But how many gay men in the US are virally
suppressed? The CDC release says that 61% of gay and bisexual men diagnosed
with HIV have a viral load of below 200 copies/ml, their definition of
suppression. This is based on a more detailed report in the CDC’s Morbidity and
Mortality Weekly
Report (MMWR: Singh et al.) for 22 September.

This does indeed report that 61.2% of gay and bisexual men
who had at least one viral load test in 2014 were virally
suppressed.

However, this disguises a lot of detail. Firstly, the data is
two years old. Things may have changed since, probably for the better.

The second issue is that the MMWR figures come from the 37
states and one territory (the District of Columbia) that report viral load
suppression rates and whether patients are regularly in care. The 13 states
that only report HIV and AIDS diagnoses and deaths include some populous ones
with high HIV prevalence such as Florida and Pennsylvania, so we don’t have a
complete picture.

More interesting is the variation between gay men, which
varies by ethnicity and age (see graphic). Just over 45% of black gay men aged under 24 were
virally suppressed: conversely, about 68% of white gay men aged over 45 were.
Viral suppression rates increased among all ethnicities by age – but black gay
men over 55 still had a lower suppression rate (57%) than white gay men aged
20-24 (61%).

Then there is the issue of diagnosis. The US has a high
diagnosis rate. The CDC estimates that (among all groups and in all 50 states
plus DC) only 15% of people living with HIV are undiagnosed, with a slightly higher
proportion of gay men (17%). This is even lower among people over 45 (less than
10% undiagnosed). Conversely, however, 44% of people aged 13-24 and 29% of
people aged 25-34 are undiagnosed.

This would mean that less than 28% of HIV-positive gay men
aged under 25 are actually virally suppressed, and under 39% of 25-34-year olds
– but around 60% of men over 55.

In addition, the definition of suppressed viral load is
quite lax, requiring only one test result in the previous year. The percentage
of diagnosed gay men “retained in care” in 2014 was actually lower than this,
at 58%, and 54% in black men. (“Retention in care” is defined as the patient
having had at least two CD4 or viral load tests more than three months apart in
the previous year.) This might be a better guide to consistent viral
suppression than just one test.