Hepatitis C is a blood borne virus. Transmission of the virus may only occur when an infected persons blood enters the bloodstream of an uninfected person. The point of entry for infected blood can be a fresh cut or broken or punctured skin.
The hepatitis C virus cannot get into the body through unbroken skin and is killed by digestive juices if it is swallowed. The vulnerable parts of the body are broken skin and the eyes. As the blood vessels underneath the eyelids are very close to the surface, blood containing hepatitis C splashed into the eye may provide a route of transmission.
The risk of transmission can be influenced by a person's viral load (the level of virus in the blood). For this reason, risk of transmitting hepatitis C is increased during the initial acute phase of infection - lasting up to six months after catching the virus.
Below is a list of some of the most common ways in which a person can become infected with the hepatitis C virus:
Sharing and re-using injecting equipment - very high risk
This includes needles, syringes, spoons, swabs, tourniquets, water and filters. Sharing injecting drug equipment is the most common way of becoming infected in Australia. Around 80% of infections in Australia have resulted from the sharing and re-using of injecting equipment and currently 90% of new infections occur this way.
Blood will always be present when people inject drugs, and although it is safer to inject in the company of other people due to the risk of overdose, sharing any equipment is a high risk activity for the transmission of hepatitis C and other viruses such as hepatitis B and HIV. Re-using other peoples injecting equipment carries the same risk.
People who are already hepatitis C positive can become re-infected with different strains (genotypes) of the virus and may experience another initial acute phase of infection. Because of the many possible risk factors involved with injecting drug use, people might consider other ways of taking drugs, such as smoking, drinking or eating them.
Unsafe Body Piercing or Tattooing - medium to high risk
These procedures are not always carried out under sterile conditions and although single-use needles are now common, dye and dye tubs (inkpots) may sometimes be re-used for multiple customers.
Anyone considering a piercing or a tattoo should make sure that their tattoo artist or body-piercer adopts infection control procedures, which means using single-use disposable needles, dye tubs, surgical gloves, and so on. Customers have the right to ask the practitioner about their use of standard infection control procedures and their understanding of why these procedures are important. Practitioners are obliged by law to apply infection control procedures.
Some tattoo shops may ask clients to disclose their hepatitis C status. This practice is unlawful and no one is obliged to disclose their status if they do not wish to do so. It is the responsibility of the practitioner to practice standard infection control procedures.
Blood transfusions - before 1990 medium to high risk - post 1990 extremely low risk
In Australia, blood banks began testing for the hepatitis C virus as soon as tests became available in 1990. Prior to 1990, all blood transfusions and blood products carried some risk, with 5- 10% of people contracting the virus through contaminated blood or blood products.
Blood banks now test all donated blood. A new standard for screening fresh blood products for hepatitis C and HIV was introduced in June 2000. Risk of hepatitis C transmission from blood transfusion is now thought to be extremely low.
Mother to Baby - low risk
The hepatitis C virus is not assumed to pass through the placenta during pregnancy. The risk of transmission is greatest during the birthing process when the mother's blood is present and there is the possibility of a skin injury to the baby, allowing blood to blood contact to occur and therefore potentially transmission.
Mothers in the acute phase of infection, those with serious liver damage, or those with high levels of the virus in their blood have an increased chance of transmitting the virus to their child.
It is recommended that mothers who believe that they may have hepatitis C are tested, and inform those involved in the birth (such as midwives, doctors, etc) of their status. Delivery techniques can be slightly modified in order to minimise any damage to the baby's skin (not using forceps, for example). Up to 57% of babies may acquire the virus from a mother who has hepatitis C if precautions are not taken during birth.
Due to the passive acquisition of the mother's antibodies, it is not recommended that children are tested for hepatitis C until they are 18 months of age. Before then, there is an increased risk of getting incorrect results.
Breast-Feeding - very low risk
The hepatitis C virus has been found in a small number of samples of breast milk taken from hepatitis C positive women. However, the viral levels are not significant enough to represent a risk of transmission.
Mothers with hepatitis C are encouraged, like all mothers, to breastfeed their baby. As hepatitis C is a blood borne virus, breast-feeding mothers should check their nipples before each feed and temporarily suspend breast-feeding if they are cracked or bleeding, or if there is blood present. Any expressed milk should also be discarded.
A midwife or Lactation Consultant will be able to provide information about proper techniques for positioning the baby for breast-feeding that may help to prevent cracked nipples.
Occupational needle stick injuries - low risk
These occur mainly in occupational settings such as hospitals, prisons and clinics, where handling bloody items may also present a risk. Overall the risk of acquiring hepatitis C from needle-stick (or sharps) injury in a medical setting ranges from 3% to 10%, depending on a number of factors, such as the size of the needle and the depth of penetration. Health care and custodial workers are advised to practice standard infection control procedures at all times and may consider getting vaccinated against hepatitis A and B.
Non-occupational needle stick injury - very low risk
Stepping on a used needle in a public place, such as a street, a park or a beach, is regarded as very unlikely as a source of transmission. As at January 2008 there have been only three documented cases worldwide of hepatitis C transmission via community needle stick injury.
Personal items - very low risk
Items used for everyday hygiene may present a possible transmission risk if blood is present. To minimise the risk of transmission within the home, it is suggested that people do not share razor blades, tooth brushes (due to the possibility of bleeding gums) and sharp personal grooming aids. When wiping up blood spills, it is advisable to wear gloves, use paper towels and good quality detergent or bleach and cold water.
Sexual Transmission - very low risk
Hepatitis C is not classified as a sexually transmitted infection (STI). Many people make the mistake of assuming that because hepatitis C and HIV are both blood borne viruses they both pose the same level of risk sexually. This is not true. There is no relation between HIV and hepatitis C. Levels of hepatitis C virus found in body fluids usually exchanged during sex such as semen, saliva and vaginal secretions, are not high enough to be considered as posing a risk.
However, all sexually active people may wish to consider the benefits of safe sex in regard to the wide range of sexually transmissible infections. If either partner has a condition that involves scratching, sores or blisters (especially when these may come into contact with a sexual partner during sexual activity) the possibility of blood to blood contact and therefore transmission is increased.
When one partner is hepatitis C positive, couples may need to rethink their sexual practices to reduce the risk of blood to blood contact during sex. Using condoms and dams when a female partner is menstruating or when having anal sex may be advisable. Water-based lubricants can also minimise skin damage or abrasions during sex.
Hepatitis C is spread through blood to blood contact. Thus for transmission to occur, the blood of an infected person needs to come into contact with the bloodstream of another person. In the ordinary course of things, hepatitis C is not easily caught, however, it is worth thinking about any instances in which blood to blood contact may take place and taking appropriate precautions.
Hepatitis C cannot be caught from sharing hugs, kisses, food, cups, gym equipment, office space or public transport.