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Published Date: 2004-04-09 23:50:00
Subject: PRO/EDR> Melioidosis - Singapore
Archive Number: 20040409.0968

MELIOIDOSIS - SINGAPORE
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[1]
Date: Fri, 9 Apr 2004
From: Denis Green <snoigel@hotmail.com>
Source: IOL and Straits Times [edited]
<http://www.iol.co.za/index.php?newslett=1&click_id=3&art_id=qw1081501200937B243&set_id=1>

Soil disease kills 15 in Singapore
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Bacteria lurking in soil and muddy water have killed 15 out of 31 victims
in Singapore so far in 2004, 2 times the normal toll, the Straits Times
newspaper reported on Fri 9 Apr 2004.
Recent floods may have carried to the surface bacteria that normally live
below the surface, the health ministry fears. The city state sees an
average of 59 cases of the disease melioidosis each year, the paper said,
and in 2003 there were 5 deaths among the 42 infections reported.
The disease spreads when people inhale infected dust particles or consume
contaminated water or food. Cuts in the skin are another route. Symptoms
such as swelling, lung infection, high fever, cough, chest pains, diarrhea,
and skin lesions may surface within 2 days or only after several years.
There is no vaccine for melioidosis, which is caused by the organism
_Burkholderia pseudomallei_, but the disease can be treated with
antimicrobials.
--
Denis Green
<snoigel@hotmail.com>
******
[2]
Date: April 9, 2004
From: "Alfonso Rodriguez" <arodriguezm@SaludFMV.org>
Source: Yahoo News, UK [edited]
<http://uk.news.yahoo.com/040408/323/eqmuw.html>

Tropical disease kills 15 people in Singapore this year
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A tropical disease linked to heavy rainfall has killed 15 people in
Singapore this year, the health ministry said, amid concern the number of
fatalities is unusually high. Ministry spokeswoman Bey Mui Leng told AFP on
Thursday that a directive had been issued to doctors and hospitals across
the island-state on Wednesday to report all cases to the government as it
seeks to contain the disease, called meliodosis.
The ministry has also put information on its website to inform the public
about the disease, which is most commonly contracted through contact with
contaminated water and mud. Mey said that out of 31 cases of meliodosis
this year, 15 people had died, for a fatality rate of nearly 50 per cent.
This compares with a fatality rate of 27.4 per cent out of an average 59
cases annually between 1990 and 2003, according to statisics on the
ministry's website.
Meliodosis is caused by a bacteria that rises up from below the soil
surface during wet weather. "After heavy rainfall, the bacteria can be
found in surface water and mud," the ministry's website said. It said the
most common form of transmission was through direct contact with the water
and mud, but it could also be acquired by inhaling contaminated dust
particles or drinking infected water. Human-to-human transmission is also
possible, but rare, the ministry's website said. People with depleted
immune systems, such as the elderly and diabetics, are most at risk of
contracting the disease, but local media reports said it had claimed the
life of an 18 year old this year.
Health authorities believe heavy unusually rain this year is responsible
for the increase in the number of deaths, Bey said.
--
ProMED-mail
<promed@promedmail.org>
[_Burkholderia pseudomallei_ exists as an environmental saprophyte living
in soil and surface water in endemic areas (South East Asia and northern,
tropical Australia), particularly in rice paddies. In endemic countries,
the organism exists primarily in focal areas and is not equally distributed
throughout the landscape. Sporadic cases have been reported to have been
acquired in parts of Africa and the Americas. The organism may exist in a
viable, non-cultivable state in the environment, interacting with other
organisms, particularly protozoa, which might explain its adaptation to an
intracellular niche. 2 outbreaks in Australia have also implicated potable
water supplies rather than surface water as a potential source of the
infection.
Melioidosis is a disease of rainy season in the endemic areas. It mainly
affects people who have direct contact with soil and water. Many have an
underlying predisposing condition such as diabetes (commonest risk factor),
renal disease, cirrhosis, thalassemia, alcohol dependence,
immunosuppressive therapy, chronic obstructive lung disease, cystic
fibrosis, and excess kava consumption. Kava is an herbal member of the
pepper family that can be associated with chronic liver disease.
Melioidosis may present at any age, but peaks in the 4th and 5th decades of
life, affecting men more than women. In addition, although severe
fulminating infection can and does occur in healthy individuals, severe
disease and fatalities are much less common in those without risk factors.
The most commonly recognized presentation of melioidosis is pneumonia,
associated with high fever, significant muscle aches, chest pain and --
although the cough can be nonproductive -- respiratory secretions can be
purulent, significant in quantity, and associated with on-and-off bright
red blood. The lung infection can be rapidly fatal -- with bacteremia and
shock -- or somewhat more indolent.
Acute melioidosis septicemia is the most severe complication of the
infection. It presents as a typical sepsis syndrome with hypotension, high
cardiac output, and low systemic vascular resistance. In many cases, a
primary focus in the soft tissues or lung can be found. The syndrome,
usually in patients with risk factor comorbidities, is characteristically
associated with multiple abscesses involving the cutaneous tissues, the
lung, the liver, and spleen and a very high mortality rate of 80 to 95 per
cent. With prompt optimal therapy, the case fatality rate can be decreased
to 40 to 50 per cent.
The melioidosis bacillus is intrinsically insensitive to many
antimicrobials. It should be noted that bioterrorism strains may be
engineered to be even more resistant. _B. pseudomallei_ is usually
inhibited by tetracyclines, chloramphenicol, trimethoprim-sulfamethoxazole
(SXT), antipseudomonal penicillins, carbapenems, ceftazidime, and
amoxicillin/clavulanate or ampicillin/sulbactam. Ceftriaxone and cefotaxime
have good in vitro activity but poor efficacy; and cefepime did not appear,
as well, to be equivalent to ceftazidime in a mouse model. The unusual
antimicrobial profile of resistance to colistin and polymyxin B and the
aminoglycosides but sensitivity to amoxicillin/clavulante is a useful tool
to consider in treatment of infection with the organism.
The randomized and quasi-randomized trials comparing melioidosis treatment
have been reviewed, and it was found that the formerly standard therapy of
chloramphenicol, doxycycline, and SXT combination had a higher mortality
rate than therapy with ceftazidime, imipenem/cilastatin, or
amoxicillin/clavulanate (or ampicillin/sulbactam). The
betalactam-betalactamase inhibitor therapy, however, seemed to have a
higher failure rate.
Source: Tolaney P, Lutwick LI. Meliodosis. In: Lutwick LI, Lutwick SM
(eds). Bioterror: the weaponization of infectious diseases. Totowa, NJ:
Humana Press, (in press). - Mod.LL]

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