Detection and Genetic Characterization of Hepatitis B and D Viruses: A Multi-Site Cross-Sectional Study of People Who Use Illicit Drugs in the Amazon Region
Bibliographic record
Abstract
Hepatitis B (HBV) and delta (HDV) viruses are endemic in the Amazon region, but vaccine coverage against HBV is still limited. People who use illicit drugs (PWUDs) represent a high-risk group due to common risk behavior and socioeconomic factors that facilitate the acquisition and transmission of pathogens. The present study assessed the presence of HBV and HBV-HDV co-infection, identified viral sub-genotypes, and verified the occurrence of mutations in coding regions for HBsAg and part of the polymerase in HBV-infected PWUDs in municipalities of the Brazilian states of Amapá and Pará, in the Amazon region. In total, 1074 PWUDs provided blood samples and personal data in 30 municipalities of the Brazilian Amazon. HBV and HDV were detected by enzyme-linked immunosorbent assay and polymerase chain reaction. Viral genotypes were identified by nucleotide sequencing followed by phylogenetic analysis, whereas viral mutations were analyzed by specialized software. High rates of serological (32.2%) and molecular (7.2%) markers for HBV were detected, including cases of occult HBV infection (2.5%). Sub-genotypes A1, A2, D4, and F2a were most frequently found. Escape mutations due to vaccine and antiviral resistance were identified. Among PWUDs with HBV DNA, serological (19.5%) and molecular (11.7%) HDV markers were detected, such as HDV genotypes 1 and 3. These are worrying findings, presenting clear implications for urgent prevention and treatment needs for the carriers of these viruses.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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 teacher head, 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".