Pneumocystis jirovecii Pneumonia Outbreaks in Renal Transplant Populations in Quebec, Canada: Clinical and Molecular Epidemiology
Bibliographic record
Abstract
Background. In 2013 and 2014, four Pneumocystis jirovecii pneumonia (PJP) outbreaks occurred among renal transplant recipient cohorts in three academic hospitals in Quebec, Canada. We investigated the outbreaks seeking to (1) determine risk factors associated with development of PJP and (2) elucidate the likely mode of transmission. Methods. A case-control study was conducted. Cases were defined as patients who had undergone kidney transplantation in one of the three centers and who were diagnosed with proven PJP during outbreak periods. Controls were randomly selected among all patients followed through outpatient transplant clinics during the outbreak periods. Bronchoalveolar lavage samples from 16 cases were available and used for PJ genotyping by multilocus sequence typing. Air samples were collected for detection of PJ DNA (mitochondrial large subunit RNA gene) using real-time polymerase chain reaction. Results. A total of 22 cases and 88 control patients were identified. Genotyping confirmed isolate clonality within each outbreak. The cases occurred a median of 112 months after transplantation. None of the cases was receiving targeted PJP prophylaxis at time of diagnosis. Independent risk factors for developing PJP included administration of anti-thymocyte antibodies after the transplant (adjusted odds ratio [aOR] 4.73, 95% confidence interval [95% CI] 1.12-19.89), glomerular filtration rate < 30 mL/min (aOR 4.65, 95% CI 1.22-17.78), and absolute lymphocyte counts below 1000 (aOR 5.53, 95% CI 1.40-21.94). Analysis of contacts in the outpatient clinic showed an increased tendency for cases to have attended the outpatient clinic the same day as a future (within two months) case of PJP (OR 1.56, 95% CI 0.59-4.13). Air sampling carried out in one center also showed the presence of PJ DNA in outpatient transplant clinic samples. Conclusion. The development of PJP is associated with host risk factors that translate to increased immunosuppression. Collectively, the molecular and epidemiological data support person-to-person transmission of the disease, possibly via airborne particles. This study underlines the need for prophylaxis in certain contexts and the importance of avoiding close contact between patients with PJP and other susceptible hosts. Disclosures. All authors: No reported disclosures.
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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 | 0.002 |
| Science and technology studies | 0.002 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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".