When my GP suggested I do a blood test for tuberculosis, neither of us expected a positive result

I knew something wasn’t right when the lymph nodes in my neck began to swell, causing intense pain and headaches, unlike anything I’d experienced before.

But when my GP suggested doing a blood test for tuberculosis (TB) in April neither of us expected a positive result. 

She was the second doctor I’d seen in three months — both were equally perplexed by my prior blood test results, which had ruled out COVID-19, the flu and other respiratory viruses and pointed to a bacterial infection.

Aside from having a rugby player’s neck, I had moderate night sweats, loss of appetite, fatigue and flu-like body aches.

I didn’t have a temperature, cough, runny nose or sore throat but it was clear my immune system was in overdrive. 

Results from my first blood test in February showed I had “markedly elevated” levels of inflammation — more than 25 times above normal. Two months later it was higher again. 

My results particularly caught the attention of the second GP, who was from India and had witnessed the burden of tuberculosis before moving to Australia.

“Have you travelled overseas recently?” the GP asked.

“Kind of,” I replied. “My partner and I spent about a month travelling around Bali and Vietnam in October last year.”

She reassured me it would be “very unlikely” and “very unlucky” to have contracted TB given I’d only spent two weeks in each location.

I also did not meet any of the main three risk factors associated with TB: I wasn’t born overseas in a high-risk country, nor had I spent three months or more living in one of these places, and I didn’t have any household members or close contacts with TB.

As a precaution she prescribed a five-day course of strong antibiotics and recommended I have a specific blood test to detect TB if my symptoms got any worse.

I went downhill two days later.

The next time I spoke to my GP it was over the phone. 

I remember the concern in her voice as she told me I’d tested positive for TB, and that we needed to determine if it was a latent or active infection.

She apologised for being the bearer of bad news and said she would be in touch.

The call ended and I burst into tears.

A million questions whirled inside my head: Was I infectious? If so, how many people could I have unknowingly infected? And, of course, can you die from TB? 

I’ve learned a lot about TB since then. Here are some of the things I wished I’d known sooner.

So, what is tuberculosis?

TB is a highly infectious disease caused by the bacterium Mycobacterium tuberculosis, which can result in serious illness and death if left untreated.

It represents one of the most significant public health threats globally and was the second leading infectious killer after COVID-19 in 2022, causing an estimated 1.3 million deaths worldwide.

The disease typically spreads when people who are sick with TB expel the bacteria into the air, for example, by coughing or sneezing.

But, not everyone infected will become sick or contagious.

Most people will have a latent TB infection, where the body’s defences control the bacterium, which can stay alive in a dormant or inactive state.

A global modelling study, published in 2016, estimated that a quarter of the world’s population had latent TB.

However, in approximately 5–10 per cent of cases, the bacterium will overcome the body’s immune system defences, progressing from latent infection to TB disease.

According to the World Health Organization (WHO), an estimated 10.6 million people fell ill with TB in 2022. 

Most of those new cases live in the WHO’s 30 high TB burden countries — which includes India, Indonesia, Philippines, Pakistan, and Vietnam — with almost half occurring in the South-East Asian region.

What are the symptoms of TB?

Some people with TB disease may only have mild symptoms, while those with a latent TB infection will often have no symptoms at all.

Common symptoms of TB disease include a prolonged cough, chest pain, weakness or fatigue, weight loss, fever, and night sweats, according to WHO’s Tuberculosis Programme team lead Kerri Viney.

“Often, these symptoms will be mild for many months, leading to delays in seeking care and increasing the risk of spreading the infection to others,” Dr Viney says.

TB disease predominantly affects the lungs, and is known as pulmonary TB.

But TB can also affect other parts of the body, including the central nervous system (a condition known as TB meningitis), as well as the bones and joints, lymph nodes, abdomen, and blood. This is known as extrapulmonary TB.

Only people with pulmonary TB can be infectious. 

The time it takes for a TB infection to become active varies from person to person.

For some, it can be shortly after infection, while others might not develop TB disease until years later when their immune system becomes weak. 

The probability of this happening is much higher among people living with HIV, Dr Viney says.

Other risk factors include malnutrition, diabetes, smoking and alcohol consumption.

Is TB common in Australia?

The short answer is no. 

The incidence of TB in Australia is relatively low, but experts say we must remain alert, particularly with the growing threat of drug-resistant TB disease.

TB disease is nationally notifiable in Australia, by both laboratories and clinicians, and all confirmed cases are reported to the National Notifiable Diseases Surveillance System.

However, this data does not include the number of Australians with a latent TB infection.

According to the Federal Department of Health and Aged Care, the national incidence of TB post-COVID has remained consistent with previous years.

In 2023, the rate of the disease in Australia was 5.3 cases per 100,000 people, with 1,430 TB notifications. 

In total, 67 Australians were reported to have died due to TB from 2021 to 2023.

“Without treatment, the death rate from TB is high,” Dr Viney says.

But TB is treatable and “usually curable”.

‘Every GP will be aware of TB’

It’s not often that GPs see patients with TB, Tim Senior, a general practitioner based in south-west Sydney and Aboriginal health medical advisor for the Royal Australian College of General Practitioners, says.

“Having said that, I think every GP will be aware of TB and the potential for it to present,” Dr Senior says.

“Even if we’re not seeing it, it’s there at the back of our minds.”

The frequency of TB patients would also depend on the community profile and area a GP is working in, he adds.

For example, GPs working in the Northern Territory see more patients with TB than those in NSW or Tasmania.

The NT has the highest rate of TB in Australia, with most cases occurring in those born overseas and in First Nations peoples. 

Due to its close geographic proximity to South-East Asia, studies have attributed the increase in TB cases to sporadic influxes of arrivals from neighbouring countries.

“People who are at highest risk of TB are Aboriginal and Torres Strait Islander people, and people from TB-epidemic countries,” Dr Senior says.

“Being Aboriginal is a marker of exposure to all the disadvantages and risk factors that predispose you to [the disease], and that puts you at higher risk of TB.”

This includes facing poorer living conditions and healthcare services.

How is TB diagnosed and treated?

TB infections can be identified through a tuberculin skin test or a blood test, known as an interferon-gamma release assay or Quantiferon TB Gold-Plus. 

However, these tests cannot identify whether the TB infection is active or latent.

If the test is positive, you may have to do a chest X-ray, a physical examination, or a sputum test that looks for signs of the bacterium in mucous, to confirm if you have active TB.

In my case, I returned two positive blood test results after my specialist suspected my first result was a false positive. 

I also had a chest X-ray, which is used to identify pulmonary TB.

Thankfully my results came back clear. But, if a doctor suspects you have TB outside the lungs, you’ll usually need to have a different test, such as a biopsy.

I was reassured my TB infection was most likely latent, and not active, so I was not infectious.

Two weeks later, I was prescribed a four-month course of an antibiotic called rifampicin.

Treatment for TB disease is slightly different and requires a combination of specific antibiotics (isoniazid, rifampicin, ethambutol and pyrazinamide) for at least six months.

This also varies for each patient, depending on their age, type of TB, and whether the strain is drug-resistant.

TB that is resistant to rifampicin and isoniazid is defined as multidrug-resistant TB. It is treatable by using second-line drugs, although they may not be as effective or available.