An outbreak of hepatitis B associated with reusable subdermal electroencephalogram electrodes.
Bibliographic record
Abstract
BACKGROUND: In early 1996 an outbreak of hepatitis B was detected among patients who attended an electroencephalogram (EEG) clinic in Toronto operated by a neurologist. In this article we report the results of an investigation conducted to determine the extent and source of the outbreak. METHODS: Notifications were sent to 18 567 patients who had attended any of 6 EEG clinics operated by the neurologist between 1990 and 1996 asking them to see their physician to be tested for hepatitis B virus (HBV) infection; 2957 envelopes were returned. Of the remaining 15 610 patients, results of laboratory tests were available for 10 244 (65.6%). A detailed follow-up of patients with newly acquired hepatitis B and those with chronic infection (carriers) was conducted. Viral DNA sequencing was used to compare strains of available HBV isolates. RESULTS: A total of 75 patients were identified in whom hepatitis B developed between 1991 and 1996; all of them had had at least one EEG performed in which reusable subdermal electrodes had been used. No cases were detected among patients who participated only in sleep studies, for which disk electrodes had been used. The peak rate of HBV infection (18.2 cases per 1000 person-EEGs) occurred in 1995. One technician performed all of the EEGs at the clinics and was found to be positive for hepatitis B e antigen. DNA sequencing confirmed that the virus isolated from the technician was identical to the virus isolated in 4 cases of hepatitis B tested. Infection control procedures were found to be inadequate. INTERPRETATION: The hepatitis B outbreak was a result of a common source of infection, the technologist, and inadequate infection control practices. Reusable subdermal EEG electrodes were the likely vehicles of transmission. Health care workers should follow recommended infection control practices and be vaccinated against hepatitis B.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.004 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.003 | 0.002 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.006 | 0.005 |
| Insufficient payload (model declined to judge) | 0.002 | 0.001 |
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".