In the United States, an estimated 7.3% of confirmed cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection (COVID-19) are among persons aged less than 18 years. Data regarding clinical manifestations in this age group are still evolving. An upper airway predilection has been reported in children. We describe the case of a 15-year-old female with supraglottitis and unilateral hypomobility of vocal cord with concern for critical airway, associated with COVID-19. She was managed by a multidisciplinary team including critical care, infectious diseases, and otolaryngology. This report adds to the sparse but evolving body of literature on the clinical presentation of COVID-19 disease in children.

A commercial anti-dengue virus (anti-DENV) indirect IgG enzyme-linked immunosorbent assay (ELISA) for serological diagnosis was evaluated for its utility in determining previous DENV exposure in U.S. travelers. The Boston Area Travel Medicine Network clinics used Focus Diagnostics anti-DENV IgG ELISA to measure anti-DENV IgG antibodies in 591 pretravel specimens from U.S. residents who had traveled to countries where dengue is endemic. When using the manufacturer's index cutoff value for this ELISA, false-positive results were observed that overestimated the perceived past DENV exposure in U.S. travelers. Validation of 121 of these anti-DENV IgG results by plaque reduction neutralization test (PRNT) was used for receiver operating characteristic (ROC) curve optimization of the index cutoff value from 1 to 3.0, improving the specificity of the anti-DENV IgG ELISA from 24% to 95.7%. Additionally, previous vaccination with yellow fever virus contributed to 52.8% of the false-positive rate in the anti-DENV IgG ELISA results. Optimization of the cutoff value of the anti-DENV IgG ELISA provided better interpretation and confidence in the results and eliminated the need for confirmation by PRNT. The travel history of U.S. travelers was also useful for categorizing these travelers into groups for analysis of previous DENV exposure. Dengue is a major, global health problem, with an estimated 2.5 billion people at risk of contracting the disease and over 50 million infections annually (1). Dengue virus (family Flaviviridae, genus Flavivirus) is mosquito-borne with four antigenically distinct serotypes (DENV-1 to -4). There is sufficient antigenic homology among the four DENV serotypes and within the genus Flavivirus to create cross-reactivity in many immunoassays. This cross-reactivity is a diagnostic challenge when testing samples in regions where multiple DENV serotypes circulate and other flaviviruses cocirculate. Hence, immunoassays, such as the IgM enzyme-linked immunosorbent assay (ELISA) and the IgG ELISA, often require testing using a second method, such as a plaque reduction neutralization test (PRNT), to confirm the specificity of the antibody response (2).Anti-DENV IgG ELISAs are used to measure prevalence of previous infection by DENV and for conducting vaccine studies. The Boston Area Travel Medicine Network (BATMN) clinics used commercial anti-DENV IgG ELISAs to determine exposure to DENV in U.S. travelers; dengue is the leading cause of acute febrile illness in U.S. travelers returning from countries where DENV is endemic, as observed by GeoSentinal clinics (3). Among these patients, the Focus Diagnostics anti-DENV IgG ELISA had low specificity (24%) and high sensitivity (100%), as determined by the PRNT confirmatory test. Further evaluation of the cutoff value of the anti-DENV IgG ELISA was conducted in an attempt to increase the specificity of the test. MATERIALS AND METHODSStudy. Travelers were enrolled from five travel clinics from the BATMN group in Boston, MA, from August 2008 through June 2009. Appro...

Nineteen percent of participants who were born, lived in, or traveled to dengue-endemic countries had anti-DENV IgG antibody by ELISA; 12% had antibodies by PRNT, 85% of whom had no history of dengue. Presence of DENV antibodies was associated with years lived in dengue-endemic countries and self-reported history of dengue.

Abstract. We conducted a prospective study to measure dengue virus (DENV) antibody seroconversion in travelers to dengue-endemic areas. Travelers seen in the Boston Area Travel Medicine Network planning to visit dengueendemic countries for ≥ 2 weeks were enrolled from 2009 to 2010. Pre-and post-travel blood samples and questionnaires were collected. Post-travel sera were tested for anti-DENV IgG by indirect IgG enzyme-linked immunosorbent assay (ELISA) and anti-DENV IgM by capture IgM ELISA. Participants with positive post-travel anti-DENV IgG or IgM were tested for pre-travel anti-DENV IgG and IgM; they were excluded from the seroconversion calculation if either pre-travel anti-DENV IgG or IgM were positive. Paired sera and questionnaires were collected for 62% (589/955) of enrolled travelers. Most participants were 19-64 years of age, female, and white. The most common purposes of travel were tourism and visiting friends and relatives; most trips were to Asia or Africa. Median length of travel was 21 days. DENV antibody seroconversion by either anti-DENV IgM or IgG ELISA was 2.9-6.8%; lower range percent excluded potential false-positive anti-DENV IgG due to receipt of yellow fever or Japanese encephalitis vaccines at enrollment; upper range percent excluded proven false-positive anti-DENV IgM. Eighteen percent of those with seroconversion reported dengue-like symptoms. Seroconversion was documented for travel to Africa as well as countries and regions known to be highly dengue endemic (India, Brazil, southeast Asia). Given widespread risk of dengue, travel medicine counseling should include information on risk of dengue in endemic areas and advice on preventing insect bites and seeking prompt medical attention for febrile illness. BACKGROUND