Australia and
northern European countries are doing far better than North America at
retaining people living with HIV in care and achieving viral suppression, according
to a comprehensive survey of 'treatment cascades' in high-income countries
presented on Tuesday at the HIV Drug Therapy Glasgow conference.
However, even in
the best-performing countries viral suppression falls short of the aspirational
target recently set by UNAIDS, and the survey identified country-specific
weaknesses in performance. In the United Kingdom, diagnosis of HIV infection is
the major weakness preventing higher rates of viral suppression in the
population living with HIV, whereas retention in care emerged as the primary
weakness in the United States.
People taking
HIV therapy who have an undetectable viral load have a low risk of disease
progression and onward HIV transmission. However, a large number of individuals
are not benefiting from antiretroviral treatment because they are not engaged
with the so-called “treatment cascade”. This has five stages, specifically
diagnosis, linkage to care, retention in care, initiation of HIV therapy,
adherence to therapy and achievement of an undetectable viral load.
UNAIDS has
recently proposed a 90 / 90 / 90 target in order to reduce transmission and
obtain the maximum benefit from antiretroviral therapy. The target calls for
90% of people living with HIV to be diagnosed, for 90% of those diagnosed to be
linked to care and taking antiretroviral treatment, and for 90% of people
taking antiretroviral therapy to have undetectable viral load. If this target
could be achieved, around three-quarters of all people living with HIV would
have suppressed viral load (73%).
In order to judge
the gap between reality and the new target, investigators from the UK sought to
establish the proportion of people with HIV who were retained at each stage
of the cascade in seven high-income countries: USA, UK, France, Denmark, the
Netherlands, Australia and Canada (British Columbia). Key points where a break in
the cascade – a fall-off of 19% compared to the previous stage – were identified. Break points indicate areas
where national treatment programmes are under-performing.
Data sources
included national and UNAIDS surveillance reports, articles in peer-reviewed
journals and conference presentations.
The proportion of
all people living with HIV who had an undetectable viral load ranged from 62% in
Australia to a low of just 25% in the United States. In Denmark, the UK, the Netherlands
and France, over 50% of people living with HIV had an undetectable viral load (59%, 58%, 53% and 52%,
respectively). In British Columbia, just over a third (35%) of all people living with HIV had
an undetectable viral load.
|
Living with HIV
|
Diagnosed
|
Linked to care
|
In care
|
On ART
|
Adherent
|
<50
|
Australia
|
27,674
|
86%
|
78%
|
76%
|
66%
|
|
62%
|
Denmark
|
6,500
|
85%
|
81%
|
75%
|
62%
|
|
59%
|
United Kingdom
|
98,400
|
n/a
|
79%
|
70%
|
67%
|
|
58%
|
Netherlands
|
25,000
|
n/a
|
73%
|
68%
|
59%
|
|
53%
|
France
|
149,000
|
81%
|
n/a
|
74%
|
|
60%
|
52%
|
Canada (BC)
|
72,000
|
71%
|
67%
|
57%
|
51%
|
44%
|
35%
|
United States
|
1,148,000
|
82%
|
66%
|
37%
|
33%
|
|
25%
|
Note: discrepancies in
data provided indicate differences in national surveillance criteria. For Canada, the cascade percentages used are taken from a study in British Columbia, and have been applied to the numbers of people living with HIV in Canada as a whole.
Remarkably, a
higher proportion of people in sub-Saharan African countries were shown to
have an undetectable viral load than people living with HIV in the USA (29 vs 25%).
Every country –
even those with the best outcomes – had attrition at each stage of the
treatment cascade. For instance, in Australia, 86% of people living with HIV were diagnosed,
78% were linked to care, 76% were retained in care, 66% were on HIV therapy and
62% had an undetectable viral load.
Important breaks
in the cascade were identified in several countries. In the UK and Netherlands
this was the high number of undiagnosed infections (21-27%) not linked to
care. For France and Canada, the breakpoint was undiagnosed infections
(19-29%). In the USA, there was a big gap between the proportion of people
linked to care (66%) and the percentage retained in care (37%).
The investigators
believe the different break points in the cascades are due to underlying
inequalities in HIV care between countries.