Background: Coxsackievirus B (CVB) is the most common cause of viral myocarditis. It targets cardiomyocytes through coxsackie and adenovirus receptor, which is highly expressed in the fetal heart. We hypothesized CVB3 can precipitate congenital heart defects when fetal infection occurs during critical window of gestation. Methods and Results: We infected C57Bl/6 pregnant mice with CVB3 during time points in early gestation (embryonic day [E] 5, E7, E9, and E11). We used different viral titers to examine possible dose‐response relationship and assessed viral loads in various fetal organs. Provided viral exposure occurred between E7 and E9, we observed characteristic features of ventricular septal defect (33.6%), abnormal myocardial architecture resembling noncompaction (23.5%), and double‐outlet right ventricle (4.4%) among 209 viable fetuses examined. We observed a direct relationship between viral titers and severity of congenital heart defects, with apparent predominance among female fetuses. Infected dams remained healthy; we did not observe any maternal heart or placental injury suggestive of direct viral effects on developing heart as likely cause of congenital heart defects. We examined signaling pathways in CVB3‐exposed hearts using RNA sequencing, Kyoto Encyclopedia of Genes and Genomes enrichment analysis, and immunohistochemistry. Signaling proteins of the Hippo, tight junction, transforming growth factor‐β1, and extracellular matrix proteins were the most highly enriched in CVB3‐infected fetuses with ventricular septal defects. Moreover, cardiomyocyte proliferation was 50% lower in fetuses with ventricular septal defects compared with uninfected controls. Conclusions: We conclude prenatal CVB3 infection induces congenital heart defects. Alterations in myocardial proliferate capacity and consequent changes in cardiac architecture and trabeculation appear to account for most of observed phenotypes.

The research for this study was undertaken to examine association between perinatal infection with Coxsackievirus B (CVB) and congenital heart defects (CHD). Suggestive, although inconclusive, data exists of an association between CVB infection during pregnancy and CHD. We present data from a clinical study showing that CVB infection in early pregnancy induces heart defects. In a prospective study of 123 pregnant women with pregnancies affected with CHD we found circulating CVB IgG and IgM in the serum. A significant number of the women were positive for CVB antibodies; 30.9% for IgG and 6.5% for IgM. Our data demonstrates not only an association of CVB with CHD in pregnant women but this is the first report showing significant association between in-utero CVB infection and Pulmonary Atresia (PA) and HLHS (AA/MS variant). Elevated levels of IgG were seen in 55.5% of women carrying babies with PA and 60% of women carrying babies with HLHS (AA/MS), with p-values of 0.01 and 0.03 respectively. To determine specific CVB serotypes involved, neutralizing antibody titers to CVB1, CVB3, and CVB4 were analyzed on samples with positive IgG/IgM levels, and showed a possible association between CVB4 and CHD in the cohort. Our study has broad implications for the future understanding and potential management of CHD as well as introduces a new avenue of research for cardiac defects.

Background: Probiotics are co-prescribed with co-amoxiclav to prevent antibiotic-associated diarrhea (AAD). The study assesses the co-prescription pattern of probiotics with co-amoxiclav in pediatric patients with respiratory tract infections (RTIs). Methods: This was a mixed methods research study with a retrospective study and a prospective survey. The retrospective part included a multicenter, observational, real-world study utilizing patients’ electronic medical records for three years (2018-2020) from seven outpatient pediatric clinics and hospitals. The qualitative evaluation was performed with a predefined questionnaire. Results: The patients having RTIs (N=984) were prescribed Clamp® (46.7%), CAA (23.8%), and CAM (29.5%). The mean age of the patients was 4.05 years, with 59.25% males and most patients having upper RTIs. Co-amoxiclav was prescribed twice daily for one to 15 days. A significantly lesser number of probiotic co-prescriptions were observed with Clamp® (19.57%) than with CAA (38.46%) and CAM (29.31%) at baseline (p<0.001). Similar findings were observed for follow-up visits one and two. Saccharomyces boulardii, Bacillus clausii, and lactic acid bacillus were the most commonly co-prescribed probiotics. The qualitative evaluation indicated that most clinicians were aware of the co-amoxiclav-related gastrointestinal side effects and the benefits of probiotics in preventing them. Conclusion: The frequency of co-prescriptions of probiotics with Clamp® among pediatric patients with RTIs was significantly less, potentially indicating better gastrointestinal tolerability.

Aims: Coxsackievirus B (CVB), the most common cause of viral myocarditis, targets cardiomyocytes through Coxsackie and Adenovirus Receptor, which is highly expressed in the fetal heart. We hypothesized CVB3, a well-recognized culprit for viral myocarditis, can precipitate congenital heart defects (CHD), when fetal infection occurs during critical window of gestation. Methods & Results: We infected C57Bl/6 pregnant mice with CVB3 during serial time points in early gestation (E5, E7, E9 and E11). We used different viral titers to examine possible dose- response relationship and assessed viral loads in various fetal organs as well as kinetics of virus passage into the fetus during gestation. Provided viral exposure occurred between E7-E9, we observed characteristic features of ventricular septal defect (33.6%), abnormal myocardial architecture resembling non-compaction (23.5%), and double outlet right ventricle (4.4%) among 209 viable fetuses examined. We observed a direct relationship between viral titers, severity and incidence of CHD, with apparent predominance among female fetuses. Infected dams remained healthy; we did not observe any maternal heart or placental injury suggestive of direct viral effects on developing heart as likely cause of CHD. We examined signaling pathways in CVB3-exposed hearts using RNAseq, KEGG enrichment analysis and immunohistochemistry. Signaling proteins of the Hippo, tight junction, transforming growth factor β1 and extracellular matrix proteins were the most highly enriched in CVB3-infected fetuses with VSD (log fold change >1.9, P<0.02). Moreover, cardiomyocyte proliferation was 50% lower in fetuses with VSD compared with uninfected controls. Conclusion: Prenatal CVB3 infection can induce CHD, provided the infection occurs during a critical window. Alterations in myocardial proliferate capacity and consequent changes in cardiac architecture and trabeculation appear to account for the majority of observed phenotypes. GRAPHICAL