HIV/AIDS & Transmission
- Transmission
mode varies regionally throughout the U.S. In California, 77% of
cumulative AIDS cases are attributed to the combined risk factors of
MSM and MSM/IDU. This figure compares to over 54% nationally for the
same combined categories.
- According to the CDC, during
2003 new HIV infections in 41 areas with confidential name-based HIV
reporting indicate that 18% are attributable to heterosexual sex and
34% to sex between men. Twelve percent are due directly to injection
drug use. The remaining 36% were due to other risk factors, or the risk
factor was not reported or identified.
AIDS Cases by Transmission Category: United States, California, and San Francisco, 1981-Present
| Location |
MSM [1] |
IDU [2] |
MSM/IDU |
Heterosexual |
Transfusions |
Hemophilia |
Pediatric (0-12) |
Other/Unknown |
| United States |
441,380 |
248,813 |
64,833 |
159,114 |
(see Other) |
(see Other) |
9,443 |
20,271 |
| California |
96,077 |
14,709 |
13,303 |
8,223 |
1,715 |
566 |
778 |
7,142 |
| San Francisco |
19,990 |
2,025 |
3,754 |
355 |
143 |
16 |
38 |
574 |
Percentage of Adult AIDS Cases by Transmission Category: United States, California, and San Francisco, 1981-Present
Percentage of Adult AIDS Cases by Exposure Category: California, 1987, 1992, 1997, 2002, 2005
| Exposure Category |
1987 |
1992 |
1997 |
2002 |
2005 |
| MSM |
80% |
71% |
59% |
53% |
57% |
| IDU |
4% |
12% |
14% |
13% |
9% |
| MSM/IDU |
10% |
9% |
7% |
9% |
13% |
| Blood Products |
3% |
2% |
1% |
1% |
<1% |
| Heterosexual |
2% |
4% |
9% |
11% |
13% |
| Other/Unknown |
2% |
3% |
10% |
13% |
9% |
Note: Numbers may not add exactly due to rounding.
1) Men who Have Sex with Men
2) Injection Drug Use
Page last updated: 9/17/2007