Hepatitis C Virus Remains Infectious Weeks After Drying
More than 170 million people are living with the hepatitis C virus (HCV), for which no vaccine is available and limited treatment options exist. For these reasons, prevention remains the primary strategy for limiting new infections, which are transmitted through exposure to HCV-infected blood or bodily fluids. Prevention is especially important to oral health professionals, who will likely deliver care to patients with HCV. New research, however, suggests that surfaces not properly disinfected may harbor infectious HCV pathogens for up to 6 weeks after drying. The paper, “Hepatitis C Virus Maintains Infectivity for Weeks After Drying on Inanimate Surfaces at Room Temperature: Implications for Risks of Transmission,” was published online last November in the Journal of Infectious Diseases.
Researchers at Yale’s School of Medicine and School of Public Health tested the hypothesis that HCV infection could be acquired through contact with dried blood spots contaminated with the virus. The goal was to determine the risk of transmission in health care settings via contact with HCV-infected surfaces. Experiments were conducted to determine how HCV-infected dried blood reacted to various temperature controls (4° C, 22° C, and 37° C). While all samples maintained infectivity for up to 3 weeks, droplets stored at room temperature were found to retain their ability to transmit the virus for as long as 6 weeks.
Furthermore, the team tested the ability of common antiseptics—bleach, isopropanol, and ethanol—to reduce HCV-transmission risk. When utilized as directed, each antiseptic was effective in destroying the dried blood droplets; diluted concentrations, however, were significantly less effective. The authors concluded that the ability of HCV to remain infectious at room temperature for such long periods may explain why the rate of hospital-acquired HCV infections continues to grow, as well as high HCV incidence among intravenous drug users.
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