American tegumentary leishmaniasis (ATL) was studied in 143 dogs in a rural area in the county of Mariluz, northwestern Paraná State, Brazil, using direct parasite search, indirect immunofluorescence (IIF), and polymerase chain reaction (PCR). Thirty-nine dogs (27.3%) presented lesions suggestive of the disease, 5 (12.8%) of which were positive in direct parasite search and PCR (lesion), and of...

The serology of human Trypanosoma cruzi infection in the Rio Negro microregion is very complex because of the large numbers of false-positive cases that result from low antibody titres and cross-reactions with other infections. In the present study, we collected 4,880 blood samples on filter paper; of these, indirect immunofluorescence (IIF) was strongly reactive in 221 (4.5%), which were consi...

In the diagnosis of autoimmune diseases, an important task is to classify images of slides containing several HEp-2 cells. All cells from one slide share the same label, and by classifying cells from one slide independently, some information on the global image quality and intensity is lost. Considering one whole slide as a collection (a bag) of feature vectors, however, poses the problem of ho...

Rabbits were inoculated with untreated whole cells of 16 strains of Haemophilus ducreyi. Homologous titres in an indirect immunofluorescence test ranged from 1/320 to 1/1280. No cross reactions, or very few, were observed between antisera to these strains and 22 other (possible taxonomically related) species, strains, and genera. A large diversity in types of antigen was observed among the stra...

Immunofluorescence staining methods for respiratory syncytial virus antigen detection were compared. Of 50 specimens originally positive for respiratory syncytial virus by direct immunofluorescence and culture, 49 were positive by repeat direct immunofluorescence and 32 were positive by indirect immunofluorescence. Additional results obtained on specimens originally negative for respiratory syn...