Melioidosis

Symptoms | Treatments

What is

Symptoms

Causes and Risk Factors

Diagnosis

Treatment

What is - Melioidosis

Melioidosis is a community cause of community acquired infection in Southeast Asia, including Singapore. It is an infection caused by the environmental gram negative bacillus, Burkholderia pseudomallei. This organism is widely distributed in soil and fresh water in endemic regions.

It can be associated with severe infections with mortality rates as high as 40% in some cases.

Symptoms of Melioidosis

Melioidosis can present in many different ways. It can range from asymptomatic infection to chronic infections (frequenltly mimicking cancer or tuberculosis. It can also present as fulminant acute infections.

It can cause the following conditions:

Pneumonia (most common)
Genitourinary infections
Skin infections
Bloodstream infections
Joint infections
Bone infections
Central nervous system infections
Intra-abdominal infections (including liver, splenic and prostatic abscesses)
Parotid abscesses

Recurrent infections are not uncommon. They can be due to new infections or due to relapse / reactivation disease. Melioidosis often run a protracted course.

Melioidosis - Causes and Risk Factors

Melioidosis affects individuals who are in regular contact with soil and water. It is also causes seasonal infections and is more common during the rainy or monsoon season. The bacteria, Burkholderia pseudomallei, can be inoculated, inhaled, aspirated or ingested. The most common transmission routes being direct innoculation and inhalation. Person to person spread is extremely uncommon.

Risk factors for melioidosis are diabetes, heavy alcohol intake, chronic kidney disease, chronic lung disease, thalassaemia and cancer. Patients who are on immunosuppressive therapy (including steroid therapy) are also at higher risk of melioidosis. Having said this, it is also important to know that fulminant melioidosis can occasionally occur in healthy individuals.

Diagnosis of Melioidosis

When one comes in with signs and symptoms of infection, blood or body fluid (sputum, pleural fluid, urine, pus from abscess cavity, cerebrospinal fluid) is collected and sent for cultures. The diagnosis of melioidosis is made when Burkholderia pseudomallei is isolated from these specimens.

Treatment for Melioidosis

Melioidosis treatment is often prolonged, associated with an intensive phase (2-6 weeks) of injectable antibiotic (intravenous ceftazidime, meropenem or imipenem) followed by oral eradication therapy (trimethoprim-sulfamethoxazole +/- doxycyline +/- amoxicillin-clavulanic acid) for 3-6 months.