Sexual health & PrEP ·Preventive & general health

Hepatitis A, B and C: What Is the Difference?

By Dr Christian Peut, FRACGP · 13 min read

You have probably already had at least one hepatitis vaccine.

In Australia, hepatitis B vaccination begins at birth. You may also have received a hepatitis A vaccine before travelling overseas, or a combined hepatitis A and B vaccine through a sexual health clinic.

Despite sharing a name, hepatitis A, B and C are not variations of the same infection. They are separate viruses that spread differently and have very different long-term implications.

Two can be prevented through vaccination. One can now usually be cured with tablets. Some infections disappear naturally, while others can remain silent for decades.

Hepatitis A, B and C compared

Feature	Hepatitis A	Hepatitis B	Hepatitis C
Main way it spreads	Contaminated food, water or hands; close contact; sexual contact involving faecal-oral exposure	Blood, sex, shared injecting equipment and during birth	Mainly blood-to-blood contact
Can it become chronic?	No	Yes	Yes
Is there a vaccine?	Yes	Yes	No
Can treatment cure it?	Usually clears without antiviral treatment	Treatment usually controls rather than cures it	Usually curable with tablets
Main long-term concern	Rare severe acute liver failure	Cirrhosis and liver cancer	Cirrhosis and liver cancer

Having one type does not cause it to turn into another. Vaccination or previous infection with one type also does not provide general protection against the others.[1-3]

Can hepatitis cause symptoms?

Hepatitis can cause:

fatigue;
nausea or loss of appetite;
discomfort in the upper right abdomen;
dark urine;
pale bowel motions;
itchy skin;
yellowing of the skin or eyes, known as jaundice.

However, many people with viral hepatitis have few or no symptoms. Chronic hepatitis B and C can remain unnoticed for years while liver damage develops.[3,4]

Globally, most people living with chronic hepatitis B have not been diagnosed. Diagnosis rates are better in Australia, but more than 220,000 Australians are estimated to have chronic hepatitis B and approximately one in three do not know they have it.[4,5]

This is why hepatitis testing is based on your background and exposure history, not symptoms alone.

Hepatitis A: usually short-term but highly infectious

Hepatitis A spreads when microscopic amounts of infected faeces reach another person’s mouth. This can occur through contaminated food or water, inadequate hand hygiene, close household contact or sexual activity involving faecal-oral exposure.[1]

Unlike hepatitis B and C, hepatitis A does not become chronic. Most people recover completely and develop long-term immunity. Occasionally, however, it can cause severe acute liver inflammation, particularly in older adults and people who already have chronic liver disease.[1]

There is no specific antiviral treatment. Management usually involves fluids, rest, avoiding alcohol and monitoring for complications.

Why hepatitis A matters for gay and bisexual men

Hepatitis A is often associated with food or overseas travel, but it can also spread during sex. Outbreaks have occurred among communities of gay, bisexual and other men who have sex with men.[2,3]

Transmission can occur during sexual activity involving oral-anal contact or indirect faecal-oral exposure. Someone can be infectious before they realise they are unwell, making outbreaks difficult to control once they begin.

Australian guidance recommends hepatitis A vaccination for people who have anal intercourse, including men who have sex with men.[2] This recommendation is about the possible route of exposure rather than sexuality itself.

Hepatitis A is not usually included in a standard asymptomatic STI screen. Prevention therefore relies mainly on vaccination rather than regular blood testing.[3]

If you are unsure whether you received both doses, or whether a previous combined hepatitis A and B course was completed, it is worth checking your vaccination record with your GP.

Who else should consider hepatitis A vaccination?

Australian guidance also recommends vaccination for groups including:

travellers to countries where hepatitis A is common;
people with chronic liver disease, including hepatitis B or C;
people who inject drugs;
people in correctional facilities;
early-childhood educators and carers;
plumbers and sewage workers;
certain Aboriginal and Torres Strait Islander children, including eligible children in South Australia.[2]

Most adults need two doses, usually separated by at least six months. A combined hepatitis A and B vaccine may be appropriate when protection against both infections is needed.[2]

Hepatitis B: preventable, but potentially lifelong

Hepatitis B spreads through infected blood and certain body fluids. Transmission can occur through:

transmission from mother to baby during birth;
sex;
shared injecting equipment;
unsterile tattooing, piercing or medical equipment;
needlestick injuries;
sharing razors or toothbrushes contaminated with blood;
household contact involving exposure to infected blood.[4]

It is not spread through hugging, coughing, sharing meals or ordinary social contact.

