Human antibody response to a 56-kDa purified excretory/secretory product of Dirofilaria immitis

Canine dirofilariasis is widespread in urban areas of central and northern Colombia. Previously we detected specific antibodies against complex antige ns from Dirofilaria immitis adult worms in individuals from an isolated Tik una Indian community in the Colombian Amazon. In this study a 56 kDa polype ptide from the adult D. immitis excretory/secretory (E/S) products is ident ified by Western blot, isolated by elution from polyacrilamide gels and app lied in an ELISA-based test for the detection of specific IgG. Eleven of 74 serum samples analysed were positive by ELISADi56. Positive individuals cr ime from five different areas of Colombia. The highest number of positives was found in the Amazon (4), followed by Bogota (3). The physicians of the area must be alerted regarding the existence of human D. immitis infections and include dirofilariasis in the differential diagnosis of pulmonary nodu les.