- A Toronto hospital is treating several cases of extensively
drug resistant tuberculosis, with one of the patients being held in isolation
under court order, the doctor overseeing the treatment said Mon 22 Jan
2007.
-
- Public health experts fear the dangerous strain of tuberculosis,
which is susceptible to very few of the anti-tuberculosis medications normally
used to treat TB, is a global health crisis in the making. Dr. Monica Avendano,
the physician in charge of the tuberculosis service at West Park Healthcare
Centre, said since 2004, her unit has treated 5 or 6 patients with XDR
TB, as it is called. All the patients were either infected abroad or infected
by a family member who picked up the highly resistant strain elsewhere,
she said.
-
- "Currently, I am treating 3," said Avendano.
"All of them have a previous history of tuberculosis that was not
well managed."
-
- Multi-drug resistant TB and the more difficult extensively
drug resistant TB can arise one of 2 ways. A person with tuberculosis can
fail to take all their medication, as in the case of the "not-well
managed" patients to which Avendano referred. This spotty treatment
allows the bacterium to survive the assault of the drugs and develop resistance
to them. Or a person can be infected by contact with a person sick with
XDR TB. Two of the cases Avendano has treated fall into this latter category.
-
- "Both of the cases are young women who went to their
country of origin to look after their ailing grandmothers. And the ailing
grandmothers gave them TB. And it was XDR TB," she said.
-
- She did not identify the countries involved. XDR TB has
been found in a number of places, including China, South Africa, and many
republics of the former Soviet Union. It is believed to have spread, still
at low levels, from these jurisdictions to developed countries.
-
- The Public Health Agency of Canada currently doesn't
know the scope of the problem in this country. The last time Canadian TB
statistics were gathered, the provinces and territories were not asked
to report XDR TB cases. The TB statistics for 2006 -- which will be reported
sometime in 2007 -- will include XDR TB figures, agency spokesperson Alain
Desroches said in an e-mail.
-
- Where such cases arise, they are treated in isolation,
either with the consent of the patient or with the help of the courts.
"All provinces and territories will use their public health legislation
if necessary to ensure treatment of XDR TB," said Dr. Edward Ellis,
manager of tuberculosis prevention and control with the public health agency.
"With TB, in my experience, there's never a problem getting a court
order if necessary. And nobody stands there saying: 'Oh, no, let them go.'"
-
- Avendano said treatment with alternative drug regimes
is effective, but it can take months of in-hospital care. Even then, it's
not clear whether these patients -- who will be required to be seen on
an ongoing basis -- are cured for life. That's because the strain hasn't
been around long enough, and the treatment regime being used is too new
to gauge its long-term efficacy.
-
- http://thechronicleherald.ca/Canada/554590.html
-
-
- ProMED-mail
- promed@promedmail.org
-
- ProMED thanks Mary Marshall for this posting. A relevant
discussion on the XDR problem in tuberculosis can be found at: CDC: Emergence
of _Mycobacterium tuberculosis_ with Extensive Resistance to 2nd-Line Drugs
--- Worldwide, 2000-2004. 2006;55: 301-305. Parts of the report are found
below:
-
- "17 690 isolates from the period 2000-2004 were
tested for susceptibility to at least 3 of the 6 2nd line drugs (SLD) classes.
Of these, 11 939 were from South Korea, of which 1298 (11 percent) were
multidrug-resistant (MDR, defined as resistance to at least isoniazid and
rifampin). From the other Global Supranational TB Reference Laboratory
(SRLs), 2222 (39 percent) of 5751 isolates were MDR.
-
- Of the 3520 MDR isolates, 347 (10 percent) were XDR (defined
as cases in persons with TB whose isolates were resistant to isoniazid
and rifampin and at least 3 of the 6 main classes of SLDs (aminoglycosides,
polypeptides, fluoroquinolones, thioamides, cycloserine, and para-aminosalicyclic
acid), including 200 (15 percent) of 1298 from South Korea and 147 (7 percent)
of 2222 from other SRLs. The drug-susceptibility testing results were tabulated
by year and geographic region (on the basis of the country of origin of
the isolates) (Table 1; for table, see original URL. - Mod.LL).
-
- XDR TB was identified in all regions but was most common
in South Korea (n = 200; 15 percent of all MDR TB isolates) and countries
of eastern Europe/western Asia (Armenia, Azerbaijan, Czech Republic, Republic
of Georgia, and Russia, n = 55; 14 percent of all MDR TB isolates). The
total number and proportion of XDR TB isolates observed worldwide (excluding
South Korea) increased from 14 (5 percent of MDR TB isolates) in 2000 to
34 (7 percent of MDR TB isolates) in 2004. Year-specific proportions were
stratified by geographic region. Increasing proportions of XDR TB were
found among isolates from countries of eastern Europe/western Asia (n =
5 [9 percent] in 2000; n = 11 [17 percent] in 2003) and the group of industrialized
nations (Australia, Belgium, Canada, France, Germany, Ireland, Japan, Portugal,
Spain, UK, and USA, n = 3 [3 percent] in 2000; n = 25 [11 percent] in 2004).
-
- USA national TB surveillance data included 169 654 patients
with drug-susceptibility testing results. During 1993-2004, a total of
2689 (1.6 percent) MDR TB cases were identified, of which 1814 (67 percent)
had results reported for 3 or more SLD classes. Of these, 74 (4.1 percent)
had resistance to 3 or more SLD classes and thus met the criteria for XDR
TB. Despite an overall decline in MDR TB incidence in the USA, the proportion
of XDR TB increased slightly, from 37 (3.9 percent) of 944 cases during
1993-1996 to 20 (4.1 percent) of 489 during 1997-2000, to 17 (4.5 percent)
of 381 in 2001-2004 (chi-square test for trend = 0.20; p = 0.66). During
1993-2002, patients with XDR TB were 64 percent more likely to die during
treatment (relative risk [RR] = 1.6; 95 percent confidence interval [CI]
= 1.2-2.2) than patients with MDR TB.
-
- Among 605 MDR TB patients in Latvia who initiated therapy
during 2000-2002, 115 (19 percent) had XDR TB. The proportion with XDR
TB increased from 30 (15 percent) of 204 in 2000, to 46 (21 percent) of
215 in 2001, to 39 (21 percent) of 186 in 2002 (chi-square test for trend
= 2.57; p = 0.11). Patients with XDR were 54 percent more likely to die
or have treatment failure (RR = 1.5; CI = 1.1-2.2)." - Mod.LL
-
-
- Patricia A. Doyle DVM, PhD
- Bus Admin, Tropical Agricultural Economics
- Univ of West Indies
-
-
- Please visit my "Emerging Diseases" message
board at:
- http://www.emergingdisease.org/phpbb/index.php
- Also my new website:
- http://drpdoyle.tripod.com/
- Zhan le Devlesa tai sastimasa
- Go with God and in Good Health
|
