In a pair of new modeling studies, researchers examined how policy reform in terms of drug decriminalization (in Mexico) and access to drug treatment (in Russia) might affect two regions hard hit by the HIV pandemic: Tijuana, Mexico and the Russian cities of Omsk and Ekaterinburg.

While global incidence rates of HIV have declined notably in recent years, the virus that causes AIDS remains a major and, in some ways largely unmitigated, public health threat in some countries and regions.

In a pair of new modeling studies, researchers examined how policy reform in terms of drug decriminalization (in Mexico) and access to drug treatment (in Russia) might affect two regions hard hit by the HIV pandemic: Tijuana, Mexico and the Russian cities of Omsk and Ekaterinburg.

In the most recent study, published in the journal Lancet Public Health, researchers evaluated the impact of public health-oriented drug law reforms on HIV incidence among people who inject drugs in Tijuana, Mexico.

In 2012, Mexico reformed its drug laws, decriminalizing possession of small amounts of specified drugs and instituting drug treatment instead of incarceration. However, implementation of the reforms has been uneven and limited. Borquez and colleagues looked at the specific impact of the reforms on HIV incidence among people who inject drugs. 

"Unfortunately, the predominant type of drug 'rehabilitation' available in Tijuana is compulsory drug abstinence, which our modeling showed could potentially increase HIV transmission, underscoring the need for affordable evidence-based opioid agonist treatment which is effective at preventing HIV and other health harms," said co-author Steffanie Strathdee. 

Said Borquez: "Monitoring and evaluation of public health-oriented drug law reforms is essential to inform their implementation at the local and global levels if we are to successfully guide this shift in drug policy."

Risk of HIV and fatal overdose

In the second study, published in Lancet HIV, first author Javier Cepeda, senior author Martin and colleagues employed epidemic modeling to determine the detrimental impact of Russian government policy prohibiting access to opiate agonist therapy, a key intervention used to prevent the risk of HIV and fatal overdose.

The study also explored how the potential benefits of scaled-up opiate agonist therapy, needle/syringe programs and antiretroviral therapy (ART) might have on preventing new HIV infections and fatal overdoses among people who inject drugs in Russia.

"Opiate agonist therapy, which uses drugs like methadone to treat addiction and is highly effective at reducing the risk of HIV and overdose, is prohibited. Needle exchange programs are scarce and access to ART is very, very limited."

The researchers found that without intervention, HIV prevalence among people who inject drugs in Omsk could increase to 34% by 2028 and remain even higher in Ekaterinburg at 61%.

However, scaling up opiate agonist therapy and needle exchange programs to half of people who inject drugs and tripling ART recruitment could prevent 53% of new HIV infections among people who inject drugs in Omsk and 38% of new HIV infections in Ekaterinburg by 2028. Additionally, these programs could prevent roughly 30% of fatal overdoses over this time period.

"The data are unequivocal," said Martin. "Without intervention, modeling shows the burden of HIV among people who inject drugs in Russia will worsen, escalating in places like Omsk and remaining endemically high in places like Ekaterinburg."

"However, by implementing already known and proven interventions, HIV and overdose rates can be significantly reduced and many lives saved. The Russian government urgently needs to reverse its policies towards harm reduction access."  These findings were also highlighted in a Lancet Commission report.