HIV Serodiscordant Partnerships Among MSM Diagnosed with Early Syphilis in Philadelphia

Background: Serosorting is a strategy some men who have sex with men (MSM) use in an effort to reduce HIV risk or transmission. MSM who have early syphilis likely have engaged in unprotected sex in the past year, and may be employing serosorting as a risk reduction method. PDPH Partner Services (PS) interview records for syphilis cases were reviewed to determine HIV concordancy among partnerships.  

Methods:  Syphilis patient interviews and STD clinic medical records are maintained in an electronic data base and partner records are linked to the original record. All information on individuals reported with early syphilis and named as a contact to early syphilis in 2012 available was reviewed to determine the HIV status of syphilis patients and their contacts.  

Results:  Of the 535 males reported with early syphilis in 2012, 371 (69%) were identified as MSM. Most (353, 95.1%) reported cases received PS interviews. Many patients named anonymous partners who were not located. PS identified 361 contacts, accounting for 332 unique individuals (as some contacts were named by more than one case). Of the 295/361 partnerships where HIV status was known for both partners, 66% were among seroconcordant partners (150 HIV positive and 45 HIV negative) and 34% were among serodiscordant partners.

Conclusions:  The high percentage of concordant partnerships may indicate that high risk positives are using serosorting as a means of risk reduction; however, this practice may also lead to increased risk of other STDs. Concordant partnerships may also be a chance result of an overall high rate of HIV in MSM infected with syphilis. The number of serodiscordant partnerships is more alarming. All 100 of the HIV negative partners are at high risk for new infection and may benefit from specific public health messaging, enhanced counseling and frequent testing.