Hepatitis C: How Is It Transmitted and Who Should Be Tested?
How Do People Acquire Hepatitis C?
Hepatitis C (HCV) is one of the more common chronic viral infections in the United States, thought to affect nearly four million Americans. Discovered less than 30 years ago, hepatitis C is passed via blood-to-blood contact. Before its discovery, there was no widespread screening of the blood supply, so infections were common among people who received blood and organ donations and among people who unknowingly came in contact with infected blood.
Today, however, modes of transmission have changed, and it's very rare for a person to be infected as part of a routine medical or dental procedure. Instead, most new infections are among young people who inject drugs, according to the Centers for Disease Control and Prevention (CDC). With the opioid epidemic raging across the country, 30 states have reported more than a 200% increase in the number of new infections in recent years. The communities hardest hit by the opioid epidemic -- including rural counties in the Appalachian states -- also report the highest numbers of new hepatitis C infections.
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Why Is Needle Sharing So Dangerous?
Sharing needles is the most common way people contract hepatitis C because the virus is transmitted via infected blood when a contaminated object is jabbed through the skin, touching an open wound. The virus can survive outside the human body for up to three weeks. Although hepatitis C is highly contagious, it cannot be transmitted by touching, kissing or coughing. It's other modes of transmission, via sexual intercourse or from mother to child, are rare.
Before 1992 -- the year blood screening for hepatitis C became available -- blood transfusion was the leading mode of transmission in the United States. That's one reason that baby boomers, or people born from 1945-1965, are five times more likely to have hepatitis C, according to the CDC, which recommends universal screening for this group. Baby boomers still comprise about 75% of all infections in the United States, but an alarming number of new infections are cropping up in people younger than 30 who share needles and other non-sterile equipment to inject drugs.
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What About Sex and Other Body Fluids?
Although hepatitis C has been found in semen, vaginal and menstrual fluid, the rate of infection via sexual contact is extremely low. In fact, transmission is so rare that the CDC does not even recommend condoms for monogamous couples. There's also no evidence that hepatitis C can be transmitted during oral sex.
However, the risk of infection goes up among people who have multiple sexual partners, have HIV or another sexually transmitted infection or have rough sex that might cause bleeding. Anal sex is thought to be riskier than vaginal sex because of the increased likelihood of abrasions. The CDC does recommend condoms for people who have multiple sexual partners and people coinfected with HIV.
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What Are the Other Ways HCV Is Transmitted?
Hepatitis C cannot be transmitted by hugging, kissing or coughing. Before the virus was discovered, transmission used to be common in hospitals and at tattoo and piercing parlors, but today's sterilization and testing guidelines mean transmission at licensed facilities is rare. Occasionally, nurses and other health care professionals can be infected from an accidental needle stick injury.
Transmission is also possible in non-licensed tattoo settings, and people who have been incarcerated have a higher risk of contracting hepatitis C. In addition, while household transmission is rare, it is possible to contract hepatitis C by sharing personal care items, such as razor blades or toothbrushes, which may have been exposed to blood.
Mother-to-child transmission is still a risk. For every 100 pregnant women with hepatitis C, about six babies will be born with the infection. The risk of transmission goes up if mothers are coinfected with HIV.
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Who Should Get Tested for HCV?
According to current CDC guidelines, everyone in the baby-boom generation (people born from 1945 to 1965) should get tested. In addition, the CDC recommends testing for anyone who has ever injected drugs, even if it was years ago, and even if it was only once. Anyone treated for a blood clotting condition before 1987, the year hepatitis C was discovered, should get tested. The same is true for anyone who received a blood transfusion before 1992, the year blood detection was widely implemented.
The CDC also recommends testing for anyone who has been on long-term hemodialysis for kidney disease or anyone who has been exposed to potentially contaminated blood via accidental needle stick or injury with a sharp object. Babies born to a mother with hepatitis C should also be tested, although the CDC recommends waiting to test until the child is at least 18 months old. The child is likely to still have hepatitis C-fighting antibodies for months after birth, so an earlier test might register a false positive.
Finally, the CDC recommends universal testing for anyone who has HIV, as the risk factors for the two infections are similar.
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