Most chronic hepatitis B begins early in life

Chronic hepatitis B is sometimes thought of mainly as an adult-acquired sexually transmitted or blood-borne infection. In reality, much of the global burden begins at birth or during early childhood.

In countries where hepatitis B is common, transmission most often occurs from mother to baby during birth or between young children. Infection acquired at this age is much more likely to become chronic than infection acquired as an adult.[3,5]

In Australia, 72% of people living with chronic hepatitis B are from culturally and linguistically diverse backgrounds or are Aboriginal and Torres Strait Islander people who likely acquired the infection at birth or in early childhood.[6]

This history may have occurred decades before the person migrated to Australia or became aware that hepatitis B existed. It should not be assumed that a chronic infection reflects recent sexual activity or injecting drug use.

Why is hepatitis B vaccine given at birth?

Australia recommends a hepatitis B vaccine birth dose for every newborn, preferably within 24 hours.

The birth dose provides early protection against:

transmission from a mother with chronic hepatitis B;
delays or errors in antenatal testing or communication;
exposure from another household or close contact during the first months of life.[7]

Babies born to mothers with chronic hepatitis B require both hepatitis B vaccine and hepatitis B immunoglobulin promptly after birth, followed by the remaining scheduled vaccine doses and later blood testing.[7]

This early protection matters because infection acquired at birth is very likely to become chronic. Vaccination after an infection has already been acquired cannot remove it.

Hepatitis B and liver cancer

Chronic hepatitis B is a leading cause of primary liver cancer. Hepatitis B can increase liver-cancer risk even before cirrhosis has developed.[3,6]

Hepatitis B and C together are estimated to account for about 80% of liver cancers globally.[6]

Some people with chronic hepatitis B need antiviral treatment, while others need monitoring without immediate treatment. Anyone with a positive hepatitis B surface antigen should receive ongoing follow-up, even if they feel well and their current liver tests are normal.[3]

Current medicines can strongly suppress hepatitis B and reduce the risk of liver damage and cancer. They do not usually eliminate the virus completely.

How is hepatitis B tested?

A complete initial hepatitis B screen commonly includes three blood tests:

HBsAg: may indicate current hepatitis B infection;
anti-HBs: indicates immunity;
anti-HBc: indicates previous or current exposure to the virus.

These results need to be interpreted together. Checking anti-HBs alone may show whether antibodies are present, but it cannot identify every important pattern of current or previous infection.[8]

Testing is particularly relevant for people who:

were born in a country where hepatitis B is more common;
are Aboriginal or Torres Strait Islander;
have a household or sexual contact with hepatitis B;
are men who have sex with men;
have ever injected drugs;
have HIV or hepatitis C;
have been in a correctional facility;
are pregnant or planning pregnancy;
are starting chemotherapy or significant immune-suppressing treatment;
have unexplained abnormal liver tests.[8]

Hepatitis B testing is also usually undertaken before starting HIV PrEP. Some PrEP medicines also suppress hepatitis B, so a known chronic infection needs to be considered before the medicine is later changed or stopped.

Hepatitis B vaccination for adults

Most people born in Australia after universal infant vaccination was introduced will have been vaccinated during childhood. Susceptible adults may still need vaccination if they were born before routine vaccination, were born overseas or did not complete the course.

Vaccination is particularly relevant for sexually active men who have sex with men, household or sexual contacts of someone with hepatitis B, people who inject drugs, healthcare workers and people with certain medical risks.[7]

A common adult schedule involves three doses given over six months, although other schedules may be used. A combined hepatitis A and B vaccine can be useful for gay and bisexual men who are not immune to either infection.[7]

Hepatitis C: blood-borne and now usually curable

Hepatitis C spreads when infected blood enters another person’s bloodstream.

