San Francisco HIV cases fall to a new low

The annual number of new HIV diagnoses in San Francisco has dipped below 200, falling to its lowest level since the peak of the epidemic in the early 1990s, according to the city's HIV Epidemiology Annual Report for 2018.

Total new diagnoses fell to 197, with decreases seen in most population groups. However, diagnoses among African-American and Latino men showed an increase after declining for several years.

Indicators of care improved as well, including the proportion of HIV-positive people with viral suppression. But people who inject drugs and homeless people did not fare as well.

The report was released last week at a press conference featuring San Francisco Mayor London Breed, Department of Public Health officials and providers at Zuckerberg San Francisco General Hospital, which established the first dedicated AIDS ward and HIV clinic in the US in the 1980s.

"I started here as a medical student at Ward 5a in 1992 and have seen the progress we've made," said San Francisco Health Director Dr Grant Colfax. "But we still have much more work to do. We must be bold and we must be innovative, both with HIV and with mental health and with substance use and with addressing the intersection between health and homelessness."

New diagnoses

The 197 new HIV diagnoses in 2018 represent a 13% decline from 227 new cases in 2017. Because of the city's high testing rate, HIV incidence (total new infections) is thought to be about the same as the number of new diagnoses.

As has historically been the case, most people newly diagnosed in 2018 were men (88%) and 63% were gay or bisexual, while 9% were cisgender (non-trans) women. In the US as a whole, the corresponding figures are 81%, 66% and 19%, respectively. Transgender women and trans men accounted for 3% and 1% of new cases. No infants or children under 13 have been diagnosed with HIV in San Francisco since 2005.

While white and Asian/Pacific Islander men saw a continued decline in new cases, the number of new HIV diagnoses rose among black and Latino men between 2017 and 2018. Incidence rates for these four groups were 27, 11, 145 and 89 per 100,000 population, respectively.

For the first time ever, the number and proportion of new HIV diagnoses among Latino people exceeded those among white people (38% and 29%, respectively). Although African Americans have the highest diagnosis rate, they make up a smaller proportion of the population, accounting for 21% of new cases. Asians/Pacific Islanders had the lowest diagnosis rate at 8%. (The corresponding proportions in the San Francisco population are around 15%, 53%, 6%, and 36%, respectively.) Nationwide, African Americans have the highest diagnosis rate, at 43%, while making up about 13% of the population, according to the Centers for Disease Control and Prevention (CDC).

New HIV diagnoses among people who inject drugs continues to rise, reaching 14% of new cases in 2018; another 10% were attributed to those who are both injection drug users and men who have sex with men. Heterosexuals who do not inject drugs accounted for only 5% of new diagnoses in San Francisco, compared with 24% nationwide. The proportion of new diagnoses among homeless people also rose, from 10% in 2017 to 20%.

Thanks to improvements in treatment, HIV-positive people are living longer. A total of 15,990 San Francisco residents were diagnosed and living with HIV at the end of 2018, accounting for 2% of all HIV-positive people in the US.

The report also shows that the HIV population in San Francisco continues to shift into older age groups: 66% were over age 50, including 30% over 60 and 7% over 70. Although many are long-term survivors, people over 50 accounted for 13% of new diagnoses. Nationwide, 47% of people with HIV are over 50, according to the CDC.

According to the report, almost 100 HIV-positive people (88 men and eight women) died in 2017. HIV-related conditions remain the leading cause of death, accounting for 38% of deaths among people diagnosed between 2014 and 2017 and 52% of deaths among people diagnosed between 2006 and 2009. The next most common causes of death were non-AIDS cancers (15%; most often lung, liver and anal cancer), accidents (13%, of which 10% were drug overdoses), heart disease (11%), suicide (3%) and liver disease (3%).

Engagement in care

San Francisco has been a leader among US cities in providing timely access to HIV care and treatment. In 2018, an estimated 94% of people living with HIV had been tested and knew their status; nationwide, this figure is 86%, according to the CDC. Although a large proportion were diagnosed with CD4 counts above 500 cells/mm³, 19% were diagnosed late, meaning they developed AIDS within three months after diagnosis.

Among newly diagnosed people, 91% were linked to care within a month, 64% were retained in care for three to nine months and 78% achieved viral suppression within a year. Looking at all people living with HIV, both diagnosed and undiagnosed, the report estimates that 70% of people with HIV in San Francisco have achieved viral suppression, compared with 62% nationwide.

However, the aggregate figures mask some notable disparities. Cisgender women and trans women diagnosed with HIV have lower rates of viral suppression than men (66%, 68% and 74%, respectively). African-American and Latino people have lower rates than white people (68%, 70% and 76%). Among people who inject drugs, this rate was 65%. The most dramatic disparity was the low rate of viral suppression among homeless people, at just 33%.

The median time from HIV diagnosis to the first care visit fell to four days in 2017, and the median time from that first visit to initiation of antiretroviral therapy fell to zero days – that is, treatment is typically started during the first visit. The median time from diagnosis to viral suppression fell to 62 days.

Getting to Zero

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

The decline in new diagnoses is attributed to multiple factors, including the early and widespread adoption of pre-exposure prophylaxis (PrEP) by the city's large gay community and a high rate of early HIV treatment.

In 2010, San Francisco was the first US city to recommend antiretroviral therapy for everyone diagnosed with HIV regardless of CD4 count, well before US federal guidelines and World Health Organization guidelines did the same. The city's RAPID antiretroviral therapy programme, which aims to start people on treatment the day they are diagnosed, has led to faster viral suppression. Because those with undetectable viral load do not transmit the virus, more people with viral suppression means a lower risk of acquiring HIV on a community level.

But there also some negative factors. San Francisco's rapid gentrification and skyrocketing housing costs have driven some of the groups at highest risk for HIV out of the city, as demonstrated by the low and declining proportion of African Americans. Across the bay in Oakland, where 24% of the population is black, HIV prevention and care services are not as widely available or as well funded.

Further reducing new infections will require tailored efforts to increase PrEP use in currently underserved groups such as young black and Latino gay men, expand harm reduction services – ideally including supervised injection facilities – and develop strategies to enable people struggling with mental health issues, substance use and homelessness to access care and stay on treatment.

Speaking on behalf the city's Getting to Zero Consortium, Dr Diane Havlir, chief of the Division of HIV, Infectious Diseases and Global Medicine at Zuckerberg San Francisco General Hospital said, "We are pleased, but not satisfied. We are pleased that we broke the 200 barrier. In San Francisco, over the last five years, new HIV diagnoses have gone down by 50%, while in the United States it's been completely flat…But we are not satisfied because we had nearly 200 new infections and it's a preventable disease. We're not satisfied because of these disparities."

Havlir stressed the need for innovative approaches using tools we already have, like PrEP, and upcoming tools like long-acting injectable therapy, along with addressing structural barriers and gaps in housing and mental health and substance use services.

"There's no way that reaching this last 10 of people isn’t going to be resource-intensive, but we think it's worth the investment to reach this last group," added associate division chief Dr Monica Gandhi.