International success stories in HIV prevention: What can Canada learn?

Prevention in Focus PiF 2019 Fall

Want to receive publications straight to your inbox?

CATIE
PiF international success

We now have more highly effective tools than ever to help prevent HIV. Despite this expanding tool box, the number of new HIV diagnoses has increased in Canada in recent years. However, there are international examples of dramatic decreases in the number of new diagnoses. This article profiles three regions that are having success at different levels of government: the United Kingdom (national), New South Wales (state level) and San Francisco (municipal). This article will review the factors that have contributed to their success.

Number of new HIV diagnoses in Canada increasing despite an expanding tool box

Over the past decade, we have seen groundbreaking developments in HIV prevention. We can now unequivocally say that when a person takes HIV treatment and maintains an undetectable viral load, they cannot pass HIV to their sex partners.1,2,3 This concept is often referred to as “treatment as prevention” or by the slogan “undetectable = untransmittable” (U=U). We also now know that pre-exposure prophylaxis (PrEP) is a highly effective HIV prevention strategy for people who are HIV negative.4,5

The new tools are in addition to tried and true prevention methods. Condoms continue to be a cornerstone for preventing HIV transmission through sex. Harm reduction methods, including needle and syringe programs, opiate agonist therapy and safe injection sites, continue to help prevent transmission among people who use injection drugs. Testing also plays an important role in preventing HIV, because when people know that they have HIV, they can start treatment and take measures to prevent passing HIV to others.

Treatment as prevention and PrEP mean that we now have more tools than ever to help prevent HIV, but despite these exciting developments the annual number of new diagnoses in Canada has increased in recent years. In 2017, there were 2,402 HIV diagnoses in Canada, which is a 3% increase from 2016 and a 17% increase from 2014.6 However, it should be noted that trends in new diagnoses vary across the country. For example, from 2016 to 2017, British Columbia saw a 22% decrease in new diagnoses, and Quebec saw a 13% increase.6 In 2016 in Canada overall, 56% of new infections were among gay, bisexual and other men who have sex with men (gbMSM; some of whom use injection drugs), 33% were from heterosexual sex and 11% were from injection drug use.7

UPDATE: For more up-to-date epidemiological information see the CATIE fact sheet on the Epidemiology of HIV in Canada.

Though the number of new diagnoses in Canada has increased in recent years, several regions around the world have started to see substantial declines. By looking at the strategies that these places have used, we can learn from models with proven results.

National-level example: the United Kingdom

What does the HIV epidemic look like in the United Kingdom, and how has it changed in recent years?

Over the last decade in the UK, about half of new HIV diagnoses have been among gbMSM. Most other diagnoses have been from heterosexual sex. The UK consistently has low rates of transmission from injection drug use.8 This is because the UK began to embrace harm reduction practices in the early years of the HIV epidemic and continues to have strong harm reduction programming.9 In 2017, there were 4,363 new HIV diagnoses in the UK. This is a 17% decrease from 2016 and a 28% decrease from 2015.10 The decline was steepest among gbMSM, with a 31% decrease in new diagnoses from 2015 to 2017. There was also a more gradual decline in new HIV diagnoses from heterosexual sex. The decline in diagnoses was steepest in the London area, but there were also substantial declines in other parts of England and in Scotland, Wales and Northern Ireland.

What is the United Kingdom doing to achieve this change?

The recent decline in diagnoses has been attributed to a scale up of testing and prompt treatment for people who test positive11 along with free access to antiretroviral therapy (ART).

Many initiatives have helped to increase HIV testing:

  1. Guidelines released in 2012 recommended the routine offer of HIV testing to people who access sexual health and other genitourinary medicine services, as often as every three months for people deemed at high risk.12
  2. A number of campaigns have aimed to increase testing in a variety of settings, including sexual health clinics13, hospitals14 and novel settings (e.g., workplaces, community events).15,16
  3. In 2017, a national quality standard was released to encourage more testing in hospitals and general practice in areas of England with high HIV prevalence.17
  4. In 2015, Public Health England launched a self-sampling HIV testing service; this testing is done at home by an individual and then sent to a lab for analysis.18
  5. Also in 2015, the first self-test was approved for sale in the UK.19 Like self-sampling tests, self-tests are done at home by individuals. Unlike self-sampling tests, the person can interpret their results at home rather than having to send the test to a lab.

