...Age article

TB test a measure of security in global migration
By Garry Barker
June 3 2002




Tony Radford and Jim Rothel are confident of the technology supporting their TB testing.
Picture: MICHAEL CLAYTON-JONES


The floods of illegal immigrants and asylum seekers pouring into Europe and the United States could become a river of gold for a Melbourne bioscience company.

Cellestis, a publicly-listed research company in Carnegie, has begun marketing a more reliable test for tuberculosis based on work done at the CSIRO over the past 15 years. Offices have been set up in the US and agreements signed with distributors in Japan and Europe.

The test depends on the measurement of gamma interferon levels produced in blood taken from suspected TB sufferers. According to the principals of Cellestis, chief executive officer Tony Radford and chief scientific officer Jim Rothel, their test is more accurate, easier to administer and cheaper overall than conventional Mantoux skin-reaction tests or chest X-rays.

Dr Radford and Dr Rothel both worked on the basic technology at CSIRO in the 1980s in a campaign to eradicate bovine TB in Australian herds. Since then the test has been refined and developed by Cellestis for use on humans under the brand name of Quantiferon. Dr Rothel said Quantiferon was the first of several generations of medical tests that would be developed using the basic technology of Quantiferon.

Clinical trials of the TB test on a total of 3000 people have now been completed in the US by the Centres for Disease Control and Prevention and the US Navy, and official approval has been obtained from the Food and Drug Administration .


Cellestis will do its own marketing in the US, initially to health, immigration and prison authorities and to the military, four areas that account for about 10 million tests a year.

Marketing in Europe would be handled by Launch Diagnostics of the UK and in Japan by Nichirei, a large bioscience company, Dr Radford said. More than 25 million tests for TB are conducted in Japan each year, mostly by chest X-ray because widespread BCG vaccination has rendered the Mantoux test unreliable.

Initial US reaction to the benefits of the Australian test had been favourable, Dr Radford said. Although the cost of an individual Quantiferon test was higher than for a skin test, huge savings were possible because a second visit, to check reaction, was not needed.

"The skin test can only measure that there has been a reaction. Our test measures more widely and with greater accuracy," he said. "With the skin test, the subject has to return within 72 hours if a passable result is to be obtained. A high percentage do not return. Cook County Jail in Chicago does 100,000 skin tests a year on inmates but gets to read only 30 per cent of them. Chicago health authorities say 49 per cent of patients identified with active TB have passed through that jail."

Tuberculosis is endemic in the third world with Afghanistan reported as having the highest per capita infection rate of any country.

Almost equally high rates are to be found in the former USSR, in Eastern Europe and Asia, from which the majority of the thousands of asylum seekers and migrants, legal and illegal, are now flooding into Britain and Western Europe. Health authorities in western countries believed to be relatively free of the disease are concerned that each undetected carrier increases the likelihood of a TB epidemic.

Dr Radford said that while the health map of the UK showed TB rates relatively low overall, the picture changed under closer examination.

For instance, Brixton, in south London, is home to many illegal migrants and asylum seekers, and is an area of high infection, he said.

Tuberculosis kills more than two million people a year, a number that is rising rapidly as a result of the HIV/AIDS epidemic and the flood of refugees from places such as Afghanistan, the former Yugoslavia, Chechnya and the poor countries of Africa.

The World Health Organisation says a global TB epidemic is growing, fuelled by a breakdown in health services, the spread of HIV/AIDS, and the emergence of multi-drug-resistant TB. It estimates that between 2000 and 2020, nearly one billion people will be newly infected, 200 million people will fall ill, and 35 million will die from TB, if control is not strengthened.

Dr Radford said that it was unlikely that Quantiferon would be used in the poor countries, but because infection was being transferred at high rates by refugees and others to developed countries, there was a need for a more accurate test to find and treat carriers of the disease.

"Cellestis is not trying to become a generic diagnostic company," Dr Radford said. "We want to be a recognised brand for latent TB testing; meeting major medical needs is the way for us to go. We will look for antigens for other diseases that work in the Quantiferon system."

The company saw no future for the test in developing countries but, given the risks now apparent, advanced countries were increasingly anxious to prevent an upsurge of active disease, he said.

Dr Radford said Cellestis aimed to reach profit by the end of 2003, when it should be selling about 1.5 million of its TB tests in the US. "We hope to reach 3.5 million tests by 2005 and up to 12 million a year by 2007," he said. "And by then we will be well into our second generation of the technology."