Trypanosoma cruzi in a low- to moderate-risk blood donor population: seroprevalence and possible congenital transmission.
BACKGROUND
Several recent studies documented the seroprevalence of Trypanosoma cruzi in blood donors at high risk for infection, but little information is available regarding donors with lower levels of risk. Thus, the present study was designed to measure the seroprevalence of T. cruzi in a donor population with a low to moderate risk for infection.


METHODS
During a 10-month period, donations from all allogeneic blood donors in the American Red Cross Southwest Region were tested for T. cruzi antibodies by enzyme immunoassay, and results were confirmed by radioimmunoprecipitation. Confirmed-seropositive donors were counseled and lookback investigations were initiated for those who were repeat donors.


RESULTS
A total of 100,089 donations were tested: 150 were repeatably reactive, and 3 (0.003%) were confirmed as positive for T. cruziantibodies. All three seropositive donors were from the Waco, TX, area, where the estimated seroprevalence rate was 1 in 7700. Two of these three donors reported no risk factors; both were born in the United States and had not traveled to an endemic area. Both had extensive familial histories of cardiac disease and complications.


CONCLUSIONS
Blood donors seropositive for T. cruzi are present in populations with low to moderate risk, albeit at lower rates. The presence of seropositive blood donors without the usual identifiable risk factors argues against the use of a geographic screening question and also suggests that other routes of transmission, including the congenital route, should be considered in efforts to increase blood safety.
Leiby
D A
DA
Department of Transmissible Diseases, American Red Cross, Rockville, Maryland 20855, USA.
Fucci
M H
MH
Stumpf
R J
RJ
D000293:Adolescent; D000328:Adult; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood*; D001782:Blood Donors; D014355:Chagas Disease / Q000097:blood / Q000151:congenital / Q000175:diagnosis / Q000276:immunology / Q000517:prevention & control* / Q000635:transmission; D016358:Contact Tracing; D004641:Emigration and Immigration; D005192:Family Health; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D007843:Latin America / Q000208:ethnology; D008297:Male; D008431:Maternal-Fetal Exchange; D017058:Mexican Americans; D008875:Middle Aged; D010375:Pedigree; D011247:Pregnancy; D015995:Prevalence; D011863:Radioimmunoassay; D012306:Risk; D016036:Seroepidemiologic Studies; D015206:Southwestern United States / Q000453:epidemiology; D013781:Texas / Q000453:epidemiology; D065227:Transfusion Reaction; D014195:Travel; D014349:Trypanosoma cruzi / Q000276:immunology*
D000913:Antibodies, Protozoan