Under-recognition of dengue infection may lead to increased morbidity and mortality, whereas early detection is shown to help improve patient outcomes. Recent incidence and outbreak reports of dengue virus in the United States and other temperate regions where dengue was not typically seen have raised concerns regarding appropriate diagnosis and management by healthcare providers unfamiliar with the disease. This study aimed to describe selfreported clinical symptoms of dengue fever in a non-endemic cohort and to establish a clinically useful predictive algorithm based on presenting features that can assist in the early evaluation of potential dengue infection. Volunteers who experienced febrile illness while traveling in dengue-endemic countries were recruited for this study. History of illness and blood samples were collected at enrollment. Participants were classified as dengue naive or dengue exposed based on neutralizing antibody titers. Statistical analysis was performed to compare characteristics between the two groups. A regression model including joint/muscle/bone pain, rash, dyspnea, and rhinorrhea predicts dengue infection with 78% sensitivity, 63% specificity, 80% positive predictive value, and 61% negative predictive value. A decision tree model including joint/muscle/bone pain, dyspnea, and rash yields 77% sensitivity and 67% specificity. Diagnosis of dengue fever is challenging because of the nonspecific nature of clinical presentation. A sensitive predicting model can be helpful to triage suspected dengue infection in the non-endemic setting, but specificity requires additional testing including laboratory evaluation.
ObjectiveTo assess the diagnostic accuracy of antigen compared with reverse transcriptase (RT)-PCR testing in an asymptomatic athlete screening programme and to monitor infection in college athletes.MethodsQuidel Sofia-2 SARS-CoV-2 Antigen Tests were performed daily before sports participation for football, basketball, wrestling and water polo from 29 September 2020 to 28 February 2021. Paired RT-PCR and antigen tests were performed at least once a week. Positive antigen tests were confirmed with RT-PCR.Results81 175 antigen and 42 187 RT-PCR tests were performed, including 23 462 weekly paired antigen/RT-PCR screening tests in 1931 athletes. One hundred and seventy-two athletes had a positive screening RT-PCR (0.4%), of which 83 (48%) occurred on paired testing days. The sensitivity of antigen tests varied with the frequency of RT-PCR testing and prevalence of COVID-19. The sensitivity of antigen testing was 35.7% (95% CI: 17% to 60%) and specificity 99.8% (95% CI: 99.7% to 99.9%) with once-a-week RT-PCR testing after adjusting for school prevalence. Daily antigen testing was similar to RT-PCR testing two to three times a week in identifying infection. Antigen testing identified infection before the next scheduled PCR on 89 occasions and resulted in 234 days where potentially infectious athletes were isolated before they would have been isolated with RT-PCR testing alone. Two athletic-related outbreaks occurred; 86% of total infections were community acquired.ConclusionAntigen testing has high specificity with a short turnaround time but is not as sensitive as RT-PCR. Daily antigen testing or RT-PCR testing two to three times a week is similar. There are benefits and drawbacks to each testing approach.
Background
Battarrea puffball mushrooms are found extensively worldwide and contain spore-containing sacs. Inhalation of the spores of similar mushrooms, such as Lycoperdon, have been implicated in cases of lycoperdonosis—a syndrome of hypersensitivity pneumonitis. We report a case of hypersensitivity pneumonitis confirmed to be secondary to Battarrea spore exposure diagnosed by broad-range PCR.MethodsA 23-year-old homeless man with a history of methamphetamine use presented to the emergency department with a 2-week history of fevers, chills, productive cough, and malaise. He reported his symptoms began soon after eating a long-stemmed mushroom he found growing next to a building. He reported inhaling particles from the mushroom when he picked it up prior to eating it. He vomited within 1 hour of ingestion, and then had a worsening progression of cough and malaise over the following 2 weeks. In the emergency department, he was noted to have leukocytosis and mild elevation of transaminases. He required supplemental oxygen due to hypoxemia. CT scan of his chest demonstrated extensive bilateral nodular pulmonary infiltrates. He was admitted and started on treatment for community-acquired pneumonia. Over the next several days, he had worsening respiratory failure, and routine work up for infectious etiologies was unrevealing. To further investigate, bronchoscopy and bronchoalveolar lavage (BAL) was performed and routine bacterial, fungal and mycobacterial cultures and cytology with Gomori Methanamine-silver and acid-fast stains were negative. BAL fluid was sent for broad range DNA testing by PCR. Antibiotic therapy was stopped, and he was started on steroids to treat presumed hypersensitivity pneumonitis. He recovered rapidly and was discharged on a course of oral corticosteroids.ResultsAfter the patient was discharged, molecular testing of BAL fluid resulted with detection of Battarrea species DNA using 28s and ITS primer sets. DNA from no other pathogens was detected.ConclusionIdentified through broad range DNA PCR testing, exposure to Battarrea mushroom spores may be a previously unreported cause of hypersensitivity pneumonitis. PCR testing should be considered in the workup of hypersensitivity pneumonitis with known or suspected exposure to mushroom spores.
Disclosures
All authors: No reported disclosures.
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