TUBERCULOSIS: Tuberculosis: threatening Australia’s borders

Tony Radford, CEO of Cellestis. (Cellestis offers a solution to curb influx of tuberculosis brought in by immigrants and refugees.)

Tuberculosis (TB) is regarded by many as a disease of the past, but as a recent tuberculosis outbreak in Australian’s customs offices shows, there is a case for modernising testing for TB in developed nations, and Melbourne-based company Cellestis offers a way to do so.
The recent scare involving six Australian customs officials who appear to have contracted a latent tuberculosis infection has called into question the current protection and testing measures. The episode also highlights that while TB infection rates in Australia are relatively low – around 1000 new cases are reported per year – we remain exposed to real risks.
Additionally, a study released last year, following a review of Victorian health department data from 1998 to 2007, found there was an increase in the number of people who were diagnosed with MDR-TB, a mutant strain that is resistant to two of the most effective antibiotics used to treat TB. Even more dangerously, resistant strains of TB exist and are becoming more common around the world, and it can’t be ignored that this disease kills one person every 17 seconds worldwide.
This recent scare focuses our attention on TB in immigrants, and rightly so. In Australia, the chances of contracting TB from an Australian-born person are very low. The infection is mostly imported – because we make no effort to stop anything but the most developed cases from entering the country.
We allow people to enter the community carrying TB infection, possibly drug-resistant, in a manner that we would never consider allowable for any animal crossing our borders. Not even considering the rising number of boats arriving on our shores – 173 illegal boats since 2008 – even legal immigrants aren’t receiving the necessary TB testing to prevent a further outbreak of the highly infectious respiratory disease.
Tools which far more accurately detect TB infection and indicate who will develop TB are now available, rendering the old-fashioned mind-set that finding TB and treating it is too hard is simply that – old and out of date. This, coupled with the rising number of immigrants coming in from countries with a high rate of TB (Asia accounts for 55 per cent and Africa accounts for 30 per cent of all TB cases), are good reasons for Australian authorities to reconsider TB control. Demands need to be made for an overhaul and upgrade in the country’s testing and protection against the infectious disease.
Australia needs to step up its action plan against TB to match the global standard of disease management. The world-wide strategy is being led by the US, which this year released new guidelines recommending that the modern IGRAs (simple blood tests known as interferon-gamma release assays, like Cellestis’ QuantiFERON) are used to test for TB, and similarly endorsed their use in screening immigrants.
Other countries that have realised they need to take a tougher stance against TB include Ireland, which recently experienced an outbreak of TB in a primary school. With a usually low rate of TB – around 480 cases a year – the outbreak has caused the country to urgently review its testing and protection methods for the disease to prevent a reoccurrence. The clearly acknowledged fact is that some countries with low rates took their eye off the ball, and now, with rising TB rates they are paying the price. Australia is in a unique position with its geographical separation, and needs to develop and enact modernised TB control guidelines in immigration to prevent a similar situation occurring on our shores.
This is to the benefit of all. Latent TB carriers will be detected and will be treated before progressing to TB disease, it is clearly to their benefit. It is not expensive to diagnose or treat latent TB infection – it is expensive to wait and treat TB disease. The current immigrant testing protocol simply does not allow for testing and treating TB infection, but relies only on chest X-ray, which can only and inefficiently detect advanced disease, not latent infection.
Why is it so? X-ray can largely avoid the embarrassment of an immigrant immediately infecting others straight after arrival, but does little to stop importing the disease. But until Australians invented interferon testing, first for cattle TB, the only method to find TB infection was the tuberculin skin test, the TST or Mantoux test.
The TST is over 100 years old, extremely subjective to measure, and very frequently produces false positives. Such an unreliable test causes undue stress, and adds extra and unnecessary pressure on the health system and economy. Doctors are often uncomfortable prescribing treatment based on such a test, and this ‘do nothing’ mindset has permeated immigration testing. Customs workers are exposed on a daily basis to possible infection, and deserve better.
Cellestis’ QuanitFERON test (QFT) is scientifically proven to be six times more accurate than the TST – that is, six times fewer people need to be treated to stop the same amount of TB – and has demonstrated that the new test offered economic advantages of time saving through the elimination of producing false positives as with the TST tests.
It is clear that despite having the possibility of virtually eliminating TB in this country, saving money while showing a shining light to the world that a country can achieve this goal with a comparative modicum of effort and thought, Australia is lagging behind other nations. We have little control over TB infection coming into the country, and little to no guideline on interferon testing for TB infection.
The federal government in fact facilitates and subsidises the import and use of the TST reagents from the USA – where the US Centers for Disease Control and Prevention recommends use of QFT as beneficial in BCG (Bacillus Calmette-Guérin) vaccinated people, which is in fact common in immigrants and those most likely to have TB infection – to compete with this Australian product.
Cellestis’ has a declared an emphatic strategy to make latent TB diagnosis and treatment the paradigm in all countries. It makes solid health and economic sense. Current world TB-control strategies have had only limited success, and it’s clear that killing latent infection before it becomes a serious disease stops further spread – and if a test with high predictive capacity for future TB such as QuantiFERON is used, this will be achieved very economically.
The World Health Organisation has published reports clearly showing that only treatment of latent TB can make any significant impact on TB disease. The outcome of effective TB control is not only to save existing carriers but to cut the chain of transmission before the situation worsens.
The Stop TB Partnership, which gathered in early October to discuss a global plan to tackle TB, predicted that up to ten million people will die of the respiratory disease in the next five years. There is little cause to think it will go away in the world, and a lot of reason to worry about antibiotic resistant strains. Although only 1000 cases are reported in Australia each year, this number is set to rise if our borders are not protected with sufficient testing, and disease protection, for immigrants.

