Cervical melioidosis: an infrequent cause of neck abscess

INTRODUCTION

Melioidosis, caused by the gram-negative Burkholderia pseudomallei bacillus, is an infectious disease associated with significant mortality due to an early onset of fulminant sepsis. The disease is endemic in Southeast Asia and Northern Australia and is being increasingly reported in other tropical regions of the world such as India, China, Brazil etc.¹ Diagnosis remains a challenge, as it mimics many other conditions, especially tuberculosis, hence its other name, the ‘great mimicker’.²

Here we would like to share our experience of detecting B. pseudomallei bacillus by using paediatrics BD BACTEC bottle which to the best of our knowledge had never been reported before.

CASE REPORT

Case 1

A thirty-three years old lady with no known medical illness presented to the emergency department with complaint of left neck swelling for 1 month. It was gradually increasing in size and associated with pain. There were no other constitutional symptoms. Clinical examination revealed a 4×3 cm circular swelling at level IV, fluctuant, erythematous and tender on palpation (Figure 1 A and B).

Fluctuant, erythematous, tender 4×3 cm swelling over lower one third of left sternocleidomastoid.

Patient had sought treatment at general practitioner and was treated for cervical lymphadenitis. She was given one course of antibiotics but swelling remained status quo.

Bedside needle aspiration done and samples were sent for pus for culture and sensitivity and pus for acid fast bacilli staining. Report for pus culture and sensitivity came back as B. pseudomallei. Patient was treated with intravenous antibiotics. Subsequently swelling reduced and patient was alive and well.

Case 2

A previously healthy fifteen years old boy came with complaint of fever for three weeks and bilateral neck swelling for one week. Swelling initially started on the left side which gradually increase in size and associated with pain. On early clinical assessment, there was swelling at level II measuring 3×2 cm with no skin changes. Blood for culture and sensitivity shows no growth.

Left neck swelling at level II and III about 8×6 cm, fluctuant, erythematous skin changes and tender on palpation.

Patient was empirically treated as extrapulmonary tuberculosis. He was started with anti-tuberculosis and was discharged. He was seen back in otorhinolaryngology clinic 3 weeks later. It was noted that the left neck swelling at level II and III had tremendously increased in size about 8×6 cm, fluctuant, erythematous with underlying skin changes and tender on palpation (Figure 2 A and B).

Bedside needle aspiration was done and we are able to aspirate 16 cc of hemopurulent discharge from the swelling. Samples sent; pus for culture and sensitivity, pus for acid fast bacilli staining and pus for culture and sensitivity in BD BACTEC paediatrics bottle.

Formal report came back with pus for culture and sensitivity in BD BACTEC paediatrics bottle came back as gram negative cocci, B. pseudomallei while other samples shows no growth. By this time, patient had already completed day 39 of intensive phase for anti-tuberculosis drugs.

Patient was re-admitted back for intravenous antibiotics and anti- tuberculosis was stopped.

Case 3

Our next case is a two years four months old girl from Kakus. Child presented with left neck swelling for three months which was tender upon palpation. The swelling progressively increases in size. Otherwise, child had no other constitutional symptoms.

Mother had bought the child to a clinic and was treated as cervical lymphadenitis and was given oral antibiotics. However, swelling remains the same.

On examination of the neck, noted swelling over left neck at level II measuring 2x1cm, fluctuant, tender on palpation with erythematous skin changes (Figure 3).

We proceed with bedside needle aspiration and sent three samples namely pus for culture and sensitivity, pus for culture and sensitivity in BD BACTEC paediatrics bottle (Figure 4) and pus for acid fast bacilli staining.

Formal report came out as B. pseudomallei. All other cultures came back as no growth.

Subsequently child was given intravenous antibiotics and discharged well.

DISCUSSION

Melioidosis is a bacterial infection occurring in tropical regions of the world.¹ Factors that may influence the distribution of B. pseudomallei in the environment may include physical factors such as rainfall, humidity, UV radiation, and temperature; chemical factors such as soil composition, other vegetation, and the use of fertilizers; and recent soil disturbances such as excavation and plowing.³ In this case series, majority of the patient are from Tatau district mainly in Kakus area where most of the communities grow the paddy hill at a fertile land (Table 1). This condition affects all age group.

Melioidosis can affect multiple systems; however, the reports on head and neck regions are relatively uncommon.⁴ Positive histories from all cases is neck swelling mimicking a neck abscess with the earliest presentation is three weeks after the onset. It is worth mentioning that diagnosing cervical melioidosis is a challenge in view of the bacterium is often not readily isolated from clinical specimens and may not be correctly identified even when isolated. Serological tests are neither sensitive nor specific.⁴

Based on the cases discussed, blood culture and sensitivity failed to detect the bacterium and other blood investigations and ultrasound abdomen varies between patients (Table 2). However, we managed to culture B. pseudomallei by inserting the pus aspirate in BD BACTEC paediatrics bottle (Table 1). Thus, with positive culture, we are able to exclude other causes of neck swelling including extrapulmonary tuberculosis and treatment can be commenced immediately.

Ceftazidime is the drug of choice in systemic melioidosis. Ceftazidime (120 mg/kg/day) has shown to reduce the mortality significantly in severe melioidosis.⁵ In all the cases, intravenous ceftazidime was given for two weeks followed by four weeks of oral Bactrim.

CONCLUSION

Early detection of cervical melioidosis is crucial to reduce morbidity and avoid misdiagnosis. We wish to highlight the detection of B. pseudomallei by using BD BACTEC paediatrics bottle. No surgical intervention is required, and antibiotics remains the mainstay treatment.

Funding: No funding sources

Conflict of interest: None declared

Ethical approval: Not required

REFERENCES

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