About Melioidosis

Key points

  • Melioidosis is a bacterial infection in people and animals.
  • Melioidosis is spread through contact with contaminated soil, air, or water.
  • Cases may increase after hurricanes, heavy rain, and other severe weather events.
  • The disease is often confused for other conditions, making diagnosis difficult.
  • Melioidosis is treated with antibiotics.
pair of work boots in standing in dirt


Melioidosis is caused by bacteria called Burkholderia pseudomallei, or B. pseudomallei. It's spread to people and animals through direct contact with soil, air, or water contaminated by the bacteria. Cases may increase after hurricanes, heavy rain, and other severe weather events because the bacteria rise to the surface of the soil.

People can get melioidosis by:

  • Breathing in contaminated dust or water droplets
  • Having contact with contaminated soil or water, especially through skin breaks (cuts, scrapes, etc.)

It's very rare for people to get the disease from another person.

Many kinds of animals can get melioidosis, including:

  • Sheep
  • Goats
  • Pigs, hogs, boar
  • Horses
  • Cats
  • Dogs
  • Cows

B. pseudomallei is mostly found in tropical climates, especially in Southeast Asia and northern Australia, where it causes widespread melioidosis. In the United States, B. pseudomallei occurs in Puerto Rico, the U.S. Virgin Islands, and the Gulf Coast area of the state of Mississippi. Most melioidosis illnesses in the United States occur in people who have traveled to areas where the disease is more common. Some cases have also occurred in people who have had contact with contaminated products made overseas.

Signs and symptoms

Melioidosis has a wide range of signs and symptoms. You usually develop symptoms of melioidosis within 1 to 4 weeks after you've been exposed to it. Some cases have developed symptoms months or years after exposure. The disease can affect one body system or affect the entire body. Because of these factors, melioidosis is hard to diagnose and may be mistaken for other diseases.

Sometimes the illness is just in one area (localized), and it may look like an ulcer or skin sore. You might have a fever, swelling, and muscle aches.

Most often, melioidosis shows up as a lung infection. You might have a cough, chest pain, high fever, headache, and you might not feel like eating.

Whether you've just come down with melioidosis or you've had it for a long time, it can affect different organ systems throughout the body (disseminated infection). It can cause problems with the liver, spleen, prostate, joints, bones, lymph nodes, skin, or brain. Melioidosis can lead to a dangerous bloodstream infection (sepsis).

Symptoms of disseminated infection include:

  • Fever
  • Headache
  • Trouble breathing
  • Stomach or chest pain
  • Muscle pain
  • Confusion
  • Seizure

Risk factors

Although healthy people may get melioidosis, having the following medical conditions may increase your risk:

  • Diabetes
  • Heavy alcohol use
  • Liver disease
  • Kidney disease
  • Thalassemia (a blood disorder)
  • Cancer, or another condition that weakens the immune system
  • Chronic lung disease, like cystic fibrosis, chronic obstructive pulmonary disease (COPD), or bronchiectasis

Certain activities also may increase your risk of being exposed to the bacteria that causes melioidosis, including:

  • Travel to areas where the disease is common.
  • Breathing in contaminated water droplets or soil dust that get into the air after severe weather like hurricanes or heavy rainfall.
  • Hobbies or jobs that could put you in contact with contaminated soil or water.
  • Drinking unchlorinated or untreated drinking water.

Reducing risk

In areas where the disease is widespread, contact with contaminated soil or water can put people at risk for melioidosis. To help lower the risk of exposure:

  • If you have open skin wounds, or if you have chronic conditions like diabetes or kidney disease, avoid contact with soil and standing water.
  • If you perform agricultural work or have hobbies or jobs that raise your risk of exposure, wear boots, which can prevent infection through your feet and lower legs.
  • Healthcare workers can use standard precautions when treating patients with melioidosis to help prevent infection. They should also label samples appropriately if they suspect melioidosis to protect lab personnel.
  • Laboratory personnel should follow good laboratory practices, including using appropriate personal protective equipment (PPE) and respiratory protection.

Treatment and recovery

If you are diagnosed with melioidosis, doctors will decide how long you'll need treatment based on how bad the infection is. Treatment generally includes:

It's important to complete your treatment so that the infection goes away completely.

What CDC is doing

One reason public health authorities study the disease is because the bacteria that cause melioidosis might be used as a weapon in a biological attack. A biological attack is the intentional release of pathogens (germs) that can sicken or kill people, livestock, or crops.

We don't know if this kind of attack will ever happen. CDC and other federal agencies prepare for many of biological attacks to protect as many people as possible.

CDC works with state, tribal, local, and territorial agencies to investigate potential cases of melioidosis. Among other cases, in 2021, CDC linked four cases of melioidosis in patients from Georgia, Kansas, Minnesota, and Texas. A public health investigation eventually linked all cases to a commercially imported product from a melioidosis-endemic country that each of the patients used in their homes.

B. pseudomallei was recently found to occur naturally in the Gulf Coast region of the United States. CDC is working with health departments to learn more about how widespread the bacteria is and what impact it's having on health.