Case report of severe myocarditis in an immunocompromised child with Respiratory Syncytial Virus infection

Abstract Background Respiratory syncytial virus (RSV) infection is common and may be severe among patients with preexisting cardiac anomalies, but direct involvement of myocardial damage is not common in those patients. Additionally, myocardial involvement has been rarely described among immune compromised children. Case presentation A 4-year-old girl with acute lymphoblastic leukemia who received maintenance chemotherapy in an outpatient clinic developed systemic inflammatory response syndrome. RSV infection was confirmed by a positive rapid antigen test and serological assay. Subsequently, she was diagnosed with severe myocarditis caused by RSV infection, which was diagnosed by abnormal findings of cardiac echography and ECG and elevated biomarkers for myocardial damage. Then, she was treated in the intensive care unit for 13 days. High amounts of RSV type B RNA was detected in tracheal aspirates and serum sample. Conclusion This case report emphasizes that RSV infection may be associated with myocarditis in immunocompromised children receiving maintenance chemotherapy

The electrophysiological index can effectively predict subsequent coronary artery aneurysm in children with Kawasaki disease

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Dry loop-mediated isothermal amplification assay for detection of SARS-CoV-2 from clinical specimens

Objectives: To establish a point-of-care test for coronavirus disease 2019 (COVID-19), we developed a dry loop-mediated isothermal amplification (LAMP) method to detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA. Methods: We carried out reverse transcription (RT)-LAMP using the Loopamp SARS-CoV-2 Detection kit (Eiken Chemical, Tokyo, Japan). The entire mixture, except for the primers, is dried and immobilized inside the tube lid. Results: To determine the specificity of the kit, 22 viruses associated with respiratory infections, including SARS-CoV-2, were tested. The sensitivity of this assay, determined by either a real-time turbidity assay or colorimetric change of the reaction mixture, as evaluated by the naked eye or under illumination with ultraviolet light, was 10 copies/reaction. No LAMP product was detected in reactions performed with RNA from any pathogens other than SARS-CoV-2. After completing an initial validation analysis, we analyzed 24 nasopharyngeal swab specimens collected from patients suspected to have COVID-19. Of the 24 samples, 19 (79.2%) were determined by real-time RT-PCR analysis as being positive for SARS-CoV-2 RNA. Using the Loopamp SARS-CoV-2 Detection kit, we detected SARS-CoV-2 RNA in 15 (62.5%) of the 24 samples. Thus, the sensitivity, specificity, positive predictive value, and negative predictive values of the Loopamp 2019-CoV-2 detection reagent kit were 78.9%, 100%, 100%, and 55.6%, respectively. Conclusions: The dry LAMP method for detecting SARS-CoV-2 RNA is fast and easy to use, and its reagents can be stored at 4°C, solving the cold chain problem; thus, it represents a promising tool for COVID-19 diagnosis in developing countries

Evaluation of perinatal autonomic development in infants using the QT/RR variability ratio

OBJECTIVES: Development of the autonomic nervous system may play a role in myocardial repolarization lability in infants, but its relationship to repolarization abnormalities remains unclear. Thus, the aim of the present study was to evaluate the relationship between gestational age and ventricular repolarization lability using the variability ratio (VR). METHODS: Infants who underwent electrocardiography at a 1-month check-up were included (n=209; 125 males). Gestational age and the following four VR parameters at 1 month of age were compared: VR-I, SDQT/SDRR; VR-II, SDQT/rMSSD; VR-III, SDQTc/SDRR; and VR-IV, SDQTc/rMSSD; where SD, QTc, and rMSSD are standard deviation, QT interval corrected using Fridericia’s formula, and root mean square difference of successive RR intervals, respectively. Twenty-eight preterm infants born at <37 weeks of gestation and 181 full-term infants were included. RESULTS: Significant correlations were observed between gestational age and VR-I, -III, and -IV (all p<0.05). All VR values were significantly higher in preterm infants compared with full-term infants (I: 0.54 vs 0.48, II: 1.15 vs 0.96, III: 0.88 vs 0.68, IV: 1.59 vs 1.39; median, all p<0.05). CONCLUSION: VR assessed at 1 month after birth was impaired in preterm infants, suggesting immaturity of their cardiac autonomic nervous system and ventricular myocardial repolarization