A review on melioidosis with special respect on molecular and immunological diagnostic techniques.

Melioidosis is an 'emerging' tropical disease which causes diagnostic problems in endemic and especially in nonendemic areas e.g. Germany when imported. In the last decade, many efforts have been made to develop new molecular and immunological techniques for diagnostic use. However, an actual comprehensive review does not exist. Apart from classical microbiological procedures (microscopy, culture and biochemical identification) efforts have been made to identify Burkholderia pseudomallei using specific antibodies and PCR. The direct antigen detection can be done within a few hours leading to diagnosis days before cultural proof. ELISA and immunoblot techniques were examined for their ability to replace indirect hemagglutination and immunofluorescence test in serology. The diagnostic value of serological procedures for early detection of melioidosis is limited, however. The rapid and reliable diagnosis of melioidosis is required for an adequate onset of therapy. But no evaluated test kit based on the detection of specific antibodies, specific antigens, or on the amplification of species-specific DNA sequences is commercially available up to now. Even PCR testing--primers can easily be ordered by many gene technology companies--can not be recommended as B. pseudomallei DNA for positive controls is not available. Therefore, only microscopy and biochemical identification systems like the API 20NE can be used in the routine laboratory up to now. At this point, it has to be stressed that B. pseudomallei is a level 3 agent in many countries e.g. Germany and that only laboratories with high containment are allowed to handle it. In all cases the help of an experienced reference laboratory is adviced.