What Is Melioidosis?

Overview

Melioidosis is predominantly a disease in subtropical and tropical regions and can affect both humans and animals. Clinical manifestations of melioidosis can range from localised infections to extensive abscesses and pneumonia. Direct inoculation, inhalation, or ingestion are three common methods of transmission. Common risk factors for melioidosis are diabetes mellitus, alcoholism, and immunosuppression.

Introduction

Melioidosis, also commonly known as Whitmore's illness, is an infection that can affect both humans and animals caused by the bacterium Burkholderia pseudomallei or B. pseudomallei. The bacteria is widely found in contaminated soil and water in tropical and subtropical climates, most notably in Southeast Asia and Northern Australia, and is most common during the rainy seasons.¹

Transmission

Melioidosis can be caused by coming into direct contact with B. pseudomallei contaminated soil or water. It is quite uncommon for someone to contract the sickness from another person. While a few cases have been identified, polluted soil and surface water remain the principal sources of contamination. Inhaling contaminated dust or water droplets, drinking contaminated water, or having direct contact with contaminated soil or water through cuts, wounds, or skin abrasions can all lead to melioidosis.²

Animals that are susceptible or vulnerable to melioidosis include:

• Sheep
• Goats
• Swine
• Horses
• Cats
• Dogs
• Cattle

Symptoms

The time between exposure to the bacteria that causes the disease and the onset of symptoms is known as the "incubation period". Although it might take anything from one day to several years, symptoms often start to show two to four weeks after exposure.

Melioidosis can present in various ways depending on the type/form, and this can range from minor symptoms to serious infections that could be lethal. Fever, coughing, breathing issues, chest pain, skin ulcers, abscesses, joint pain, headaches, and confusion are possible symptoms. The lungs, liver, spleen, kidneys, and skin are just a few of the various organs that the illness may impact.

Although healthy people may get melioidosis, underlying medical conditions can increase the risk of the disease. The major risk factors are:

• Diabetes
• Liver disease
• Renal/Kidney disease
• Thalassemia - a genetic blood disorder in which your blood has less haemoglobin than normal
• Cancer
• Other conditions that weaken the immune system (Not related to HIV)
• Chronic Lung diseases such as bronchiectasis, chronic obstructive pulmonary disease (COPD), and cystic fibrosis

Complications of melioidosis:

The disease can spread to most parts of your body and cause complications, such as:

• Bone infection (osteomyelitis)
• Joint infection (septic arthritis).
• Abscesses in the skin, lungs, liver, spleen, brain or other organs.
• Acute respiratory distress syndrome (ARDS).
• Sepsis (a potentially fatal immune response to infection that causes organ damage).

Diagnosis

Diagnosing melioidosis can be challenging due to its diverse clinical presentations. Laboratory tests, including blood cultures and molecular techniques, are typically used to confirm the presence of Burkholderia pseudomallei in samples.³

Samples can include:

• Blood
• Urine
• Phlegm (sputum)
• Pus swab

For treatment to be successful, early diagnosis is essential.

Treatment

Melioidosis is mainly treated with antibiotics, often requiring an initial/intensive phase of intravenous antibiotics followed by a prolonged/eradication course of oral antibiotics. The choice of antibiotics depends on the severity of the infection and the patient's overall health.

• In the intensive/Initial phase, your healthcare provider will give you medicine through an IV (directly into a vein) for at least two weeks.

Intravenous therapy consists of:

Ceftazidime is administered every 6–8 hours, or Meropenem is administered every 8 hours

•  Eradication/Prolonged phase, which consists of taking pills for at least three months.

Oral antimicrobial therapy consists of:

Trimethoprim-sulfamethoxazole is taken every 12 hours, or Amoxicillin/clavulanic acid (co-amoxiclav) taken every 8 hours

Additional therapies or treatments, such as draining of abscesses, can be helpful depending on the type of infection or severity.⁴

Without appropriate treatment, melioidosis can progress to severe forms, such as septicemia or disseminated infection, which means that the infection has spread throughout the body.

Prognosis

The mortality from melioidosis ranges from 20 - 50 % but can vary depending on various factors, which include;

• Severity of infection
• Timely diagnosis and treatment
• Presence of underlying health conditions
• Antibiotic resistance
• Complications

It can even be higher (>50%) in resource-poor settings with limited access to modern diagnostic techniques and treatment modalities.⁴

Prevention

Melioidosis can be contracted by polluted soil or water in regions where the disease is common. However, there are several things that specific groups of individuals can do in these regions to assist in reducing the risk of exposure.

By taking the following precautions, you can lower your risk of melioidosis, particularly in locations where B. pseudomallei is prevalent or common;

• Keep your distance from the soil and any standing water if you have diabetes or a chronic kidney condition.
• When going through mud, standing water, or moist soil, wear waterproof boots.
• When working with soil or gardening, wear gloves.
• Cover open wounds or sores with waterproof dressings.
• Avoid putting potentially contaminated dirt or water into open wounds.
• After working outside or being in dirty water or soil, take a shower or thoroughly wash your hands.
• When weed-whacking, using a high-pressure spray around the soil, or mowing the lawn, wear a mask that covers your mouth and nose.
• Contact your healthcare practitioner if you believe you have been exposed to B. pseudomallei. They may suggest taking antibiotics to fend against melioidosis (post-exposure prophylaxis).

Additionally, boots are recommended for those who work in agriculture as they can help prevent infection in the lower legs and feet.

When caring for individuals with melioidosis, healthcare professionals can employ precautions to assist in preventingthe spread of infection.

Summary

In conclusion, melioidosis is an infectious disease caused by the bacterium Burkholderia pseudomallei. It is primarily transmitted through contact with contaminated soil and water and can lead to a range of symptoms, from mild to severe. Early diagnosis and appropriate antibiotic treatment are essential for managing the disease. Preventive measures include avoiding exposure to contaminated environments, especially for individuals with underlying health conditions.

FAQs

What are the symptoms of melioidosis?

Fever, coughing, breathing issues, chest pain, skin ulcers, abscesses, joint pain, headaches, and confusion are possible symptoms.

How do you catch melioidosis?

Melioidosis is contracted through direct contact with B. pseudomallei-contaminated water or soil.

B. pseudomallei can get into your body:

• Through a break in your skin
• Breathing it in (inhalation)
• By aspirating polluted water into your lungs
• Drinking contaminated water (ingestion)

Is melioidosis curable?

Melioidosis can be cured with a 2-phase course of antibiotics. The majority of people who have no underlying medical conditions and receive prompt therapy recover completely from melioidosis. However, at times, it can get severe quickly, and treatment may not be effective in all cases.

Is melioidosis fatal?

Melioidosis is deadly in 10% to 20% of cases, even when treated promptly and appropriately. The risk of major complications and death from melioidosis, on the other hand, increases as follows; 

• Whether or not you have an underlying illness
• The availability of quality healthcare
• What organs are affected

How do I take care of myself with melioidosis?

If you have melioidosis, make sure to take all of your medications as directed. You may become ill again if you stop taking antibiotics too soon.

Maintain all appointments with your healthcare practitioner. Inform them if your symptoms disappear and reappear or if you experience new or worsening symptoms.