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.

Abstract

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(25th-75th 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.

• Authors: Yanink Caro-Vega, Carlos del Rio, Viviane Dias Lima, Malaquias Lopez-Cervantes, Brenda Crabtree-Ramirez, Sergio Bautista-Arredondo, M Arantxa Colchero, Juan Sierra-Madero
• Journal: PloS one (PLoS One) Vol. 10 Issue 8 Pg. e0136534 ( 2015) ISSN: 1932-6203 [Electronic] United States
• PMID: 26302044 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Topics

• Adult
• Antiretroviral Therapy, Highly Active
• Female
• HIV (pathogenicity)
• HIV Infections (epidemiology, therapy, transmission)
• Homosexuality, Male
• Humans
• Male
• Mass Screening
• Mexico
• Models, Theoretical
• Risk-Taking
• Sexual Behavior (physiology)