DIAGNOSTIC-VALUE OF AN ANTIBODY ENZYME-LINKED-IMMUNOSORBENT-ASSAY USING AFFINITY-PURIFIED ANTIGEN IN AN AREA ENDEMIC FOR MELIOIDOSIS

Melioidosis, an infection caused by Burkholderia pseudomallei, is ende mic In southeast Asia. The septicemic form of melioidosis is the leadi ng cause of death from nonhospital-acquired septicemia in the northeas tern part of Thailand. A major factor that contributes to the high mor tality is tile delay in isolation and identification of the causative organism. The present study tvas undertaken to evaluate the use of enz yme-linked;ed immunosorbent assays based on an immunoaffinity-purified antigen for detecting specific IgG and IgM antibodies to this organis m as a rapid serodiagnostic method for melioidosis. The diagnostic val ue of these tests was evaluated in an actual clinical situation in an area endemic for melioidosis. The specificity of specific IgG test (82 .5%) and the specific IgM test (63.5%) were significantly better than that of the indirect hemagglutination (IHA) test (74.7%). The sensitiv ity of the specific IgG assay (85.7%) was higher than that of the IHA test (71.0%) and the specific IgM lest (63.5%). Specific IgG antibody was detected in a majority of septicemic melioidosis (87.8%), as well as in localized forms (8.6%). The specific IgG test was also better th an the specific IgM test and the IHA test in identifying acute melioid osis cases in the first live days after admission. In addition, the Ig G antibody level to this antigen remained high over a period of more t han five years in chose who had recovered from melioidosis and remaine d clinically free of the disease. These results indicate that the dete ction of specific IgG antibody is clinically useful for the diagnosis of acute melioidosis in an endemic area.