Melioidosis of the Female Genitourinary Tract

Prostatic abscess is a common manifestation of melioidosis in men, but the characteristics of female genitourinary melioidosis are incompletely defined. There were 453 cases of melioidosis in Far North Queensland, tropical Australia, between January 1998 and April 2023; genitourinary involvement was less common in women than in men (13/140 [9%] versus 76/313 [24%], odds ratio [95% confidence interval]: 0.32 [0.17-0.60], P = 0.0004). In 11 of these 13 (85%) women, other organs were also affected. The two women with disease involving only the genitourinary tract had underlying anatomical abnormalities: one had an ovarian malignancy, the only case to involve the female reproductive system in the cohort, while the other had a urethral diverticulum. In 3 of 13 (23%) women, genitourinary involvement was identified only with computed tomography, emphasizing the importance of early imaging of patients with melioidosis to identify unexpected foci of disease and to inform the optimal duration of antibiotic therapy.

Clinical-radiological features and diagnostic modalities for mediastinal melioidosis

Melioidosis is a potentially life-threatening infection caused by the Gram-negative bacillus Burkholderia pseudomallei. Mediastinal melioidosis has a range of clinical presentations, making it difficult to diagnose: we therefore reviewed the evidence on the clinical characteristics, radiological features and invasive diagnostic modalities or interventions. An electronic search was conducted on three databases (PubMed, SCOPUS, Google Scholar) from November to December 2022. The initial search yielded 120 results, of which 34 studies met the inclusion criteria, but only 31 full-texts were retrievable. Among these, 4 were cohort studies, 26 case reports or series and 1 a conference abstract. The four main themes covered were mediastinal melioidosis as a diagnostic dilemma, unexpected complications, invasive interventions or an accompanying thoracic feature. Radiological manifestations included matting, necrosis and abscess-like collection. Severe presentations of mediastinal melioidosis included superior vena cava obstruction, sinus tract formation and pericardial tamponade. Transbronchial needle aspiration was the most common invasive diagnostic modality. Further research is needed to understand the relationship between the thoracic features of melioidosis on patient prognosis, its relationship to melioidosis transmission and potential preventive measures.

Imaging manifestations of pulmonary melioidosis: A case series

Melioidosis is an endemic disease in Southeast Asia and Oceania caused by the gram-negative bacillus Burkholderia pseudomallei. We studied 15 adult patients from Colombia with microbiologically diagnosed pulmonary melioidosis. We reviewed 15 chest X-rays and 10 chest computed tomography (CT) studies. Of the 15 patients, 87% met the criteria for acute infection and 13% met the criteria for chronic infection. The most common findings on chest X-rays were consolidation (86%), nodules (26%), and cavitation (20%). On CT studies, consolidation and nodules were observed in 90% of cases; the areas of consolidation were predominantly located in the basal and central zones in 60%. Areas of cavitation were observed in 50%, pleural effusion in 60%, and mediastinal lymph nodes in 30%. In patients with acute pulmonary melioidosis (n=8), the findings observed were nodules (100%), mixed pattern with nodules and consolidation (87%), pleural effusion (88%), and mediastinal lymph nodes (25%). The two patients with chronic pulmonary melioidosis both had cavitation. Acute lung infection with B. Pseudomallei has radiologic manifestations similar to those of pneumonia due to other causes. In areas where the disease is endemic, it is essential to include acute melioidosis in the differential diagnosis of pulmonary nodules and chronic melioidosis in the differential diagnosis of cavitated chronic lung lesions.

Three New Cases of Melioidosis, Guadeloupe, French West Indies

Melioidosis has been detected in the Caribbean, and an increasing number of cases has been reported in the past few decades, but only 2 cases were reported in Guadeloupe during the past 20 years. We describe 3 more cases that occurred during 2016–2017 and examine arguments for increasing endemicity.

Disseminated Melioidosis with Spinal Intraosseous Abscess

Melioidosis is endemic in the State of Sabah, Malaysia. We report a case of a 34-year-old man with one-week history of fever and cough, three days history of diarrhoea and vomiting, which was associated with a loss of appetite and loss of weight for one-month. Clinically, he had hepatosplenomegaly and crepitation over his right lower zone of lung. Chest radiograph showed right lower lobe consolidation. Ultrasound abdomen showed liver and splenic abscesses. Ultrasound guided drainage of splenic abscess yielded Burkholderia pseudomallei. Magnetic resonance imaging (MRI) lumbosacral confirmed right sacral intraosseous abscess after he developed back pain a week later. He received 6 weeks of intravenous antibiotics and oral co-trimoxazole, followed by 6 months oral co-trimoxazole and had full recovery.

