Melioidosis Explained: A Rare but Dangerous Disease

In 1911, researchers Alfred Whitmore and C.S. Krishnaswami found that morphine addicts in the Yangon area of Myanmar (formerly known as Rangoon) were getting a deadly illness that looked like glanders, a disease mainly affecting horses.

When they examined the bodies of these patients after death, they saw that their lungs were filled with a cheesy substance, and they had abscesses in their liver, spleen, kidney, and under the skin. Whitmore named the newly discovered bacterium Bacillus pseudomallei – the causative agent of melioidosis.

In 1913, a severe distemper-like illness affected the animal facility at the Institute of Medical Research in Kuala Lumpur. This was identified to be melioidosis several years later.

In 1932, researchers Stanton and Fletcher, who worked at the same institute, published a comprehensive book about melioidosis. The name of the disease was derived from the Greek words ‘melis’, meaning distemper of asses, and ‘eidos’, denoting resemblance.

In 1989, research showed that the antibiotic ceftazidime was linked to a 50% decrease in overall mortality compared to a combination of chloramphenicol, doxycycline, and trimethoprim-sulphamethoxazole. This is why Ceftazidime is widely used to treat melioidosis even today.

Melioidosis is endemic in 83 countries, primarily in South-East Asia, including Thailand and Vietnam, and Sub-Saharan Africa. The disease causes approximately 164,938 cases and 88,979 deaths each year. It is also largely located in Northern Australian region.

In addition to its endemic regions, sporadic cases of melioidosis have been reported in various countries, including Pakistan, India, Bangladesh, Indonesia, the Philippines, Sri Lanka, Papua New Guinea, Madagascar, France, Mexico, Brazil, Colombia, Venezuela, Ecuador, Iran (Middle East), and several Caribbean nations.

People at a higher risk of contracting the infection include those with diabetes, chronic kidney or lung disease, and those with direct contact with the soil, like farmers or gardeners. It’s also more frequent in those with impaired immune systems, like people living with HIV/AIDS or receiving cancer therapies. A history of alcohol abuse can also make a person more susceptible to the infection.

In Australia, melioidosis was first discovered during a sheep outbreak in 1949 in Winton, located in northern Queensland. The first recorded case in humans was reported in 1950 in Townsville, where a diabetic individual succumbed to septicemic melioidosis. In the Northern Territory, the first documented case occurred in 1960.

Between 1913 and 2018, a total of 15,202 cases of melioidosis were identified worldwide. The reported incidences varied significantly, ranging from 5 cases to 7,126 cases. Southeast Asia had the highest number of cases among the different sub-regions, with 12,518 instances, accounting for 82.5% of all cases.

Within Southeast Asia, Thailand reported the most cases, with 7,690 cases, making up 50.7% of the global total. Oceania and East Asia followed Southeast Asia, with 1,066 and 994 cases, respectively. The lowest reported cases came from Kenya, a country in Africa, with only 5 cases. Europe reported 110 cases, while America had 123 cases.

Melioidosis can spread through:

• Direct contact with contaminated soil and water.
• Infection in humans and animals occurs through inhaling contaminated dust or water droplets, consuming contaminated water, ingesting soil-contaminated food, or having contact with contaminated soil, mainly if skin abrasions exist.
• Person-to-person transmission of melioidosis is rare, but a few cases have been documented. Contaminated soil and surface water remain the primary sources of infection.
• Tropical freshwater fish pose a potential risk for melioidosis infection.
• Melioidosis can affect various animal species, including sheep, goats, swine, horses, cats, dogs, and cattle.

Once inside the body, this sneaky pathogen can wreak havoc on various organs, causing a range of symptoms. The bacteria have unique survival mechanisms that allow them to resist many antibiotics and evade host immune responses, making treatment a real challenge.

Melioidosis can be hard to diagnose because it presents with a wide range of symptoms. The average incubation period of melioidosis is 1-21 days, though it may extend beyond that in certain cases.

The most frequent signs of melioidosis include:

• Fever
• Coughing
• Chest discomfort, which could be mistaken for pneumonia.

