Ocular syphilis and HIV coinfection among syphilis patients in North Carolina, 2014-2016

Abstract

Background:

Ocular syphilis (OS) has been associated with HIV coinfection previously. We compared demographic and clinical characteristics of syphilis patients with and without HIV to identify risk factors for developing OS.

Methods:

We reviewed all syphilis cases (early and late) reported to the North Carolina (NC) Division of Public Health during 2014-2016 and categorized HIV status (positive, negative, unknown) and OS status based on report of ocular symptoms with no other defined etiology. We estimated prevalence ratios (PR) and 95% confidence intervals (CI) for OS by HIV status. Among syphilis patients with HIV, we compared viral loads and CD4 cell counts by OS status. We compared symptom resolution by HIV status for a subset of OS patients.

Results:

Among 7,123 confirmed syphilis cases, 2,846 (39.9%) were living with HIV, 109 (1.5%) had OS, and 59 (0.8%) had both. OS was more prevalent in syphilis patients with HIV compared to HIV-negative/unknown-status patients (PR: 1.8; 95% CI: 1.2, 2.6). Compared to other patients with HIV, the prevalence of OS was higher in patients with viral loads >200 copies/mL (1.7; 1.0, 2.8) and in patients with a CD4 count ≤200 cells/mL (2.3; 1.3, 4.2). Among 11 patients with severe OS, 9 (81.8%) were HIV-positive. Among 39 interviewed OS patients, OS symptom resolution was similar for HIV-positive (70.0%) and HIV-negative/unknown-status (68.4%) patients.

Conclusion:

Syphilis patients with HIV were nearly twice as likely to report OS symptoms as were patients without documented HIV. HIV-related immunodeficiency possibly increases the risk of OS development in co-infected patients.

Short Summary:

Ocular syphilis is more prevalent in syphilis patients with HIV, particularly those with unsuppressed viral loads or low CD4 counts. Complaints of ocular symptoms may help detect previously undiagnosed HIV.