http://www.lifescientist.com.au/article/367368/opinion_tuberculosis_threatening_australia_borders/

TUBERCULOSIS: CDC Issues New Guidelines for TB Testing

Jun 28, 2010
The U.S. Centers for Disease Control and Prevention estimates that between 9 and 14 million Americans are tuberculosis (TB)-infected and asymptomatic -- with three-quarters remaining undiagnosed -- and at risk of progressing to a highly contagious form of TB disease. On Friday, CDC issued new and important guidelines on the detection of Mycobacterium tuberculosis infections, the causative agent of TB. In the guidelines, the agency advises that Interferon Gamma Release Assay (IGRA) blood tests are now preferred over the 100+-year-old tuberculin skin test (TST) for diagnosing TB infection in certain populations, including people who typically do not return for the necessary reading of TST results, and those who have received Bacille Calmette-Guérin (BCG) as a vaccine or for cancer therapy.
The CDC report, "Updated Guidelines for Using Interferon Gamma Release Assays to Detect Mycobacterium tuberculosis Infection -- United States, 2010," along with a companion implementation guide, appears in the June 25 issue of CDC's Morbidity & Mortality Weekly Report (MMWR, Volume 59, No. RR-5). In making its recommendations, CDC factored in TST's drawbacks, which its says include a higher risk for false positives, especially in people who have been BCG-vaccinated; irritating TB-extract that must be injected under the skin; and the need for a second doctor's visit.
According to the World Health Organization, about one person dies of TB every 17 seconds, causing nearly 2 million deaths annually. TB continues to be a contagious scourge in developing countries, and with the world shrinking rapidly due to global migration, it is a major public health threat in developed nations as well, including the United States. Each infected person represents a potential yet preventable future outbreak.
TB bacteria usually attack the lungs, but can affect any part of the body such as the kidney, spine, and brain. If not treated properly, TB can be fatal. TB bacteria is spread through the air when a person with TB disease of the lungs or throat coughs, sneezes, speaks, or sings, which may lead people in close proximity to become infected.
The populations specified by the new CDC guidelines represent a majority of those being screened for TB infection. Better, more reliable testing for TB infection is vital in order to efficiently identify the appropriate persons for treatment and thereby prevent its spread, the agency said.
http://ohsonline.com/Home.aspx

TUBERCULOSIS: Mass.. Harvard

A Harvard undergraduate was diagnosed with tuberculosis by University Health Services several weeks ago, and roughly forty students at risk for exposure have been asked to submit to a TB skin test, according to information provided by UHS and the Cambridge Public Health Department.
The student, whose identity has not been made public, was released earlier this week after public health officials determined he or she was no longer infectious, according to an e-mail from Jennifer B. Anderson, a UHS Communications Officer.
Anderson also said that no other students have presented signs of an active TB infection.
“We know of no other confirmed cases of TB at Harvard,” she wrote.
But among those students who have been asked to submit to a Mantoux Test, which determines whether an individual has produced antibodies to the tuberculosis bacterium, some have tested positive, according to Kate Matthews, a nurse in the Cambridge Public Health Department.
Matthews stressed that a positive skin test does not mean an individual is actively sick with TB.
“What it means to have a positive skin test is that you’ve had the TB germ in your body at one point. It doesn’t mean you’re sick or contagious,” she said, noting that roughly one in three individuals worldwide have been exposed to TB at some point in their lives.
According to Eric Rubin, a professor of immunology and infectious diseases at Harvard Medical School, those students who test positive for TB without showing signs of illness will be recommended to start a nine month regimen of daily antibiotics.
Rubin also said that there was another case of tuberculosis at a Harvard graduate school within the past two years.
But Matthews, who noted that there are roughly eight to twelve cases of tuberculosis in Cambridge each year, said that this was the first case among undergraduates in “a long time.”
http://www.thecrimson.harvard.edu/article/2010/4/23/tb-test-tuberculosis-health/