<i>Trypanosoma cruzi</i> in Los Angeles and Miami blood donors: impact of evolving donor demographics on seroprevalence and implications for transfusion transmission
Bibliographic record
Abstract
BACKGROUND: Trypanosoma cruzi, the agent of Chagas' disease, continues to be a concern for blood safety, as demonstrated by recent transfusion-transmitted cases in the United States and Canada. The chronic nature of Chagas', coupled with increasing numbers of immigrants from T. cruzi-endemic countries, suggests that Chagas' is a long-term public health problem. Herein, we report on a multiyear epidemiologic study of T. cruzi in Los Angeles and Miami blood donors. STUDY DESIGN AND METHODS: From May 1994 to September 1998, blood donors in Los Angeles and Miami were queried regarding birth or time spent in an endemic country. Donations of "yes" respondents were tested by EIA, confirmed by radioimmunoprecipitation assay, and if confirmed as seropositive, enrolled in look-back investigations. RESULTS: A total of 1,104,030 Los Angeles and 181,139 Miami donors were queried regarding risk; 7.3 and 14.3 percent, respectively, responded yes. Seropositive rates were 1 in 7,500 Los Angeles and 1 in 9,000 Miami donors. In Los Angeles, seroprevalence rates increased significantly from 1996 to 1998 and were significantly higher for directed donors than nondirected donors. Look back identified 18 recipients, all of whom were seronegative for T. cruzi. CONCLUSION: Significant numbers of T. cruzi-seropositive donors contribute to the U.S. blood supply. The incidence of seropositivity is enhanced by minority recruitment efforts necessitated by donor demographic shifts. Similarly, high rates among directed donations in Los Angeles are attributable to a disproportionate number of at-risk directed donors. Current look-back data likely underestimate the frequency of transfusion- transmitted T. cruzi. These results indicate that continued evaluation of transfusion as a mode of T. cruzi transmission in the United States is needed.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".