Tests done in different settings have helped to reach different populations. Testing at sexual health clinics has been most effective for reaching gbMSM,8 whereas testing in hospitals and general practice has helped to diagnose people who contracted HIV through heterosexual sex or injection drug use.20 Self-sampling tests have helped to reach first-time testers and those that haven’t tested in the past year.18 They have been particularly effective for diagnosing HIV in black African individuals. Of the self-sampling tests done by black African individuals between November 2017 and October 2018, 1.82% were reactive.18 Of all self-sampling tests done in that period, 0.98% were reactive.

Along with an increase in testing, the UK has seen a big increase in the number of people who started treatment within three months of diagnosis. In 2013, 49% of people started treatment within 91 days of their diagnosis, compared with 72% by 2017.8 This reflects changes in guidelines based on the health and prevention benefits of treatment. In 2015, it was recommended that ART be offered to everyone when they were first diagnosed, regardless of CD4 count.21 HIV medications are free in the UK, making treatment very accessible.8

In the UK an estimated 92% of people with HIV are diagnosed, 98% of those diagnosed are on treatment and 97% of those on treatment are virally suppressed.8 This is well past the UNAIDS 90-90-90 target (the goal that each of these numbers be at least 90%).22

It is very likely that PrEP has played a role in reducing new transmissions in the UK; however, the exact impact is not known. PrEP is currently not universally available across the UK. It is available at sexual health clinics at no cost in Scotland, Wales and Northern Ireland, but in England it is only available for free to a set number of people through a clinical trial.23 Without coverage, the out-of-pocket cost of buying PrEP from a local clinic is too high for most people to afford. Some people in the UK access PrEP online from other countries to save money.24

State-level example: New South Wales, Australia

What does the HIV epidemic look like in New South Wales, and how has it changed in recent years?

In New South Wales (NSW), around 80% of HIV diagnoses are among gbMSM. Most other diagnoses are from heterosexual sex.25 There are very few infections from injection drug use25, because of the early and ongoing commitment to harm reduction in Australia.26 Between 2015 and 2018, the number of new diagnoses per year in NSW decreased from 349 to 278, a 20% decline.25 This included a 24% decline among gbMSM, while the number of diagnoses from heterosexual sex stayed relatively stable. In 2018, 106 people who were diagnosed showed evidence of becoming infected in the last year, 25% less than the yearly average between 2013 and 2017.25 This may be further evidence that the number of new infections is decreasing.

What is New South Wales doing to achieve this change?

In 2012, the NSW government launched a 2012–2015 strategy to “virtually eliminate” HIV by 2020.27 The strategy focused on increasing HIV testing and access to treatment. Working from that strategy, the government increased testing options, including introducing rapid testing.28 This has resulted in a gradual increase in the number of tests done each year, for a total of a 32% increase between 2013 to 2018.25 In that time, the government also removed barriers to treatment by recommending immediate treatment regardless of CD4 count, by eliminating the co-pay needed to access treatment and by allowing community pharmacies to dispense treatment (before this, only hospital pharmacies could dispense treatment).28 Efforts to connect more people to treatment have been effective, with the most recent numbers (July–September 2018) showing that over 90% of people diagnosed with HIV in NSW are receiving treatment.

Despite the positive changes in testing and treatment rates starting in 2012, the number of new diagnoses in NSW stayed relatively stable until 2015.25 Researchers attribute the recent decline in diagnoses to the widespread rollout of PrEP in NSW, noting that the success of PrEP was made possible because NSW was already strong in the areas of testing and treatment. In March 2016, NSW began recruitment for a PrEP implementation study, which documented the rollout of PrEP in the state. The rollout was done across 27 clinics throughout NSW. In many clinics, including the largest sexual health clinic in NSW, PrEP care was nurse led.29 This nurse-led model allowed the clinics to take on the work of providing PrEP by shifting some of the workload away from doctors.29 With this nurse-led model, the clinics were able to handle the PrEP scale up without much new investment from the government.30 PrEP was free for anyone enrolled in the study.30

In less than two years, over 8,000 people enrolled.30 It was originally estimated that 3,700 people would enrol, but demand was much higher. The researchers compared the 12 months before recruitment started to the 12 months after the first 3,700 people were recruited. They found that among all gbMSM in NSW, there was a 32% decline in the number of recent infections between these time periods.