Mycotic aneurysm secondary to melioidosis in China: A series of eight cases and a review of literature

Burkholderia pseudomallei is the causative agent of melioidosis, endemic in Southeast Asia and Northern Australia, and increasingly recognized in southern China, especially in Hainan Province. Mycotic aneurysm caused by B. pseudomallei is a rare but potentially severe illness with a high mortality rate. The clinical features of the mycotic aneurysm secondary to melioidosis have not been illustrated in China. Over a seven-year period (2013 to 2019), 159 patients with bacteremic melioidosis were retrospectively analyzed in Hainan province, China, of whom eight patients were confirmed to have mycotic aneurysm through the combination of imaging examination, pathologic examination and aneurysm tissue culture. We summarized these eight patients’ clinical characteristics, demographical features, treatments and outcomes. The susceptibilities to five commonly-used antibiotics for these eight B. pseudomallei isolates were also determined by E-test strips. Furthermore, the mycotic aneurysm cases secondary to melioidosis retrieved from the literature were also reviewed. Of the eight cases, six had abdominal mycotic aneurysms, one had a left iliac aneurysm, and the other one had an infectious mesenteric aneurysm. They were aged from 48 to 69 years old, and had the underlying risk factors of diabetes mellitus (2 patients), long-term smoking (4 patients), hypertension (6 patients), and soil and water contact history (6 patients), respectively. The positive arterial aneurysm imaging was observed in all patients via computed tomography (CT) or angiography. Eight B. pseudomallei isolates collected from both blood and mycotic aneurysm tissues remained 100% susceptible to imipenem and ceftazidime. After surgery combined with antibiotic administration, six patients survived, with a mortality rate of 25%. In melioidosis endemic areas, the mycotic aneurysm secondary to melioidosis might be underdiagnosed, and increased awareness of predisposing risk factors and clinical features of the mycotic aneurysm is required. Following a positive B. pseudomallei blood culture, the diagnosis of mycotic aneurysm should be under consideration in those with abdominal pain and/or hypertension. Imaging by CT or angiography is indispensable for its timely diagnosis and management.

Burkholderia pseudomallei has the potential to cause mycotic aneurysm, an infrequently-occurred complication of melioidosis, with a high mortality rate despite appropriate antibiotic therapy and vascular surgery. The comprehensive clinical features of mycotic aneurysm due to B. pseudomallaei have not been documented in the People’s Republic of China and might be underrecognized. Therefore, we described eight patients with mycotic aneurysm from 159 bacteremic melioidosis patients in Hainan, China, over a seven-year period (between 2013 to 2019). We summarized their clinical characteristics, demographical features, treatments and outcomes. To our knowledge, this is the first comprehensive report of mycotic aneurysm secondary to melioidosis in China. In summary, in melioidosis endemic areas, or for those returning from endemic areas, increased awareness of the risk factors is required for early diagnosis and management of mycotic aneurysm secondary to melioidosis.

The Tunnel Sign Revisited: A Novel Observation of Cerebral Melioidosis Mimicking Sparganosis

The tunnel sign has been described as a specific feature of cerebral sparganosis. We present a case of a 55-year-old gentleman found to have cerebral melioidosis and with initial imaging mimicking the appearance of sparganosis. This suggests that the tunnel sign in brain abscesses may be specific for infection by Burkholderia Pseudomallei, Spirometra Mansoni or Listeria Monocytogenes.

[Melioidosis in a Danish tourist returning from North-eastern Thailand]

Melioidosis, an infectious disease caused by Burkholderia pseudomallei, is endemic in South East Asia and Northern Australia. It has a wide clinical diversity, spanning from asymptomatic cases to rapid septic shock and death. We present a case of pulmonary melioidosis in a Danish tourist returning from North-eastern Thailand. The patient was treated with intravenous ceftazidime followed by oral therapy with trimethoprim/sulfamethoxazole and subsequently switched to doxycycline due to abnormal liver function tests and eosinophilia, with no sign of relapse two months after antibiotic cessation.

