Transmission of Hepatitis A virus (HAV) during sexual activity occurs due to fecal-oral contact or contamination. Measures typically used to prevent the transmission of other STDs (e.g., use of condoms) do not prevent HAV transmission. Vaccination is the most effective means of preventing HAV transmission among persons at risk for infection.
Among adults seeking treatment in STD clinics, as many as 10%–40% have evidence of past or current Hepatitis B virus (HBV) infection. Many of these infections could have been prevented through universal vaccination during delivery of STD prevention or treatment services. A study of adults diagnosed with acute Hepatitis B found that 39% had sought care or been screened for an STD before they were infected with HBV, indicating a significant missed opportunity to vaccinate at-risk persons when they first access STD prevention or treatment services.
Although not common, Hepatitis C virus (HCV) can be transmitted through sexual activity. The factors found to be associated with sexual transmission of HCV are sex with multiple partners, presence of other STDs, or sex with trauma. Case-control studies have reported an association between acquiring HCV infection and exposure to a sex contact with HCV infection or exposure to multiple sex partners. Surveillance data also indicate that 15%–20% of persons reported with acute HCV infection have a history of sexual exposure in the absence of other risk factors.