City-level example: San Francisco, California, United States

What does the HIV epidemic look like in San Francisco, and how has it changed in recent years?

Compared with most cities in high-income countries, San Francisco has a very high prevalence of HIV. An estimated 2% of people living with HIV in the United States live in San Francisco.31 Most new diagnoses in San Francisco are among gbMSM (including gbMSM who inject drugs). Heterosexual sex and injection drug use each are responsible for less than 10% of new infections per year. Between 2013 and 2017, San Francisco had a 44% reduction in new diagnoses (from 394 to 221). This decline was steepest among gbMSM. Rates among people who inject drugs, trans people, homeless individuals and people of colour have stayed fairly stable.31

What is San Francisco doing to achieve this change?

Political and public will to respond to HIV has consistently been very strong in San Francisco. Since the early years of the HIV epidemic, San Francisco has had a high prevalence of HIV, and it has been a hub of activism in the fight against HIV.32 When new evidence for both treatment and prevention become available, San Francisco is often an early adopter. This includes PrEP and early treatment.

In 2010, the city recommended that all people living with HIV be offered treatment immediately, regardless of their CD4 count.33 San Francisco was ahead of the curve in recommending this approach, which wouldn’t become standard practice in most parts of the developed world for another five years. In 2012, when the Food and Drug Administration approved PrEP, San Francisco immediately started PrEP programs.34

In 2014, San Francisco launched a city-wide consortium called San Francisco Getting to Zero. Getting to Zero is a multisectoral strategic plan to improve prevention and care. It initially aimed to strengthen prevention and care through three key strategic initiatives: expansion of PrEP, rapid ART uptake after diagnosis and retention in care.35

Once the consortium was launched, the city promoted PrEP aggressively, particularly to gbMSM.36 PrEP navigators help to link people to appropriate care providers and help them find insurance coverage. In 2017, it was estimated that between 16,300 and 20,000 gbMSM had used PrEP in the past year, representing between 37% and 45% of HIV-negative gbMSM in San Francisco.31

In 2015, San Francisco launched a city-wide RAPID program. The program engaged healthcare providers in many settings to facilitate rapid engagement in care after diagnosis, with the goal of starting people on treatment within five business days of diagnosis.37 A linkage navigator helped people to select an appropriate clinic on the basis of their needs and insurance options. Between 2013 and 2016, among all people newly diagnosed with HIV in San Francisco, the median number of days from diagnosis to first care appointment went from eight to five, and the median number of days from first care appointment to initiating treatment went from 27 to one. In that time, the median number of days from diagnosis to viral suppression (<200 copies/mL) went from 134 to 61.37

San Francisco also operates a program called Linkage Integration Navigation Comprehensive Services (LINCS), which is aimed at re-engaging those who have fallen out of care.31 This program has been successful. Of those who completed the LINCS program in 2016, 80% were engaged in care within three months of starting the program.31 The program was effective at engaging homeless individuals in care.38

Challenges

Though the UK, NSW and San Francisco have all had success in reducing the annual number of new diagnoses, each region continues to have some challenges. In the UK, a large proportion of people are diagnosed at a late stage, which has potential consequences for a person’s health and also may increase the chance of passing HIV.8 The proportion of people diagnosed late is highest among black African heterosexual men and women. This shows that the UK has work to do to reach more people who do not routinely get tested. Also, the fact that PrEP is not universally available in the UK23 limits the number of people who can access it.

While NSW has seen impressive declines in diagnoses among gbMSM, the decline has been largest among older men, men who live in Sydney’s “gay suburbs” and men who were born in Australia.30 This indicates that some groups are benefiting from PrEP more than others in NSW, and more effort is needed to reach underserved groups. As the PrEP study ends, people will need to pay a co-pay or order PrEP from other countries if they want to continue taking PrEP.39 This cost could hinder the uptake of PrEP in NSW.