[A case of melioidosis occurring after a long-term stay in Vietnam that developed pulmonary cavitation and relapsed with multiple pulmonary nodules]

A 69-year-old man complained of fever in September 2009, after returning from Vietnam where he has been working for 20 years. He had diabetes mellitus and was on diabetic oral medication. He was examined at a nearby hospital, and found out to have pneumonia with cavity formation in the right upper lobe which was found out to be not due to tuberculosis. Although the patient once recovered with antibacterial medicine, after a few months, in January 2010, he was admitted to our hospital because of recurrent fever. Computed tomography revealed multiple pulmonary nodules which were thought to be pulmonary emboli, as well as subcutaneous abscess, spleen abscess, and kidney abscess. Blood test showed that he also had DIC. As Burkholderia pseudomallei was cultured from the subcutaneous abscess and blood, was diagnosed as melioidosis. The patient was treated with meropenem for 8 weeks, and then a maintenance oral antibacterial medicine was continued for the next 6 months. The patient fully recovered after those treatments and has not relapsed since then. This is the ninth case report of melioidosis in Japan which is an imported infectious disease.

Computerized tomographic findings of hepatic fascioliasis compared with melioidosis-caused liver abscesses

OBJECTIVE

To compare the computerized tomographic (CT) findings of hepatic fascioliasis (HF) vs. melioidosis-caused liver (ML) abscesses.

MATERIAL AND METHOD

CT images of 15 patients with hepatic fascioliasis (HF) and 16 patients with melioidosis-caused liver (ML) abscesses were retrospectively reviewed. The authors evaluated and compared HF and ML abscesses (by chi2 and Fisher exact tests) vis-a-vis their location of liver involvement, size, shape, number margins, enhancement patterns, subcapsular lesions, internal architecture, dilatation of intrahepatic bile duct and combination with splenic abscesses.

RESULTS

Fourteen HF patients had only liver abscesses and 1 had combined liver and splenic abscesses. Four ML patients had liver abscesses alone while 12 had combined liver and splenic abscesses (p = 0.000). Eight of the 15 HF (53.3%) and 2 of the 16 ML (12.5%) patients had subcapsular lesions (p = 0.019). The liver abscesses were round or oval with linear tracts in 8 of the 15 HF (53.3%) and none of the ML patients (p = 0.001). Between the respective HF and ML patients, there was a significant difference in those with round shaped in ML (p = 0.008), multiple and conglomerately distributed in HF (p = 0.050), multiple and discretely distributed in ML (p = 0.001) no (or minimal) peripheral contrast enhancement in HF (p = 0.011) and moderate or mark peripheral enhancement in ML (p = 0.011).

CONCLUSION

The CT findings of liver abscesses that helped to differentiate hepatic fascioliasis from melioidosis liver abscesses were: their number shape, enhancement pattern, presence of subcapsular lesion (s) and co-occurrence with splenic abscesses. The diagnosis of hepatic fascioliasis by CT is suggested when the following characteristics were seen: (1) multiple, small round or oval (with linear tracts) conglomerates presenting as hypodense lesions; (2) no (or minimal) peripheral contrast enhancement; (3) subcapsular lesions; or (4) less frequent co-occurrence with splenic abscesses.

The man with the boggy head: cranial melioidosis

Melioidosis is known to cause abscesses in various organs, including the cranium, though less commonly. We present a patient with scalp abscess and subdural empyema that was visible on computed tomography of the brain. The neurosurgical drainage grew Burkholderia pseudomallei. Despite our best effort to treat the patient using parenteral antibiotics and surgical drainage, the patient did not survive.

CT findings of liver and splenic abscesses in melioidosis: comparison with those in non-melioidosis

OBJECTIVE

To compare the CT findings of liver and splenic abscesses in melioidosis (ML) with non-melioidosis (NML).

MATERIAL AND METHOD

CT (computed tomography) images of 47 patients with liver and splenic abscesses were retrospectively reviewed. The 28 patients with ML abscesses and 19 with NML abscesses were recruited into the present study. The sizes, shapes, distributions, margins, enhancement patterns and internal architectures of abscesses on CT images were evaluated and analyzed by Chi-square and Fisher exact tests.

