A resurgent HIV-1 epidemic among men who have sex with men in the era of potent antiretroviral therapy.
OBJECTIVE
Reducing viral load, highly active antiretroviral therapy has the potential to limit onwards transmission of HIV-1 and thus help contain epidemic spread. However, increases in risk behaviour and resurgent epidemics have been widely reported post-highly active antiretroviral therapy. The aim of this study was to quantify the impact that highly active antiretroviral therapy had on the epidemic.


METHODS
We focus on the HIV-1 epidemic among men who have sex with men in the Netherlands, which has been well documented over the past 20 years within several long-standing national surveillance programs.


METHODS
We used a mathematical model including highly active antiretroviral therapy use and estimated the changes in risk behaviour and diagnosis rate needed to explain annual data on HIV and AIDS diagnoses.


RESULTS
We show that the reproduction number R(t), a measure of the state of the epidemic, declined early on from initial values above two and was maintained below one from 1985 to 2000. Since 1996, when highly active antiretroviral therapy became widely used, the risk behaviour rate has increased 66%, resulting in an increase of R(t) to 1.04 in the latest period 2000-2004 (95% confidence interval 0.98-1.09) near or just above the threshold for a self-sustaining epidemic. Hypothetical scenario analysis shows that the epidemiological benefits of highly active antiretroviral therapy and earlier diagnosis on incidence have been entirely offset by increases in the risk behaviour rate.


CONCLUSIONS
We provide the first detailed quantitative analysis of the HIV epidemic in a well defined population and find a resurgent epidemic in the era of highly active antiretroviral therapy, most likely predominantly caused by increasing sexual risk behaviour.
Bezemer
Daniela
D
HIV Monitoring Foundation, Amsterdam, The Netherlands.
de Wolf
Frank
F
Boerlijst
Maarten C
MC
van Sighem
Ard
A
Hollingsworth
T Deirdre
TD
Prins
Maria
M
Geskus
Ronald B
RB
Gras
Luuk
L
Coutinho
Roel A
RA
Fraser
Christophe
C
D000163:Acquired Immunodeficiency Syndrome / Q000188:drug therapy / Q000453:epidemiology; D019380:Anti-HIV Agents / Q000627:therapeutic use*; D023241:Antiretroviral Therapy, Highly Active; D004196:Disease Outbreaks; D015658:HIV Infections / Q000188:drug therapy* / Q000453:epidemiology*; D015497:HIV-1; D018451:Homosexuality, Male; D006801:Humans; D008297:Male; D015233:Models, Statistical; D009426:Netherlands / Q000453:epidemiology; D012309:Risk-Taking; D012725:Sexual Behavior / Q000706:statistics & numerical data; D012747:Sexual Partners
D019380:Anti-HIV Agents