Transmission of hepatitis C

Transmission of hepatitis C predominantly occurs through blood to blood contact.

  • Hepatitis C enters the bloodstream of a person by way of any rupture or opening in the skin.

  • Screening blood supplies for the virus did not begin in New Zealand until July 1992. Before this some people were infected with hepatitis C when they received blood or blood products containing the virus.

Hepatitis C is found in other body fluid but the viral concentration is generally too low for efficient transmission to occur. Accordingly, it is not regarded as a sexually transmissible infection. However, sexual transmission is possible if there is blood-to-blood contact during sexual contact.

Other factors which influence transmissions are:

  • the level of susceptibility of the recipient.

  • the viral load of the virus.

  • the amount of blood involved.

Modes of transmission

Sharing Drug Injecting Equipment

In New Zealand the highest risk of transmission occurs through the sharing of drug injecting equipment. It is not only the needle and syringe that present a risk of contamination with the virus. Exposure to other injecting equipment (spoon, filter, tourniquet etc.) and surfaces around the preparatory site may also result in a transmission risk. See section on Injecting Drug Use.

Tattooing and skin piercing

Contamination of tattooing and piercing equipment can transmit hepatitis C.

Simple principles for safe and healthy skin piercing

  • Premises must be kept clean and hygienic.

  • Any article used for penetrating the skin must be a sterile, single-use disposable article.

  • Any article contaminated with blood must be either disposed of immediately as an infectious or biological waste, or cleaned and sterilised (with autoclave) and transferred to a sterile bag before being used on another person.

  • Operators must keep themselves and their clothing clean and any cuts, abrasions or wounds must be covered.

  • Animals shall not be permitted on the premises where skin penetration activities are carried out, except guide dogs for the blind.

  • Employers in the skin piercing and tattooing  industries should provide adequate training for staff in all areas of hygiene, blood borne viruses transmission and risk, standard infection control and first aid.

  • Hepatitis B vaccinations are advised for all skin piercing and tattooing operators.

  • Home-based operations should take the same precautions and training that their industry counterparts are advised to do.

It is the Operators’ responsibility to ensure that the whole service is provided to a sufficient standard of hygiene to ensure client and operator safety.

This section is taken from Guidelines for the Safe Piercing of Skin. Ministry of Health publication, Safety and Regulation Branch 1998.

Other points of relevance:

  • Activities other than tattooing involving skin penetration i.e. body piercing, acupuncture and electrolysis are thought to present a low risk of transmission.

  • Some beauty therapy techniques involve skin penetration and require the same safety guidelines outlined above to avoid transmission of hepatitis C and other blood borne viruses.

  • No one having a tattoo or undergoing any skin penetration technique is obliged by law to disclose their hepatitis C status (assume all clients are potentially infectious).

In the health care setting

Transmission of blood borne viruses in the health care setting is generally through needle stick or sharps injury while handling items contaminated with blood. If standard infection control procedures are not met, all blood spills and handling of sharps present transmission risks.

  • Although rare, blood splashes in the eyes may also transmit blood borne viruses in particular hepatitis B.

  • In the health care setting the risk of acquiring hepatitis C from a needle stick injury ranges between 2%-8%.

Hepatitis C transmission from needle stick injuries is 10 times more likely a risk than HIV and hepatitis B is 100 times more likely than HIV. In the healthcare setting the risk of HIV transmission is around 0.3%.

A small number of nosocomial transmissions (infections that occur in the hospital setting) have been reported; such as people undergoing dialysis procedures, endoscopies and other minor surgery.

Vertical Transmission (Mother to baby)

Babies born to hepatitis C positive mothers will test antibody positive for up to 18 months after birth. These are maternal antibodies and up to 95% of these babies will test negative for hepatitis C after that time.

It is still poorly understood and controversial just when transmission from mother to baby might occur. Some studies have suggested transmission might occur during pregnancy while most evidence suggests that it occurs during the birth process.

Until further research is conducted to determine conclusive evidence about the timing of infection, caesarean section is not recommended for women with hepatitis C. The use of forceps and scalp electrodes should be avoided during delivery as they can break the integrity of the baby’s skin.