RESULTS

Seven and 6 ML patients had liver and splenic abscesses alone respectively, and 15 patients had combined liver and splenic abscesses. All NML patients had only liver abscesses. For liver abscesses, there were 3 ML and 13 NML patients with abscess size > or = 3 cm. Eleven ML and no NML patients had abscesses < 3 cm (p = 0.00). The abscesses were multiple and discretely distributed in all 11 ML patients, but none in NML patients (p = 0.002). Seven ML and 13 NML patients had moderate to marked peripheral enhancement (95% CI: -0.7, -0.01). All splenic abscesses (21 patients) found that B. pseudomallei was the causative organism. They were mostly smaller than 3 cm in size (85.71%), multiple (95.24%), and had no or minimal enhancement (85.71%).

CONCLUSION

The CT findings of liver abscesses that can help to differentiate ML from NML include sizes, distributions, and enhancement patterns. The features of ML splenic abscesses in the present study were small, multiple, with no or minimal contrast enhancement.

Rheumatological manifestations in patients with melioidosis

Melioidosis, an infection caused by the bacterium Burkholderia pseudomallei, has a wide range of clinical manifestations. Here, we describe rheumatological melioidosis (involving one or more of joint, bone or muscle), and compare features and outcome with patients without rheumatological involvement. A retrospective study of patients with culture-confirmed melioidosis admitted to Sappasithiprasong Hospital, Ubon Ratchathani during 2002 and 2005 identified 679 patients with melioidosis, of whom 98 (14.4%) had rheumatological melioidosis involving joint (n=52), bone (n = 5), or muscle (n = 12), or a combination of these (n=29). Females were over-represented in the rheumatological group, and diabetes and thalassemia were independent risk factors for rheumatological involvement (OR; 2.49 and 9.56, respectively). Patients with rheumatological involvement had a more chronic course, as reflected by a longer fever clearance time (13 vs 7 days, p = 0.06) and hospitalization (22 vs 14 days, p < 0.001), but lower mortality (28% vs 44%, p = 0.005). Patients with signs and symptoms of septic arthritis for longer than 2 weeks were more likely to have extensive infection of adjacent bone and muscle, particularly in diabetic patients. Surgical intervention was associated with a survival benefit, bur not a shortening of the course of infection.

Variable presentation of neurological melioidosis in Northeast Thailand

We describe three instructive cases of neurologic melioidosis that demonstrate the variable nature of clinical manifestations and disease pathology. The appropriate duration and choice of parenteral and oral antimicrobial therapy for neurologic melioidosis are also discussed.

A case of prostatitis due to Burkholderia pseudomallei

BACKGROUND

A 67-year-old male, with a history of stable lower urinary tract symptoms, diabetes mellitus, benign prostatic hyperplasia, gonococcal urethritis, and excessive alcohol consumption, presented to the emergency room with sepsis and acute bacterial prostatitis. He had recently returned from a visit to Indonesia, where he had been a first-hand witness to the 2004 tsunami.

INVESTIGATIONS

Complete blood cell count, urine analysis, blood, urine, and prostatic abscess cultures, chest X-ray, contrasted CT of the abdomen and pelvis, and (18)F-fluorodeoxyglucose PET.

DIAGNOSIS

Melioidosis.

MANAGEMENT

Broad-spectrum empiric antibiotics were administered initially; therapy was then changed to intravenous imipenem plus cilastatin with slow initial clinical improvement. (18)F-fluorodeoxyglucose PET localized the prostate as the only nidus of infection. Ultrasound-guided fine needle aspiration of a small fluid collection of the prostate also grew Burkholderia pseudomallei. The patient improved clinically and was discharged to complete a 2-week course of intravenous imipenem plus cilastatin followed by a 3-month course of oral trimethoprim plus sulfamethoxazole. This medication was switched to co-amoxiclav and doxycycline to complete the 3-month course. The patient was well at his last follow-up, 3 months following hospital discharge.

Thoracic Radiology of Infections Emerging After Natural Disasters

When natural disasters demolish shelter, destroy sources of clean drinking water, and disrupt the availability of medical care, vast numbers of people are placed at increased risk of disease. The infectious diseases that propagate under these conditions are usually common ones. Occasionally, a natural disaster alters the local environment in ways that markedly increase the prevalence of a disease that is endemic to a geographic region, occurring only as isolated cases under normal conditions. Many of these infections may affect the thorax. In this article, we discuss the radiologic findings of 4 infectious diseases, coccidioidomycosis, leptospirosis, melioidosis, and Chagas disease, which may flourish after natural disasters strike areas where they are endemic.