Other symptoms may involve:

• Weight loss
• Muscle or joint pain
• Headache
• Localized swelling or abscesses
• In extreme cases, septic shock and organ dysfunction can happen.

It is crucial for healthcare professionals to recognize these symptoms early on as prompt treatment significantly improves patient outcomes.

Complications include:

• Abscess formation in organs such as the lungs, liver, and spleen
• Septicemia (life-threatening bloodstream infection)
• Multiple organ failure
• Osteomyelitis (bone or bone marrow infection)
• The potential need for amputation, especially in patients with diabetes
• Higher risk of complications for patients with underlying conditions like diabetes
• Timely detection and proper management can reduce the risk of adverse outcomes.

Melioidosis is a serious disease that requires accurate diagnosis and prompt treatment. To diagnose melioidosis, doctors perform laboratory tests, specifically culture tests of blood, urine, or sputum samples. Hence, it is vital to seek medical assistance as soon as possible if one suspects they have melioidosis since failure to do so can be life-threatening.

Once melioidosis is diagnosed, appropriate medication is employed for its treatment. The specific type and duration of treatment influence the long-term outcome.

Typically, the treatment regimen begins with intravenous administration of antimicrobial therapy, which lasts for a minimum of 2 weeks and may extend up to 8 weeks, depending on the extent of the infection.

Ceftazidime, given every 6 to 8 hours, or meropenem, administered every 8 hours, are common choices for intravenous therapy.

This is followed by a transition to oral antimicrobial treatment, lasting 3 to 6 months. Oral options include trimethoprim-sulfamethoxazole, taken every 12 hours, or amoxicillin/clavulanic acid (co-amoxiclav), taken every 8 hours. Patients with penicillin allergies should inform their doctor to receive alternative treatment options.

Here are a few preventive measures that can be implemented to safeguard against melioidosis:

• If you live in an area where melioidosis is prevalent, take precautions such as wearing protective clothing and footwear when working outdoors.
• Avoiding direct contact with the bacteria that causes the disease, which is found in soil and standing water.
• Healthcare professionals recommend wearing protective clothing when gardening or doing agricultural work to prevent skin contamination.
• Drinking boiled or bottled water instead of untreated surface water is also a smart move.
• Regular hand hygiene practices are crucial too. And if you have open wounds, proper wound care management is essential to reduce the risk of bacterial infection.

What is the survival rate for melioidosis?

The survival rate for melioidosis varies depending on early diagnosis and appropriate treatment, with prompt antibiotic therapy it can be as high as 70% to 90%.

How long can you live with melioidosis?

Melioidosis is a serious infection that requires immediate treatment, if left untreated, it can lead to severe complications and death within weeks or months of onset, however, with proper treatment, patients can recover completely.

How fatal is melioidosis?

Melioidosis has a high fatality rate if not treated promptly, mortality rates range between 40%-50%, and the risk increases among those with underlying conditions like diabetes mellitus.

What are the key facts about melioidosis?

• Melioidosis is caused by Burkholderia pseudomallei bacteria found in soil and water.
• The disease primarily affects people living in Southeast Asia and Northern Australia, but cases have been reported worldwide.
• Symptoms vary widely from fever, cough, and chest pain to more severe manifestations such as sepsis and organ failure.

Melioidosis is a severe and potentially fatal disease caused by Burkholderia pseudomallei bacteria. It poses a significant global health concern, with high mortality rates and the potential for bioterrorism. While endemic in Southeast Asia and Africa, sporadic cases have been reported in various regions.

Prevention, early diagnosis, and prompt treatment are essential in combating this infectious disease. Further research and investment in healthcare resources, especially critical care facilities, are needed to improve outcomes and reduce the impact of melioidosis on affected individuals and communities worldwide.

GIDEON is one of the most well-known and comprehensive global databases for infectious diseases. Data is refreshed daily, and the GIDEON API allows medical professionals and researchers access to a continuous stream of data. Whether your research involves quantifying data, learning about specific microbes, or testing out differential diagnosis tools– GIDEON has you covered with a program that has met standards for accessibility excellence.

Learn more about melioidosis on the GIDEON platform.

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