Follow-up of a human accidental infection by Leishmania (Viannia) braziliensis using conventional immunologic techniques and polymerase chain reaction.

The results of a two-year follow-up study of an accidental human infection with Leishmania (Viannia) braziliensis are presented. Western blots, indirect immunofluorescence, and intradermal reaction assays were not able to detect the infection before week 18 postinfection, whereas using the polymerase chain reaction (PCR) on blood samples, parasite DNA was detected at week 8. All test results, except the intradermal reaction followed the cure process and 12 weeks after the last chemotherapy injection (week 36 postinfection), all were negative. However, a year after cure, the PCR became positive again and has remained so for two years. To determine in which blood cell fraction the parasite was evident, enriched lymphocyte and monocyte fractions were assayed by the PCR. These results are discussed in the context of persistent infections.