Melioidosis: Emerging Evidence from India

Context

A recent multicentre study published in The Lancet Global Health detected melioidosis among high-risk hospitalised patients across several Indian tertiary-care centres, raising concern that the disease may be under-recognised in India. The findings have renewed attention on its environmental transmission, vulnerable groups and diagnostic challenges.

Nature and Environmental Presence

1. Melioidosis is an infectious disease caused by the bacterium Burkholderia pseudomallei, which naturally occurs in soil and water.
2. It is mainly associated with tropical and subtropical regions, where environmental conditions support persistence of the bacterium.
3. Cases often rise during the rainy or monsoon season, as greater contact with contaminated soil and water increases exposure risk.

Transmission and Vulnerable Groups

1. Infection mainly occurs when contaminated soil or water enters the body through cuts or wounds; inhalation and ingestion are less common routes.
2. Human-to-human transmission is extremely rare, making melioidosis primarily an environmentally acquired infection.
3. People with diabetes, chronic kidney disease, liver disease, heavy alcohol use or chronic lung disease are more vulnerable to severe illness because underlying conditions reduce the body’s ability to control infection.

What the Indian Study Indicates

1. Possible under-recognition: Detection among high-risk hospitalised patients raises concern that melioidosis may be missed or misidentified among patients with severe bacterial infections.
2. Regional and seasonal pattern: Variation across regions and clustering during the monsoon period indicate that local ecology and rainfall influence exposure to the bacterium.
3. Environmental exposure: Associations with outdoor occupations and groundwater use reinforce the role of contact with contaminated soil and water.
4. Clinical implication: The findings support greater clinical suspicion and targeted testing in vulnerable patients, without implying widespread infection in the general population.

Clinical Manifestations

1. Melioidosis can affect different organs and may cause pneumonia, bloodstream infection, skin infections, internal abscesses, and bone or joint infections.
2. Its symptoms may resemble other infections, including tuberculosis, which can make early diagnosis difficult.

Diagnosis and Treatment

1. Laboratory culture is important for confirming infection because the symptoms are not specific to melioidosis alone.
2. Treatment generally begins with intravenous antibiotics, followed by prolonged oral antibiotic therapy to clear the remaining infection and reduce the risk of relapse.

FAQs

Q1. What is melioidosis?
It is an infectious disease caused by Burkholderia pseudomallei.

Q2. Where is Burkholderia pseudomallei found?
It naturally occurs in soil and water, especially in tropical regions.

Q3. How does melioidosis spread?
Mainly through exposure to contaminated soil or water.

Q4. Who is more vulnerable to severe melioidosis?
People with conditions such as diabetes and chronic kidney disease are at greater risk.

Q5. Why is melioidosis currently important for India?
Recent Indian research suggests that the disease may be under-recognised among vulnerable hospital patients.