Abstract

Cynthia Turner72449*, Tuan Phan72450, OsaroMgbere72451, Jennifer Perez72452 and Lupita Thornton72453

Objective: Observations at the Houston Health Department revealed that syphilis infection has potentially emerged beyond Human Immunodeficiency Virus (HIV) infection as a highly relevant indicator of susceptibility to sexually transmitted Hepatitis C Virus (HCV) infection. Identification of syphilis as a relevant predictive indicator of HCV infection  susceptibility may facilitate optimization of diagnostic algorithms for HCV detection among targeted populations.

Methods: A multifaceted proof of concept study compared the prevalence of syphilis co-infection to HIV co-infection among individuals with Hepatitis C Virus antibody (HCVab). Remnant serum samples previously tested for HIV and syphilis were analyzed for HCVab presence using an Enzyme-Linked Immunosorbent Assay (ELISA). Conversely, remnant HCVab positive samples were analyzed for syphilis and HIV infection using conventional diagnostic assays. The independent associations between data sources of positive cases and demographic characteristics (gender, age category and race/ethnicity) were determined using the Chi-square (χ2) test or Fisher test where cases were <5. Prevalence of HCV, HIV and syphilis infections and its associated co-infections by demographic characteristics were assessed using the Chi-square test. Predictive screening and ranking of independent factors and the associated relative risks of HCV, HIV and syphilis infection diagnosis and co-infections with HCV were also determined. All statistical tests performed were 2-tailed with a p-value, 0.05 as statistical significance. Data management and statistical analysis was conducted using JMP (statistical software) version 14.3 (SAS Institute, Cary, North Carolina, USA).

Results: Assessment of the association of mono- and co-infection with HIV, syphilis and HCV among the study individuals was statistically relevant (p<0.0001). Overall, 8.22% of the study samples were HCV/syphilis co-infected compared to 1.37% HCV/HIV co-infected.

Conclusion: The prevalence of HCV/syphilis co-infection far exceeded prevalence of HCV/HIV co-infection in this study. This may be attributed, in part, to advances in HIV treatment which lead to undetectable levels of HIV. Identification of syphilis infection, confirmed by T. pallidum seropositivity, may serve as a highly relevant predictor of HCV infection susceptibility in the absence of identifiable HIV infection, thereby proving to be an efficacious diagnostic tool in the early detection, intervention and treatment of HCV infection.