Computed tomography characteristics of Burkholderia pseudomallei liver abscess

We report 3 cases of Burkholderia pseudomallei liver abscesses that have a characteristic "honeycomb" appearance on computed tomography scans. Such a finding should prompt physicians to include B. pseudomallei infection in the differential diagnoses of liver abscesses and consider initiation of empirical therapy for melioidosis in high-risk patients from areas of endemicity.

Changing epidemiology of melioidosis? A case of acute pulmonary melioidosis with fatal outcome imported from Brazil

Melioidosis is an infectious disease caused by Burkholderia pseudomallei. It is endemic in South East Asia and tropical regions of Northern Australia. Sporadic cases have been described elsewhere. In this article we present a case of acute pulmonary melioidosis with fatal outcome imported from Brazil. The most common pathogen causing severe community-acquired pneumonia in Brazil is Streptococcus pneumoniae. Other possible pathogens include Legionella spp., Mycoplasma pneumonia, Gram-negative rods and viruses. There are few reports of melioidosis in the Americas. This article represents the second known human case of melioidosis from Brazil. Recognition of melioidosis as a possible cause of severe pneumonia, even if a patient has not been travelling in a highly endemic area, is important because of the therapeutic consequences. The epidemiology of melioidosis will be reviewed.

Relative uptake of technetium 99m stannous colloid by neutrophils and monocytes is altered by gram-negative infection

Gram-negative infection alters phagocytic cell function; hence, it could affect phagocytic uptake of inorganic colloids by these cells. Neutrophil and monocyte uptake of technetium 99m stannous colloid (99mTc SnC) in whole blood was measured in 10 patients with gram-negative infection (Burkholderia pseudomallei) and 7 controls. Mean uptake per individual neutrophil was reduced in infection. Uptake per monocyte was not significantly different. Blood from six normal individuals was incubated with lysed B. pseudomallei and colloid, which showed reduced neutrophil uptake, but increased monocyte uptake. These results indicate that uptake of 99mTc SnC stannous colloid can be used to measure alteration in phagocytic cell function. They suggest that infection with B. pseudomallei is associated with reduced phagocytosis by individual neutrophils, possibly through toxic effects of bacterial products. This could have immunopathogenic consequences for this gram-negative infection and may explain why it responds to granulocyte colony-stimulating factor.

Bacteraemic melioidosis pneumonia: impact on outcome, clinical and radiological features

OBJECTIVES

Melioidosis is an endemic disease in South-east (SE) Asia and bacteraemia in melioidosis is associated with high mortality. We describe some clinical and radiological features of bacteraemic pneumonia due to Burkholderia pseudomallei as well as a comparison with bacteraemic patients without pneumonia.

METHODS

Patients with positive blood cultures for B. pseudomallei from October 1997 to November 2001 were included. Patients were grouped as 'Pneumonia' and 'Non-pneumonia' according to clinical and radiological features.

RESULTS

Eighteen (60%) out of total 30 patients were in the pneumonia group. There was no significant difference in age, WBC count, platelet counts and bilirubin levels between the groups. However the 'Pneumonia' group had higher incidences of hyponatraemia, acidosis, diabetes with poor control, renal impairment and shorter length of stay. Twelve (66%) of 18 patients in the pneumonia group required ICU admission compared to none in the non-pneumonia group; all required mechanical ventilation. Only 13/30 (43%) patients had initial empiric antibiotic therapy that is appropriate for melioidosis. The pneumonia group also had significantly higher mortality (13/18, 72%) rate than the non-pneumonia group (3/12, 25%, P=0.03). Chest radiographs were non-specific. 7/18 (38%) had unilobar involvement of the lung, mostly left sided; the rest had multilobar or bilateral involvement. Six (33%) had pleural effusion. No patient had cavitary lung disease. Visceral abscesses (spleen, liver and prostate) were also common in ultrasound and CT scans in both groups.

CONCLUSION

(1) Bacteraemic melioidosis with pneumonia carries high mortality with most patients dying early. (2) Radiological features of melioidosis pneumonia are non-specific. (3) Clinicians who treat patients from SE Asia need to be aware of this condition to institute early and appropriate antibiotic therapy.

