Published Date: 2006-08-20 00:00:00
Subject: PRO/EDR> Melioidosis 2005 - USA (FL) ex Honduras
Archive Number: 20060820.2334
MELIOIDOSIS 2005 - USA (FLORIDA) EX HONDURAS
A ProMED-mail post
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International Society for Infectious Diseases
Date: Fri, 18 Aug 2006
From: ProMED-mail <email@example.com>
Source: Morbidity and Mortality Weekly Report 2006; 55: 873-76 [edited]
In 2005, 2 cases of melioidosis (1 in Aug, 1 in Oct) were reported to
the Florida Department of Health, the first cases since reporting the
disease became mandatory in Florida in 2003. In one case,
_Burkholderia pseudomallei_ was not recognized as the bacterium that
causes the disease melioidosis, which led to a delay in reporting the
case to the local health department. In both cases, delayed
recognition and unsafe laboratory practices resulted in laboratory
workers being exposed to _B. pseudomallei_.
This report summarizes the clinical and laboratory aspects of the
cases and the epidemiologic study conducted by the Florida Department
of Health. The findings emphasize the need for improved laboratory
recognition and reporting of _B. pseudomallei_, safe laboratory
handling of _B. pseudomallei_, and close adherence to antibiotic
regimens for treating and preventing recurrence of melioidosis.
Melioidosis is a potentially serious illness caused by the
gram-negative, saprophytic bacterium _B. pseudomallei_ (formerly
_Pseudomonas pseudomallei_). Most commonly, the disease manifests as
pneumonia, with or without septicemia, but melioidosis also can cause
abscesses, particularly of the skin and soft tissues. Abscesses of
the internal organs are less common (1). Melioidosis is endemic in
Southeast Asia and northern Australia but can be found sporadically
in tropical areas between latitudes 20 DEGREES north and south (2).
In areas where melioidosis is endemic, humans become infected by
inoculation and inhalation through exposure to organisms in soil and
water (2); the median incubation period from exposure to illness
onset is 9 days (range: 1-21 days). Persons with type 2 diabetes are
especially susceptible to symptomatic infection; additional risk
factors include thalassemia, renal disease, chronic alcoholism, and
liver disease (2). Human immunodeficiency virus has not been
determined to be a risk factor (2).
Asymptomatic infections can arise, and symptomatic reactivation of
the disease can occur years after exposure. Where melioidosis is
endemic, the case-fatality rate for cases with septicemia and
pulmonary involvement ranges from 20 to 50 percent. Reduced fatality
rates have been associated with improved antibiotic regimens and
supportive care (2).
Case 1: Broward County. On 22 Aug 2005, a man aged 48 years with a
history of adult-onset diabetes and Guillain-Barre syndrome was
evaluated at a local hospital for back pain, fever (102.6 degrees F
[39.2 degreees C]), and bilateral lower extremity weakness and
numbness. He received a diagnosis of left lower lobe pneumonia,
perirectal abscess, which was drained on admission, and possible
recurrent Guillain-Barre syndrome. He was admitted for antibiotic
treatment with ceftriaxone and azithromycin.
On 27 Aug 2005, _B. pseudomallei_ was identified in cultures of blood
drawn on admission. On 31 Aug 2005, the patient was discharged with a
prescribed 21-day regimen of oral levofloxacin. On 11 Sep 2005, he
returned with severe back and left-sided pleuritic chest pain. In the
emergency department, he had onset of acute bilateral leg paralysis
and sensation loss. Spinal magnetic resonance imaging revealed
epidural abscesses along thoracic vertebrae T6-T10. The patient
underwent emergency surgery for spinal decompression. On 16 Sep 2005,
_B. pseudomallei_ was isolated from cultures of abscess fluid. On 26
Sep 2005, the patient remained paraplegic and was discharged to
inpatient rehabilitation, with a prescribed regimen of 8 weeks of
intravenous imipenem/cilastatin and ceftazidime followed by 20 weeks
of oral antibiotics.
The epidemiologic investigation determined that the patient had
traveled to Honduras during 17 Jul-7 Aug 2005, where he visited the
city of La Ceiba (capital of Atlantida Department) and the island of
Roatan. He had not been ill while traveling and did not recall being
injured. He traveled with 7 family members who were not ill and had
no known contact with ill persons. In addition, the patient reported
that before his trip to Honduras, he had never traveled out of the country.