In San Francisco, there are also inequities in who is accessing prevention technologies and care. Though many gbMSM have started taking PrEP, uptake has been much higher among white gbMSM than among black gbMSM.40 There are also inequities in terms of access to care. For example, in 2016 only 32% of homeless individuals were virally suppressed.31 The cost of treatment and prevention drugs is a barrier in the United States, as there is no universal government drug insurance plan. Though help is available in San Francisco to assist people in figuring out ways to cover their drug costs, some people may not access drugs that they would access if the medications were free under a universal drug plan. For example, some people do not access PrEP because of concerns about insurance coverage.40

Lessons learned from international success stories

These international examples show that it is possible to leverage new evidence in HIV prevention and treatment to achieve dramatic reductions in HIV. This type of change is possible to achieve at national, state/provincial and municipal levels of government. Some lessons that can be learned from these international success stories are as follows:

A clear and detailed strategy, guideline or plan must be in place.

In all three examples, there was a strategy, guideline or plan in place that helped to achieve results. A clearly defined plan provides guidance to service providers on how to broaden access to PrEP, testing and treatment. A strategy can also help to advocate for increased funding or resources.

Free, universal access to prevention strategies helps to reach all key populations affected by HIV.

The UK and NSW have had great success in getting a high proportion of people with HIV on treatment, in part because 100% of the cost of treatment is covered. NSW has also had success rolling out PrEP with no out-of-pocket costs for the individual. In San Francisco, while health navigators are available to help figure out coverage of HIV drugs and PrEP, the lack of universal coverage remains a barrier. The lack of universal coverage of PrEP is also a barrier in the UK.

Special efforts are needed to make sure that access to testing, PrEP and treatment are equitable.

In all three cases, there were challenges reaching all groups who would benefit. It may be easier to reduce diagnoses by targeting people who live in an area with a relatively high prevalence of HIV. For example, the UK has seen the most success in London, and NSW has seen the most success in the “gay suburbs” of Sydney. However, it is crucial to also implement strategies to reach people outside of these areas.

It is important to realize that healthcare is not one-size-fits-all and to look at ways to improve access for people who are marginalized and have unique barriers to accessing care. For example, specific efforts and programs may be needed to address barriers that prevent people who were born in other countries from accessing care, and people who do not have stable housing may have different needs from people who are housed.

Population-level success comes from using a combination of interventions at once.

None of the regions profiled in this article achieved a reduction in new diagnoses using a single strategy. In each region there was a strong push for people to embrace new HIV prevention measures, along with ongoing encouragement to use traditional prevention methods. This multifaceted approach to prevention is referred to as combination prevention.41 Making as many prevention tools available as possible empowers people to find a strategy (or combination of strategies) that works for them.

Keep in mind

The number of new diagnoses in a region is an important measure of progress, but there are some things to be aware of when interpreting the information in this article:

  • Diagnoses are not the same as infections. The number of new diagnoses is the number of people who test positive for HIV in a given timeframe. This is different from the number of new infections, which is the number of people who contract HIV in a given timeframe.
  • It can take time to see results after making a change. Initiatives that aim to prevent HIV might not produce results right away. For example, if there is an increase in testing in a region the number of new diagnoses might temporarily increase, but more people being aware of their status would help to prevent new infections in the long term.
  • People don’t always contract HIV in the same place as where they are diagnosed. In cases where a lot of people have contracted HIV outside of the region, the number of new diagnoses does not necessarily reflect the prevention programming in that region.

 

