Multiple liver,splenic and psoas abscesses due to melioidosis: A case report

Abstract

Melioidosis is caused by community-acquired gram-negative bacillus Burkholderia pseudomallei which resides in soil and water. It was first described in 1912 in Burma and 1927 in Sri Lanka. Melioidosis presents with non-specific clinical and biochemical findings. Diagnosis is confirmed by the isolation of bacteria in cultures or demonstrating antibody response. Once the diagnosis is made, patients are managed with a course of intravenous antibiotics followed by a long course of oral antibiotics. Even with antibiotic treatments, most patients do not achieve complete recovery which results in chronic disease. Prolonged antibiotic therapy makes patients less compliant with treatment. Here we present a 50-year-old Sri Lankan male with diabetes mellitus presented with low-grade fever and back pain. He was found to have multiple abscesses involving the liver, spleen and left psoas muscle. Initially, he was evaluated for tuberculosis and later only melioidosis was diagnosed. The patient was managed with guided aspiration of abscesses and intravenous antibiotics. Subsequently, the patient defaulted on all treatments. It is important to consider melioidosis as a differential diagnosis in immunocompromised patients presented with multiple abscesses. It is important to maintain a registry for follow-up melioidosis patients to prevent becoming chronic melioidosis patients and to save healthcare costs.

Introduction

Melioidosis/Whitmore’s disease was first described in Burma in 1912 and it is becoming an important cause of morbidity in Asia and Northern Australia. ¹ In Sri Lanka, overall mortality is 20.4%. ² It is a community-acquired gram-negative bacillus Burkholderia pseudomallei which resides in soil and water. ³ Underdiagnosis is still common due to the absence of specific clinical and radiological findings and the lack of laboratory facilities in Sri Lanka. We report a case of melioidosis presenting with multiple liver, spleen, and psoas abscesses.

Case presentation

A 50-year-old male manual labourer from Sri Lanka, with a history of diabetes mellitus presented with a history of the left hip and back pain for a 1-month duration associated with on and off mild fever, generalized malaise and loss of appetite.

Physical examination was unremarkable except for mild tenderness over the left groin and pain elicited during left hip extension. There was no documented fever. Full blood count showed leucocytosis with white blood cells of 16 × 10³/µl. His erythrocyte sedimentation rate (ESR) was 110 mm in 1st hour and C-reactive protein was 180 mg/l. His trans-abdominal ultrasound scan showed an 8 × 5 × 5.5 cm size left psoas abscess and multiple abscesses involving the spleen and liver. Further cross-sectional imaging with contrast-enhanced computed tomography showed multi-loculated left psoas abscess extending from T11-L5 level (4.6 × 7.6 × 14.3 cm), multiple well-defined, round-shaped hypodense areas without enhancing the ring in both liver and spleen (Figures 1 and 2).

Figure 1.

Left psoas abscess on contrast-enhanced computed tomography.

Figure 2.

Multiple liver and splenic abscesses on contrast-enhanced computed tomography.

The first differential diagnosis was tuberculosis due to high ESR, insidious onset of symptoms and multiple abscesses. Blood and pus cultures were negative and tuberculosis was excluded with negative nucleic acid analysis (GeneExpert).

Ultrasound-guided aspiration and a pigtail catheter were inserted into the left psoas abscess. 75 ml of pus was drained on the 1st 24 h and subsequent drainage was minimal.

Burkholderia pseudomallei was isolated from psoas abscess aspiration culture and serum showed a significant level of antibodies. Thus, the patient was managed with intravenous (IV) meropenem 1 g 8 h for 72 h and transferred to a local hospital with the availability of a microbiologist for the continuation of IV antibiotics. The patient received IV meropenem at the local hospital only for 3 days and the patient left the hospital against medical advice.

Discussion

Melioidosis occurs predominantly in Southeast Asia, Northern Australia, the Indian subcontinent and China. It has become an important cause of morbidity, mortality, and fatal community-acquired pneumonia since it was first described in 1912 in Burma ¹ and Sri Lanka in 1927. ² It can be acquired from exposure to infected soil and water through damaged skin, inhalation of soil dust and aspiration or ingestion of contaminated water. ⁴

Burkholderia pseudomallei is a gram-negative, facultative, intracellular bacterium that resides in tropical soil. Direct zoonotic transmission is not known to occur. ³ Predisposing factors include diabetes, cirrhosis, alcoholism, chronic renal disease, chronic lung disease, thalassemia, malignancy and glucocorticoid or other non-HIV-related immune suppression. ³

Melioidosis is diagnosed by isolation of Burkholderia pseudomallei from blood, urine, sputum, throat swabs or pus from an abscess or by demonstrating antibody response (IgM) to the bacteria.^3,5 Our patient’s diagnosis was confirmed with a positive antibody response from psoas abscess pus culture analysis.

Liver abscess by melioidosis is clinically indistinguishable from other causes of pyogenic liver abscess. Thus, excluding other causes of pyogenic liver abscess and sepsis by blood, pus, urine and throat swab cultures is very important. In our patient, initial blood and pus cultures were negative for pyogenic bacteria as well as for tuberculosis. Abdominal computed tomography findings of peripheral enhancement with a honeycomb appearance seen in the spleen increase the suspicion of melioidosis. ⁶ But definite diagnosis can only be made by direct isolation or demonstrating antibodies against bacteria. In our patient, we treated abscesses based on psoas abscess aspirate results.

Varying presentations of the clinical picture and nonspecific radiological findings make the diagnosis of melioidosis difficult in this patient. Thus, a high index of suspicion is necessary, especially in endemic areas, patients with risk factors or a recent visit to a high endemic area. ⁵

It has to be considered as a differential diagnosis in the setting of multiple visceral abscesses in an immunocompromised individual.

Melioidosis is managed with IV antibiotics (IV ceftazidime 6–8 h or meropenem 8 h) for 10–14 days followed by 3–6 months of oral antibiotics (trimethoprim-sulfamethoxazole 12 h or doxycycline 12 h). ³ High-risk groups mostly include the poorly educated people and this leads to poor compliance. They tend to present with recurrent disease and are a burden to themselves and healthcare facilities. Thus, close follow-up with community health workers and the help of administration services is notable in this regard. However, this could not be achieved in this case and we did not have contact information to track down and educate the patient on the importance of follow-up.

Prevention is much more important in endemic regions since it could lead to sepsis (69%), severe sepsis (16.5%), septic shock (34.2%), death in 32.9% and recurrent infections in 2.6%. ¹ Prevention is mainly by minimizing exposure; therefore, high-risk people with skin wounds should avoid contact with soil and standing water. Contaminated wounds and burns should be immediately and thoroughly cleaned. ³

Conclusion

Melioidosis should be considered in differential diagnosis in an immunocompromised patient with multiple visceral abscesses in the early course of investigations, especially in endemic areas like the Indian subcontinent. Even though it is associated with a high mortality rate, early diagnosis and timely start of proper antibiotics lead to better outcomes. High-risk patients who are mostly the less educated groups in society have poor compliance to treatment and need thorough education and advice. Maintaining a registry of patient contact details for follow-up can help prevent them from defaulting to treatment, similar to this patient. This would reduce the number of chronic melioidosis patients and save healthcare costs in resource-limited settings. Prevention is critical as well as treating the patient. Thus, educating high-risk groups on prevention needs to be considered in endemic regions.