There may be an increased risk of vertical transmission if the mother:

  • Is in an acute (newly acquired) stage of infection.

  • Has serious liver damage.

  • Has high levels of viremia in her blood (as determined by a quantitative PCR test)

  • Is co-infected with HIV (N.B. Transmission rates have been recorded as high as 25% for mothers co-infected with hepatitis C and HIV, compared to 5-7% for those with hepatitis C alone).


Breast-feeding is not generally considered to present a risk of hepatitis C transmission. Hepatitis C has been detected in breast milk but the levels of virus are too low for efficient transmission.

  • The overall benefits of breast-feeding outweigh the low risk of transmission and mothers should be encouraged to breast-feed new-born babies.

  • Breast-feeding should be suspended if the mother has cracked and bleeding nipples or if the baby has any cuts or sores in or outside the mouth.

  • It may be necessary to express and discard milk (if this is not too painful) until cracked areas are healed. Supplementing with milk formula may be possible.

  • If problems do arise women should contact a lactation consultant or midwives to learn more about positions and techniques to help prevent cracked nipples.

Sexual transmission

Although hepatitis C is not generally classified as a sexually transmitted infection (STI) it is still theoretically possible. However, low concentration of viremia in semen means that transmission via this route is unlikely to occur.

Some circumstances may influence transmission:

  • If blood is present in the genital tract such as during menstruation.

  • Sexual practices causing trauma to skin membrane.

  • The presence of other STI's which may increase a person’s susceptibility to infection, i.e. genital herpes.

  • The person with hepatitis C is in the acute stage of the infection and has a high viral load.

Longitudinal studies of married couples suggest very low rates of sexual transmission between partners even after many years; therefore, it is not recommended that barrier protection is necessary in long-term monogamous relationships.

People with hepatitis C should discuss their health status with prospective sexual partners and use protection until the risks are fully understood by each other. People with multiple partners or those engaging in casual sex should always practice safe sex using lubricant and condoms.

Transmission risks in the home

People are naturally concerned about passing on the virus in their home to other family members.

It is important to reassure infected people and their significant others that hepatitis C is a blood borne virus and is not passed on by hugging, kissing, sharing food, drinks, crockery and cutlery, sneezing or coughing, washing clothes together, or using the same toilet facilities.

People should be aware that personal care items like razors, clippers, toothbrushes and scissors can carry infected blood with viable virus outside the body, posing a potential threat.

Families should try to keep personal items separate from each other, particularly toothbrushes and razors.

Some basic ideas for first aid and infection control in the home

  • Liquid soap is better than the bar soap.

  • Wash hands before and after handling blood spills.

  • Rubber gloves should always be kept in supply and should be used for any potential contact with blood.

  • Always cover cuts, abrasions and open sores with waterproof dressings as skin is our barrier to infection with hepatitis C.

  • Use disposable material like paper towels to wipe blood spills so they can be incinerated.

  • Blood spills must be soaked in very strong bleach for at least ten minutes in order to kill the virus but even this may not be enough to deactivate the virus completely.

  • During first aid be aware of blood spills and splashes and try to keep blood from coming in contact with broken or unprotected skin.

After first aid

  • Use soap and cold running water to wash hands and parts of body that may have blood on them.

  • Wash blood stained areas with detergent and cold water, then disinfect with bleach.

  • Bag blood-stained articles and dispose of in a plastic lined rubbish bin or incinerate.

  • Wash any blood stained clothing in cold water and detergent. Use the same solution for washing carpet and soft furnishings.

Recipients of Blood Transfusions and Blood Products

Post transfusion hepatitis is relatively rare in developed countries since donors at risk of blood borne viral infections are excluded from donating blood. The risk of post transfusion hepatitis (NonA-NonB) before July 1992 in N.Z. was 190 per 100,000 units transferred. After the introduction of sensitive and effective tests for the detection of hepatitis C, the risk is less than 0.0001% or 1 per 1,000,000 units transfused.