Published Date: 2008-01-23 03:00:13
Subject: PRO/EDR> Melioidosis - Australia: (NT)
Archive Number: 20080123.0279
MELIOIDOSIS - AUSTRALIA: (NORTHERN TERRITORY)
A ProMED-mail post
ProMED-mail is a program of the
International Society for Infectious Diseases
Date: Wed 23 Jan 2008
Source: Northern Territory News [edited]
A person has died and 3 more are fighting for their lives in intensive care
after contracting melioidosis in the Top End. A further 7 people have been
diagnosed with the tropical disease this wet season, but have since been
treated. One case was a visitor who developed the disease after returning
to their home interstate. No children have been affected.
The NT Department of Health and Community Services (DHCS) would not give
the circumstances surrounding the death from the disease. All the
department would say is that there had been cases "all over the Territory,"
including Darwin and Katherine and in remote areas.
DHCS Centre for Disease Control director Vicki Krause yesterday [22 Jan
2008] warned that more people could fall victim to the disease before
April. "This is a serious disease; every year we have people dying from
melioidosis," she said. "We just want people to be reasonable and know they
live in an environment where this bacteria is in the soil, particularly
Melioidosis is caused by the bacteria _Burkholderia pseudomallei_. It
killed 5 people in the Territory during the last Wet, and more than 30
cases were reported. Dr Krause said the bacteria lives below the soil's
surface during the dry season but after heavy rainfall can be found in
surface water and mud. She said it can also become airborne, and people are
more at risk after cyclonic weather.
There was widespread flooding in Darwin last week [14-18 Jan 2008] after
the NT capital recorded its 5th highest ever rainfall since records were
kept. It came a week after Cyclone Helen.
Melioidosis can enter the body through small cuts in the skin. It can also
be contracted through inhalation of dust, droplets, or swallowing
contaminated water. People with diabetes, alcoholism, and kidney or lung
disease are at more risk. Dr Krause urged people to wear protective
clothing if working in the garden or in muddy or wet areas. Anyone who has
symptoms should visit their personal physician.
[byline: Rebekah Cavanagh]
[Infection due to _Burkholderia pseudomallei_ (melioidosis) is endemic in
focal areas of South East Asia and northern Australia. In Australia, it is
also known as Nightcliff gardeners' disease (Nightcliff is a northern
suburb of the city of Darwin in the Northern Territory of Australia. The
Nightcliff area was the site of RAAF camps with spotlights and large guns
used to defend Darwin from bombing during World War II. - Mod.LL). _B.
pseudomallei_ is deemed to be a category B biowarfare agent. It is
primarily an infection of humans with underlying diseases such as
alcoholism, malnutrition, cirrhosis, and immunosuppresion, but can also
affect healthy individuals, as in this report. In animal models, higher
inocula can cause more serious infection in immunocompetent individuals.
The manifestations of illness in these patients are not stated nor whether
the individuals had underlying risk factors. Clinically, infection due to
_B. pseudomallei_ may be subclinical, but rapidly progressive disseminated
disease involving the skin, liver, or spleen can occur. Pneumonia may be
the presenting form, either acute or chronic. The latter may present years
after exposure, when the individual is no longer in an endemic area and may
look very much like pulmonary tuberculosis. The diagnosis can be confirmed
microbiologically and/or serologically.
The disease was first described in Rangoon, Burma (now Myanmar), by
Whitmore and Krishnaswami in 1912 among homeless, debilitated morphine
addicts. Autopsies performed on the remains of these individuals revealed a
process reminiscent of glanders, an abscess-forming infection of horses
and, quite rarely now, man. Microbiologically, the physicians from Her
Majesty's Indian Health Service could distinguish the isolated organism
from the glanders bacterium and others. The term melioidosis as related by
White (1) was coined by Fletcher and Stanton from Kuala Lumpur, Malaysia,
from the Greek words melis (a distemper of asses) and eidos (resemblance).
Cases were subsequently described with isolation of the organism from
clinical specimens and soil from many countries primarily in eastern Asia.
The infection was recognized in both Allied and Japanese soldiers during
the Second World War and subsequently was recognized in Northern Australia.
Later, during the Vietnamese war of independence with France and, more so,
the United States involvement, there were many more cases described.
Because of the infection's potential to produce potentially
life-threatening reactivations several decades after exposure, the term
"Vietnam time bomb" was used. It is likely that many of the acute and fatal
cases in troops remained undiagnosed.
Also a disease of animals, melioidosis is not truly a zoonosis, since it is
not transmitted from animals to man but rather both acquire the infection
from its soil reservoir. It may cause infection in many species and has
become a significant veterinary pathogen in zoological gardens. As pointed
out by White (1), the infamous L'affaire du Jardin des Plantes was said to
have occurred after a panda donated in 1973 by Mao Tse-Tung to the French
president Pompidou was the index case of melioidosis that significantly
affected several French zoos as well as race and equestrian horses.
The disease is endemic in South East Asia and as noted above more recently
in Northern Australia, but cases have been described in the western
hemisphere without travel histories as well. There are some _B.
pseudomallei_-like organisms that are much less virulent. Formerly
considered to be a separate biotype, these L-arabinoside assimilators are
now classified as _B. thailandensis_ and account for about a quarter of
soil isolates in Thailand. This is a hard-core survivalist organism that
can persist in triple-distilled water for long periods of time.
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,
antipseudomonal penicillins, carbapenems, ceftazidime (ceftriaxone and
cefotaxime have good in vitro activity but poor efficacy), and
amoxicillin/clavulanate or ampicillin/sulbactam. A commonly recommended
initial parenteral therapy for severe disease is a 10- to 14-day course of
ceftazidime or imipenem followed by oral doxycycline plus
trimethoprim-sulfamethoxazole to finish 20 weeks of treatment, sometimes
with chloramphenicol for the first 8 weeks. This prolonged course is to
diminish the risk of relapse.
In mild infections, an entirely oral course can be used.
Amoxicillin/clavulanate or ampicillin/sulbactam can be used, as available,
as initial parenteral therapy but has a higher failure rate. These
penicillin-betalactamase inhibitors, as available, are also used for oral
follow up therapy.
There is no commercially available vaccine for melioidosis prevention in
man, although experimental vaccines are under development and have been
used in animals. A conjugate of flagellin and lipopolysaccharide has been
found to produce IgG antibodies that protected diabetic rats from a
challenge with heterologous _B. pseudomallei_ (2). Antibodies against the
LPS II of the organisms seemed to correlate with human survival from
melioidosis when examined retrospectively (3).
1. White NJ. Melioidosis. Lancet 2003; 361: 1715-22.
2. Brett PJ, Woods DE. Structural and immunological characterization of
Burkholderia pseudomallei O-polysaccharide-flagellin protein conjugates.
Infect Immun 1996; 64: 2824-8.
3. Charuchaimontri C, Suputtamongkol S, Nilakul C, et al.
Antilipopolysaccharide II: an antibody protective against fatal
melioidosis. Clin Infect Dis 1999; 29; 813-8.
A map of Australia showing the location of the Northern Territory can be
found at <http://www.staffordmall.com/media/australia-map.gif>. - Mod.LL]