3. Overview
Melioidosis is an infectious disease:
o caused by the environmental gram-negative
bacterium Burkholderia pseudomallei
o Found in surface water and soil.
o recognized as a pediatric disease in the endemic
regions of tropical South East Asia & Northern
Australia. May also present in nonendemic areas.
Infection can be acute, chronic or latent.
Melioidosis can be asymptomatic or can manifest as a
localized infection or as fulminant septicemia.
5. Epidemiology
• Melioidosis is endemic in parts of southeast
Asia (Thailand, Laos, Singapore, Brunei, Malaysia,
Burma, Cambodia and Vietnam), China, Taiwan and
northern Australia.
• Also found in India, Central and South America, the
Middle East, the Pacific and several African countries
• In Laos, a high isolation frequency was found in
Vientiane capital and Vientiane province.
11. Pathogen
Burkholderia genus comprises more than 90 species.
Burkholderia pseudomallei (Pseudomonas
pseudomallei): motile, aerobic, Rod-shaped bacterum,
gram-negative bacillus, bipolar staining, length 2-5 μm
and diameter 0.4-08 μm.
Other species include: B. cepacia, B. gladioli, B. mallei,
B. thailandensis, B. oklahomensis.
12.
13. Environmental exposure and contact with
contaminated fomites
• Cutaneous inoculation: contaminated with water
or soil
• Inhalation: Aerosolizes organisms or dust
particles containing organisms.
• Aspiration: Near-drowning
• Ingestion: contaminated soil or water or food.
• Can be laboratory exposure: proper technique or
personal protective.
Person to person (rare): hospital exposure, human
milk transmission.
Route of acquisition
14. Incubation period
depends on:
• Amount of inoculum, mode of transmission
• host risk factors
• Presents much earlier following inhalational/aspiration
events, wet season.
• Incubation period range 1-21 days (mean 9 days)
• Latent period range 14-24 years (possibly up to 62
years)
15. Risk Factor
Diabetes 23-60%
Chronic kidney disease 10-27%
Thalassemia 7%
Malignancy 5%
Steroid use 5%
Chronic pulmonary disease 12-27% (COPD,
Cystic fibrosis, bronchiectasis)
Immune-suppressing condition not related to HIV
Occupations contact with soil and water
Rainy season >75% of cases
16. Classification
Classification
Number
of organ
involved
Blood
culture
Severity of illness
Mortality
rate
Melioidosis with septic
shock
Any positive
Fulminant sepsis /
septic shock
80-90%
Disseminated septicemic
melioidosis
>1
Positive
(mostly)
Sepsis to severe
sepsis
40-50%
Septicemic melioidosis 1 positive
Sepsis to severe
sepsis
10-40%
Localized melioidosis 1 Negative Fever to sepsis 0-10 %
Bacteremia melioidosis 0 Positive Nil to fever 0%
Asymptomatic melioidosis 0 Negative Healthy 0%
ເອກະສານປະກອບການສອນ
melioidosis ໂດຍ นายแพทย์พัชรสาร
17. Sign and Symptoms
• Fever and chill (variable)
• Pneumonia
• Skin ulcer and abscesses
• Bacteremia and sepsis
• Septic arthritis or Osteomyelitis
• Encephalomyelitis
• Suppurative Parotitis
• Internal organs abscesses
19. Pediatric melioidosis commonly manifests as localized
cutaneous disease in immunocompetent hosts.
The disease can be fatal, especially in individuals with risk
factors for disease.
Melioidosis with encephalomyelitis can result in severe residual
disability
Prompt diagnosis requires a high index of clinical suspicion in
endemic area
Pediatric Melioidosis: An update. CID 2015:60. McLeod et al
Clinical of Melioidosis in
children
23. Summary of clinical manifestation of melioidosis
Asymptomatic
seroconversion
Mos common, as suggested by seroprevalence studies in endemic regions
Many risk factors are described for infection
Acute infection (85%)
Mean incubation period approximately 9 days (range 1-21 days), but
presents much earlier following inhalation/aspiration events. Wet season.
