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 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
Signs and Symptoms


Melioidosis is an emerging disease in the United States, Mexico, and South America, and it's widespread in Southeast Asia and Australia. There are few cases in the U.S. and a wide range of clinical presentations, so healthcare workers should confirm a diagnosis with lab testing and begin treatment as soon as possible.

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 any occupational or recreational activities involving the handling of soil, like gardening, agriculture, or construction
  • Have had recent contact with water, such as swimming or fishing in lakes, ponds, or rivers
  • 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)

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 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

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 about 9 percent present with ongoing illness of at least two months. Long-term outcomes and survival depend on disease severity and course of treatment.

Treatment generally consists of intravenous followed by oral antimicrobial therapies:

Intravenous (IV) round lasts from 2 weeks to more than 8 weeks:

  • Ceftazidime, every 6–8 hours
  • OR if the illness is critical, meropenem, every 8 hours

Followed by oral antimicrobial therapy, which lasts 3 to more than 6 months:

  • First choice: Trimethoprim-sulfamethoxazole (TMP-SMX), every 12 hours
  • OR Amoxicillin/clavulanic acid (co-amoxiclav), every 8 hours
  • OR Doxycycline, once daily at 200 mg OR every 12 hours at 100 mg

If oral antibiotics are not taken for the length of time prescribed, recurrence is common. Be aware that even after treatment is completed, relapse may occur.

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.

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