Progress in reducing new HIV diagnoses much slower for Black men in the US

Lifetime risk of acquiring HIV has decreased for Black gay and bisexual men in the US, from 1 in 2 from 2010 to 2014 to 1 in 3 from 2017 to 2021, according to data presented to the Conference on Retroviruses and Opportunistic Infections (CROI 2024) by researchers from the US Centers for Disease Control and Prevention (CDC) last week.

However, racial disparities between White and Black men persist and have widened over the past few years by some estimates, despite decreases in the numbers of new diagnoses for both groups.

The studies

Data were collected for the period 2017 to 2021, from sources such as the National HIV Surveillance System, to gain estimates of disparities based on the number of new diagnoses. For lifetime risk estimates, mortality data and census data were also included (as were previously published estimates of the number of men who have sex with men in the US (around 7% according to national survey data).

Data from 2020 were excluded due to COVID-19-related reductions in HIV testing and diagnoses. Importantly, it was assumed that 2017 to 2021 diagnosis rates continue in the future.

Trends in Black-White HIV disparities

Disparities can be measured as absolute or relative disparities. For example, in 2021, the rates of HIV diagnosis for those aged 13 or older was 41.8 per 100,000 for Black people and 5.3 for White people. The absolute disparity looks at the difference between the two rates, by subtracting one from the other. In this case, there was an absolute difference of 37 per 100,000. Another way of putting this is if Black and White people were to have similar numbers of new HIV diagnoses in 2021, there would need to be a reduction of 37 cases per 100,000 Black people.

Another measure, the relative disparity, or a ratio between these rates, reflects the fact that Black people are around eight times more likely to be diagnosed with HIV than White people.

Andre Dailey presented updated trends in Black-White disparities in HIV diagnoses between 2017 and 2021.

Between 2017 and 2021, for Black and White males aged 13 to 24, the absolute disparity decreased by 1.8% per year (95% confidence interval: -2.3 to -1.2) while the relative disparity increased by 7.4% per year (95% CI: 7 to 7.7) per year. This shows that while both groups have seen decreases in new diagnoses, the rate of improvement has been slower for Black males.

Dailey highlighted one regional difference: for Black and White males living in the western US, the relative disparity increased by 2% per year (95% CI 1.1 to 2.9), while the absolute disparity did not change.

There were no absolute or relative disparity changes for females, for any of the age groups.

When considering changes in the White-Black disparity by transmission risk group comparing 2017 and 2021, there were increases of 6% for gay and bisexual men overall, 175% for male injecting drug users and 68% for female injecting drug users. However, the disparity was reversed for injecting drug users, with more White people than Black people being diagnosed with HIV. When considering gay and bisexual men who inject drugs, there was a 12% increase between 2017 and 2021, with more White men acquiring HIV.

Lifetime risk for gay and bisexual men

Dr Sonia Singh presented updated lifetime risk estimates for gay and bisexual men. While these estimates are frequently used for diseases such as cancer, they are less often applied to HIV. One of the benefits of this approach is that it helps with public education as lifetime risk estimates are easily understood.

Overall, gay and bisexual men living in the US have a 1 in 7 chance of getting an HIV diagnosis over their lifetime. The chances of this happening are highest for Black men, who have a 1 in 3 chance, followed by Latino men with a 1 in 5 chance. Asian and White men have the lowest lifetime chances of getting an HIV diagnosis at 1 in 15 for both groups. For Native Hawaiian and Other Pacific Islander men the risk is 1 in 7, while it is lower for American Indian men at 1 in 11.

There have been adjustments to the lifetime risk data for the 2010 to 2014 period for most groups – only Latino men retained a 1 in 5 chance. For Black men, it has improved slightly from 1 in 2, while there has been an improvement from 1 in 11 for White men and 1 in 14 for Asian men to the current estimate. Overall, lifetime risk has only changed slightly between these two periods: from 1 in 6 for the 2010 to 2014 data to the current estimate of 1 in 7.

When looking at the risk estimates by age, the chances of getting an HIV diagnosis within the next ten years tend to be highest for men in their twenties and thirties. By age 50, gay and bisexual men have accumulated 89% of their risk for acquiring HIV. For a Black gay man, there is a 1 in 5 chance that he will get diagnosed with HIV by the time he turns 30. If he remains HIV negative at that age, his risk goes down to 1 in 9 by the time he turns 40. Comparatively, the ten-year risk estimate is 1 in 12 for Latino men at 20 and 1 in 15 at 30, whereas it is 1 in 47 for White men at 20 and goes down to 1 in 54 by age 30.

These estimates present a stark racial disparity: Black gay and bisexual men are five times more likely to be diagnosed with HIV than White and Asian men, while Latino men are three times more likely to be diagnosed. Native Hawaiian and Other Pacific Islander men are 2.1 times more likely to diagnosed than White men, whereas American Indian men are 1.4 times more likely to be diagnosed.

Conclusion

“Lifetime risk can be a useful tool to more effectively communicate the burden of HIV overall and in specific communities. It can help to highlight disparities and identify where prevention efforts can be accelerated. For groups with the highest ten-year conditional risk, these estimates may suggest a need for more testing,” Singh concluded.

Commenting on the persistent and increasing racial disparities, Dailey highlighted the social determinants of health: “Health is shaped by many behaviours. These behaviours occur in the context of living and working conditions that influence them, and these living and working conditions are shaped by factors that reflect a person’s economic and social opportunities and resources, or lack thereof, thereby influencing their ability to make healthier choices.”