Evaluation of the specificities of the recombinant proteins with serum samples from individuals with unrelated diseases and healthy controls. The specificities of the reactivities of the proteins to serum samples from patients with other febrile illnesses and healthy donors were determined by ELISA. The symbols represent the reactivities against recombinant proteins MPL17 (A) and MPL21 (B) of each serum sample tested in duplicate at a 1:100 dilution. DE, individuals with dengue (n = 13); Mal, individuals with Plasmodium vivax or P. falciparum malaria (n = 13), HIV, individuals infected with HIV (n = 15); Cha, individuals with Chagas' disease (n = 20); healthy, healthy individuals (n = 6). The dashed lines represent the cutoff values (0.325 and 0.168 for MPL17 and MPL21, respectively).