TB Anywhere is TB Everywhere
Saskatoon, March 21 - In 2005, there were 8.8 million new cases of tuberculosis (TB) and 1.6 million people died from TB, equal to an estimated 4,400 deaths a day.
Most of the cases of TB in the world can be cured by taking a combination of four drugs for six months. These four drugs are called the first-line drugs and there are only four of them.
However, one in ten new cases of TB is resistant to at least one first-line drug. Cases that are resistant to two or more drugs are labelled multi-drug resistant or MDR-TB. The treatment for such cases uses second-line drugs which are not as effective and must be taken for a year or more. Second-line drugs have more toxic side effects than first-line drugs and are much more expensive.
The 2007 World TB Day messages contain a new term to describe TB which is resistant to both first- and second-line drugs. It is called extensively drug resistant or XDR-TB. There are few treatment options for such cases.
The world first heard about XDR-TB at the International AIDS Symposium in Toronto in August 2006 where a report on 52 such cases was given. 51 died within a month of being tested, including health care workers who were infected while treating XDR-TB patients.
In October 2006, the World Health Organisation established a definition of XDR-TB based on levels of drug resistance (ref).
At the February 2007 Conference on Retroviruses and Opportunistic Infections in Los Angeles, Dr. Paul Nunn of the World Health Organisation estimated that the spread of XDR-TB is currently 27,000 new cases per year, resulting in 16,000 deaths (ref). Most cases are in people who also have HIV infection.
XDR-TB does not appear to spread easily, but it does represent a threat to both patients and health care workers who are HIV positive.
XDR-TB cases are already being found in Canada. 2006 will be the first year for reporting XDR-TB in Canada, so numbers of cases are not yet available.
There are two ways for a person to develop MDR-TB or XDR-TB. One way is by poor treatment. If a case of ordinary TB is treated inappropriately or if the full treatment is not completed, TB can develop a resistance to the drugs that were used. The second way is by being infected by someone who has an active case of MDR-TB or XDR-TB.
The TB germ does not respect national or provincial borders. TB travels into Canada as people travel back and forth to high incidence countries. In 2005, 63% of all new TB cases in Canada occurred in people born outside of Canada.
Someone with infectious TB can spread the disease by coughing, sneezing, or simply talking, as this propels TB germs into the air. A person only needs to breathe in a small number of these germs to become infected (although only a small proportion of people will develop TB disease). Sometimes the bacteria are already drug resistant if they come from a person who already has drug-resistant TB.
“The best defence against MDR- and XDR-TB is to have a first-class TB control program which provides high quality detection, treatment and prevention of ordinary TB,” said
Dr. Heather Ward, Chair of the Canadian Thoracic Society TB Committee. “This includes identifying and testing all persons who are at risk because of their contact with an active case of TB,” added Dr. Ward.
Dr. Vernon Hoeppner, Director of TB Control for the province of Saskatchewan agrees, saying, “The only prevention of MDR- and XDR-TB is a better drug delivery program, one that ensures patients take every dose of all the prescribed drugs so that they complete prescribed treatment.”
“We are very fortunate to have had one of the best programs in Canada operating here in Saskatchewan. In the past 15 years there have not been any new cases of MDR-TB developed in Saskatchewan. This is a strong indicator of excellent TB control,” said
Dr. Brian Graham, CEO of the Lung Association of Saskatchewan.
One case of MDR-TB could cost the province about $500,000 while one XDR-TB case could cost an estimated $1 million, which is roughly an entire year’s budget for the TB control program. The average treatment cost for a case of ordinary TB in Canada is about $20,000.
Thanks to a good TB control program, the number of cases of TB in Saskatchewan is relatively small, in the order of 100 new cases per year, and deaths from TB are rare. Even in northern communities where the incidence of TB is highest, the rates are declining. “The investment in TB control is paying off. However, a high level of vigilance must be continued,” said Dr. Graham.
Internationally, Canada must continue its support of the global fund for AIDS, TB and Malaria, and must continue to support research into the development of new tools to fight TB, since our current treatment options are no match for XDR-TB.
Canada must also help other countries to control TB. Canada has a wealth of TB experts. We need funding to keep Canadian TB experts engaged in global TB control, because TB anywhere is TB everywhere!
On March 24, 1882, Robert Koch announced before the Physiological Society of Berlin that he had isolated and grown the tubercle bacillus, which he believed to be the cause of all forms of tuberculosis. World TB Day is held on March 24 of each year in commemoration of Koch’s announcement. Koch was awarded the Nobel Prize in Medicine in 1905.
The Lung Association is Canada’s oldest health charity, helping Canadians to breathe easier since 1900. Our predecessor, the Saskatchewan Anti-Tuberculosis League, was founded in 1911 to fight the raging TB epidemic of the time. We are a non-profit, non-governmental organization that relies on the generous support of the public through donations to campaigns such as Christmas Seals to fund our many programs and activities. You will find the Lung Association active in your community conducting programs on asthma, COPD and sleep apnea, providing training for health professionals, delivering health education in schools, facilitating patient support groups, and lobbying for clean air. The Lung Association is the premier source for respiratory health information.