Test and treat studies show high rates of HIV diagnosis, viral suppression

Two large studies of community-based universal test and treat campaigns to promote HIV diagnosis, treatment and prevention, presented at the 22nd International AIDS Conference (AIDS 2018) in Amsterdam on Wednesday, show that the campaigns achieved very high rates of HIV diagnosis and viral suppression, as well as reductions in HIV incidence on some measures.

Large-scale community campaigns that go beyond the HIV clinic to offer testing and link people to HIV care have been piloted in several African countries, adopting methods such as door-to-door testing and community health events to reach people who might not attend health facilities or otherwise be offered an opportunity to test for HIV.

The studies presented today were large trials of different approaches to maximise HIV diagnosis and linkage to care, that may be suitable for different country settings and funding contexts.

The SEARCH study, carried out in Uganda and Kenya, tested an offer of HIV testing and rapid treatment initiation within a multi-disease campaign also designed to diagnose and treat high blood pressure, diabetes and tuberculosis among the entire community.

The Ya Tse study, carried out in Botswana, evaluated the impact of an intensive community testing campaign, immediate treatment initiation and scaled-up provision of male circumcision.

SEARCH study: multi-disease prevention campaigns

The SEARCH study was designed to test whether offering HIV testing alongside a larger community screening programme for non-communicable diseases such as diabetes would increase demand for testing, whether a streamlined linkage-to-care model improves treatment initiation, and whether the sequence of enhanced linkage and person-centred treatment improved retention and viral suppression. The campaigns were designed in consultation with local communities in order to address a broad range of health needs.

The study randomised 32 communities in Uganda and Kenya, each with around 10,000 inhabitants, to receive either the intervention or standard of care according to national guidelines. The intervention consisted of:

• A multi-disease prevention campaign that included testing for HIV, diabetes and hypertension, with a two-week health fair and household testing in each community.
• Linkage to care of anyone who tested positive
• Immediate antiretroviral therapy (ART), regardless of CD4 count

(Read more about the SEARCH study interventions here.)

During the study period, which lasted from 2013 to 2016, treatment guidelines changed so that eligibility for antiretroviral therapy in the standard-of-care arm expanded from people with a CD4 cell count below 350 cells/mm³ to everyone with a CD4 cell count below 500 cells/mm³.

The study enrolled 186,354 adults in Uganda and Kenya, of whom 90.1% underwent HIV testing. The study found higher HIV prevalence in Kenya (19.3%) than in the two study regions in western and eastern Uganda (6.6 and 3.5% respectively). Prior to the study, 57% of participants in the intervention and control group communities knew their HIV status.

Sixty per cent in the intervention communities and 17% in the control communities started ART within six months of diagnosis; after two years, 80% in intervention communities and 40% in control communities had started treatment.

Overall, the study found that by the end of year three, 79% of people with HIV in the intervention communities had a fully suppressed viral load compared to 68% in the control communities, an 11% difference (p < 0.001). However, viral suppression was substantially lower in young people: only 55% had a fully suppressed viral load by the end of year three.

The effects of the multi-disease campaign went beyond viral suppression. People with HIV in the intervention communities were 20% less likely to die during the study than people with HIV in the control communities, and the mortality rate was 11% lower among all people enrolled in the intervention communities compared with the control communities.

The multi-disease prevention intervention had a significantly greater impact on non-HIV health outcomes:

• TB incidence was almost 60% lower in the intervention communities (RR 0.41, 95% CI 0.19-0.86, p = 0.02).

• The proportion of the population with hypertension who had controlled hypertension was 26% higher in the intervention communities at year three (p < 0.01) and was also higher in people with HIV. Findings were similar for diabetes but were not presented at this meeting.

However, the total number of new HIV infections over three years did not differ significantly between the two study arms: 0.8% of the population in each study arm acquired HIV during the three-year trial. The investigators think that the high rate of HIV testing and awareness of HIV diagnosis in both study arms may partly explain the lack of difference in HIV incidence, but they also note that new treatment guidelines introduced in the first year of the study mean that both intervention and control communities were being offered immediate ART, regardless of CD4 cell count.

Looking at the three different regions in which the study took place, investigators found that in intervention communities in Western Kenya – the area with the highest incidence measured at baseline (0.7%) – HIV incidence declined by 45% in intervention communities between baseline and year three, with the greatest reduction in men. In comparison, annual incidence did not change over the study period in Ugandan communities.

Botswana: Ya Tse study

A second cluster-randomised trial, in Botswana, evaluated the effect of community-wide testing and counselling, linkage to care, earlier ART initiation and enhanced male circumcision services on HIV incidence between 2013 and 2018. The Ya Tse study, or the Botswana Community Prevention Project study, randomised 30 rural or periurban communities to receive either the intervention or the standard of care (which included universal ART from mid-2016). The communities covered about 10% of the population of Botswana.

The intervention consisted of home-based testing and counselling or mobile testing, linkage to care with SMS reminders and active follow-up if people missed an appointment, universal ART starting from the first clinic visit (from June 2016) and expanded male circumcision.

In the control group communities, treatment was provided to everyone with a CD4 cell count below 350 cells/mm³ until June 2016, and thereafter to everyone diagnosed with HIV, through clinics. No other expanded services were provided.

To measure the impact of the interventions on HIV incidence, a random sample comprising 20% of adult residents was enrolled in a longitudinal HIV incidence study. The longitudinal sample recruited 12,610 people, of whom 29% were HIV positive at baseline. Of those HIV positive at baseline, 79% were already on antiretroviral therapy and 97% of those on treatment had an undetectable viral load (<400 copies/ml).

The HIV-negative participants were followed for a median of 29 months. During the follow-up period, 95% of participants re-tested for HIV at least once.

In the intervention arm, 57 people acquired HIV infection compared to 90 in the standard-of-care arm, representing a 30% reduction in incidence in the intervention arm (incidence ratio 0.70, 95% CI 0.50-0.99, p = 0.04).

The study found a high rate of viral suppression among people diagnosed with HIV at baseline (75% in the control group and 70% in the intervention group). The proportion of people who were virally suppressed increased by 18% in the intervention group and 7% in the control group. By the end of the study, 88% of all people diagnosed with HIV in the intervention group had an undetectable viral load.

Conclusion

Moeketsi Joseph Makhema of Botswana-Harvard AIDS Institute stressed the very high levels of HIV diagnosis and viral suppression achieved in Botswana, but warned, “We need to sustain these targets over a ten-year period to achieve the target of epidemic control by 2030”.

Diane Havlir, lead investigator on the SEARCH study, concluded that to drive incidence down further, after achieving such high levels of coverage and viral suppression, would require a greater focus on viral suppression in young people, a better understanding of local transmission dynamics and the wider implementation of prevention innovations such as pre-exposure prophylaxis (PrEP), the vaginal ring and male circumcision.

She also drew attention to the potential for multi-disease campaigns to attract funding from a range of sources and achieve broader health goals, so helping to integrate HIV into the wider health system.