References

  1. Cohen MS, Chen YQ, McCauley M et al. Antiretroviral therapy for the prevention of HIV-1 transmission. New England Journal of Medicine. 2016;375:830-9. Available from: http://www.nejm.org/doi/pdf/10.1056/NEJMoa1600693
  2. Rodger AJ, Cambiano V, Bruun T et al. Sexual activity without condoms and risk of HIV transmission in serodifferent couples when the HIV-positive partner is using suppressive antiretroviral therapy. Journal of the American Medical Association. 2016;316(2):171-81. Available from: http://jama.jamanetwork.com/article.aspx?articleid=2533066
  3. Rodger AJ, Cambiano V, Bruun T et al. Risk of HIV transmission through condomless sex in serodifferent gay couples with the HIV-positive partner taking suppressive antiretroviral therapy (PARTNER): final results of a multicentre, prospective, observational study. The Lancet. 2019;393:2428-38.
  4. Grant RM, Lama JR, Anderson PL et al. Preexposure chemoprophylaxis for HIV prevention in men who have sex with men. New England Journal of Medicine. 2010;363(27):2587-99.
  5. Riddell J, Amico KR, Mayer KH. HIV preexposure prophylaxis: a review. Journal of the American Medical Association. 2018 Mar 27;319(12):1261-8.
  6. Haddad N, Li JS, Totten S, et al. HIV in Canada—Surveillance Report, 2017. Canada Communicable Disease Report. 2018 Dec 6;44(12):324-32.
  7. Public Health Agency of Canada. Summary: Estimates of HIV Incidence, Prevalence and Canada’s Progress on Meeting the 90-90-90 HIV targets, 2016. Ottawa: Public Health Agency of Canada; 2018. Available from: https://www.canada.ca/en/public-health/services/publications/diseases-conditions/summary-estimates-hiv-incidence-prevalence-canadas-progress-90-90-90.html
  8. Public Health England. Progress towards Ending the HIV Epidemic in the United Kingdom: 2018 Report. London: Public Health England; 2018. Available from: https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/759408/HIV_annual_report_2018.pdf
  9. McKeganey N. The lure and the loss of harm reduction in UK drug policy and practice. Addiction Research & Theory. 2006 Jan 1;14(6):557-88.
  10. Public Health England. Trends in New HIV Diagnoses and People Receiving HIV-related Care in the United Kingdom: Data to the End of December 2017. London: Public Health England; 2018. Available from: https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/738222/hpr3218_hiv17_v2.pdf
  11. Brown AE, Nash S, Connor N et al. Towards elimination of HIV transmission, AIDS and HIV‐related deaths in the UK. HIV Medicine. 2018 Sep;19(8):505-12.
  12. Clutterbuck DJ, Flowers P, Barber T et al. UK national guideline on safer sex advice. International Journal of STD & AIDS. 2012 Jun;23(6):381-8.
  13. Brown AE, Mohammed H, Ogaz D et al. Fall in new HIV diagnoses among men who have sex with men (MSM) at selected London sexual health clinics since early 2015: testing or treatment or pre-exposure prophylaxis (PrEP)?. Eurosurveillance. 2017 Jun 22;22(25).
  14. Bath R, O'Connell R, Lascar M et al. TestMeEast: a campaign to increase HIV testing in hospitals and to reduce late diagnosis. AIDS Care. 2016 May 3;28(5):608-11.
  15. Lampejo T, Turner R, Roberts C et al. Novel outreach settings to enhance sexually transmitted infection/HIV awareness, diagnosis and treatment in hard-to-reach populations. International Journal of STD & AIDS. 2018 Mar;29(3):266-72.
  16. Blake H, Hussain B, Hand J et al. Employers’ views of the “Healthy Hub Roadshow”: a workplace HIV testing intervention in England. AIDS Care. 2019 Feb 1;31(2):181-5.
  17. National Institute for Health and Care Excellence. HIV Testing: Encouraging Uptake. London: National Institute for Health and Care Excellence; 2017. Available from: https://www.nice.org.uk/guidance/qs157/resources/hiv-testing-encouraging-uptake-pdf-75545545013701
  18. Public Health England. National HIV Self-sampling Service November 2017 to October 2018. London: Public Health England; 2019. Available from: https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/789793/national_HIV_self_sampling_service_november_2017_to_october_2018.pdf
  19. NAM. First HIV home test approved for sale in UK. NAM aidsmap. London: NAM: 2015. Available from: http://www.aidsmap.com/ First-HIV-home-test-approved-for-sale-in-UK/page/2964537/
  20. Croxford S, Yin Z, Kall M et al. Where do we diagnose HIV infection? Monitoring new diagnoses made in nontraditional settings in England, Wales and Northern Ireland. HIV Medicine. 2018 Aug;19(7):465-74.