Symptom duration <2months most develop acute melioidosis, with 50%
bacteraemia on presentation, and approximately 20% develop septic shock.
Pulmonary infection
Pediatric presentations 20%
Variable radiologic appearances: minimal infiltrates/cavitation/diffuse
parenchymal disease
Cutaneous infection
Pediatric presentations 60%
Single lesions are typically of sign of inoculation
Pyogenic infection
Parenchymal visceral abscesses are common including spleen, liver, kidneys
Prostatic abscess/parotitis
Central nervous system
infection
Intracerebral abscesses: thought to be secondary to bacteraemic spread
Encephalomyelitis: typically produces brainstem signs
Bone/joint infection
Seen in 4% of cases, due to direct extension of through hematogenous
spread
Other (rare)
Mycotic aneurysms, pericarditis, mediastinal masses, thyroid and scrotal
abscesses
24. Summary of clinical manifestation of melioidosis
Chronic infection
Defined as symptom >2 months
Much better prognosis then acute melioiidosis
Pulmonary infection
Fever, weight loss and productive cough, often mimics pulmonary
tuberculosis
Predominantly upper lobe infiltrates on chest radiography
Cutaneous infection
Non-healing cutaneous lesion, often unresponsive to multiple courses of
antibiotics
Reactivation of latent
disease (4%)
Typically pulmonary reactivation disease
Latent periods 14-24 years (possibly up to 62 years)
Risk factors
Concurrent infections: influenza, bacterial sepsis
Traditional risk factors for disease are diabetes mellitus, hazardous alcohol
intake, chronic renal disease and/or urolithiasis and chronic lung disease.
(Chakravorty and Heath 2019)
25. Diagnosis
Culture (gold standard): blood, sputum, throat,
urine, rectum, and ulcer or skin lesion specimens.
A throat swab is not sensitive (34%), but is 100%
specific if positive. (J Clin Microbiol. 2001 Oct; 39(10):3801-3802)
Polymerase chain reactive (PCR): more rapid than
culture but less sensitive.
28. Intensive phase:
Ceftazidime 50mg/kg/dose Q8H for 2 weeks (max 2g
Q8H)
Meropenem 50mg/kg/dose Q8H (max 1gQ8H)
(severe/bacteremia or neurologic involve) for 4 weeks
Eradication phase:
Co-trimoxazole 8mg/kg/day (TMP) or 40mg/kg/day
(SMX) divide BID for 12-20 weeks after intensive phase.
(max 160/800mg BID for W <40kg and 320mg/1600mg
BID for W>40kg)
Co-amoxiclav 25mg/kg/dose (amoxi) TID for 12-20
weeks (max 1000mg Amox TID for W<60kg, and
1500mg Amox TID for W>60kg)
Management
Lao pediatric Antimicrobial Prescribing Guidelines ສະບ
ັ ບທ
ີ 1, 2020
29. Management
Notes:
Folic acid 0.1mg/kg/day (max 5mg) in case taking Co-
trimoxazole for long time, and follow CBC monthly.
Localized infection in endemic area with/without other
pathogen and no organ involved, consider started in
Eradication phase if culture negative.
30. Prognosis
The mortality from acute melioidosis is 20-50% worldwide
Mortality is even higher (>50%) in resource-poor settings
with limited to diagnosis and ICU facilities.
Host comorbidities are key factors in determining disease
severity (adult)
Thai data determining that independent risk factors for
death and treatment failure are bacteraemia, respiratory
failure, renal failure and age >50%
Prognosis for Neurologic melioidosis is guarded
Outcome for patients with chronic melioidosis are much
better than for those with acute melioidosis
Limited data for reactivation of latent infection.