A case of imported melioidosis presenting as prostatitis

We report a case of melioidosis in a previously healthy Belgian man. He presented with septicemia and prostatic abscesses 1 week after a trip to Vietnam. Burkholderia pseudomallei was isolated from multiple hemocultures. He was treated successfully with intravenous ceftazidime and trimethoprim-sulfamethoxazole, followed by a per-oral maintenance therapy of amoxicillin-clavulanate with supplementary amoxicillin. There was no need for surgical drainage. This is the second reported case of melioidosis in Belgium.

Demonstration of different patterns of musculoskeletal, soft tissue and visceral involvement in melioidosis using 99m Tc stannous colloid white cell scanning

Melioidosis is an infectious disease that can present with multiple foci of disease involvement. Assessment of disease extent can be difficult, especially in musculoskeletal, visceral and soft tissue infection. This study examined the usefulness of white cell scans in this condition. 99mTc stannous colloid white cell scanning was performed in 21 patients with culture-proven melioidosis. Scan results were compared with clinical assessment and correlated with other forms of imaging. White cell scans demonstrated all but one of the clinically apparent sites of musculoskeletal, visceral and other soft tissue infection. Unsuspected disseminated soft tissue lesions were seen in two patients, including femoral node uptake in both, and these patients subsequently presented with relapsing musculoskeletal disease. Unsuspected musculoskeletal disease was found in one patient. Clinically suspected musculoskeletal disease was accurately excluded by white cell scan in another patient. The results of white cell scanning were also examined in disease of other viscera. Renal and prostatic disease were visualized. Unsuspected parotid involvement was found in two patients. Only one of two spinal lesions was visualized. Pulmonary disease was not necessarily associated with abnormal uptake. White cell scanning is a quick and effective way of assessing the extent of musculoskeletal, visceral and soft tissue disease in melioidosis.

Visceral organ abscesses in melioidosis: sonographic findings

PURPOSE

We describe the sonographic appearances of extrapulmonary visceral organ abscesses in melioidosis and examine the role of sonography in early detection and follow-up of this elusive disease.

METHODS

The sonograms and records of 80 patients with melioidosis were retrospectively reviewed. The number, size, sonographic appearances, and distribution of abscesses in the abdominal visceral organs were analyzed.

RESULTS

The most common suspected diagnoses upon hospital admission were septicemia and pyrexia of unknown origin (39%). Abdominal visceral organ abscess was suspected in only 28% of patients. Fifty-seven patients (71%) had single organ involvement, and 23 (29%) had multiple organ involvement. There were lesions in the spleen in 59 patients (74%), liver in 37 (46%), and kidney in 10 (12%). Multiple abscesses were much more common than a solitary abscess in each organ and were demonstrated in 83%, 68%, and 75% of patients with spleen, liver, and kidney involvement, respectively. The sonographic findings of multiple small abscesses with a "target-like" appearance and larger multiloculated abscesses were common in every organ.

CONCLUSIONS

The findings of multiple small, discrete abscesses in visceral organs, particularly the spleen, should raise the suspicion of this disease. In endemic areas, screening sonography should be done in every patient presenting with septicemia or fever of unknown origin.

Burkholderia pseudomallei infection in a Puerto Rican patient with chronic granulomatous disease: case report and review of occurrences in the Americas

Burkholderia species, notably Burkholderia cepacia and Burkholderia gladioli, are important pathogens in patients with chronic granulomatous disease (CGD). Burkholderia pseudomallei, the causative agent of melioidosis, is endemic in Southeast Asia and northern Australia but is a rare pathogen in other parts of the world. We describe the occurrence of B. pseudomallei infection in a Puerto Rican patient with CGD. This is one of only a small number of documented cases of melioidosis autochthonous to the Americas and is the first reported case of B. pseudomallei infection in a CGD patient from the Americas. We conclude that B. pseudomallei, like B. cepacia and B. gladioli, should be considered a potential pathogen in patients with CGD and that melioidosis should be considered in the differential diagnosis for ill residents of or travelers to Puerto Rico.

