No abstract

Three new cases of reactivation of Chagas' disease in patients with AIDS, with central nervous system and/or cardiac involvement, are reported. One patient had histological evidence of acute esophageal and gastric Trypanosoma cruzi myositis, a previously unrecognized finding in patients with reactivated Chagas' disease. The patients had a low CD4 lymphocyte count and had other AIDS-defining opportunistic infections. One patient's condition improved with benznidazole therapy. Analysis of these three cases and review of the 13 others published in the literature revealed that the central nervous system is the most commonly involved site (75%), followed by the heart (44%). Early diagnosis and treatment with benznidazole or nifurtimox probably improve the survival rate. Long-term secondary prophylaxis should be recommended for patients who respond to therapy, although it is uncertain which drug to use for this purpose. T. cruzi should be included in the list of opportunistic pathogens causing infection in severely immunocompromised patients with AIDS.

Considering that little is known about the epidemiology of Neospora caninum infection in humans, particularly in populations with high Toxoplasma gondii infection rates, the present study aimed to investigate the presence of antibodies to N. caninum in T. gondii-seropositive and -seronegative individuals. A total of 256 serum samples divided into four groups (61 samples from human immunodeficiency virus [HIV]-positive patients, 50 samples from patients with neurological disorders, 91 samples from newborns, and 54 samples from healthy subjects) were assessed for N. caninum and T. gondii serologies by indirect fluorescent-antibody test, enzyme-linked immunosorbent assay, and immunoblotting (IB). Immunoglobulin G antibodies to N. caninum were predominantly detected in HIV-infected patients (38%) and patients with neurological disorders (18%), while newborns and healthy subjects showed lower seropositivity rates (5% and 6%, respectively). Seropositivity to N. caninum was significantly associated with seropositivity to T. gondii in both HIV-infected patients and patients with neurological disorders. Seroreactivity to N. caninum was confirmed by IB, with positive sera predominantly recognizing the 29-kDa antigen of N. caninum. The results of this study indicate the presence of N. caninum infection or exposure in humans, particularly in HIV-infected patients or patients with neurological disorders, who could have opportunistic and concurrent infections with T. gondii. These findings may bring a new concern for the unstable clinical health of HIV-infected patients and the actual role of N. caninum infection in immunocompromised patients.