIV in LA and 52 % of adults in the Caribbean are women. Unprotected sex is the main route of HIV transmission in LAC. Men who have sex with men and transgender women are the populations with the highest prevalence (10.6 % and 17.7 % respectively); however other key populations such as female sex workers (4.9 %), drug users (range 1 %-49.7 % for intravenous drug users), prisoners and indigenous populations are also important. LAC has the highest anti-retroviral treatment coverage of any low- and middle-income region in the world, but women and children are less likely than men to receive treatment. There is an important pending agenda to address the gaps in information, prevention, and care for HIV in LAC.

The disproportionate burden of HIV and STIs among male sex workers in Mexico City and the rationale for economic incentives to reduce risks

Introduction

The objective of this article is to present the rationale and baseline results for a randomized controlled pilot trial using economic incentives to reduce HIV and sexually transmitted infection (STI) risk among male sex workers (MSWs) in Mexico City.

Methods

Participants (n=267) were tested and treated for STIs (chlamydia, gonorrhoea, syphilis and HIV) and viral hepatitis (hepatitis B and C), received HIV and STI prevention education and were randomized into four groups: (1) control, (2) medium conditional incentive ($50/six months), (3) high conditional incentive ($75/six months) and (4) unconditional incentive ($50/six months). In the conditional arms, incentives were contingent upon testing free of new curable STIs (chlamydia, gonorrhoea and syphilis) at follow-up assessments.

Results

Participants’ mean age was 25 years; 8% were homeless or lived in a shelter, 16% were unemployed and 21% lived in Mexico City less than 5 years. At baseline, 38% were living with HIV, and 32% tested positive for viral hepatitis or at least one STI (other than HIV). Participants had a mean of five male clients in the previous week; 18% reported condomless sex with their last client. For 37%, sex work was their main occupation and was conducted mainly on the streets (51%) or in bars/discotheques (24%) and hotels (24%). The average price for a sex transaction was $25 with a 35% higher payment for condomless sex.

Conclusions

The findings suggest that economic incentives are a relevant approach for HIV prevention among MSWs, given the market-based inducements for unprotected sex. This type of targeted intervention seems to be justified and should continue to be explored in the context of combination prevention efforts.

Global, regional, and national incidence and mortality for HIV, tuberculosis, and malaria during 1990-2013: a systematic analysis for the Global Burden of Disease Study 2013

BACKGROUND

The Millennium Declaration in 2000 brought special global attention to HIV, tuberculosis, and malaria through the formulation of Millennium Development Goal (MDG) 6. The Global Burden of Disease 2013 study provides a consistent and comprehensive approach to disease estimation for between 1990 and 2013, and an opportunity to assess whether accelerated progress has occured since the Millennium Declaration.

METHODS

To estimate incidence and mortality for HIV, we used the UNAIDS Spectrum model appropriately modified based on a systematic review of available studies of mortality with and without antiretroviral therapy (ART). For concentrated epidemics, we calibrated Spectrum models to fit vital registration data corrected for misclassification of HIV deaths. In generalised epidemics, we minimised a loss function to select epidemic curves most consistent with prevalence data and demographic data for all-cause mortality. We analysed counterfactual scenarios for HIV to assess years of life saved through prevention of mother-to-child transmission (PMTCT) and ART. For tuberculosis, we analysed vital registration and verbal autopsy data to estimate mortality using cause of death ensemble modelling. We analysed data for corrected case-notifications, expert opinions on the case-detection rate, prevalence surveys, and estimated cause-specific mortality using Bayesian meta-regression to generate consistent trends in all parameters. We analysed malaria mortality and incidence using an updated cause of death database, a systematic analysis of verbal autopsy validation studies for malaria, and recent studies (2010-13) of incidence, drug resistance, and coverage of insecticide-treated bednets.

FINDINGS

Globally in 2013, there were 1·8 million new HIV infections (95% uncertainty interval 1·7 million to 2·1 million), 29·2 million prevalent HIV cases (28·1 to 31·7), and 1·3 million HIV deaths (1·3 to 1·5). At the peak of the epidemic in 2005, HIV caused 1·7 million deaths (1·6 million to 1·9 million). Concentrated epidemics in Latin America and eastern Europe are substantially smaller than previously estimated. Through interventions including PMTCT and ART, 19·1 million life-years (16·6 million to 21·5 million) have been saved, 70·3% (65·4 to 76·1) in developing countries. From 2000 to 2011, the ratio of development assistance for health for HIV to years of life saved through intervention was US$4498 in developing countries. Including in HIV-positive individuals, all-form tuberculosis incidence was 7·5 million (7·4 million to 7·7 million), prevalence was 11·9 million (11·6 million to 12·2 million), and number of deaths was 1·4 million (1·3 million to 1·5 million) in 2013. In the same year and in only individuals who were HIV-negative, all-form tuberculosis incidence was 7·1 million (6·9 million to 7·3 million), prevalence was 11·2 million (10·8 million to 11·6 million), and number of deaths was 1·3 million (1·2 million to 1·4 million). Annualised rates of change (ARC) for incidence, prevalence, and death became negative after 2000. Tuberculosis in HIV-negative individuals disproportionately occurs in men and boys (versus women and girls); 64·0% of cases (63·6 to 64·3) and 64·7% of deaths (60·8 to 70·3). Globally, malaria cases and deaths grew rapidly from 1990 reaching a peak of 232 million cases (143 million to 387 million) in 2003 and 1·2 million deaths (1·1 million to 1·4 million) in 2004. Since 2004, child deaths from malaria in sub-Saharan Africa have decreased by 31·5% (15·7 to 44·1). Outside of Africa, malaria mortality has been steadily decreasing since 1990.

INTERPRETATION

Our estimates of the number of people living with HIV are 18·7% smaller than UNAIDS's estimates in 2012. The number of people living with malaria is larger than estimated by WHO. The number of people living with HIV, tuberculosis, or malaria have all decreased since 2000. At the global level, upward trends for malaria and HIV deaths have been reversed and declines in tuberculosis deaths have accelerated. 101 countries (74 of which are developing) still have increasing HIV incidence. Substantial progress since the Millennium Declaration is an encouraging sign of the effect of global action.

FUNDING

Bill & Melinda Gates Foundation.