Hepatitis C is transmitted through blood-to-blood contact. The virus must enter your bloodstream to cause infection, and even a tiny amount of infected blood, invisible to the naked eye, can carry enough virus to spread it. Most new infections happen through shared needles, unsafe medical procedures, or other situations where one person’s blood reaches another person’s bloodstream.
Shared Needles and Drug Equipment
Sharing needles and syringes is the most common way hepatitis C spreads today. Each time someone shares injection equipment with an infected person, the chance of transmission is roughly 0.6% per event. That sounds small, but it adds up fast. The cumulative lifetime prevalence of hepatitis C among people who inject drugs reaches as high as 90%, depending on how long someone has been injecting. Even sharing cookers, cotton filters, or water used to prepare drugs carries risk, because trace amounts of blood contaminate the equipment.
The virus is remarkably durable outside the body. It can survive on dry surfaces and equipment for up to six weeks, far longer than HIV or hepatitis B. This means a syringe or cooker that looks clean may still harbor infectious virus days or weeks after last use.
Medical and Healthcare Settings
Before 1992, blood transfusions and organ transplants were a major source of hepatitis C infections. Routine screening of donated blood wasn’t in place yet. Anyone who received a blood transfusion, blood products, or an organ transplant before July 1992 has an elevated risk and should be tested. Clotting factor concentrates produced before 1987 also posed a significant risk.
In countries with well-regulated blood supplies, transfusion-related transmission is now extremely rare. But in parts of the world where sterilization practices and blood screening are less reliable, unsafe injections and medical procedures remain a leading cause of new infections. Reused or improperly sterilized needles, surgical instruments, and dialysis equipment can all transmit the virus.
Healthcare workers face a small but real occupational risk. After a needlestick injury involving blood from someone with hepatitis C, the estimated transmission rate is about 0.2%. Mucosal exposures (a splash of blood to the eyes or mouth) carry an even lower risk, with no confirmed infections in a study of 458 such exposures.
Tattoos, Piercings, and Unregulated Settings
Getting a tattoo or piercing at a licensed, professional studio does not appear to carry a meaningful hepatitis C risk. Research has found no definitive evidence of increased infection rates when these procedures are performed in regulated parlors using sterile, single-use equipment.
The picture changes in unregulated settings. Tattoos applied in prisons or by friends carry a significantly higher risk, with studies showing two to nearly four times the odds of hepatitis C compared to people without tattoos. The difference comes down to equipment: makeshift tattoo guns, shared ink, and reused needles create a direct pathway for blood-to-blood contact.
Sexual Transmission
Hepatitis C is not efficiently spread through sex, but it can happen. The risk depends heavily on the type of sexual activity and whether HIV is also present. Among long-term monogamous heterosexual couples where one partner has hepatitis C, transmission is uncommon enough that most guidelines don’t recommend condom use solely for this reason.
The risk rises in specific circumstances. Men who have sex with men and are living with HIV face notably higher rates, with an incidence of roughly 6 per 1,000 person-years. Activities that involve mucosal tearing or blood exposure, such as condomless anal intercourse, fisting, or sex during menstruation, increase the likelihood of transmission. Group sex, multiple partners, and recreational drug use during sex (sometimes called chemsex) are also associated with higher rates. Having a concurrent sexually transmitted infection, particularly one that causes ulcers or inflammation, creates additional entry points for the virus.
From Parent to Baby During Pregnancy
A pregnant person with an active hepatitis C infection (meaning the virus is detectable in their blood) has roughly a 6% to 7% chance of passing it to their baby during pregnancy or delivery. When poorly controlled HIV coinfection is also present, that rate climbs to about 11% to 12%. Effective HIV treatment during pregnancy brings the risk back down closer to the baseline rate.
Certain delivery circumstances may increase risk. Prolonged rupture of membranes (six hours or more before delivery) and the use of internal fetal monitoring have both been associated with higher transmission rates. Importantly, breastfeeding does not transmit hepatitis C. The World Health Organization has confirmed the virus is not spread through breast milk.
Sharing Personal Items at Home
Any personal item that might carry traces of blood can theoretically transmit hepatitis C within a household. Razors, nail clippers, toothbrushes, and shared medical devices like glucose monitors all fall into this category. You won’t always see blood on these items, but microscopic amounts are enough given the virus’s ability to remain infectious on surfaces for weeks.
The fix is straightforward: don’t share items that might contact blood. Keeping razors, toothbrushes, and nail care tools separate eliminates this risk almost entirely.
How Hepatitis C Is Not Spread
Hepatitis C does not spread through casual, everyday contact. Hugging, kissing, holding hands, sharing food or drinks, sneezing, and coughing pose no risk. You cannot get it from toilet seats, swimming pools, or being in the same room as someone who is infected. Sharing plates, cups, or utensils is safe. The virus requires a blood-to-blood pathway, so situations without that pathway carry no transmission risk.
Who Should Get Tested
The CDC recommends that every adult aged 18 and older get tested for hepatitis C at least once in their lifetime. Pregnant individuals should be tested during each pregnancy. These are universal recommendations, not based on risk factors.
Beyond that baseline, people with specific risk factors should be tested even if they’ve had a negative result before. This includes anyone who has ever injected drugs, people living with HIV, recipients of blood transfusions or organ transplants before July 1992, and anyone on long-term hemodialysis. People who currently inject drugs should get tested periodically, not just once. And anyone who simply wants a test should be able to get one, regardless of whether they disclose a specific risk factor.
Testing involves two steps. A blood test first checks for antibodies, which show whether you’ve ever been exposed. If that’s positive, a second test looks for the virus’s genetic material to confirm whether the infection is still active. Many people clear hepatitis C on their own, so a positive antibody test doesn’t necessarily mean you’re currently infected.