HIV Viral Loads Among Young HIV-Infected Men with Early Syphilis

Background: Increasing rates of syphilis have been reported among men who have sex with men (MSM), with high rates of HIV co-infection among these cases. HIV viral load data as a surrogate for HIV infectivity was evaluated among young men diagnosed with HIV and syphilis in Maricopa County, Arizona. 

Methods: Syphilis case report and HIV and STD surveillance data were abstracted to identify cases meeting the following criteria: (1) male, (2) 24 years of age or younger, (3) diagnosis of early syphilis (primary, secondary, or early latent) during 2009-2012, and (4) HIV-infected at the time of syphilis diagnosis.  HIV viral load and CD4 cell count data nearest to the time of syphilis diagnosis were abstracted.

Results: During 2009-2012, there were 56 HIV-infected, early syphilis cases meeting the age criteria. The median age was 22; 23 (41%) were Hispanic; 17 (30%) were White; and 14 (25%) were African American.  Of men with available information on gender of sexual partners (N=54, 96%), 53 (98%) reported MSM behavior.  Syphilis stages included: 5 (9%) with primary; 23 (41%) with secondary; and 28 (50%) with early latent syphilis.  Of the 56: only 4 (7%) patients had an undetectable viral load (< 100 c/mL) collected within a year of syphilis diagnosis; 32 (57%) had a detectable viral load collected within one year of syphilis diagnosis (median 21,000 c/mL, range 130 – 302,844 c/mL); and 20 (36%) had no reported viral load or a viral load collected greater than one year from syphilis diagnosis.  The median CD4 count was 375 cells/mm³ (N = 20, range 28 – 862 cells/mm³).

Conclusions: Among this group of young men, primarily MSM, co-infected with HIV and early syphilis, few had undetectable viral loads suggesting the potential for HIV transmission.