Melioidosis en Colombia, descripción de un caso clínico y consideraciones epidemiológicas / Melioidosis in Colombia, description of a clinical case and epidemiological considerations

Resumen La melioidosis es una enfermedad infecciosa causada por Burkholderia pseudomallei cuyo diagnóstico clínico puede ser difícil debido a su variada presentación clínica y a las dificultades del diagnóstico microbiológico, por lo cual pueden requerirse técnicas moleculares para su adecuada identificación una vez se sospecha su presencia. Son pocos los antibióticos disponibles para el tratamiento de esta enfermedad y, además, deben usarse durante un tiempo prolongado. Aunque se conoce por ser endémica en Tailandia, Malasia, Singapur, Vietnam y Australia, en Colombia se han reportado algunos pocos casos. Se presenta un caso de melioidosis en la región norte de Colombia, se hace una revisión de las características clínicas y el tratamiento, y se describe la epidemiología local de esta enfermedad.

Abstract Melioidosis is an infectious disease caused by Burkholderia pseudomallei whose clinical diagnosis can be difficult due not only to its varied clinical presentation but also to the difficulties in the microbiological diagnosis.Thus, it may be necessary to use molecular techniques for its proper identification once it is suspected. There are few antibiotics available for the treatment of this disease, which must be used over a long period of time. Although it is known to be endemic in Thailand, Malaysia, Singapore, Vietnam, and Australia, in Colombia there are few reported cases. We describe a case of melioidosis in the northern region of Colombia. Additionally, we review its clinical characteristics and treatment and we describe the local epidemiology of this disease.

Imported case of melioidosis in Oman: case report

Melioidosis is an infectious disease caused by the bacterium Burkholderia pseudomallei. It is most commonly described in Southeast Asia and Northern Australia and some imported cases in non-endemic areas. We describe the case of a 55-year-old Omani man with fulminant sepsis who worked in Laos, Cambodia. B. pseudomallei was isolated from the patient's blood and was identified by means of microbiological and biochemical tests. We highlight the importance of careful attention to non-fermentative gram-negative rods in a septic patients who have worked or travelled to Southeast Asia

Severe coinfection of melioidosis and dengue fever in northeastern Brazil: first case report / Coinfecção grave de melioidose e dengue no nordeste do Brasil: primeiro caso

This report focuses on a fatality involving severe dengue fever and melioidosis in a 28-year-old truck driver residing in Pacoti in northeastern Brazil. He exhibited long-term respiratory symptoms (48 days) and went through a wide-ranging clinical investigation at three hospitals, after initial clinical diagnoses of pneumonia, visceral leishmaniasis, tuberculosis, and fungal sepsis. After death, Burkholderia pseudomallei was isolated in a culture of ascitic fluid. Dengue virus type 1 was detected by polymerase chain reaction in cerebrospinal fluid (CSF); this infection was the cause of death. This description reinforces the need to consider melioidosis among the reported differential diagnoses of community-acquired infections where both melioidosis and dengue fever are endemic.

Estudo de caso fatal de coinfecção de melioidose e dengue grave em um motorista de 28 anos, residente no município de Pacoti, nordeste do Brasil. O paciente apresentou inicialmente sintomas respiratórios com evolução por 48 dias. Foi internado em três diferentes unidades de saúde com suspeitas de pneumonia, leishmaniose visceral, tuberculose e sepse fúngica. Após o óbito, a cultura de líquido ascítico identificou a bactéria Burkholderia pseudomallei. O vírus da dengue tipo 1 foi detectado por PCR no líquor do paciente. Esta descrição reforça a necessidade de considerar a melioidose entre os diagnósticos diferenciais de infecções comunitárias onde as duas doenças são endêmicas.

Un caso de melioidosis en la Argentina / A case of melioidosis in Argentina

Se describe el caso de un varón de 17 años oriundo de República Dominicana, con antecedente de linfoma de Hodgkin, que presenta tumoraciones blandas con supuración espontánea. En sus cultivos desarrolló Burkholderia pseudomallei, agente etiológico de la melioidosis. El paciente recibió tratamiento antibiótico con imipenem y luego con amoxicilina-ácido clavulánico con muy buena evolución clínica del proceso infeccioso. En razón de la baja incidencia de Burkholderia pseudomallei en nuestro continente el diagnóstico de melioidosis pudo haber sido subestimado. Su diagnóstico definitivo depende del aislamiento e identificación del agente causal en la muestra clínica.

