Posts Tagged ‘tuberculosis’

London – New Infectious Disease Hot Spot?

Monday, December 20th, 2010 by

The esteemed British medical journal, the Lancet, reported this week that the incidence of tuberculosis in London had risen 50% in the last decade.  Unlike neighboring countries, and the rest of the Western world, where tuberculosis has been on the decline for dozens of years, London saw a jump from 2,309 cases in 1999 to 3,450 in 2009. Most tuberculosis cases in Great Britain appear in people born overseas, although not in recent arrivals. About 85 percent of people with tuberculosis have been in Britain for at least two years, meaning the disease is not being imported, but circulating locally.

In separate reports, the H1N1 virus, or the so called “swine flu” also saw a big jump in the number of London cases over the past month.  The Health Protection Agency released a report that London had experienced 10 deaths from the swine flu in the last six weeks. In addition, dozens of patients have been admitted to intensive care units in hospitals throughout London with severe respiratory problems related to infection with the H1N1 virus.  Professor John Watson, the HPA’s head of respiratory disease, said he was “surprised” at the rapid spread of the virus, adding “It is more than I would have expected.”

Britain is one of the world’s biggest foreign aid donors, with considerable investments in projects fighting tuberculosis and swine flu in poor countries.  “We need to clean up our own back garden first,” says Alimuddin Zumla of University College, calling for new strategies and more money to reverse the recent London jump. “Charity begins at home,” he added.

Should tourists avoid London?  Most public health officials would say “no”, citing the fact that the number of cases thus far is not impressive, despite their shock value. Nonetheless, travelers to developed countries should not abandon the universal precautions, such as frequent hand washing, avoiding large crowds and covering one’s mouth when coughing, that are observed with more vigilance in areas endemic for exotic infectious diseases.

Photo by emiana.

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WHO Announces Milestone Test for Tuberculosis

Wednesday, December 8th, 2010 by

The World Health Organization (WHO) announced today that it is endorsing a new technology to diagnose tuberculosis.  The test, done on sputum samples and taking less than 2 hours to perform, identifies the presence of tuberculosis genetic material (coined the nucleic acid amplification test, or NAAT).  By contrast, conventional methods for diagnosing tuberculosis, such as sputum cultures, take several weeks.  In addition to confirming a diagnosis, the new test is also able to identify drug resistance, a particularly critical benefit in parts of the world where commonly used drugs to treat tuberculosis may not be effective.

According to Dr. Mario Raviglione, the director of WHO’s signature program to the halt the spread of tuberculosis “This new test represents a major milestone for global TB diagnosis and care.  It represents new hope for millions of people who are at the highest risk of TB and drug resistant disease.”  In a related development, co-developer of the test FIND ( the Foundation for Innovative and New Diagnostics) announced that the manufacturer of the new test (Cepheid) will offer a deep price discount to 116 low and middle income countries where TB is highly endemic. 

One of the main reasons tuberculosis killed 1.7 million people last year and infects almost 10 million worldwide annually (see map below for high risk areas)  is the rapid spread of tuberculosis among contagious, but undiagnosed persons.  The new test will dramatically reduce the time required for diagnosis, allowing quicker isolation of infected individuals and more timely initiation of treatment.  It will also allow physicians to rapidly identify patients for whom medications are not working. 

A few obstacles to the universal use of the NAAT test remain.  The machine requires an uninterrupted electrical source, a companion computer, and must be calibrated at least annually.  Nonetheless, scientists are hopeful that the new technology will significantly reduce both the spread and the ineffective treatment of a pathogen that remains endemic and deadly in much of the world.

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Multi-drug Resistant TB: Where Is It Winning?

Friday, July 23rd, 2010 by

My eyes were opened to the threat posed by multi-drug resistant tuberculosis (MDR-TB) when I read about Dr. Paul Farmer’s evangelical efforts to raise the world’s consciousness in Tracy Kidder’s book Mountains Beyond Mountains.  Years later I’ve learned the threat continues to grow. The World Health Organization works very closely with Farmer’s Partners In Health organization to monitor and combat MDR-TB around the world.  The WHO’s 2010 report is cause for alarm but also offers some seeds of hope.

First some worldwide statistics from the report:

  • In 2008, there were estimated 440,000 MDR-TB cases and 150,000 deaths
  • Only 7% of all MDR-TB patients were diagnosed and notified
  • 60% of those enrolled in treatment programs were cured
  • In 2010, only 22% of the $1.3 billion needed to fund MDR-TB control is available
  • In 2015, funding required to control MDR-TB will be nearly $4.5 billion

How did we arrive at this dangerous place?

Tuberculosis thrives in the poorest neighborhoods and in prisons and hospitals that house the poor.  Treatment with antibiotics is effective, but the course of treatment is long, and the side effects can be serious.  Therefore, it is not unusual for patients to abandon their antibiotics too early, giving rise to the MDR strain.  Today the prevalence of MDR-TB is growing, and so is the risk of encountering it on your travels, especially if you are visiting any of the 27 countries with a high burden of TB.

See the chart below for the prevalence of MDR-TB in these countries and the number of cases annually.  Travelers should also note that MDR-TB has a significant foothold in Jordan and Peru.  Further, only 22 of 46 African countries provide data to the WHO.

On the hopeful side, treatment efforts seem to have turned the tide in Estonia, Latvia, Hong Kong, the U.S. and certain parts of Russia. Twenty of the 27 high burden countries are strengthening their efforts by scaling up access to diagnostic tests.  As is so often true, sustained progress depends on increasing resources, expertise and coordination around the globe.  The price tag to control MDR-TB is relatively affordable when compared to global expenditures to combat HIV and H1N1, but until the problem reaches crisis proportions, adequate funding may not materialize.

And don’t bet against the microbes.  They have continued to evolve to elude even more forms of antibiotics.  The Extensively Drug-Resistant (XDR-TB) strain has now appeared in 58 countries, and the WHO estimates there are 25,000 cases annually.

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