East Bay Getting to Zero

East Bay HIV/STI Case Management Manual

Section 5: Alameda County HIV Epidemiology

Section Navigation:East Bay HIV/STI Case Management Manual

Author: Megan Crowley

As of 2022, 6,286 people with a confirmed HIV diagnosis are living in Alameda County, or approximately 1 in every 270 residents. The county’s population of people living with HIV (PLWH) reflects both national trends in HIV epidemiology and the region’s demographic diversity. Several key communities are disproportionately impacted by HIV, including Black and Latine residents, and men who have sex with men. The local data summarized below provide important context to help funders and service providers prioritize their efforts to have the greatest impact on individual health and reduce the spread of HIV in the community. 

Alameda County Epidemiology 

Race

The local HIV epidemic has had devastating consequences for Black populations. In 2022, Black residents made up 37% of PLWH in Alameda County, despite being only 11% of the broader population—an overrepresentation of over 300%. Black residents also made up 28% of new HIV diagnoses between 2020 and 2022, showing a slight decline in incidence for this population.

While Latine residents are only slightly overrepresented among PLWH compared with the general population (24% vs. 22%), they make up the largest proportion of new HIV diagnoses (35.1% between 2020 and 2022). This reflects a disturbing trend in recent years and highlights the importance of culturally and linguistically appropriate prevention services and public health messaging.

White (non-Hispanic) people represented approximately 27% of PLWH and 15% of recent new diagnoses. Though these are significant proportions, white people are not overrepresented among PLWH overall, unlike Black and Latine PLWH. Similarly, Asian and Pacific Islanders, who make up 35% of Alameda County residents, are underrepresented in both PLWH (7%) and new diagnoses (9%). 

Gender and sexual orientation

Approximately 84% of PLWH were assigned male at birth while 16% were assigned female at birth. While still a minority of the overall population, cisgender women are a much higher proportion of PLWH in Alameda County compared with other counties in California (e.g., 11% in Los Angeles County and 6% in San Francisco County). Historical data limitations have made it difficult for Alameda County to accurately calculate the impact of HIV on transgender residents, but it estimates that 2% of PLWH are transgender women.

Over two thirds (67%) of the county’s PLWH acquired HIV through male–male sexual contact, while over 13% acquired HIV through heterosexual contact. Combined with prevalence estimates for transgender women, these statistics demonstrate the disproportionate impact of the epidemic on LGBTQ+ communities and the importance of service providers who explicitly welcome clients of all sexual orientations and gender identities.

Age

Over half (57%) of PLWH in Alameda County are age 50 or older, demonstrating the effectiveness of current treatments in extending life expectancy to near-normal levels as well as the importance of service providers who are adept at serving older adults. Conversely, less than 6% of PLWH are ages 13–29; however, nearly 24% of people newly diagnosed with HIV between 2020 and 2022 were in this age group. This comparatively high incidence underscores the importance of developmentally and generationally appropriate prevention messages.

People Who Inject Drugs

Approximately 6% of PLWH are believed to have acquired HIV through injection drug use, while an additional 6% may have acquired HIV through either injection drug use or male–male sexual contact. While these numbers are comparatively lower among newly diagnosed PLWH (3% and 2%, respectively), the opioid epidemic is cause for great concern regarding the role of injection drug use in the future spread of HIV. Goals to end the HIV epidemic must include a focus on harm reduction and better support for people who use drugs.

Perinatal Infections

Approximately 0.5% of PLWH (32 total) acquired HIV perinatally (from a parent with HIV during pregnancy, childbirth, or breastfeeding). Many of these transmissions occurred decades ago, before effective treatments were widely available. From 2020 to 2022, no perinatally acquired cases were reported in Alameda County, highlighting the great strides made in reducing the risk of this form of transmission since the early days of the epidemic. 

Definitions

  • Epidemiology: The study of the incidence and distribution of diseases and other factors related to health. Epidemiology is focused at the population level rather than the individual level. 
  • Prevalence: The number of people in a population who have a particular characteristic (such as a disease). Usually, prevalence is defined by a specific timeframe and geographical area, e.g., total number of people known to be living with HIV in Alameda County as of 12/31/2022. 
  • Incidence: The number of people in a population who were newly counted as having a disease or other characteristic in a specific timeframe and geographic area, e.g., total number of people living in Alameda County newly diagnosed with HIV during 2022. 
  • Disparity: When a particular subpopulation is more or less likely to have a particular characteristic than a comparison population, e.g., Black residents are more likely to have an HIV diagnosis than the general population. 

Takeaways & tips for case managers

  • Local epidemiology data can provide helpful context for understanding how your agency’s clients fit into the broader population of people living with HIV in our region.
  • Combined with agency-level data, epidemiology data can help with setting priorities and determining which intervention(s) may have the greatest impact.
  • Official Alameda County HIV Surveillance Reports can be found at https://acphd.org/data-reports/. 

    Note: The most recent official HIV report is a brief summary of HIV in Alameda County from 2019–2021. The data used in this section was provided by special request and is not yet publicly available. 

References: 

Author

Megan Crowley started her career in healthcare as a medical assistant and HIV test counselor in 2006. She earned her Master of Public Health degree in 2008 and has worked with Ryan White Programs ever since. Her professional interests include grant writing and quality improvement. She is constantly inspired by her colleagues in the East Bay HIV community, who are constantly working to improve access to care and quality of care for people living with HIV.

Section 6: HIV 101 & HIV Treatment