RESUMO
The status of Chagas' disease in Ecuador is not clear. In response to reports suggesting the possibility of transfusion-associated transmission of Chagas' disease in the blood bank in Quito, the Ecuadorian Red Cross in collaboration with the Instituto Nacional de Higiene, Zona Norte and the Tropical Disease Institute of Ohio University implemented a pilot Chagas' disease screening of the donated blood in the Quito blood bank. The results of the screening showed a low incidence of seropositivity among the donors (0.01% in 1994, 0.04% in 1995, and 0.02% in 1996) to the Quito blood bank and a higher seropositivity in samples donated to smaller blood banks (0.4% in 1994, 0.28% in 1995, and 0.13% in 1996) located in areas considered endemic, as well as from at least two areas previously considered nonendemic for Chagas' disease. This report highlights the need for a comprehensive evaluation of the prevalence and distribution of Chagas' disease in Ecuador.
Assuntos
Anticorpos Antiprotozoários/análise , Doença de Chagas/epidemiologia , Trypanosoma cruzi/imunologia , Animais , Anticorpos Antiprotozoários/sangue , Anticorpos Antiprotozoários/imunologia , Bancos de Sangue , Doadores de Sangue , Doença de Chagas/imunologia , Doença de Chagas/transmissão , Transmissão de Doença Infecciosa , Equador/epidemiologia , Humanos , Incidência , Cruz Vermelha , Estudos SoroepidemiológicosRESUMO
Sera from 9,254 individuals that presented at one of three outpatient clinics in Quito, Ecuador were assayed by indirect hemagglutination for the presence of antibodies reactive with antigens from Taenia solium cysts. Immunoblot analysis of 81 selected sera with IHA titers ranging from 0 to 1,028 showed that a titer of > or = 32 was suggestive of exposure to the parasite. Nine percent (9%) of the 9,254 patients had titers of 32 or greater. Of 3,503 sera from one clinic, which included sera from food handlers undergoing yearly physicals, 390 (11%) were positive. In addition, a correlation with age was seen in some, but not all, populations. In situations where age-related effects were noted, the highest incidence was seen in the youngest (0-20 years) and in the oldest (51-60 years) group. Thus, a resurgence of infection after a period of lower prevalence may be developing. Overall, this study shows that cysticercosis is relatively common and potentially a serious health problem in this region.
Assuntos
Anticorpos Anti-Helmínticos/sangue , Cisticercose/diagnóstico , Taenia/imunologia , Adolescente , Adulto , Animais , Criança , Pré-Escolar , Equador , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Pacientes AmbulatoriaisRESUMO
Chagas' disease is a serious health problem for the population of South and Central America. Blood transfusion is the second most common way in which this disease is transmitted. Several studies have reported finding Trypanosoma cruzi-infected blood in blood banks in endemic areas. Serum samples were taken from the Red Cross blood bank in Quito, a nonendemic and vector free zone of Ecuador, in December 1992 and May 1993 and analyzed by enzyme-linked immunosorbent assay using crude epimastigote extract from the Brazil strain of T. cruzi. Of 162 samples examined in December 1992, 12.1%, 13.9%, and 74% were seropositive, indeterminate, and seronegative, respectively. Of 173 samples taken in May 1993, 6.2%, 17.9%, 75.9% were seropositive, indeterminate, and seronegative, respectively. Western blot analysis of these sera using sodium dodecyl sulfate-polyacrylamide gel electrophoresis with 7.5% gels separated T. cruzi epimastigote antigen proteins, and revealed a reaction with a 205-kD doublet antigen with most of the seropositive samples. These results indicate the necessity for long-term screening of blood bank donors to reduce the risk of transfusion transmission of the disease even in areas of endemic countries where the vector is not present.
Assuntos
Anticorpos Antiprotozoários/sangue , Doadores de Sangue , Doença de Chagas/epidemiologia , Trypanosoma cruzi/imunologia , Animais , Western Blotting , Doença de Chagas/transmissão , Equador/epidemiologia , Ensaio de Imunoadsorção Enzimática , Humanos , Reprodutibilidade dos Testes , Reação TransfusionalRESUMO
Treatment of susceptible C3H(He) mice with 10(7) live Corpus Christi strain culture-derived Trypanosoma cruzi provided protection against a subsequent Brazil strain challenge. This protection was indicated by a greater than 10-fold decrease in parasitemia and an increase in longevity (including survival) in many groups. The Corpus Christi organisms were unable to establish an apparent infection, but viability is an important element in the treatment in that freeze-thawed, non-viable preparations of the Corpus Christi strain were unable to provide protection. Adoptive transfer of resistance was achieved with spleen cells from Corpus Christi-treated, Brazil-infected mice which had recovered from the acute phase of infection. The T cell-depleted population of these spleen cells was able to transfer resistance whereas the T cell-enriched population was not protective. Passive transfer of serum from Corpus Christi-treated and Brazil-infected mice provided a temporary decrease in parasitemia in infected mice. The results presented herein suggest that Corpus Christi-induced protection to virulent T. cruzi challenge is mediated by antibody mechanisms.