Case 2: Miami-Dade County. On 22 Sep 2005, a woman aged 80 years was
admitted to a local hospital with pneumonia after 4 days of fever
(103 degrees F [39.4 degrees C]), headache, weakness, and muscle
pain. She was treated with intravenous fluids, ceftriaxone, and
azithromycin. On 23 Sep 2005, she experienced a myocardial infarction
and respiratory complications, and on 24 Sep 2005, her antibiotics
were changed to vancomycin and cefepime but died on that day. On 26
Sep 2005, local public health authorities were notified that _B.
pseudomallei_ had been identified in a culture of blood drawn when
the patient was admitted. The isolate was sent to the Florida
Department of Health reference laboratory in Miami, where the
presence of _B. pseudomallei_ organisms was corroborated by real-time
polymerase chain reaction.
The epidemiologic investigation indicated that the patient had been a
resident of San Juan Pueblo in Atlantida Department in Honduras. She
had arrived in Florida on 18 Sep 2005 to visit family members.
On 4 Oct 2005, more than 5 weeks after _B. pseudomallei_ organisms
had been isolated in case 1, the Broward County Health Department
received the report from the hospital infection-control practitioner.
No isolates had been saved for confirmation at the state public
health laboratory. An investigation into the hospital's reporting
procedures for this case determined that the laboratorians handling
the specimens did not associate the organism _B. pseudomallei_ with
the disease melioidosis, which is a mandatory reportable disease in Florida.
Laboratorians from the hospitals in Broward County and Miami-Dade
County were contacted on 12 Oct 2005 and 26 Sep 2005, respectively,
regarding the possibility of exposure while handling the specimens.
Exposures were considered high risk if isolates had been manipulated
outside of a biosafety cabinet or if isolate manipulation could have
resulted in aerosol or droplet formation (e.g., sniffing an open
culture plate to detect characteristic odors emitted by certain
bacteria). A total of 9 laboratorians (6 from the Broward County
hospital and 3 from the Miami-Dade County hospital) had high-risk
exposures. All were offered prophylaxis and _anti-B. pseudomallei_
antibody testing. The 3 laboratorians in the Miami hospital
reportedly sniffed the culture plates, and all requested prophylaxis.
None of the 6 laboratorians in the Broward County hospital had
sniffed the plates containing _B. pseudomallei_, but they all had
handled the cultures outside of a biosafety cabinet. On 19 Oct 20!
05, specimens for diagnostic serology were obtained from these 6
laboratorians; all were negative for presence of _B. pseudomallei_,
and no prophylaxis was prescribed. None of the 9 exposed
laboratorians reported symptoms consistent with melioidosis.
[Reported by: A Kite-Powell, MS, JR Livengood, MD, J Suarez, R
Hopkins, MD, Florida Dept of Health. TA Clark, MD, Div of Foodborne,
Bacterial, and Mycotic Diseases, National Center for Zoonotic,
Vector-Borne, and Enteric Diseases (proposed); D Chertow, MD, EIS Officer, CDC]
MMWR Editorial Note:
Melioidosis is a rare disease in the USA; approximately 5 cases are
reported annually, although it is not a nationally notifiable disease
(3). The cases in this report are the first to be reported from
Florida. However, melioidosis is a relatively common disease in areas
where it is endemic, is likely underreported in nonendemic tropical
areas (4), and can affect travelers returning from tropical regions
(5). The bacteria are found in contaminated water and soil in
melioidosis-endemic areas worldwide. The organisms can be aerosolized
and are capable of producing severe and even fatal illness. No
vaccine is available to prevent melioidosis (2, 6).
A current treatment recommendation for melioidosis includes an
initial intensive treatment phase followed by eradication therapy
[for box, see original URL - Mod. LL]. Relapse rates can increase
from 10 to 30 percent when antibiotic treatment is conducted for less
than 8 weeks (1). Laboratory workers with high-risk exposures can be
offered postexposure prophylaxis with doxycycline (2 mg/kg up to 100
mg orally, twice daily) or trimethoprim-sulfamethoxazole (8 + 40
mg/kg, up to 320 + 1600 mg orally, twice daily) (7), but the optimum
duration of treatment and its efficacy have not been defined clearly
by human studies. Serologic assays are not readily available for _B.
pseudomallei_ and are not useful in endemic settings (because they do
not differentiate between active infection and background
seroprevalence) but have proven useful for previously unexposed
persons who have experienced a high-risk exposure (2, 5).
