Melioidosis: review and update.

Melioidosis prevails in Southeast Asia and northern Australia. Sporadic cases have been increasingly reported from countries located between 20 degrees north latitude and 20 degrees south latitude as well as in travelers and in soldiers who have resided in these areas. The organisms are commonly found in water and soil and are usually transmitted to humans by cutaneous or respiratory routes. Clinical manifestations range from subclinical infection to overwhelming septicemia that resembles disseminated or localized suppurative infection due to various pathogens. A rapid and accurate diagnosis can be made by demonstration of small, few, and frequently bipolar-stained gram-negative bacilli in exudate or pus. The indirect hemagglutination test is of diagnostic value in cases with involvement of the internal organs or pyrexia of unknown origin. Chloramphenicol, doxycycline, trimethoprim-sulfamethoxazole, and kanamycin constitute conventional and effective chemotherapy. Newer antimicrobial agents such as piperacillin, amoxillin-clavulanic acid, ceftazidime, imipenem, and carumonam are active in susceptibility tests against the causative microorganism, Pseudomonas pseudomallei. Clinical trials for demonstration of the effectiveness of the latter agents in overwhelming septicemic melioidosis are ongoing in endemic areas.