We describe a case of 17-year- old man native of Dominican Republic, with Hodgkin´s lymphoma, who presented soft espontaneous draining nodules. In the clinical samples grew Burkholderia pseudomallei; the etiological agent of melioidosis. He received antimicrobial treatment with imipenem and amoxicillin/clavulanic with very good clinical evolution of the infectious process. Melioidosis diagnosis could be underestimated due to the low incidence of Burkholderia pseudomallei in our continent. The definitive diagnosis depends of the isolation and identification in the clinical sample.

The public health implications of melioidosis

Melioidosis, which is caused by the bacterium Burkholderia pseudomallei, is a potentially fatal tropical infection, little known outside its main endemic zone of Southeast Asia and northern Australia. Though it has received more attention in recent years on account of its claimed suitability as a biological weapon agent, the principal threat from melioidosis is a result of naturally occurring events. Occasional case clusters, sporadic cases outside the known endemic zone and infections in unusual demographic groups highlight a changing epidemiology. As melioidosis is the result of an environmental encounter and not person-to-person transmission, subtle changes in its epidemiology indicate a role environmental factors, such as man-made disturbances of soil and surface water. These have implications for travel, occupational and tropical medicine and in particular for risk assessment and prevention. Practical problems with definitive laboratory diagnosis, antibiotic treatment and the current lack of a vaccine underline the need for prevention through exposure avoidance and other environmental health measures. It is likely that the increasing population burden of the tropical zone and extraction of resources from the humid tropics will increase the prevalence of melioidosis. Climate change-driven extreme weather events will both increase the prevalence of infection and gradually extend its main endemic zone.

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.

Atypical presentations of melioidosis as emerging threat: a case report.

We report two atypical presentations of melioidosis as mediastinal lymphadenitis and prostatic abscess with Burkholderia pseudomallei, the emerging category 2 organism which led to diagnostic and therapeutic dilemma and thereby, delay in appropriate management. Any similar presentation should always be supported by microbiological opinion without any delay, which can help in instituting proper antibiotics with successful outcome.

Isolated liver abscesses in melioidosis.

Melioidosis is a suppurative chronic infection caused by a gramnegative bacterium, Burkholderia pseudomallei. We report two patients who presented with isolated liver abscesses caused by this pathogen. Both patients presented with high-grade fever and abdominal pain. On examination they were toxic and had tender hepatomegaly. Investigations showed leucocytosis and a shift to the left. Early diagnosis of melioidosis was made by culture and growth of Burkholderia pseudomallei from aspirated pus from the abscesses and the patients were treated with ceftazidime and co-trimoxazole. Despite institution of antibiotics both the patients succumbed to their illness. Melioidosis is an emerging infection in the Indian subcontinent and can cause isolated liver abscesses.

PCR-based identification of Burkholderia pseudomallei / Identificação de Burkholderia pseudomallei baseada em PCR

DNA amplification techniques are being used increasingly in clinical laboratories to confirm the identity of medically important bacteria. A PCR-based identification method has been in use in our centre for 10 years for Burkholderia pseudomallei and was used to confirm the identity of bacteria isolated from cases of melioidosis in Ceará since 2003. This particular method has been used as a reference standard for less discriminatory methods. In this study we evaluated three PCR-based methods of B. pseudomallei identification and used DNA sequencing to resolve discrepancies between PCR-based results and phenotypic identification methods. The established semi-nested PCR protocol for B. pseudomallei 16-23s spacer region produced a consistent negative result for one of our 100 test isolates (BCC #99), but correctly identified all 71 other B. pseudomallei isolates tested. Anomalous sequence variation was detected at the inner, reverse primer binding site for this method. PCR methods were developed for detection of two other B. pseudomallei bacterial metabolic genes. The conventional lpxO PCR protocol had a sensitivity of 0.89 and a specificity of 1.00, while a real-time lpxO protocol performed even better with sensitivity and specificity of 1.00, and 1.00. This method identified all B. pseudomallei isolates including the PCR-negative discrepant isolate. The phaC PCR protocol detected the gene in all B. pseudomallei and all but three B. cepacia isolates, making this method unsuitable for PCR-based identification of B. pseudomallei. This experience with PCR-based B. pseudomallei identification methods indicates that single PCR targets should be used with caution for identification of these bacteria, and need to be interpreted alongside phenotypic and alternative molecular methods such as gene sequencing.

