Daniel Flitton, The Age 

A woman who travelled from India with a rare, mutated strain of tuberculosis and is now isolated in a United States hospital also spent several months in Victoria.

The federal Health Department confirmed on Friday that the US had warned the woman travelled to Australia with the illness, and Victorian health authorities are now screening people she lived with at the time.

The deadly tuberculosis – known as extensively drug-resistant, or XDR-TB – is spread by coughing or sneezing but not easily contracted, typically requiring an extended period of exposure rather than casual contact.

The woman is believed to have come to Australia in August 2013 and remained in the country for three months.

US media has reported doctors are carefully piecing together the woman’s movements across three American states since April to find hundreds of people who may have had contact with her while she was confirmed as infectious.

Mario Raviglione, director of the World Health Organisation’s Global Tuberculosis Program, said it was still unclear precisely how sick she had been at the time she travelled to Australia.

“What has happened in this particular patient is over the years she has developed drug resistance,” Dr Raviglione told Fairfax Media from Geneva.

He said investigations into her history indicated she first developed an active case of tuberculosis almost a decade ago, in 2006.

Her medical history included tests in 2008 showing she had drug resistant form of the disease, but Dr Raviglione said it is not known whether this was the rare XDR-TB strain.

Only two cases of XDR-TB have previously been detected in Australia, including a 20-year-old woman from Papua New Guinea who was isolated in a Cairns hospital but died in 2013.

Dr Raviglione said test needed to diagnose XDR-TB – as distinct from common tuberculosis – was sophisticated and rarely undertaken in poorer countries.

India had only in recent years introduced mandatory reporting of tuberculosis cases, where an estimated 800 people die of the disease each day.

Tuberculosis bacteria is common, with about 2 billion people, or a third of humanity, estimated to carry a dormant or latent version of the disease.

But the disease only becomes infectious in people who are malnourished, diabetic or otherwise unhealthy, an active case of tuberculosis remains second-only to HIV/AIDS as an infectious global killer, the latest figures estimating 9 million suffered an active case of the disease in 2013, resulting in 1.5 million dead.

While worldwide infection rates are dropping, the mutated drug resistant strains of the disease are a growing concern because treatment is lengthy and expensive.

The survival rate for XDR-TB, comprising just an estimated 0.5 per cent of all tuberculosis cases, is as low as 30 per cent – compared to an almost 90 per cent chance of curing common tuberculosis.

“Tuberculosis anywhere is tuberculosis everywhere,” said Maree Nutt, chief of RESULTS Australia, an organisation seeking to raise awareness for the eradication of tuberculosis.

“It is important that we look beyond this particular case towards the much needed discussion on the bigger issue of drug resistance.”

Tuberculosis is rampant in PNG, with the second-highest rate of infection in the region.

The incidence of tuberculosis in Australia is low, with the Health Department saying there had been approximately 5 to 6 cases per 100,000 population since the mid-1980s.

US authorities have declined to speculate about the woman’s reasons for travelling from India.

She was taken to isolation in a Washington DC hospital a fortnight ago, having arrived in Chicago in April, and spending time in Missouri and Tennessee before seeking treatment.

Dr Raviglione said tracing back a patient’s movements could take weeks, as they were often taken into hospital disorientated.

The woman’s name has not been made public.