HIV-HCV Epidemic Models

HIV-HCV coinfection occurs with highest frequency among people who inject drugs (PWID). Both pathogens can be blood-borne (HCV nearly exclusively so), so needles shared between PWID can be a very potent transmission pathway.

One chapter of my PhD work focuses on the HIV and HCV co-epidemics among PWID in Ho Chi Minh City, Vietnam. The HIV/AIDS epidemic in Vietnam is concentrated PWID and other high-risk groups such as men who have sex with men, and female sex workers. HIV prevalence among PWID varies greatly throughout the country, but Ho Chi Minh City is at the upper end of the prevalence scale, with an estimated 46.1% of PWID infected with HIV. PWID in Vietnam are also plagued by high prevalence and incidence of Hepatitis C Virus (HCV), with prevalence estimates ranging up to 75% since the 1990’s. Among PWID, coinfection with both pathogens is very common, with estimates of HIV-positive PWID coinfected with HCV ranging up to 100%. Coinfection introduces a host of complications: HIV speeds the progression rate of HCV, and can complicate administration of antiretroviral therapy (ART) due to increased risk of hepatotoxicity.

Along with collaborators Thuy Le, Roger Kouyos, Bryan Grenfell, and Timothy Hallett, I have designed a mathematical model of the triple epidemics of injecting drug use, HIV, and HCV in order to assess the impact of Methadone Maintenance Treatment scale-up and potential future roll-out of HCV treatment among PWID in Ho Chi Minh City.

Our manuscript has been published in PLoS ONE and is available here.