31. Prevention
o Avoiding direct contact with soil and water at the start
of each rainy season
o Wear protective gear (boots and gloves) if direct
contact with soil or water is necessary
o Drink bottled or boiled water
o Avoid outdoor exposure to heavy rain or dust clouds
o Discourage the application of herbal remedies or
organic substances to wounds.
32. Reference
1. Chakravorty, Arindam, and Christopher H Heath. 2019. “Melioidosis: An Updated Review.” Australian Journal of General Practice, May, 327–
32. https://doi.org/10.31128/AJGP-04-18-4558.
2. Chandna, Arjun, Moritz Bonhoeffer, Thyl Miliya, Keang Suy, Sena Sao, and Paul Turner. 2021. “Improving Treatment and Outcomes for
Melioidosis in Children, Northern Cambodia, 2009–2018.” Emerging Infectious Diseases 27 (4): 1169–72.
https://doi.org/10.3201/eid2704.201683.
3. Dance, David A.B., Manophab Luangraj, Sayaphet Rattanavong, Noikaseumsy Sithivong, Oulayphone Vongnalaysane, Manivanh
Vongsouvath, and Paul N. Newton. 2018. “Melioidosis in the Lao People’s Democratic Republic.” Tropical Medicine and Infectious Disease 3 (1):
21. https://doi.org/10.3390/tropicalmed3010021.
4. Mohan, Anand, Yuwana Podin, Nickson Tai, Chae-Hee Chieng, Vanessa Rigas, Barbara Machunter, Mark Mayo, et al. 2017. “Pediatric
Melioidosis in Sarawak, Malaysia: Epidemiological, Clinical and Microbiological Characteristics.” Edited by Pamela L. C. Small. PLOS Neglected
Tropical Diseases 11 (6): e0005650. https://doi.org/10.1371/journal.pntd.0005650.
5. Rachlin, Audrey, Sabine Dittrich, Koukeo Phommasone, Anousone Douangnouvong, Rattanaphone Phetsouvanh, Paul N. Newton, and
David A. B. Dance. 2016. “Investigation of Recurrent Melioidosis in Lao People’s Democratic Republic by Multilocus Sequence Typing.” The
American Journal of Tropical Medicine and Hygiene 94 (6): 1208–11. https://doi.org/10.4269/ajtmh.15-0909.
6. Rachlin, Audrey, Manophab Luangraj, Mirjam Kaestli, Sayaphet Rattanavong, Phonelavanh Phoumin, Jessica R. Webb, Mark Mayo, Bart J.
Currie, and David A. B. Dance. 2021. “Using Land Runoff To Survey the Distribution and Genetic Diversity of Burkholderia Pseudomallei Strains
in Vientiane, Laos.” Edited by Jeremy D. Semrau. Applied and Environmental Microbiology 87 (4): e02112-20.
https://doi.org/10.1128/AEM.02112-20.
7. Sanderson, Christine, and Bart J. Currie. 2014. “Melioidosis: A Pediatric Disease.” Pediatric Infectious Disease Journal 33 (7): 770–71.
https://doi.org/10.1097/INF.0000000000000358.
8. Wiersinga, W. Joost, Harjeet S. Virk, Alfredo G. Torres, Bart J. Currie, Sharon J. Peacock, David A. B. Dance, and Direk Limmathurotsakul.
2018. “Melioidosis.” Nature Reviews Disease Primers 4 (1): 17107. https://doi.org/10.1038/nrdp.2017.107.
9. https://www.melioidosis.info/map.aspx
10. Up-to-date
11. Red book 2018 (p 258-260)
12. Nelson book
13. Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit (LOMWRU).2013
14. Lao paediatric antimicrobial prescribing guidelines, 1st edition, 2020 (page 113-115)
15. ເອກະສານປະກອບການສອນม คณะแพทยศาสตร ์มหาวิทยาลัยศรีนครินทรวิโรฒ: Melioidosis, นายแพทย์พัชรสาร ลีนะสมิต
