HCV Detectable in Nasal, Rectal Fluids of Patients With High Viral Load

Hepatitis C virus (HCV) is present in the rectal and nasal fluids of infected patients with high viral loads even if blood is not, according to new research. The findings mean sharing of drug tools and unprotected sex could lead to transmission of the virus in some cases.

David Chromy, MD, of the Medical University of Vienna, told MD Magazine®that previous research has shown HCV RNA can be present in various bodily fluids. He and his colleagues aimed to gain more detail about where HCV RNA can be found, and to determine if viral RNA was being detected as a result of blood in the nasal or rectal cavities.

“[W]e actually did expect to find HCV RNA in the body fluids of our patients,” he said. “Still we aimed to carefully rule out contamination of rectal fluid by occult bleeding (as a potential confounder) by performing a respective test for occult fecal blood.”

In findings presented last month at the American Association for the Study of Liver Diseases (AASLD; Liver Meeting) in San Francisco, Chromy and colleagues reported on their findings from a study of 34 patients with acute or chronic HCV. Twenty-eight of those patients were male, and of those, 64% were men who have sex with men.

Sixty-eight percent of patients had at least 1 positive swab sample. Fifty-six percent had at least 1 positive nasal swab sample, and 52% had at least 1 positive rectal sample. All of the screenings for the presence of blood in the swab samples were negative.

Though Chromy said they were not surprised to find HCV-RNA in the samples, they were surprised by how frequently they found it. The data also showed that the presence of HCV RNA was not dependent on HIV status or gender.

The study raises the possibility that people who have unprotected anal sex or who share tools used to snort drugs could become infected with HCV. However, Chromy said such transmission likely only occurs under specific conditions.

“These bodily fluids may serve as vectors for transmission—still we strongly believe that additional mucosal trauma and/or bleeding is necessary for transmitting HCV-RNA and thus, HCV infection,” he said.

Chromy also noted that risky behavior often exposes people to multiple possible transmission routes, so it’s sometimes difficult to say exactly how the transmission occurred. About 30% of HIV-positive men who have sex with men say they engage in some form of “chemsex”—sexual intercourse under the influence of recreational drugs, he said. Research has also shown that pre-exposure prophylaxis, which is taken to prevent HIV infection, does not prevent the infection with HCV.

Chromy said research indicates patients with 4 log ranks of HCV RNA do not have the virus present in their nasal or rectal fluids, but patients with 6 log ranks do. Since most patients with chronic or acute HCV have log ranks of at least 5, Chromy said it’s likely that a significant portion of untreated patients with HCV infection have the virus present in bodily fluids such as nasal mucus.

“However, in general, those fluids should not be regarded as highly contagious since HCV transmission via rectal and/or nasal mucosal routes likely requires certain risk behavior and consecutive mucosal trauma,” he said.

The study, “HCV-RNA Is Readily Detectable in Nasal and Rectal Fluids of Patients with High Viremia,” was presented at the 2018 Liver Meeting.

This article was originally published by MD Magazine.