HCV-RNA is commonly detectable in rectal and nasal fluids of patients with high viremia

BACKGROUND: Increasing numbers of hepatitis C virus (HCV) infections among men who have sex with men (MSM) are being observed in the Western world. The actual routes of HCV transmission during high-risk sex-practices and associated drug use remain poorly understood. METHODS: 47 HCV patients were prospectively enrolled. Rectal and nasal swabs were collected to quantify HCV-RNA levels within rectal and nasal fluids. Contamination by occult rectal bleeding was ruled out by guaiac paper test. Risk-behaviour was assessed by standardized questionnaires. RESULTS: Median age was 41.9 years, 89% were HIV+ (42/47) and of 85% (40/47) male, 58% (23/40) were MSM. Acute HCV infection was diagnosed in 32% (15/47) with all patients being HIV+MSM and 93% (14/15) having a documented history of sexually transmitted disease. Thirty-three (70%) patients had at least one HCV-positive swab sample (HCV+SS; 48%, 22/46 rectal; 62%, 29/47 nasal) and contamination with blood was ruled out in all patients. Individuals with HCV+SS had significantly higher serum HCV-RNA levels than patients with HCV-negative SS (6.28 IQR 0.85 logU/mL vs. 4.08 IQR 2.45 logU/mL; p<0.001). Using ROC-curve analysis, serum HCV-RNA cut-offs for ruling in-/out any HCV+SS were established at 6.02log IU/mL and 4.02log IU/mL, respectively. CONCLUSIONS: HCV-RNA is commonly detectable in rectal and nasal fluids of both HIV+ and HIV-negative HCV patients with high serum HCV-RNA, independently of the suspected route of HCV transmission. Accordingly, high-risk sex-practices and sharing of nasal drug-sniffing 'tools' might be important HCV transmission routes, especially in patients with high serum HCV-RNA.