Background and Objectives: The study aims to explore the potential for transplacental transmission of SARS-CoV-2, focusing on its pathophysiology, placental defense mechanisms, and the clinical implications for maternal and neonatal health. Materials and Methods: A comprehensive review of the current literature was conducted, analyzing studies on SARS-CoV-2 infection in pregnancy, the expression of key viral receptors (ACE2 and TMPRSS2) in placental cells, and the immune responses involved in placental defense. The review also examined the clinical outcomes related to maternal and neonatal health, including adverse pregnancy outcomes and neonatal infection. Results: The expression of ACE2 and TMPRSS2 in the placenta supports the biological plausibility of SARS-CoV-2 transplacental transmission. Histopathological findings from the infected placentas reveal inflammation, vascular changes, and the evidence of viral particles in placental tissues. Clinical reports indicate an increased risk of preterm birth, intrauterine growth restriction, and neonatal infection in pregnancies affected by COVID-19. However, the frequency and mechanisms of vertical transmission remain variable across studies, highlighting the need for standardized research protocols. Conclusions: SARS-CoV-2 can potentially infect placental cells, leading to adverse pregnancy outcomes and neonatal infection. While evidence of transplacental transmission has been documented, the risk and mechanisms are not fully understood. Ongoing research is essential to clarify these aspects and inform obstetric care practices to improve maternal and neonatal outcomes during the COVID-19 pandemic.

To investigate the prevalence and risk factors associated with Helicobacter pylori infection in Vietnamese children. Children under 16 years old with gastrointestinal symptoms underwent esophagogastroduodenoscopy and H. pylori infection was diagnosed using rapid urease test. A total of 246 children with gastrointestinal symptoms were included. The mean age was 8.4 ± 2.6 years. A total 81.3% tested positive for H. pylori. Children infected with H. pylori had a lower rate of nausea but a higher rate of lesions in the duodenal bulb and nodular lesions than children without H. pylori infection (26.5% vs 45.6%, P <0.01; 40.0% vs 23.9%; P = 0.04; and 68.5% vs 30.3%, P <0.0001, respectively). Compared with children aged under 5 years, children aged 11 years and older were four times more likely to be infected with H. pylori, with odds ratio (OR) 3.50, 95% confidence interval (CI) 1.07-11.39, P = 0.04. Washing hands with soap was associated with a reduced risk of H. pylori infection by three times (OR 0.35, 95% CI 0.17-0.69, P = 0.002). Children living in a family where members had a history of H. pylori infection were nine times more likely to be infected with H. pylori (OR 8.87, 95% CI 1.15-68.45, P = 0.04). The prevalence of H. pylori infection in Vietnamese children with gastroenteritis is high. Our results identified several risk factors and emphasize the role of handwashing with soap before eating and after using the toilet in reducing the risk of H. pylori infection in children.

To detect clusters of dengue hemorrhagic fever in an urbanized district of Hai Phong City, Vietnam using Poisson space-time retrospective and prospective analysis. A cross-sectional and retrospective study analyzed dengue surveillance data in the period from January 01, 2018, to December 31, 2022. Spatial-temporal scanning statistics were performed using the free software SatScan v10.1.2. A total of 519 cases were recorded. The cumulative incidence per 100,000 inhabitants was 3.37, 127.36, 10.96, 0, and 296.04 in 2018, 2019, 2020, 2021, and 2022, respectively. By retrospective Poisson model-based analysis, seven clusters were detected. Six of these seven detected outbreaks occurred in November and December 2022. The largest cluster had a relative risk (RR) of 1539.5 (P <0.00001). The smallest cluster has a RR of 316.1 (P = 0.006). Prospective analysis using the Poisson model significantly detected four active case clusters at the time of the study. The largest cluster of cases with RR was 47.7 (P <0.00001) and the smallest cluster with RR was 18.2 (P <0.00001). This study provides a basis for improving the effectiveness of interventions and conducting further investigations into risk factors in the study area, as well as in other urban and suburban areas nationwide.

Dao TL, et al. Clin Exp Vaccine Res. 2024 Jul;13(3):259-262. https://doi.org/10.7774/cevr.2024.13.3.259