As técnicas de amplificação de DNA estão sendo cada vez mais utilizadas em laboratórios clínicos para a confirmação da identificação de bactérias que têm importância médica. Um método de identificação de Burkholderia pseudomallei baseado em PCR tem sido usado em nosso centro há 10 anos e foi utilizado para confirmar a identificação de bactérias isoladas de casos de melioidose no Ceará desde 2003. Este método particular tem sido usado como padrão ouro para métodos menos discriminatórios. Nesse estudo, avaliamos três métodos de identificação de B. pseudomallei baseados em PCR e usamos seqüenciamento de DNA para solucionar discrepâncias entre os resultados baseados em PCR e os métodos de identificação fenotípica. O estabelecido protocolo de PCR semi-nested para a região espacial 16-23s da B. pseudomallei produziu um consistente resultado negativo para um de nossos 100 isolados testados (BCC#99), mas identificou corretamente todos os outros 71 isolados de B. pseudomallei. Uma variação anômala da seqüência foi detectada na região interna do sítio de ligação do primer reverso para este método. Métodos de PCR foram desenvolvidos para a detecção de outros dois genes bacterianos metabólicos de B. pseudomallei. O protocolo de PCR IpxO convencional teve sensibilidade de 0,89 e especificidade de 1,0, enquanto que o PCR em tempo real mostrou-se ainda melhor, com sensibilidade de 1,0 e especificidade de 1,0. Este método identificou todos os isolados de B. pseudomallei, incluindo o isolado discrepante que teve o PCR negativo. O protocolo de PCR phaC detectou o gene de todos os B. pseudomallei e em todos exceto três isolados de B. cepacia, tornando este método de identificação de B. pseudomallei baseado em PCR inadequado. Esta experiência com métodos de identificação de B. pseudomallei baseados em PCR indica que devemos ter precaução quando estes forem utilizados sozinhos para identificação dessa bactéria e que eles necessitam ser interpretados em conjunto com métodos fenotípicos e moleculares alternativos, tais como seqüenciamento genético.

In vitro motility of a population of clinical Burkholderia pseudomallei isolates.

Melioidosis, a serious infection caused by Burkholderia pseudomallei, is a leading cause of community-acquired sepsis in Northeast Thailand, and the commonest cause of death from community-acquired pneumonia in the Top End of Northern Australia. The causative organism is a Gram-negative, motile bacillus that is a facultative intracellular pathogen. B. pseudomallei flagella have been proposed as a possible vaccine candidate and putative virulence determinant. Flagella expression was highly conserved for 205 clinical B. pseudomallei isolates, as defined by in vitro swim and swarm motility assays. No association was found between motility and clinical factors including bacteremia and death.

Melioidosis: an emerging infectious disease.

Infectious diseases account for a third of all the deaths in the developing world. Achievements in understanding the basic microbiology, pathogenesis, host defenses and expanded epidemiology of infectious diseases have resulted in better management and reduced mortality. However, an emerging infectious disease, melioidosis, is becoming endemic in the tropical regions of the world and is spreading to non-endemic areas. This article highlights the current understanding of melioidosis including advances in diagnosis, treatment and prevention. Better understanding of melioidosis is essential, as it is life-threatening and if untreated, patients can succumb to it. Our sources include a literature review, information from international consensus meetings on melioidosis and ongoing discussions within the medical and scientific community.

