Overall HIV Prevalence and Incidence

Figure 1.3 shows the number of newly diagnosed HIV and concurrently9 diagnosed AIDS cases reported in Orange County by year of diagnosis. In 2018, there were:

• 280 persons newly diagnosed with HIV. • 57 persons concurrently diagnosed with AIDS indicating that the individual was living with HIV but unaware of

their status for a significant amount of time.

Number 350 300 250 200 150 100 50 0 Figure 1.3. Number of New HIV Diagnoses and Number of Those Diagnoses Concurrently Diagnosed with AIDS by Year of HIV Diagnosis, 2009-2018

331 297 315 273 305

279 331 332

300 280

97 69 89 68 70 60 65 50 60 57

2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 Year

New HIV Diagnoses Concurrent Diagnosis

Figure 1.4 shows the rate of HIV transmission per every 100 persons living with HIV.

 Since 2009, the transmission rate has decreased 46.3%, from 8.2 to 4.4. A decrease in the transmission rate

indicates that the amount of new HIV infections is not increasing despite the increase in the number of PLWH.

Rate per 100 PLWH 9 8 7 6 5 4 3 2 1 0 8.2 Figure 1.4. HIV Transmission Rate per 100 Persons Living with HIV, 2009-2018

6.9 6.9

5.7 6.1 5.3 6.0 5.7

4.9

4.4

2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 Year

9 Concurrently diagnosed are persons who tested positive for HIV for the first time and had an AIDS defining condition (CD4 count below 200 cells/µL and/or a diagnosis of a disease that is an indicator condition for AIDS) in the same month and year. Health Promotion and Community Planning Division 13 HIV/AIDS Surveillance and Monitoring