Pleuropulmonary melioidosis with osteomyelitis rib.

Melioidosis is a multiorgan infectious disease caused by Burkholderia pseudomallei. Few cases have been reported from south India. This is a case report of pleuropulmonary melioidosis with rib osteomyelitis.

INTRODUCTION

Melioidosis is an infection caused by the gram negative bacterium Burkholderia pseudomallei. The disease can affect any organ in the body except heart valves. The disease is most prevalent in south-east Asia and Australia. Chronic melioidosis may have a similar presentation like tuberculosis.

CASE REPORT

A 52-year-old diabetic and alcoholic male presented with progressive exertional dyspnea for the past 2 months. Chest X-ray was suggestive of left side encysted pleural effusion [Figure 1] and initial pleural fluid analysis showed lymphocyte predominant exudative type pleural effusion with low adenosine deaminase (ADA). Patient's computed tomography (CT) thorax at that time confirmed encysted pleural effusion left side and small necrotic posterior mediastinal node and splenic cyst [Figure 2]. He was started on antitubercular therapy (daily regimen). On completing 2 months of ATT, patient presented to us with left-sided chest pain and swelling over left of chest for 3 weeks. On examination a chest wall swelling was present over left infra-axillary area, 3 × 3 cm size, skin over swelling was normal, soft, compressible with no local rise of temperature and tenderness present.

Figure 1

Previous X-ray

Figure 2

Previous computed tomography

Chest X-ray showed features of volume loss and blunting of left costophrenic angle with fracture of left eighth rib [Figure 3]. Patient was subjected to CT thorax which shows multiple areas of subsegmental atelectasis noted in basal segments of left lower lobe, minimum displacement fracture lateral aspect of left eighth rib with adjacent collection (osteomyelitis), multiple enhancing lesions in spleen, and splenic cysts [Figure 4]. Subsequently, the swelling was aspirated and sent for investigations. Pus culture and sensitivity report came as B. pseudomallei with corn flower colonies [Figure 5] and bipolar staining safety pin appearance on microscopy [Figure 6]. Patient was treated with intravenous injection of imipenem for 14 days followed by oral trimethoprim-sulfamethoxazole. Patient's clinical symptoms improved and swelling subsided with treatment. Repeat chest X-ray showed clearance of lung shadow [Figure 7].

Figure 3

Chest X-ray at time of presentation

Figure 4

Computed tomography new

Figure 5

Culture plate

Figure 6

Microscopy

Figure 7

Current chest X-ray

DISCUSSION

Melioidosis, also known as Whitmore's disease, is an infectious disease in humans and other animals coused by gram negative bacterium B. pseudomallei. Till 1992 the organism was called Pseudomonas pseudomallei, later changed to B. pseudomallei due to similarity to B. mallei the causative agent of glanders. The term melioidosis originated from Greek “melis” meaning a disaster of asses, “oid” meaning similar to and “osis” meaning a condition to, that is; “a condition similar to disaster of asses”.[1] Melioidosis is endemic in southeast Asia and northern Australia. Few cases are reported from India.[234] B. pseudomallei is normally found in the surface water and land soil. A history of contact with these can be found in most of the patients. Risk factors for the disease includes diabetes mellitus, thalassemia, kidney disease, occupation (farmers), and cystic fibrosis.[5]

Clinical features

Melioidosis can present with a wide range of clinical presentations ranging from localized swelling to disseminated infection. It can be of two forms, acute and chronic melioidosis. Acute melioidosis can present with fever and pain at clinical focus. Average incubation period is 9 days (1-21 days). Pneumonia presents with cough and pleuritic chest pain. Osteomyelitis or septic arthritis or cellulitis presents with pain at local site. Latent melioidosis also occurred following decades after the exposure called “Vietnam time machine” as it was recognized in US army men involved in Vietnam war decades after the exposure. Melioidosis can affect any organ of the body except heart valves. Patients present with fever, pain at the site of injury, cough and pleuritic chest pain in pneumonia, bone and joint involvement in the form of osteomyelitis, septic arthritis, or cellulitis. Intra-abdominal infections can present as liver or splenic abscess. Parotid abscess is characteristic of Thai children and prostatic abscess in 20% of Australian male.

Chronic melioidosis occurs when duration is more than 2 months and there is 10% chance for chronic infection. It can present with chronic skin infections, nodules, or chronic pneumonia. Pulmonary manifestations of chronic melioidosis may simulate tuberculosis (called Vietnamese tuberculosis). Fifteen percent of chronic melioidosis cases present with pleural effusion.

Melioidosis is daignosed is by culture of sputum, urine, pus, blood, or throat swab. Cultured in blood agar or Ashdown media (selective media containing gentamicin to differentiate with B. cepacia). Hemagglutinin test, direct immunoflurescent test, and enzyme-linked immunosorbent assay (ELISA) are the serological tests available. Treatment consists of intravenous antimicrobial therapy for 10-14 days, followed by 3-6 months of oral antibiotic therapy. In the intravenous phase, ceftazidime is administered every 6-8 hourly or meropenem every 8 hourly. In the eradication phase; oral antimicrobials therapy is administered with trimethoprim-sulfamethoxazole every 12 h or doxycycline every 12 h.[6] Surgery has been suggested for septic arthritis and prostatic abscess.