In Australia, the most common route is sharing injecting equipment. Other possible exposures include:

unsterile tattooing or piercing equipment;
sharing equipment when injecting performance-enhancing drugs;
needlestick or healthcare exposure;
sharing razors or toothbrushes contaminated with blood;
medical procedures performed in countries without reliable infection control;
transmission during birth;
sexual exposure involving blood contact or mucosal injury.[9]

Sexual transmission is less efficient than blood-borne transmission but is more relevant in some settings, including among men who have sex with men and people living with HIV.[9]

Hepatitis C is not spread through hugging, kissing, sharing food or ordinary household contact.

What do hepatitis C test results mean?

The first test is usually a hepatitis C antibody test.

A positive antibody result means that the person has been exposed to hepatitis C at some point. It does not confirm that the virus is still present.

A second test, usually hepatitis C RNA, is needed to identify current infection. Someone can remain antibody-positive after naturally clearing the infection or being successfully treated.[10]

Previous infection does not create immunity. Hepatitis C can therefore be acquired again after clearance or cure.[10]

Can hepatitis C be cured?

Modern direct-acting antiviral medicines can cure more than 95% of people with hepatitis C. Treatment commonly involves an eight- or twelve-week course of tablets.[11]

Before treatment, assessment usually includes:

confirmation of current infection;
liver and kidney blood tests;
assessment for cirrhosis;
review of medicines and possible interactions;
hepatitis A and B immunity;
HIV testing where relevant.

Many uncomplicated cases can be treated through general practice. Specialist involvement may be needed for advanced liver disease, previous treatment failure or more complex medical circumstances.

A follow-up hepatitis C RNA test is used to confirm cure. People who already have advanced liver scarring may still need long-term liver-cancer surveillance after the virus has been cleared.[9,11]

Who should consider hepatitis testing?

A hepatitis check may be appropriate if you:

were born or previously lived in a country where hepatitis B or C is common;
have ever injected drugs, even once;
received a tattoo, piercing or medical procedure with uncertain sterilisation;
had a blood transfusion or organ transplant before reliable Australian screening was introduced;
have a household or sexual contact with viral hepatitis;
are a man who has sex with men and are unsure about your testing or vaccination history;
have HIV or another blood-borne virus;
are starting HIV PrEP;
are pregnant or planning pregnancy;
are about to begin chemotherapy or immune-suppressing treatment;
have persistent abnormal liver tests;
have previously been told that a hepatitis test was positive;
develop unexplained jaundice.

Testing should be based on relevant exposures and background, not assumptions about someone’s identity or lifestyle.

What should you do after a possible exposure?

Seek medical advice promptly after:

a needlestick or sharps injury;
sharing injecting equipment;
blood contacting broken skin, the eyes or mouth;
sex with someone known to have hepatitis B if you are not immune;
close contact with someone diagnosed with hepatitis A.

Hepatitis A and B have time-sensitive post-exposure measures, which may include vaccination or immunoglobulin.[2,7] There is no vaccine or immunoglobulin that prevents hepatitis C after exposure, so baseline and follow-up testing are important.

The practical summary

You may already have been vaccinated against hepatitis A, hepatitis B or both, but the vaccines are not interchangeable, and there is currently no vaccine against hepatitis C.

Hepatitis A is usually a short-term infection. Vaccination is particularly relevant for travellers, people with chronic liver disease and gay, bisexual and other men who have sex with men.

Hepatitis B can become a lifelong infection and is a leading cause of liver cancer. Much of the chronic hepatitis B seen in Australia was acquired at birth or during early childhood, and one in three affected Australians do not know they have it.

Hepatitis C has no vaccine, but modern tablets can now cure almost everyone who completes appropriate treatment.

If you are unsure which hepatitis tests or vaccinations you need, a GP appointment can review your previous results, childhood vaccination history and relevant exposures. Testing, vaccination and hepatitis follow-up can be arranged through general practice in Adelaide or Paradise.

References

This article provides general information only and is not a substitute for individual medical advice.

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