Författare: Thomas Jeffries Senior Lecturer in Microbiology Western Sydn

News that a health worker at a Sydney hospital’s birth unit was infectious with hepatitis B for more than a decade has led to a health alert 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 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 are included in the health alert.

So what is hepatitis B?

Hepatitis B is a viral infection

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

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 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.

In rare cases, hepatitis B has been known to spread from a health-care worker 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. There are about 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, there were 205,549 chronic cases as of 2022. Most of the 6,000–7,000 newly detected cases in Australia each year are chronic cases.

Only 72% 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, 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 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 is recommended for all children at birth, with three doses after that. The vaccine is also recommended for adults in high-risk groups.

Acute cases can be cleared by the body, aided by antiviral drugs. 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 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. 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. Patients affected by the Nepean Hospital health alert can call 1800 716 662 for more information and support. Läs mer…

Seven people have now died from melioidosis in flood-ravaged north Queensland this year.

Dozens of cases have been reported in the state in recent weeks, which experts have described as unprecedented.

So what is melioidosis, and why are we seeing a spike in cases now?

How do people get infected?

Melioidosis is caused by the bacterium Burkholderia pseudomallei, a bug which normally lives harmlessly in soil and freshwater. But it can be dangerous when it infects humans or animals.

B. pseudomallei – sometimes called the “mud bug” – enters the body through cuts or scratches. It can also be breathed in and enter the lungs via small airborne water droplets, or by drinking affected water.

Symptoms usually develop within one to four weeks after a person has been infected. The disease can cause either local infections, such as chronic skin ulcers, or, more commonly, a lung infection which can lead to pneumonia.

Melioidosis is caused by the bacteria B. pseudomallei.
Reddress/Shutterstock

Symptoms of the infection include fever, headache, trouble breathing, chest and muscle pain, confusion and seizures. In rare cases the disease can enter the bloodstream and cause septicaemia.

Treatment involves receiving intravenous antibiotics in hospital for several weeks followed by up to six months of oral antibiotics.

How common is it?

Diagnosis is usually conducted using a specialist bacterial culture. This is where a sample isolated from the patient is grown in a petri dish to identify the bacteria, which can take several days.

Globally, around 165,000 cases of melioidosis are reported annually, and 89,000 deaths. The majority of cases occur in southeast Asia, particularly Thailand.

Because similar symptoms can be caused by so many other diseases, melioidosis is commonly misidentified, meaning reported case numbers are probably far lower than the actual number of infections.

Also, cases often occur in remote communities and resource-poor settings, which can mean they’re less likely to be diagnosed.

The disease is thought to be endemic to northern Australia. It usually infects about 0.6 per 100,000 people annually in Queensland, which would be equivalent to around 30 people.

In the Northern Territory, around 17 people per 100,000 are infected annually, which would be equivalent to about 42 cases. However, this data is several years old.

In Australia, melioidosis is often treated before fatalities occur. The mortality rate has been estimated at less than 10%.

More people die from the disease in lower-resource countries with poorer diagnostic capabilities and hospital facilities. In Thailand the mortality rate is estimated to be around 40%.

Who is at risk?

Anyone can get melioidosis, but certain people are at higher risk. This includes people with diabetes, liver and kidney disease, cancer, or other conditions which might compromise the patient’s immune system.

In Australia, the disease is also significantly more common in First Nations people than among non-Indigenous Australians.

Once infected, people who are Indigenous, older or have chronic health conditions are at higher risk of poorer outcomes.

In the current outbreak in Queensland, at least three of the victims so far have been elderly.

Parts of north Queensland, including Townsville, have recently experienced flooding.
Jamie Hervey/AAP

What’s causing the current outbreak?

Recent cases in north Queensland have been identified mainly around Townsville and Cairns.

Cairns and Hinterland Hospital and Health Service has recorded at least 41 cases since January 1, while more than 20 cases have been reported in Townsville in February.

This is most likely related to increased rainfall and flooding in and around these areas.

B. pseudomallei lives in soil and mud, and comes to the surface during periods of high rainfall. So recent heavy rain and flooding in north Queensland has likely increased the risk of melioidosis.

In the Northern Territory, 28 cases have been reported since the start of the rainy season last October. However this is lower than recent seasons.

How can you protect yourself?

If you’re in an affected region, you can protect yourself by limiting exposure to mud and water, and using appropriate personal protective equipment such as gloves and boots if spending time in muddy areas. Cover any open wounds and wear a respirator if you’re working closely with water.

Monitor for symptoms and see a doctor if you feel unwell.

Several vaccines are in development for melioidosis, and experts have recently called for it to be recognised as a neglected tropical disease by the World Health Organization.

Particularly seeing as increasing extreme weather events due to climate change may make melioidosis more common, hopefully we’ll see an increase in research into and awareness of this disease in the years ahead. Läs mer…