Outbreak of Travel-Related Pontiac Fever among Hotel Guests Illustrating the Need for Better Diagnostic Tests
Bibliographic record
Abstract
BACKGROUND: Pontiac fever (PF), a legionellosis with influenza-like symptoms and high attack rates, is rarely reported. Travel-related outbreaks can elude detection because infected persons are often widely removed geographically from the transmission source before illness onset. Thirty-one persons staying at an Illinois hotel during August 9 to 11, 2002, reported influenza-like symptoms to local health departments within 24 to 48 hours of checkout. We investigated to identify the cause and source of illness to guide control measures. METHODS: Hotel water samples were collected for culture. A telephone questionnaire detailing illness symptoms and exposures was administered to all who were guests at the hotel from August 9 to 15 (n = 380). A case was defined as onset of fever, headache, and myalgia in a guest in the 14 days following the hotel stay. Patient sera were tested by hemagglutination assay for antibodies to Legionella species. RESULTS: Among 204 questionnaire respondents from 15 states and Canada, 50 met the case definition. Among persons exposed to the swimming pool/whirlpool spa area, 63% (47 of 75) became ill versus 3% (3 of 110) of unexposed persons (relative risk 23.0, 95% CI 7.4-71.1). Illness risk increased with increasing time exposed to the pool/spa. Approximately 95 to 115 bathers per day, two to three times above the usual number, used the spa during August 9 to 11. Three Legionella species, L. dumoffii, L. maceachernii, and L. micdadei, were isolated from spa filter backwash cultures. Two of 15 ill persons with acute- and convalescent-phase sera had a greater than fourfold rise in antibody titer to L. micdadei. CONCLUSIONS: PF was associated with exposure to a hotel pool/spa area. Heavy bather usage likely contributed to a decreased effectiveness of the disinfectant in the whirlpool spa, possibly promoting bacterial aerosolization. Linking case information from many states is essential in identifying and eliminating the source of disease transmission in travel-related outbreaks of PF. Clinicians should be aware of PF in the differential diagnosis of patients with influenza-like symptoms following recent travel, particularly with exposure to a communal-use whirlpool spa.
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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 | 0.001 | 0.001 |
| 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".