Melioidosis, a multisystemic disease with a variety of presentations has been virtually a novel disease until recently in the island nation of Sri Lanka. However, over the last decade this has changed with 250 culture positive cases being reported . Most of the cases were reported from Western and North Western Provinces and very little from the central highlands. Our patient a driver by profession is based in the North Western province which is a hotspot for this emerging disease . A review article on island wide melioidosis cases describes that 71.6% of all cases were male and many of them were farmers. An interesting fact is that 15% of all males affected were drivers which can be explained by their constant exposure to dust . Aerosolized Burkholderia spp. in dust particles to which drivers in this region are constantly exposed, greatly increase the risk of inoculation and subsequent infection.
Sri Lankan data, similar to international studies have shown respiratory involvement to be predominant among cases (28%) . A Sri Lankan study revealed 20% of cases with musculoskeletal involvement, however whether they involve only bone, muscle, or both were not mentioned . An Australian study has reported the overall soft tissue involvement to be minimal; 19 out of 540 cases . Myositis has only been reported once in a hospital less than five kilometers from Kandy National Hospital to which this patient was admitted. It describes a patient with myositis affecting the same group of muscles as in our case. However, the patient had an initial presentation of pneumonia and had undergone the treatment . In addition to myositis, our subject had myonecrosis and an intramuscular abscess within quadriceps. Ours is the only case reported with myositis being the initial presentation of melioidosis and the first to have undergone successful surgical debridement for melioidosis myositis.
Liver and splenic abscesses are a common presentation of the disease especially in Thailand and most have been known to resolve with prolonged antibiotic therapy alone . Even though liver functions were deranged, no evidence of liver abscess was found on imaging in our subject. Acute liver injury could therefore be attributed to sepsis in this case. Rapid normalization of liver functions following medical and surgical management to counter sepsis further supports this. Neurological manifestations of melioidosis include brain abscess, meningoencephalitis, transverse myelitis and status epilepticus . Recent animal studies have shown the entry of B. pseudomallei from nasal mucosa via olfactory nerve to the brain . The single seizure episode in our patient most likely would have been due to sepsis and/or hepatic encephalopathy following acute liver injury. Another probable cause is meropenem which even though rare can cause seizures as an adverse effect especially in the elderly. This however is quite unlikely in this patient considering the single episode and timing of the seizure. Other causes of seizures such as electrolyte imbalances, acid–base disturbances and intra cranial lesions were excluded. However, brain involvement without evidence of brain abscess caused by Burkholderia spp. cannot be completely disregarded and such presentations may require further investigations including cerebro-spinal fluid (CSF) analysis and MRI.
Diabetes mellitus (DM) has been documented as an important risk factor in disease acquisition in many studies including the “20-year prospective Darwin study on melioidosis” [2, 5]. According to another study encompassing global data, it was found that up to 60% with the disease were having DM, type 2 being predominant . One study involving a mouse model has shown the importance of neutrophil function in resisting melioidosis infection . Neutrophil dysfunction seen in DM therefore weakens immunity and increases the chance of infection which is reflected by the high percentile of those affected being diabetic. In addition to have played a major role in disease acquisition, DM would have greatly contributed to the sudden escalation of sepsis seen in the subject owing to immunological dysfunction.
Management of melioidosis encompasses an initial intensive therapy followed by eradication regimen. Antibiotic options for intensive therapy include ceftazidime, meropenem and TMP-SMX [5, 7]. Intensive therapy for 10–14 days is recommended for isolated cutaneous or pulmonary disease whereas for severe deep-seated infection, bone or central nervous system involvement, 4 to 8 weeks of IV therapy may be warranted . Antibiotic options for eradication include TMP-SMX, doxycycline, chloramphenicol and co-amoxiclav (as a third line agent in case of treatment failure or relapse) [7, 8]. Eradication therapy needs to be continued for 3 to 6 months guided by clinical and biochemical response (WBC, CRP) . According to the antibiotic sensitivity pattern and local microbiology guidelines, the patient was prescribed IV meropenem for 21 days followed by TMP-SMX and doxycycline as eradication treatment on discharge. Prolonged IV therapy was not recommended even though he had one episode of seizure; the reason for which could have been multifold rather than infection. In case of post exposure prophylaxis, current recommendations are TMP-SMX or co amoxiclav for a duration of 21 days whilst keeping an eye for any evidence of infection . This was not required for the ward or lab staff in our case. In addition to medical management, ours is a rare case where surgical drainage and debridement was undertaken for melioidosis myositis. In fact, the condition did not improve amidst use of antibiotics until surgical debridement was undertaken emphasizing the importance of early intervention in the presence of abscess formation and myonecrosis.
Melioidosis can present as primary myositis and thus needs to be considered as an important differential diagnosis in those presenting with localized muscle pain and soft tissue swelling in endemic areas. Melioidosis myositis can lead to myonecrosis and abscess formation which can result in rapid disease escalation and sepsis. It is therefore essential to have a high degree of suspicion and carry out early diagnostic imaging followed by early surgical intervention to prevent disease progression and mortality.