- Thanks to widespread access to HIV treatment, many people with HIV in B.C. are living longer
- HIV treatment and prevention medicines are helping to reduce rates of new infections
- However, life expectancy among people with HIV has started to decrease due to the drug crisis
The widespread availability of effective HIV treatment (antiretroviral therapy, ART) since 1996 has had a massive impact on the HIV pandemic. First, taking ART as directed helps to lower the amount of HIV in the blood (viral load). Continued adherence to ART suppresses HIV to the point where routine lab tests cannot accurately detect it. Such cases of viral suppression are commonly called “undetectable.” Maintaining a suppressed viral load helps the immune system to become healthier. As a result, the risk of AIDS-related infections and cancers decreases dramatically. The power of ART is so tremendous that researchers increasingly project that many ART users will have near-normal life expectancy.
Another effect of ART is that well-designed clinical trials have found that people who take ART and achieve and maintain viral suppression do not pass on the virus to their sexual partners. Thus, ART has a benefit to society by helping to reduce the spread of HIV.
Treatment as prevention
Due to this second benefit of ART, researchers have coined the phrase “treatment as prevention” (TasP). Getting more people with HIV on effective treatment is a key part of the strategy promoted by the United Nations Joint Programme on AIDS (UNAIDS) and the World Health Organization (WHO). Initially, this strategy encouraged cities, regions and countries to reach the following goals by the year 2020:
- 90% of people with HIV know their status
- 90% of people who have HIV are taking ART
- 90% of people taking ART are virally suppressed
As many places have already hit these targets, UNAIDS and WHO have extended the goals to the following:
- 95% of people with HIV know their status
- 95% of people who have HIV are taking ART
- 95% of people taking ART are virally suppressed
These goals are expected to be met by the year 2025.
The net effect of these goals is to reduce the spread of HIV and AIDS-related deaths by 90% by the year 2030.
Prevention for people without HIV
Since 2010, clinical trials have found that taking a pill containing certain HIV medicines (tenofovir + FTC; sold as Truvada and Descovy and available in generic formulations) can reduce the risk of getting HIV by more than 99% in people who take it as directed. This use of medicines before potential HIV exposure is called pre-exposure prophylaxis (PrEP).
Decreases in new HIV infections
The BC Centre for Excellence in HIV/AIDS has collected comprehensive anonymized data on people with HIV in that province for decades. This has allowed researchers to keep track of changes to rates of new HIV infections, AIDS diagnoses and survival.
Initial analyses of data from B.C. found that new cases of HIV infection decreased after ART became available. This decrease was greater among people who injected drugs than among gay, bisexual and other men who have sex with men (gbMSM). As a result of this finding, British Columbia implemented a subsidized program of PrEP in January 2018 that focused on gbMSM at high risk of getting HIV.
After the launch of the PrEP program, researchers in B.C. found that “a sharp decrease [in new cases of HIV]” occurred in gbMSM.
Researchers in the province recently analysed the twin effects of TasP and PrEP over time and found very promising trends. If these trends are maintained (and there is continued funding for HIV treatment and PrEP), then B.C. is on track to eliminate HIV as a public health concern by 2030.
Results
The B.C. researchers had access to data collected since 1985.
Since 1992, British Columbia has provided HIV treatment to more than 16,500 people. The number of people taking ART greatly increased by 256% between 1996 (when ART first became available) and 2022.
The number of new cases of HIV decreased from 818 in 1985 to 82 in 2022.
Since January 2018, the province’s PrEP program has provided free access to PrEP for more than 11,500 people.
Survival in B.C.
Between the years 1993 and 2022, there were 4,944 deaths among people with HIV in B.C. Nearly half of these deaths (47%) were caused by complications related to HIV. In 1994, 221 people died from HIV-related causes; by 2022 the figure had fallen to 15 people. There was also a 95% decline in the rate of deaths due to HIV-related complications between 1994 and 2022.
When researchers analysed causes of deaths among people with HIV, they found that in 2014 more people began to die from causes unrelated to HIV—likely from overdose and a poisoning of the drug supply.
Taking many factors into consideration, researchers in B.C. developed a mathematical model to simulate trends in HIV transmission. They estimated that for each increase of 100 people on ART who achieved and maintained viral suppression there would be a corresponding decrease of nearly 2.5% in the rate of new HIV infections. The researchers further estimated that for people who took ART but did not achieve viral suppression (for this mathematical exercise, unsuppressed viral load was set at 200 or more copies/mL), they expected the rate of new HIV infections to reach 3.3%.
For every 100 people on PrEP, the researchers estimated that there would be a decrease in the rate of new HIV infections by 1.4%.
Bear in mind
The B.C. researchers found that rates of new HIV infections have been falling significantly over time. At the level of a large region or province, the present research shows that HIV treatment and PrEP greatly reduce the spread of the virus.
The researchers stated that B.C. is on track to meet the 2025 UNAIDS targets of 95-95-95, with the following targets reached in 2022:
- 94% of people with HIV know their status
- 92% of people diagnosed with HIV are taking ART
- 95% of people taking ART are virologically suppressed
The net effect of the above figures means that 82% of all people with HIV in B.C. in 2022 had a suppressed viral load.
The researchers noted that TasP is cost effective and they stated that providing PrEP to people at high risk for HIV will “optimize cost-effectiveness.”
A pair of leading HIV scientists in the U.S. reviewed the findings of the B.C. team and agreed with the overall results. However, the U.S. scientists noted that the B.C. study had a “[limited] ability to assess the effect of harm reduction, and specifically of needle and syringe exchange programs” on new cases of HIV among people who inject drugs. Hopefully, the B.C. team will be able to address this in the future.
Maintaining momentum
These encouraging results from B.C. show that the province has made much progress in reducing new cases of HIV as well as HIV-related deaths. However, for this progress to continue, funding for HIV treatment and prevention programs needs to be maintained and perhaps enhanced.
There is still much work to be done in B.C., as only 82% of all people with HIV in that province are virally suppressed. Efforts to enhance accessibility of HIV testing and low-barrier access to HIV treatment and care need to continue.
Although great strides have been made against HIV-related causes of death, new causes of death—related to the poisoning of the drug supply—are eating away at the gains made thanks to ART. Interim analyses from B.C. suggest that the overall life expectancy among people with HIV has decreased by at least three years in the recent period because of drug poisoning. Thus, enhanced services for mental health and harm reduction are essential for people who inject drugs.
—Sean R. Hosein
REFERENCES:
- Lima VD, Zhu J, Barrios R, et al. Longitudinal evolution of the HIV effective reproduction number following sequential expansion of treatment as prevention and pre-exposure prophylaxis in British Columbia, Canada: a population-level programme evaluation. Lancet HIV. 2024; in press.
- Duerr A, Beyrer C. Reducing HIV transmission in British Columbia, Canada. Lancet HIV. 2024; in press.
- Krentz HB, Lang R, McMillan J, et al. The changing landscape of both causes and locations of death in a regional HIV population 2010-2021. HIV Medicine. 2024 May;25(5):608-613.