Thu Mar 13

What is hepatitis B, the virus at the centre of the recent hospital infection alert?

Written by: Thomas Jeffries, Senior Lecturer in Microbiology, Western Sydney University

News that a health worker at a Sydney hospital’s birth unit was infectious with hepatitis B ^[1] for more than a decade has led to a health alert ^[2] for mothers and babies.

The staff member worked at Nepean Hospital’s birth unit in Western Sydney while infectious with hepatitis B between 2013 and 2024.

Authorities say ^[3] 223 women are in the process of being informed they and 143 of their children are at low risk of exposure. The local health district says it is not aware of any patients who had tested positive to hepatitis B as a result.

Only patients who have had certain invasive procedures ^[4] are included in the health alert.

So what is hepatitis B?

Hepatitis B is a viral infection

The hepatitis B virus ^[5] infects liver cells and is not to be confused with other types of hepatitis viruses, including the better known hepatitis A ^[6] and C ^[7].

The virus is spread by bodily fluids, such as blood, and enters the body though penetrated skin or mucous membranes such as the mouth, genitals or eyes.

This means the virus is most commonly spread ^[8] by people having unprotected sex, from mother to baby, or by using shared items such as needles or hygiene products. The virus can survive outside the body for at least seven days ^[9].

In rare cases ^[10], hepatitis B has been known to spread from a health-care worker ^[11] to a patient during certain medical procedures. This is when the health-care worker may injure themselves and expose their patients to their blood.

Symptoms of acute infections include fever, loss of appetite, nausea, vomiting, abdominal pain, fatigue, dark urine, pale stools and jaundice.

If not cleared by the body within six months the disease can progress to its chronic (long-term) form. This can lead to cirrhosis of the liver, liver failure or liver cancer.

How common is it?

Globally, hepatitis B is the most common serious liver infection ^[12]. There are about ^[13] 254 million people with chronic hepatitis B infection globally in 2022, with 1.2 million new infections each year. About 1.1 million people a year die from it, mostly due to cirrhosis and liver cancer. The worst infected regions are Africa and the Western Pacific.

In Australia ^[14], there were 205,549 chronic cases as of 2022. Most of the 6,000–7,000 ^[15] newly detected cases in Australia each year are chronic cases.

Only 72%^[16] of hepatitis B cases in Australia are diagnosed. This means the remaining 28% could be unwittingly carrying the virus, potentially spreading it to others, and missing the opportunity for treatment.

Babies of infected mothers, Aboriginal and Torres Straight Islander people ^[17], people who engage in unprotected sex, men who have sex with men, intravenous drug users, and people receiving tattoos or piercings with unsterilised equipment are all at a higher risk ^[18] of hepatitis B infection. Most chronic cases in Australia are in migrant groups from areas with higher rates of hepatitis B.

Is there a vaccine? How about treatment?

A safe and effective vaccine ^[19] is recommended ^[20] for all children at birth, with three doses after that. The vaccine is also recommended for adults ^[21] in high-risk groups.

Acute cases can be cleared by the body, aided by antiviral drugs ^[22]. However if the infection becomes chronic the symptoms of liver cirrhosis and cancer need to be monitored and treated for the rest of someone’s life. This includes having regular liver-function tests, taking antiviral medication, adopting a healthy diet and avoiding alcohol.

Due to the nature of its transmission, hepatitis B often has negative social stigma ^[23] associated with it. This may lead to people being reluctant to be tested or if they test positive, they may be reluctant to share their status with others, or seek treatment.

We do not know the personal circumstances of the health worker with hepatitis B at the centre of this health alert, including details of their diagnosis and treatment. It’s also important to note that hepatitis B infection alone does not automatically disqualify health-care workers from practice ^[24]. Their risk to patients depends on a whole range of factors including levels of virus in their blood.

Information about hepatitis B vaccination is available ^[25]. Patients affected by the Nepean Hospital health alert can call 1800 716 662 for more information and support.