foodconsumer.org: Drug Resistant TB a Global Risk; Vitamin D May Help Prevent TB

Drug Resistant TB a Global Risk; Vitamin D May Help Prevent TB
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admin on 03/21/2010 16:17:00
 
Drug Resistant TB a Global Risk
(By Rachel Howell Stockton)
Regarding tuberculosis, there’s good news and bad news.
Let’s start with the good news:  the CDC announced that the rate of
tuberculosis in the United States dropped 11.8% in 2008.
The bad news comes from estimates prepared by the World Health Organization,
which asserted this week that drug resistant tuberculosis is on the rise in
other parts of the globe, most notably in Russia, India and China.  In fact, of
the 440,000 cases of resistant TB reported in 2008, one third died and half were
in India and China.  As a result, WHO is urging these countries to devote entire
labs to fighting the disease.
New and “Improved” TB Strain
The multi-drug resistant strain, or MDR-TB, can be treated, but the course of
treatment is costly and time consuming.  Conventional treatment for TB costs
about $20 and lasts for 6 months.  MDR-TB treatment, however, costs $500 and can
last for up to two years, primarily because the strain is resistant to both the
first and second lines of antibiotic treatment, according to the Centers for
Disease Control and Prevention (CDC).
Once the leading cause of death in the United States, TB is caused by the
bacterium referred to as Mycobacterium Tuberculosis.  Due to medical advances,
of the 2 billion cases of the disease, the vast majority are latent, meaning the
patients afflicted with it are not infectious.  However, the CDC reports that 1
in ten of those patients will develop active TB, usually when the immune system
is weakened.
How TB is Spread
According to the CDC website, MDR-TB spreads the same way as conventional TB: 
since the germs are airborne (and can live for several hours), a person with TB
can infect others by simply speaking or sneezing into the air.
However, TB is not spread through shaking hands, kissing, or touching toilet
seats.
Tuberculosis symptoms include coughing for 3 weeks or longer, pain in the chest,
coughing up blood or sputum, weakness or fatigue, weight loss, no appetite,
chills, fever, and sweating at night, according to the Centers for Disease
Control and Prevention.
Tuberculosis treatments vary depending on the patient's health status and the
severity of the disease.  For latent TB, preventative drug therapy using
isoniazid may be employed to destroy the bacteria that may revive in the future.
 For active TB disease, it is likely that four medications, isoniazid, rifampin
(Rifadin), ethambutol (Myambutol) and pyrazineamide are used, according to
mayoclinic.com.
Vitamin D Boosts Immunity Against Tuberculosis
(By David Liu and editing by Rachel Stockton)   Tuberculosis is a type of
infection.  Like many other infectious diseases, TB can infect individuals with
compromised immunity more easily than those with normal immunity.  Certain
vitamins such as vitamin D are needed for a person's immunity; maintaining a
sufficient level of vitamin D may help reduce the risk of acquiring TB.   No
trial seems to have been carried out to demonstrate the efficacy of vitamin D in
preventing TB; however, evidence has emerged that suggests that possibility.  
Williams V and colleagues from North West London Hospitals NHS Trust in
Middlesex, England published an article in the Oct 2008 issue of The Pediatric
Infectious Disease Journal suggesting that the overwhelming majority of children
with TB suffered vitamin D deficiency or insufficiency.   Dr. Williams et al.
examined 64 children with either active or latent TB infection who attended the
authors' TB clinic during a 2-year period.  They found that 86 percent were
either vitamin D deficient, (defined as having serum 25-hydroxyvitamin D at
lower than 20 nmol per liter), or insufficient, defined as serum
25-hydroxyvitamin D at lower than 75 nmol per liter.   Of 26 children with
active TB, only one was vitamin D replete, which could mean that about 95
percent of children with active TB had vitamin D deficiency or insufficiency.  
Sita-Lumsden A and colleagues from Guy's and St Thomas' Foundation Trust in
London, UK also observed a similar pattern in a case-controlled study published
in the Nov 2007 issue of Thorax.    These researchers discovered that patients
with active TB had lower serum vitamin D concentrations than healthy controls.  
Vitamin D is known to help produce antimicrobial peptides that can fight both
bacteria and viruses, while also preventing infections, according to Dr. John
Cannell, a vitamin D expert and director of Vitamin D Council, a nonprofit
organization that aims to educate people about the importance of vitamin D to
their health.   Ralph A.P. and colleagues from Royal Darwin Hospital Campus in
Australia published a review on the issue in the July 2008 edition of Trends in
Microbiology saying that L-arginine and vitamin D may be used as adjunctive TB
immunotherapies.    The authors maintain that "By enhancing mycobacterial
killing in macrophages, L-arginine and vitamin D might have the potential to
enable shorter duration of treatment, reduced infectivity and improved response
in drug-resistant TB."