_B. pseudomallei_ has been classified as a category B biologic
terrorism agent by CDC.* All Level A laboratories, such as private
clinical laboratories and hospital laboratories, should have
procedures for isolation and presumptive identification of potential
biologic terrorism agents, including timely submission of isolates to
a laboratory in the Laboratory Response Network (LRN) ** that is
capable of confirmatory testing and reporting of cases to local
public health authorities. To improve the existing system and
minimize human error in identifying possible biologic terrorism
agents, the Broward County Health Department is exploring new methods
with local hospital information technology staff. For example, a
system might automatically produce a written alert and
reporting-requirement instructions on laboratory printouts when
particular organisms are detected.
Although risk for occupational exposure to _B. pseudomallei_ in
clinical laboratories exists, laboratory-acquired infections are
rare. Laboratory exposures that have resulted in the most recent
cases of infection involved aerosols, alone or in combination with
exposure to nonintact skin (8). In one study, 3 cases of asymptomatic
seroconversion were reported among laboratorians in an area where
melioidosis is endemic, making difficult a determination of whether
infection resulted from occupational or environmental exposure (9).
CDC recommends that clinical specimens suspected of containing _B.
pseudomallei_ be manipulated using biosafety level (BSL)-2
containment practices, equipment, and facilities (10). Sniffing
culture plates is an unsafe laboratory procedure and should be
prohibited. Manipulations of an isolate that might result in aerosol
or droplet exposure or contact with nonintact skin should be
conducted using BSL-3 containment practices, equipment, and
facilities. In addition, improved communication between physicians
and laboratorians might reduce the risks to laboratorians.
Clinicians should notify laboratorians when specimens are obtained
from patients with symptoms, risk factors, or history suggestive of
1. White NJ: Melioidosis. Lancet 2003;361: 1715-22.
2. Cheng AC, Currie BJ: Melioidosis: epidemiology, pathophysiology,
and management. Clin Microbiol Rev 2005;18: 383-416.
3. CDC: Melioidosis. Disease listing. Atlanta, GA: US Department of
Health and Human Services, CDC; 2006. Available at
4. Dance DA: Melioidosis as an emerging global problem. Acta Trop
5. Currie BJ: Melioidosis: an important cause of pneumonia in
residents of and travelers returned from endemic regions. Eur Respir
J 2003;22: 542-50.
6. Jeddeloh JA, Fritz DL, Waag DM, et al: Biodefense-driven murine
model of pneumonic melioidosis. Infect Immun 2003;71: 584-87.
7. CDC: Laboratory exposure to Burkholderia pseudomallei---Los
Angeles, California, 2003. MMWR 2004;53: 988-90.
8. Sewell DL: Laboratory-associated infections and biosafety. Clin
Microbiol Rev 1995;8: 389-405.
9. Ashdown LR. Melioidosis and safety in the clinical laboratory. J
Hosp Infect 1992;21: 301-306.
10. CDC, National Institutes of Health: Biosafety in microbiological
and biomedical laboratories, 4th ed. Washington DC: US Government
Printing Office; 1999.
* Category B agents (i.e., second highest priority agents) include
those that are moderately easy to disseminate, result in moderate
morbidity rates and low mortality rates, and require specific
enhancements of CDC's diagnostic capacity and enhanced disease
surveillance. Additional information available at
** The LRN, established by CDC in 1999, is an integrated national and
international network of laboratories that are equipped to respond
rapidly to acts of chemical or biologic terrorism, emerging
infectious diseases, and other public health threats and emergencies.
Additional information available at <http://www.bt.cdc.gov/lrn>.
[This is an excellent discussion regarding the laboratory hazards of
_B. pseudomallei_. Meliodoisis is primarily reported from areas of
southeastern Asia and northern Australia. ProMED has previously
posted infection from Brazil. A map of Honduras showing the location
of La Ceiba (capital of Atlantida Department) and the island of
Roatan can be found at: <http://www.turq.com/honduras/largemap.php>. - Mod.LL]