People newly infected with HIV may be at higher risk of developing ocular syphilis, MedPage Today reports. Cases of the potentially blinding form of the sexually transmitted infection (STI) have been seen in Seattle and San Francisco, prompting the Centers for Disease Control and Prevention (CDC) to issue an advisory to clinicians to test for HIV among those diagnosed with this form of syphilis.

A new pair of analyses looked at North Carolina syphilis cases in 2014 and 2015. Results were presented at the 2016 STD Prevention Conference in Atlanta.

Between the two years, overall syphilis diagnoses rose 35 percent while ocular syphilis cases in particular more than doubled, from 20 in 2014 to 43 in 2015. The two-year total of ocular syphilis diagnoses represented 1.5 percent of the 4,232 cases of all forms of syphilis.

Considering people with ocular syphilis, the researchers found that those with HIV had a 90 percent greater prevalence of ocular symptoms compared with those who did not have HIV. Fifty-six percent of those with ocular syphilis were HIV positive, compared with 40 percent of those with other forms of the STI.

Thirty-one percent of those diagnosed with ocular syphilis were diagnosed with HIV at the same time, compared with 15 percent of those with other forms of syphilis. Those diagnosed with syphilis at the same time as HIV had a 2.5 times greater rate of ocular symptoms compared with those diagnosed with HIV before syphilis.

Regardless of the timing of their HIV diagnosis, individuals living with the virus were more likely to be diagnosed with ocular syphilis than other forms of the STI if they had a lower CD4 count.

To read the MedPage Today article, click here.

To read the two conference abstracts, click here and here.