is an infectious disease caused by a gram-negative bacterium, Burkholderia pseudomallei, found in soil and water. B. pseudomallei is visualized as a bacillus with bipolar staining and is vacuolated and slender and has rounded ends; it is often described as having a “safety pin” appearance. It is oxidase positive and can be distinguished from the closely related but less B. thailandensis by its ability to assimilate arabinose.
Disease pathophysiology :
The enter the body through the skin (via breaks in the skin surface); mucosal surfaces of the eyes, nose, or mouth; or lungs.The characteristic findings of glanders include purulent oropharyngeal mucositis and widespread abscesses involving multiple organs, notably the lungs, liver, and spleen. Computed tomographic appearance of hepatic and splenic involvement can mimic echinococcal or amebic infection, so a high index of suspicion is essential in making the diagnosis.
During 2008–2013, BSPB provided technical assistance to 20 U.S. states and Puerto Rico involving 37 confirmed cases of melioidosis (34 human cases and three animal cases). Among those with documented travel history, the majority of reported cases (64%) occurred among persons with a documented travel history to areas endemic for melioidosis. Two persons did not report any travel outside of the United States. Separately, six incidents of possible occupational exposure involving research activities also were reported to BSPB, for which two incidents involved occupational exposures and no human infections occurred.
Intravenous is the current drug of choice for treatment of acute melioidosis. , and the cefoperazone-sulbactam combination (Sulperazone) are also active. Intravenous amoxicillin-clavulanate (co-amoxiclav) may be used if none of the above four drugs is available, but it produces inferior outcomes. The median fever clearance time in melioidosis is 10 days and failure of the fever to clear is not a reason to alter treatment.
Major research on disease:
There has beengrowing awareness of the disease in the Americas, particularly since the Vietnam conflict when it was diagnosed inreturning service personnel. Accidental laboratory exposure indicatesthe difficulty making a culture-based diagnosiswhen melioidosis has not been considered in the differential diagnosis. Melioidosis is most likely underdiagnosed intropical Central and South America where conditions are more suited to persistence of B. pseudomalleiin the envi-ronment. Recent melioidosis case clusters in northeastern Brazil highlight the threat posed to rural populations locatedfar from specialist services. Increased clinical awareness of the disease and improvements in laboratory diagnosticmethods are likely to bring wider recognition of melioidosis in the Americas.
As melioidosis was not suspected initially, bacterial culture was not done but electron microscopy showed morphologically viable and dividing bacilli in the lesion. Moreover, the surgical wound became infected with B. pseudomallei several days post-surgery. After treatment with ceftazidime and trimethoprim/sulfamethoxazole, the wound infection cleared. We believe this could be a unique case of asymptomatic latentmelioidosis in the spleen. In endemic countries, chronic granulomas should be investigated for B. pseudomallei infection, and if available, ISH may be helpful for diagnosis.