San Francisco annual report shows continued drop in new HIV infections

The San Francisco Department of Public Health (DPH) has released its HIV Epidemiology Annual Report for 2016, showing that the number of new infections continues to decline, with decreases seen across demographic groups. Homeless people, however, have higher rates of infection and poorer treatment outcomes.

"Highlights of this year's HIV annual report include a 16% decline in new diagnoses to 223 – the lowest number ever reported in San Francisco," said Dr Susan Scheer, director of the DPH's HIV Epidemiology Section. "This means we have cut new diagnoses by over half since 2006."

While new HIV infections nationwide decreased by 18% over 6 years (2008 to 2014), according to the US Centers for Disease Control and Prevention (CDC), San Francisco saw nearly as great a drop last year alone, and a 49% reduction over the past four years, health commissioner Dan Bernal noted at a press conference on 15 September launching the report.

The latest findings indicate that San Francisco is making progress towards achieving the goals of its Getting to Zero initiative: zero new HIV infections, zero deaths due to HIV/AIDS and zero stigma against people living with HIV.

"New HIV infections in San Francisco are declining at a faster rate than ever, and the city continues to do better than the nation in reducing new infections," said city health director Barbara Garcia. "Better yet, new infections are dropping among all groups, including African American and Latino men, and we are starting to close the disparity gap. It is essential that we focus on disparities in order to get to zero."

New and total HIV cases

The report, which covers data to the end of 2016, shows that the number of new HIV diagnoses in San Francisco fell from 265 in 2015 to 223 in 2016. This continues a decade-long drop, with a steeper decline starting around 2012.

Experts attribute the decline to a combination of factors including increased testing, the advent of pre-exposure prophylaxis (PrEP) and widespread adoption of early antiretroviral therapy. Studies show that HIV-negative people who consistently take Truvada (tenofovir/emtricitabine) PrEP can reduce their risk of HIV infection by around 90% or more, while HIV-positive people on effective antiretroviral treatment that suppresses viral load to an undetectable level do not transmit the virus.

Among newly diagnosed individuals in San Francisco, 87% are men, 11% are women and around 2% are transgender women. 

By transmission category, 70% are men who have sex with men, 9% are people who inject drugs, another 9% fall into both these categories and 6% are heterosexual. Among gay and bisexual men in particular, the report also noted an increase in sexually transmitted diseases, especially gonorrhoea.

By race/ethnicity, 39% of newly diagnosed individuals are white, 28% are Latino/Hispanic, 15% are African American and 15% are Asian or Pacific Islanders. New diagnoses declined or held steady for all groups.

White and Asian people account for a smaller proportion of new HIV diagnoses compared with their share of the city's population (about 54% and 36%, respectively), while Latino and black people accounted for disproportionately more new cases relative to their share of population (about 15% and 6%, respectively).

The HIV diagnosis rate among black men in 2016 was 96 per 100,000 people – more than double the rate of 39 per 100,000 among white men. But this was a substantial drop from 140 per 100,000 in 2015. Nationwide, the disparity is even greater: African Americans account for 45% of all new HIV cases while making up about 12% of the US population, according to the CDC.

One-third of newly diagnosed people in San Francisco were in the 30-39 year age range, followed by those aged 25-29 years (24%). Young adults aged 18-24 years accounted for 14% of new HIV diagnoses. The 40-49 year age group and people over 50 each accounted for 15% of new cases. No adolescents age 13-17 were found to be newly HIV-positive in 2016, and no infants or children under 13 have been diagnosed with HIV in San Francisco since 2005.

The number of deaths among people with HIV declined even more steeply than new infections, from 257 in 2015 to 165 in 2016. However, the report cautions that the latest number is likely an underestimate due to delayed reporting. Deaths from direct HIV- or AIDS-related causes continue to fall, while deaths due to other causes are rising, the most common being non-AIDS cancers, accidents – including drug overdoses – and heart disease.

As the death rate goes down, the number of people living with HIV goes up. At the end of 2016 there were 16,010 HIV-positive San Francisco residents, accounting for 2% of all people known to be living with HIV in the US, according to the report.

The vast majority of people with HIV in San Francisco – 92% – are men, while 6% are women and 2% are transgender. More than half (59%) are white, 19% are Latino, 12% are black, 6% are Asian/Pacific Islander and fewer than 1% are Native American.

As a consequence of improved survival, the HIV-positive population in San Francisco people is ageing. Currently, 63% are over age 50, while 26% are over age 60 and 5% are over 70. Only around 5% of people living with HIV in the city are under age 30.

"It's great news that we're seeing fewer new HIV diagnoses, better survival, and a lessening of racial/ethnic disparities, likely as a result of a whole suite of initiatives rolled out by the health department, community-based organizations, clinics, and individual providers," said Dr Susan Buchbinder, director of DPH's Bridge HIV programme. "Now is the time to double down on these efforts, not pull back. The only way to prevent new infections and ensure the health and wellbeing of people with HIV is through these comprehensive services, with a focus on our most vulnerable populations."

Disparities in care

San Francisco continues to do a better job than the US as a whole in moving people through the HIV continuum of care, from testing to initiation of treatment to achieving viral suppression.

Overall, an estimated 93% of people living with HIV know they are positive. In 2015 (the last year with complete data), 78% of newly diagnosed people were linked to care within one month of diagnosis and 64% remained in care for three to nine months.

That year, 77% of newly diagnosed people – or 73% of all people currently living with HIV in San Francisco – achieved viral suppression within a year. It took a median of 13 days from HIV diagnosis to treatment initiation and 76 days to reach an undetectable viral load.

"Deaths from HIV-related causes have continued to decline and overall linkage to HIV care and viral suppression have improved at the population level," said Dr Scheer. "Even more impressive, the amount of time it takes people who are newly diagnosed with HIV to link to care and to achieve viral suppression has become much faster. Time to viral suppression has been cut in half since 2012 from five months to two and a half months."

Yet all groups are not benefitting equally from improvements in care. Looking at all HIV-positive people living in San Francisco, men were more likely to achieve viral suppression than cisgender or transgender women (73% vs 66% and 67%, respectively). White and Asian people (both 75%) were more likely than Latinos (69%) or black people (67%) to become undetectable within a year.

Some advocates have suggested that San Francisco's overall good progress in preventing and treating HIV is in part related to its small and dwindling black population, as well as the fact that many people at risk for and living with HIV are being displaced from the city due to its high housing costs.

Underscoring the effect of socioeconomic risk factors, 13% of newly diagnosed people were homeless at the time of their diagnosis. This represents a total of 28 homeless individuals found to be HIV-positive in 2016. Homeless people currently living with HIV in San Francisco were the group least likely to reach an undetectable viral load within a year, at 31%.

However, comprehensive services can help get vulnerable people into care and lead to successful treatment. For example, the DPH's Linkage Integration Navigation Comprehensive Services (LINCS) programme tries to re-engage underserved individuals in care, including people living in homeless encampments and clients of harm reduction programmes. Among homeless people participating in LINCS, the proportion achieving viral suppression rose to 77%.

"We can't look at these numbers and not realize that we're not going to get to zero unless we address housing issues," said Jeff Sheehy, the first openly HIV-positive member of the San Francisco Board of Supervisors "We need to get people off the streets, but also look at what we can do to help people who are still on the streets. We're demonstrating with the numbers that we have the tools to dramatically change the course of the epidemic, but we need to keep our momentum going."