Tropical infection and the lung

The term "tropical lung" has been used to describe the lungs that are vulnerable to those indigenous diseases that occur with particular prevalence in tropical countries. International travel, student and cultural exchanges and changing immigration patterns are insidiously transforming the face of medicine in Europe and other developed countries. The climates of tropical countries provide an ideal environment for pathogenic organisms, and their vectors and intermediate hosts, to flourish. In an average out-patient department, 20-40% of patients have been seen with respiratory complaints, and 20-30% of hospital medical admissions are for disorders predominantly affecting the lungs. Pulmonary tuberculosis is common in tropical countries as well as the rest of the world. The other principal environmentally related tropical pulmonary diseases are melioidosis, paragonimiasis, amoebiasis, leptospirosis, gnathostomiasis and tropical eosinophilia. It is essential that the practising clinician be aware of the increasing prevalence of various new and exotic tropical lung diseases. Clinicians in developing countries can now use their clinical skills together with recent developments in immunology, molecular biology and biochemistry to improve the diagnostic accuracy and therapeutic effectiveness related to tropical lung infections. Treatment, if inappropriate, may not only be worthless but, in many cases, extremely harmful and even fatal.

The radiology of melioidosis

Melioidosis varies from subclinical infection to fulminating disease with multiple organ involvement. Although endemic in South-East Asia and northern Australia, it may be imported into temperate zones. It is the wide spectrum of manifestation that makes it 'the great imitator'. The purpose of this pictorial essay is to familiarize the radiologist with the range of radiological manifestations of this disease. Intrathoracic findings include pulmonary nodules, consolidation, necrotizing lesions, pleural effusion, pleural thickening and mediastinal abscess. Abscess in almost all organ systems can be seen in the septicaemic and suppurative infections. Both clinical and radiological findings are non-specific. A high index of suspicion is required to focus the search for bacteriological confirmation. A prompt diagnosis is essential, as melioidosis is often rapidly fatal.

Musculoskeletal melioidosis: clinical and imaging features

OBJECTIVE

Melioidosis is a tropical infection caused by a gram-negative bacillus, Pseudomonas pseudomallei. The disease manifests initially as localized suppurative lesions and can progress to acute disseminated septicemia with 65-90% mortality if inadequately treated. Musculoskeletal involvement is common. The purpose of this study was to describe the clinical features and imaging appearances of musculoskeletal melioidosis.

DESIGN

We retrospectively analyzed the clinical profiles and images of 26 patients diagnosed over a 6-year period as suffering from melioidosis.

PATIENTS

The study group comprised 11 patients with musculoskeletal melioidosis and 15 patients with nonmusculoskeletal melioidosis.

RESULTS AND CONCLUSIONS

We found that musculoskeletal melioidosis mimicks other infections both clinically and radiologically. Clinical awareness is therefore crucial, as diagnosis can only be established by bacteriological and immunological studies. Prompt treatment with long-term combination antibiotics in high dosages and surgical drainage of abscesses improves survival.

Imaging patterns in melioidosis

Melioidosis is an infectious disease caused by Pseudomonas pseudomallei. It is seldom diagnosed promptly and, if untreated, can lead to an 80-100% mortality rate. Twenty-eight patients with melioidosis were identified over a 6 year period, and their imaging patterns were analysed. Respiratory infections were the commonest form of presentation, frequently shown as diffuse airspace consolidation, and accounted for the highest mortality. Visceral and musculoskeletal infections were associated with chronicity and a high relapse rate. Multifocal splenic abscesses were a common occurrence. Septic arthritis of the knee was frequently seen. The majority of patients had diabetes mellitus and chronic ill-health. An increased awareness of the disease can contribute to its early detection and appropriate treatment.

Pseudomonas pseudomallei liver abscesses: a clinical, laboratory, and ultrasonographic study

Ultrasonography revealed evidence of liver abscess in 126 patients who were admitted to one hospital in northeastern Thailand over a 3-year period. There were 50 cases for which a pyogenic bacterial etiology was confirmed; 34 cases (group 1) were caused by Pseudomonas pseudomallei (nine patients died) and 16 cases (group 2) were caused by other bacteria (two patients died). Melioidosis was associated with anemia and underlying diabetes or renal disease; right-upper-quadrant pain and jaundice were more common in group 2 (P less than .05). Blood cultures were positive for bacteria in 68% of group 1 and 50% of group 2. Chest radiographs revealed abnormalities in 17 of 30 group 1 patients and 6 of 12 group 2 patients. The radiographic appearances of a blood-borne pneumonia suggested melioidosis. The serum indirect hemagglutination assay for antibodies to P. pseudomallei was of limited value in differentiating the two types of abscesses. Multiple hypoechoic areas on ultrasonography were significantly associated with melioidosis (P less than .01); associated splenic abscess occurred in 19 group 1 patients but only one group 2 patient (2-107, 95% confidence interval; odds ratio, 19). In an area where P. pseudomallei is endemic, these characteristic ultrasonographic findings should prompt immediate treatment for melioidosis.

