Clinical Overview of Melioidosis

Key points

  • Melioidosis is caused by Burkholderia pseudomallei bacteria. Melioidosis has a wide range of signs and symptoms and can be mistaken for other diseases. Clinicians should consider melioidosis if a patient reports recent travel to an endemic area or contact with contact with freshwater (including floodwater) or soil in the U.S. Gulf Coast. Healthy people can get melioidosis, but certain immunocompromising conditions put people at higher risk for the disease.
man in hospital bed

Overview

Melioidosis is an emerging disease in the Western Hemisphere, including the United States, and some countries within the Caribbean, Central America, and South America. Melioidosis is widespread in Southeast Asia and Australia. There is a wide range of clinical presentations and healthcare workers who suspect melioidosis in a patient should begin treatment as soon as possible and confirm a diagnosis with lab testing.

Melioidosis cases may increase after hurricanes, heavy rain, and other severe weather events. Clinicians should consider melioidosis if a patient reports recent travel to an endemic area or the Gulf Coast region of the southern United States, especially if they report activities involving:

  • Handling soil, like gardening, agriculture, or construction
  • Contact with fresh water, such as wading or swimming in floodwaters, lakes, ponds, or rivers
  • Response or recovery efforts after a hurricane or flooding event

OR

  • If they have risk factors, including diabetes, liver disease, renal disease, thalassemia, heavy alcohol use, cancer, immune-suppressing conditions not related to HIV, or chronic lung disease (such as cystic fibrosis, chronic obstructive pulmonary disease (COPD), and bronchiectasis)

Public health officials and healthcare providers:‎

CDC's Bacterial Special Pathogens Branch is available 24/7 for consultations on melioidosis with public health officials or healthcare providers who have urgent inquiries related to patient management. Public health officials and healthcare providers with urgent inquiries should call the CDC Emergency Operations Center at 770-488-7100 and request BSPB's on-call epidemiologist. Public health officials or healthcare providers with non-urgent inquiries should email bspb@cdc.gov and will receive a response during business hours Monday-Friday.

Types of melioidosis infection

Generally, symptoms appear 1 to 4 weeks after exposure to B. pseudomallei bacteria.

Melioidosis can be localized or disseminated, and sub-clinical infections are also possible.

A localized infection often presents as an ulcer, nodule, or skin abscess. Symptoms generally include fever and myalgias. Melioidosis most commonly presents as a pulmonary infection:

  • Can present clinical picture of mild bronchitis to severe pneumonia
  • Cough is the hallmark of pulmonary melioidosis, and it may be nonproductive or productive
  • Symptoms may include high fever, chest pain, headache, anorexia, and myalgias
  • Lesions on chest X-ray that might appear similar to those seen in pulmonary tuberculosis

Both chronic and acute melioidosis can lead to disseminated infection and rapid-onset septicemia can occur. These conditions are more common in patients with underlying risk factors including diabetes and renal insufficiency. Abscesses may be found throughout the body, notably in the liver, spleen, or prostate. Involvement of joints, bones, viscera, lymph nodes, skin, or brain are also possible.

Symptoms include:

  • Fever
  • Headache
  • Respiratory distress
  • Abdominal or chest discomfort
  • Myalgias
  • Disorientation
  • Seizure

For urgent or technical clinical questions, contact bspb@cdc.gov or call the CDC 24/7 Emergency Operations Center at 770-488-7100.

Testing and reporting

Melioidosis is diagnosed by isolating B. pseudomallei from blood, urine, sputum, skin lesions, cerebrospinal fluid, oropharyngeal swab, rectal swab, or abscesses, or by detecting an antibody response to the bacteria.

If B. pseudomallei is identified or suspected, contact your local public health department immediately. The health department can facilitate forwarding the isolate for confirmation to the closest reference laboratory and initiate a public health investigation.

Melioidosis (case definition) is a nationally notifiable condition (NNC) using the Council of State and Territorial Epidemiologists (CSTE) criteria for case notifications. The case reporting form can be emailed or faxed to CDC. State health departments can directly report cases via DCIPHER through SAMS credentialing. To request DCIPHER access, for more information about the system, or if there are other surveillance-related questions, contact BSPB at bspb@cdc.gov.

Burkholderia pseudomallei is a Tier 1 select agent. Tier 1 select agents require additional security measures to safeguard them from theft, loss, or release.

Label samples to avoid lab exposure‎

If you suspect a patient has melioidosis, be sure to appropriately label the samples and note the suspicion in lab orders to avoid exposures in laboratory personnel.

Patient management

Patients generally present with acute illness, but around 10 percent present with chronic melioidosis, ongoing illness of at least two months. Long-term outcomes and survival depend on disease severity and course of treatment.

Treatment consists of an initial intensive phase, followed by an eradication phase:

Initial intensive therapy lasts 2 weeks to more than 8 weeks:

  • Intravenous antibiotics
    • Ceftazidime, every 6–8 hours (or 24-hour infusers) OR
    • Meropenem, every 8 hours for critically ill patients or patients with CNS involvement

AND

  • Oral antibiotics for patients with non-pulmonary focal sites of infection
    • First choice: Trimethoprim-sulfamethoxazole (TMP-SMX), every 12 hours with folic acid to prevent or reduce antifolate toxicity OR
    • Amoxicillin/clavulanic acid (co-amoxiclav), every 8 hours OR
    • Doxycycline, once daily OR every 12 hours

Eradication therapy lasts 3 months to more than 6 months:

  • First choice: Trimethoprim-sulfamethoxazole (TMP-SMX), every 12 hours with folic acid to prevent or reduce antifolate toxicity OR
  • Amoxicillin/clavulanic acid (co-amoxiclav), every 8 hours OR
  • Doxycycline, once daily OR every 12 hours

If antibiotics are not taken for the length of time prescribed, early recrudescence or subsequent relapse can occur, usually within 1 to 2 years.

See Also: Read the detailed summary of treatment guidance and recommendations.

Post-exposure prophylaxis

Laboratory personnel who handle specimens from patients suspected of having melioidosis or cultures of B. pseudomallei are at risk of laboratory-acquired melioidosis. If they have a high-risk exposure in a lab, or if they have risk factors for melioidosis and a low-risk exposure, they should begin post-exposure prophylaxis (PEP) immediately.

In the event of a public health emergency involving B. pseudomallei or B. mallei infections, PEP should be given to anyone potentially exposed.

PEP should be administered for 21 days. If the Burkholderia strain is susceptible and the patient does not have a documented allergy to it, oral trimethoprim/sulfamethoxazole (TMP-SMX) is the agent of first choice. If the organism is resistant to TMP-SMX or the patient has an allergy to it, the second-line choice is amoxicillin/clavulanic acid.

Keep Reading: Treatment of and PEP for B. pseudomallei and B. mallei Infection

For urgent or technical clinical questions, contact bspb@cdc.gov or call the CDC 24/7 Emergency Operations Center at 770-488-7100.

Resources

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Content Source:
National Center for Emerging and Zoonotic Infectious Diseases (NCEZID)