1464
References
Seropositivity to Trypanosoma cruz; in Blood Donors in Santa Cruz, Bolivia Colleagues-Chagas' disease, caused by the protozoan parasite Trypanosoma cruzi, is a major public health problem in rural and suburban areas of Central and South America. Blood transfusion is the second-most-frequent route of transmission of this disease [I]. In Bolivia, only a few studies on the prevalence of T. cruzi infection in blood donors have been reported [2, 3]. We report here the presence oflgG and IgM antibodies to T. cruzi in blood bank sera in a Bolivian municipality. Serum samples (316) were obtained from the blood bank of Santa Cruz General Hospital during November I989-April 1990 and stored at - 20°C until used. After heat inactivation for 30 min at 56°C, the sera were screened immunologically. The indirect fluorescence antibody test (IFAT) was done essentially as previously described [4]. Formalin-fixed epimastigotes of T. cruzi tulahuen strain were used as antigen. Sera were used after 20-fold r'ilution, and specific antibodies were detected with fluorescein isothiocyanate-Iabeled goat anti-human IgG and IgM (Medical and Biological Laboratories [MBL], Nagoya, Japan). ELISA, using sonicated antigen, was also done as described [5]. Serum dilutions were 400-fold, and horseradish peroxidaselabeled goat anti-human IgG (MBL) was used as the second antibody. After development by substrate, the optical density (OD) was read. Sera were scored as positive if their OD values were >3 SD of the mean calculated from 20 Japanese control sera. The age distribution of blood donors and the numbers IFATand ELISA-positive are summarized in table I. With the IFAT,
Financial support: Japan International Cooperation Agency (JICA) Reprints or correspondence: Dr. H. Tachibana. Department ofInfectious Diseases, Tokai University School of Medicine. Bohseidai, Isehara. Kanagawa 259-11, Japan.
1992; 166 (December)
6. Levine MM, Ferreccio C, Cryz S, Ortiz E. Comparison ofenteric-coated capsules and liquid formulation ofTy21 a typhoid vaccine in randomised controlled field trial. Lancet 1990;2:891-4. 7. Simanjuntak CH, Paleologo FP, Punjabi NH, et al. Oral immunisation against typhoid fever in Indonesia with Ty21 a vaccine. Lancet 1991;2: 1055-9. 8. Ferreccio C, Levine MM, Rodriquez H, Contreras R, Chilean Typhoid Committee. Comparative efficacy of two, three, or four doses of Ty21 a live oral typhoid vaccine in enteric-coated capsules: a field trial in an endemic area. J Infect Dis 1989;159:766-9. 9. Karbwang J, White NJ. Clinical pharmacokinetics of mefloquine. Clin Pharmacokinet 1990; 19:264-79. 10. Pappaioanou M, Fishbein DB, Dreesen DW, et al. Antibody response to preexposure human diploid-cell rabies vaccine given concurrently with chloroquine. N Engl J Med 1986;314:280-4.
IgG antibody to T. cruzi was detected in 48.7% of the sera examined. It was surprising that even in young people
References
Seropositivity to Trypanosoma cruz; in Blood Donors in Santa Cruz, Bolivia Colleagues-Chagas' disease, caused by the protozoan parasite Trypanosoma cruzi, is a major public health problem in rural and suburban areas of Central and South America. Blood transfusion is the second-most-frequent route of transmission of this disease [I]. In Bolivia, only a few studies on the prevalence of T. cruzi infection in blood donors have been reported [2, 3]. We report here the presence oflgG and IgM antibodies to T. cruzi in blood bank sera in a Bolivian municipality. Serum samples (316) were obtained from the blood bank of Santa Cruz General Hospital during November I989-April 1990 and stored at - 20°C until used. After heat inactivation for 30 min at 56°C, the sera were screened immunologically. The indirect fluorescence antibody test (IFAT) was done essentially as previously described [4]. Formalin-fixed epimastigotes of T. cruzi tulahuen strain were used as antigen. Sera were used after 20-fold r'ilution, and specific antibodies were detected with fluorescein isothiocyanate-Iabeled goat anti-human IgG and IgM (Medical and Biological Laboratories [MBL], Nagoya, Japan). ELISA, using sonicated antigen, was also done as described [5]. Serum dilutions were 400-fold, and horseradish peroxidaselabeled goat anti-human IgG (MBL) was used as the second antibody. After development by substrate, the optical density (OD) was read. Sera were scored as positive if their OD values were >3 SD of the mean calculated from 20 Japanese control sera. The age distribution of blood donors and the numbers IFATand ELISA-positive are summarized in table I. With the IFAT,
Financial support: Japan International Cooperation Agency (JICA) Reprints or correspondence: Dr. H. Tachibana. Department ofInfectious Diseases, Tokai University School of Medicine. Bohseidai, Isehara. Kanagawa 259-11, Japan.
1992; 166 (December)
6. Levine MM, Ferreccio C, Cryz S, Ortiz E. Comparison ofenteric-coated capsules and liquid formulation ofTy21 a typhoid vaccine in randomised controlled field trial. Lancet 1990;2:891-4. 7. Simanjuntak CH, Paleologo FP, Punjabi NH, et al. Oral immunisation against typhoid fever in Indonesia with Ty21 a vaccine. Lancet 1991;2: 1055-9. 8. Ferreccio C, Levine MM, Rodriquez H, Contreras R, Chilean Typhoid Committee. Comparative efficacy of two, three, or four doses of Ty21 a live oral typhoid vaccine in enteric-coated capsules: a field trial in an endemic area. J Infect Dis 1989;159:766-9. 9. Karbwang J, White NJ. Clinical pharmacokinetics of mefloquine. Clin Pharmacokinet 1990; 19:264-79. 10. Pappaioanou M, Fishbein DB, Dreesen DW, et al. Antibody response to preexposure human diploid-cell rabies vaccine given concurrently with chloroquine. N Engl J Med 1986;314:280-4.
IgG antibody to T. cruzi was detected in 48.7% of the sera examined. It was surprising that even in young people