  21. British HIV Association. BHIVA Guidelines for the Treatment of HIV-1-positive Adults with Antiretroviral Therapy 2015. London: British HIV Association; 2015. Available from: http://pdf.hivaids.gr/BHIVA-2015-treatment-guidelines.pdf
  22. UNAIDS. 90-90-90: An Ambitious Treatment Target to Help End the AIDS Epidemic. Geneva: UNAIDS; 2014. Available from: http://www.unaids.org/sites/default/files/media_asset/90-90-90_en_0.pdf
  23. NAM. Factsheet: How to Get PrEP in the UK. London: NAM; 2019. Available from: https://www.iwantprepnow.co.uk/prep-on-the-nhs/
  24. Paparini S, Nutland W, Rhodes T et al. DIY HIV prevention: formative qualitative research with men who have sex with men who source PrEP outside of clinical trials. PLOS One. 2018 Aug 23;13(8):e0202830.
  25. New South Wales Government. NSW HIV Strategy 2016 – 2020 Quarter 4 & Annual 2018 Data Report. Sydney, Australia: New South Wales Government; 2018. Available from: https://www.health.nsw.gov.au/endinghiv/Publications/q4-2018-and-annual-hiv-data-report.pdf
  26. Iversen J, Wand H, Topp L et al. Extremely low and sustained HIV incidence among people who inject drugs in a setting of harm reduction. AIDS. 2014 Jan 14;28(2):275-8.
  27. New South Wales Government. NSW HIV Strategy 2012 – 2015: A New Era. Sydney, Australia: New South Wales Government; 2012. Available from: https://www.health.nsw.gov.au/endinghiv/Publications/nsw-hiv-strategy-2012-15-a-new-era.pdf
  28. New South Wales Government. NSW HIV Strategy 2016 – 2020. Sydney, Australia: New South Wales Government; 2015. Available from: https://www.health.nsw.gov.au/endinghiv/Publications/nsw-hiv-strategy-2016-2020.PDF
  29. Schmidt HM, McIver R, Houghton R et al. Nurse-led pre-exposure prophylaxis: a non-traditional model to provide HIV prevention in a resource-constrained, pragmatic clinical trial. Sexual Health. 2018 Jan 1;15(6):595-7.
  30. Grulich A, Guy RJ, Amin J et al. Rapid reduction in HIV diagnoses after targeted PrEP implementation in NSW, Australia. Conference on Retroviruses and Opportunistic Infections (CROI), March 2–7, 2019. Abstract 88.
  31. San Francisco Department of Public Health, Population Health Division. HIV Epidemiology: Annual Report 2017. San Francisco:  San Francisco Department of Public Health; 2018. Available from: https://www.sfdph.org/dph/files/reports/RptsHIVAIDS/AnnualReport2017-Green-20180904-Web.pdf
  32. Luce JM. A strange new disease in San Francisco. A brief history of the city and its response to the HIV/AIDS epidemic. Annals of the American Thoracic Society. 2013 Apr;10(2):143-7.
  33. Russell S. City endorses new policy for treatment of H.I.V. New York Times, 3 April 2010.
  34. Liu A, Cohen S, Follansbee S et al. Early experiences implementing pre-exposure prophylaxis (PrEP) for HIV prevention in San Francisco. PLOS Medicine. 2014 Mar 4;11(3):e1001613. Available from: https://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1001613
  35. Getting to Zero San Francisco. Getting to Zero July 2015 Strategic Plan. San Francisco: Getting to Zero San Francisco; 2015. Available from: http://www.gettingtozerosf.org/getting-to-zero-july-2015-strategic-plan/
  36. Kirby T. Aiming to end San Francisco’s HIV epidemic. The Lancet HIV. 2019 Feb 1;6(2):e77-8.
  37. Bacon O, Chin JC, Hsu L et al. The Rapid ART Program Initiative for HIV Diagnoses (RAPID) in San Francisco. Conference on Retroviruses and Opportunistic Infections (CROI), March 4-7, 2018. Abstract 93.
  38. Scheer S, Hsu L, Sachdev D et al. Improvement in HIV care indicators among the homeless in San Francsico. Conference on Retroviruses and Opportunistic Infections (CROI), March 4–7, 2018. Abstract 1100.
  39. Ending HIV 2020. EPIC-NSW PrEP trial. 2019. Available from: https://endinghiv.org.au/stay-safe/epic-nsw/
  40. Buchbinder S, Cohen SE, Hecht J et al. Getting to zero new HIV diagnoses in San Francisco: What will it take? Conference on Retroviruses and Opportunistic Infections (CROI), March 4–7, 2018. Abstract 87.
  41. Kurth AE, Celum C, Baeten JM et al. Combination HIV prevention: significance, challenges, and opportunities. Current HIV/AIDS Reports. 2011 Mar 1;8(1):62-72.

 

About the author(s)

Mallory Harrigan is CATIE's specialist, client publications and ordering centre. She has a Master’s degree in community psychology from Wilfrid Laurier University.