Ceftazidime monotherapy for pulmonary melioidosis in a traveler returning from Thailand

A patient with deteriorating pulmonary melioidosis rapidly recovered after treatment with ceftazidime. To prevent possible relapses, an oral maintenance regimen of amoxicillin and clavulanic acid was prescribed for a period of three months. Melioidosis is caused by Pseudomonas pseudomallei. It is an insidious disease because of its variable clinical presentation, possible long-term asymptomatic carriage, broad-spectrum resistance to first-line antibiotics, and high mortality rate. As in our patient, the diagnosis should be particularly considered when there is reduced immunologic resistance and previous exposure in endemic areas, such as Southeast Asia.

Successful surgical management of a case of pulmonary and pericardial melioidosis

A 35 year old diabetic presented with features of septicaemia and developed cardiac tamponade. He was found to have pulmonary, acute septicaemic and pericardial melioidosis. Some initial improvement was achieved with medical therapy but only with surgical intervention was a successful outcome achieved.

CT findings in melioidosis

CT findings in 5 patients with melioidosis were presented. Lungs lesions consisted of upper lobe infiltration with a small thin-walled cavity in 2 cases and lower lobe consolidation without cavity in another case. Pleural lesions may be seen as a small pleural nodule, effusion with associated lung lesion, hydropneumothorax as a complication or the end stage fibrothorax due to chronic empyema thoracis. In one case hepatosplenic microabscesses were observed.

Melioidosis with multiple cerebral abscesses

Melioidosis from Pseudomonas pseudomallei is common in endemic areas (particularly southeast Asia) and is being recognized with increasing frequency in developed countries. Central nervous system involvement is a rare complication with a high mortality. A patient with multiple cerebral abscesses caused by this organism is presented to demonstrate that successful treatment is possible when a high index of clinical suspicion leads to early diagnosis.

Pulmonary melioidosis: clinical-radiologic correlation in 183 cases in northeastern Thailand

The chest radiographs of 183 patients with pulmonary melioidosis seen over a 4-year period were evaluated retrospectively. Disseminated nodular lesions occurred in 46 of 55 patients (84%) with the acute septicemic form of the disease and in 17 of 31 (55%) with the subacute or chronic form and positive blood cultures. Alveolar lesions occurred in 26 of 50 patients (52%) with the acute pneumonic form. There was no typical pattern of pulmonary infiltrates in 16 patients with the subacute pneumonic form, but in the chronic form, 17 of 31 patients (55%) had mixed infiltrates with cavities. The lesions were confluent in the upper lobes but tended to spare the apices in nonsepticemic cases. Rapid progression and early cavitation are distinctive features in acute cases, but in chronic cases the lesions may remain unchanged up to 20 months. Pleural effusion or empyema was seen in 22 of 105 patients (21%) with acute disease and four of 31 (13%) with chronic disease. Six of 105 patients (6%) with acute disease and three of 31 (10%) with subacute or chronic disease and positive blood cultures had pericardial involvement.

Melioidosis with brain abscess

Central nervous system involvement in melioidosis is rare. We describe a 48 year old woman who developed septicaemia and a brain abscess due to Pseudomonas pseudomallei. Since there is a continuing practical problem in bacteriological confirmation of the aetiological agent, diagnosis of melioidosis has to be made on clinical suspicion.

Acute septicaemic melioidosis with pulmonary hilar prominence: a case report with a unique chest radiographic pattern

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Sensitivity of radionuclide isotope brain scan in cerebral melioidosis: case report

Melioidosis, an unusual infectious disease formerly confined to the Orient, is being seen with increasing frequency in the United States. We present a report of a patient who had recently traveled in the Far East and subsequently developed pulmonary melioidosis complicated by a fatal encephalitis. Although the radionuclide brain scan was markedly abnormal, computed tomographic studies were minimally abnormal on one occasion and within normal limits on another. The radionuclide brain scan appears to have greater sensitivity in diagnosis of early encephalitis and, therefore, may be the more valuable of the two studies in the diagnosis of this disorder.