Hepatitis C - Causes of hepatitis C

You can become infected with hepatitis C if you come into contact with the blood of an infected person.

The blood has the highest concentration of the virus, so exposure to infected blood is the easiest way to get the virus. Just a small trace of blood can cause an infection.

The virus can survive outside the body in patches of dried blood on surfaces for at least 16 hours, but no longer than four days (at room temperature conditions).

Injecting drugs

Injecting drugs is the most important risk factor for hepatitis C in the UK. Up to 49% of people who inject drugs in England are thought to have hepatitis C.

The infection can be spread by sharing needles and associated equipment. Injecting yourself with just one contaminated needle may be enough to become infected.

Cocaine

There have also been reports of people catching hepatitis C when sharing bank notes or straws to snort cocaine.

Cocaine can damage the inside of the nose, leading to bleeding. It's possible to then inhale contaminated blood and become infected.

Less common causes

Unprotected sex

Hepatitis C may be transmitted during unprotected sex (sex without using a condom), although this risk is considered very low.

The risk of transmission through sex may be higher among men who have sex with men. The risk is also increased if there are genital sores or ulcers from a sexually transmitted infection, or if either person also has HIV.

The best way to prevent transmission of hepatitis C through sex is to use a male condom or female condom.

However, as the risk is very low for couples in a long-term, stable relationship, many choose not to use a condom. If your partner has hepatitis C, you should be tested for the condition.

Blood donations before September 1991

Since September 1991, all blood donated in the UK is checked for the hepatitis C virus. If you received blood transfusions or blood products before this date, there is a possibility you were infected with hepatitis C.

Blood transfusions and treatment abroad 

If you have a blood transfusion or medical or dental treatment overseas where medical equipment is not sterilised properly, you may become infected with hepatitis C. The virus can survive in traces of blood left on equipment.

Sharing toothbrushes, scissors and razors

There is a potential risk that hepatitis C may be passed on through sharing items such as toothbrushes, razors and scissors.

Equipment used by hairdressers can pose a risk if it has been contaminated with infected blood and not been sterilised or cleaned between customers. However, most salons operate to high standards, so this risk is low.

Tattooing and body piercing

There is a potential risk that hepatitis C may be passed on through using tattooing or body piercing equipment that has not been properly sterilised.

However, most tattoo and body piercing parlours in the UK operate to high standards and are regulated by law, so this risk is low.

Mother to child

There is a small chance that a mother who is infected with the hepatitis C virus will pass the infection on to her baby. This can happen in around 2% of cases.

However, the risk is thought to increase if the mother also has HIV or particularly high levels of the virus.

Needlestick injury

There is a small (approximately one in 30) risk of getting hepatitis C if your skin is accidentally punctured by a needle used by someone with hepatitis C.

Healthcare workers, nurses and laboratory technicians are at increased risk because they are in regular close contact with blood and bodily fluids that may contain blood.