Primeira descrição de um caso autopsiado de melioidose no Estado do Ceará / First description of an autopsied case of Melioidosis in Ceará State

Relata-se um caso autopsiado de paciente acometida por sepse fulminante com lesões predominantemente pulmonares, causada pela Burkholderia pseudomallei, agente etiológico da melioidose, proveniente de município do interior do Ceará, estado do nordeste do Brasil onde ainda não tinham sido descritos casos da doença. São discutidos os achados da autópsia e os diagnósticos diferenciais.

Clinical manifestation of pulmonary melioidosis in adults.

Between 1996 and 2002, 162 cases of pulmonary melioidosis were reported from Srinagarind Hospital, Khon Kaen, northeast Thailand, 90 acute vs 72 subacute/chronic. Patients averaged 50 years of age and half worked as farmers. The male to female ratio was between 2 and 3 to 1 depending on the subgrouping. Burkholderia pseudomallei was confirmed by a culture or a four-fold rise in titer in the majority of cases, while the others were presumptive diagnoses based on response to treatment. Pulmonary melioidosis presented as either acute fulminant pneumonia or as an indolent disease. The common concurrent medical illness was diabetes mellitus. Mean incubation of the acute vs the sub-acute/chronic form was 8.7 vs 54.4 days, respectively. Leukocytosis was detected in 70% of cases. Sputum Gram's stain was not sensitive for diagnosis. Sputum culture and blood culture were diagnostic for 31.1 vs 22.2 and 40 vs 37.5% of the acute vs subacute/chronic forms, respectively. The common radiographic patterns for acute pneumonia were localized patchy alveolar infiltrate or hematogenous pattern. A bilateral diffuse patchy alveolar infiltration or multiple nodular lesions characterized the latter. Upper-lobe involvement with early cavitation and rapid progression were common. In the subacute/chronic forms, the radiographic pattern sometimes mimicked tuberculosis, with upper lobe involvement, patchy alveolar infiltrate with cavities or fibroreticular lesions. In approximately 30% of cases, liver and/or splenic abscess were common sites of extrapulmonary infection. Respiratory failure and septic shock from acute pulmonary melioidosis was 20% fatal. Early empirical antibiotic therapy should be given for severe pneumonia.

Pulmonary melioidosis presenting with right paratracheal mass.

A rare case of pulmonary melioidosis is reported. The patient was a 62-year-old man presenting with subacute fever, dry cough, and significant weight loss. A chest x-ray revealed a right paratracheal mass. The findings from fiberoptic bronchoscopy were a blunt carina and normal tracheobronchial tree. The patient had an underlying disease of poorly controlled diabetes mellitus, heavy smoking, and heavy alcoholic drinking. One of the two cultured blood specimens grew B. pseudomallei. The pathological finding of transbronchial biopsy at the apical segment of the right upper lung showed lymphocytic infiltrates. He was treated with two weeks of intravenous ceftazidime plus cotrimoxazole followed by 5 months of oral doxycycline plus cotrimoxazole. Clinical symptoms significantly improved and the right paratracheal mass disappeared.

Melioidosis; the remarkable imitator: recent perspectives.

Melioidosis is an important public health problem in some regions of the world. It is endemic in South East Asia. The clinical spectrum of melioidosis is extremely broad, and melioidosis requires awareness on the part of the clinician and the existence of a laboratory capable of isolating and identifying Burkholderia pseudomallei, the etiological agent of melioidosis. Beta-lactams such as ceftazidime is currently the treatment of choice. There is no vaccine licensed for human use. There is an urgent need for rapid diagnostic techniques and effective treatments that are affordable in countries where the disease is endemic.

Burkholderia pseudomallei: a case report of a human infection in Ceará, Brazil

O isolamento de Burkholderia pseudomallei, de meio ambiente e de espécimes clínicos, foi raramente registrado na América do Sul, particularmente no Brasil. Este relato descreve o caso de melioidose em um paciente de 10 anos de idade, de área rural do estado do Ceará (Tejuçuoca). As hemoculturas foram positivas e as análises dos testes bioquímicos e de susceptibilidade aos antimicrobianos do isolado foram indicativos para a identificação de B. pseudomallei. A fonte de contaminação foi obscura, uma vez que as análises microbiológicas de solo e água no tanque foram negativas.