Histoplasmosis acquired in Alberta, Canada: an epidemiological and genomic study
Bibliographic record
Abstract
BACKGROUND: The classic geographical range of histoplasmosis in North America primarily includes the states and provinces adjacent to the Ohio, Mississippi, and St Lawrence riverways. Although Alberta, Canada is not typically considered a region of risk for histoplasmosis, cases with suspected local acquisition have been reported. We aimed to investigate the epidemiology and geographical distribution of cases of histoplasmosis in Alberta to assess evidence for local acquisition of infections, using genomic analysis for corroboration. METHODS: We did an epidemiological and genomic investigation, in which laboratory-confirmed cases of histoplasmosis were reviewed in Alberta from 2011, when the disease became reportable, until 2018. We used data attained from Alberta Health. Travel and exposure histories and clinical features were reviewed. Definite local acquisition was defined as a case without previous travel outside Alberta or associated with a common-source outbreak within the province, whereas probable local acquisition was a sporadic case with travel outside Alberta but compelling local exposures. Genomes of selected case isolates were analysed, including those from cases suspected to have been locally acquired and imported. FINDINGS: Between Jan 1, 2011, and June 30, 2018, 45 cases of histoplasmosis were identified. Participants had a median age of 53 years (range 17-77) and 32 [71%] were male. Among 34 patients with documented travel histories, ten (29%) had never left the province. 11 cases were of definite local acquisition, including eight cases from three common-source outbreaks and three sporadic cases in patients who had never travelled outside Alberta. The common-source outbreaks all involved exposure to bats or their droppings in chimneys or attics of private dwellings or churches. Four patients had travelled outside Alberta but compelling evidence was seen for local exposure to bat guano. Genome sequencing showed that isolates from cases of definite and probable local acquisition clustered together and were genetically distinct from isolates from suspected imported cases and other published isolates. INTERPRETATION: Using epidemiological and genomic analyses, we established that cases of histoplasmosis have been acquired in Alberta, thus expanding the geographical range of Histoplasma spp much further northwest than was previously appreciated. Histoplasmosis should be considered in patients with compatible symptoms outside areas of classic geographical risk. FUNDING: None.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.005 |
| Science and technology studies | 0.003 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.001 |
| 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".