A comparison of hospitalized children with enterovirus D68 to those with rhinovirus.

BACKGROUND: During the Fall of 2014, numerous children were hospitalized with asthma or respiratory distress related to Enterovirus D68 (EV-D68). A large proportion initially tested positive for rhinovirus. During this period our laboratory noted a cross-reactivity between EV-D68 and the rhinovirus component of the GenMark multiplex respiratory viral panel. Many other laboratories used assays not designed to distinguish these Picornoviridae. METHODS: To compare the presentation and outcomes of patients with rhinovirus and EV-D68, 103 GenMark rhinovirus positive nasopharyngeal swabs from hospitalized children were retested for EV-D68. RESULTS: EV-D68 positive patients versus EV-D68 negative patients were more likely to have a history of asthma (33.3% vs. 11.0%, P = 0.02) and to present with acute respiratory illness (66.7% vs. 40.2%, P = 0.048), especially status asthmaticus (47.6% vs. 2.4%, P < 0.001). On admission they had more wheezing, respiratory distress, and lower respiratory tract involvement, and were more likely to be treated with steroids and discharged home on asthma medications. Respiratory viral coinfection was less common in EV-D68 positive vs EV-D68 negative patients. In patients without a respiratory viral coinfection the overall findings were similar. CONCLUSION: Patients with EV-D68 versus rhinovirus were more likely to have a history of asthma, to present with status asthmaticus, to wheeze on admission, and to receive treatment with asthma medications in hospital and at discharge. The inability of common assays to distinguish EV-D68 from rhinoviruses raises the possibility that the role of EV-D68 as a viral trigger of asthma has been under appreciated. Pediatr Pulmonol. 2017;52:827-832. © 2017 Wiley Periodicals, Inc.

A rapid and simple isothermal nucleic acid amplification test for detection of herpes simplex virus types 1 and 2.

BACKGROUND: A simple and rapid IsoAmp HSV assay has been developed for qualitative detection of herpes simplex virus (HSV) types 1 and 2 from genital lesions. Sample preparation involved a simple dilution step and the diluted specimens were directly added to the device and amplified by isothermal helicase-dependent amplification (HDA). Amplification products were then detected by a DNA strip embedded in a disposable cassette without any instrument. The total test turn-around time is less than 1.5h from specimen processing to result reporting. OBJECTIVES: To evaluate the analytical and clinical performance of the IsoAmp HSV assay as well as the robustness and reproducibility of the assay. STUDY DESIGN: The analytical sensitivity of the IsoAmp HSV assay was determined using both HSV-1 and HSV-2. Clinical performance was evaluated using 135 frozen specimens collected from patients with suspected HSV infection in genital area. RESULTS: The analytical sensitivity of the assays was 5.5 and 34.1 copies/reaction for HSV-1 and HSV-2 respectively with a 95% confidence interval. When the herpes viral culture was used as the reference standard, the clinical sensitivity and specificity of the IsoAmp HSV assay were 100.0% and 96.3% respectively. The inter-laboratory reproducibility achieved an overall 97.5% agreement by testing a total of 80 blinded HSV-1 samples among five laboratories. CONCLUSION: Adequate analytical and clinical performance of the IsoAmp HSV assay was demonstrated. This assay is simple to perform and has acceptable inter-laboratory reproducibility.