Travel-related Importation and Exportation Risks of SARS-CoV-2 Omicron Variant in 367 Prefectures (Cities) - China, 2022.

Introduction: Minimizing the importation and exportation risks of coronavirus disease 2019 (COVID-19) is a primary concern for sustaining the "Dynamic COVID-zero" strategy in China. Risk estimation is essential for cities to conduct before relaxing border control measures. Methods: Informed by the daily number of passengers traveling between 367 prefectures (cities) in China, this study used a stochastic metapopulation model parameterized with COVID-19 epidemic characteristics to estimate the importation and exportation risks. Results: Under the transmission scenario (R0 =5.49), this study estimated the cumulative case incidence of Changchun City, Jilin Province as 3,233 (95% confidence interval: 1,480, 4,986) before a lockdown on March 14, 2022, which is close to the 3,168 cases reported in real life by March 16, 2022. In a total of 367 prefectures (cities), 127 (35%) had high exportation risks according to the simulation and could transmit the disease to 50% of all other regions within a period from 17 to 94 days. The average time until a new infection arrives in a location in 1 of the 367 prefectures (cities) ranged from 26 to 101 days. Conclusions: Estimating COVID-19 importation and exportation risks is necessary for preparedness, prevention, and control measures of COVID-19 - especially when new variants emerge.

Systematic review and meta-analyses of superspreading of SARS-CoV-2 infections.

Superspreading, or overdispersion in transmission, is a feature of SARS-CoV-2 transmission which results in surging epidemics and large clusters of infection. The dispersion parameter is a statistical parameter used to characterize and quantify heterogeneity. In the context of measuring transmissibility, it is analogous to measures of superspreading potential among populations by assuming that collective offspring distribution follows a negative-binomial distribution. We conducted a systematic review and meta-analysis on globally reported dispersion parameters of SARS-CoV-2 infection. All searches were carried out on 10 September 2021 in PubMed for articles published from 1 January 2020 to 10 September 2021. Multiple estimates of the dispersion parameter have been published for 17 studies, which could be related to where and when the data were obtained, in 8 countries (e.g. China, the United States, India, Indonesia, Israel, Japan, New Zealand and Singapore). High heterogeneity was reported among the included studies. The mean estimates of dispersion parameters range from 0.06 to 2.97 over eight countries, the pooled estimate was 0.55 (95% CI: 0.30, 0.79), with changing means over countries and decreasing slightly with the increasing reproduction number. The expected proportion of cases accounting for 80% of all transmissions is 19% (95% CrI: 7, 34) globally. The study location and method were found to be important drivers for diversity in estimates of dispersion parameters. While under high potential of superspreading, larger outbreaks could still occur with the import of the COVID-19 virus by traveling even when an epidemic seems to be under control.

Reproduction Number of the Omicron Variant Triples That of the Delta Variant.

COVID-19 remains a persistent threat, especially with the predominant Omicron variant emerging in early 2022, presenting with high transmissibility, immune escape, and waning. There is a need to rapidly ramp up global vaccine coverage while enhancing public health and social measures. Timely and reliable estimation of the reproduction number throughout a pandemic is critical for assessing the impact of mitigation efforts and the potential need to adjust for control measures. We conducted a systematic review on the reproduction numbers of the Omicron variant and gave the pooled estimates. We identified six studies by searching PubMed, Embase, Web of Science, and Google Scholar for articles published between 1 January 2020 and 6 March 2022. We estimate that the effective reproduction number ranges from 2.43 to 5.11, with a pooled estimate of 4.20 (95% CI: 2.05, 6.35). The Omicron variant has an effective reproduction number which is triple (2.71 (95% CI: 1.86, 3.56)) that of the Delta variant.

Reproduction Numbers of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Variants: A Systematic Review and Meta-analysis.

The coronavirus disease 2019 (COVID-19) pandemic continues to pose substantial risks to public health, worsened by the emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants that may have a higher transmissibility and reduce vaccine effectiveness. We conducted a systematic review and meta-analysis on reproduction numbers of SARS-CoV-2 variants and provided pooled estimates for each variant.

Anthocyanins Are Converted into Anthocyanidins and Phenolic Acids and Effectively Absorbed in the Jejunum and Ileum.

Anthocyanins have been known for their health benefits. However, the in vivo digestion and absorption of anthocyanins through the gastrointestinal tract have not been fully clarified, creating challenges for understanding why anthocyanins have high biological activities and purported low bioavailability in vivo. Twenty-seven male rats were intubated with a 500 mg/kg dose of cyanidin-3-glucoside (C3G). Samples from rats' stomach, duodenum, jejunum, ileum, colon, and serum were collected at 0.5, 1, 2, 3, 4, 5, 6, 12, and 24 h after intubation. Three rats without C3G were used as the control with samples collected at 0 h. C3G and its metabolites in each sample were analyzed using high-performance liquid chromatography-PDA-electrospray ionization-MS/MS. These in vivo studies' results unequivocally demonstrated that cyanidin and phenolic acids were the primary C3G metabolites absorbed, mainly in the jejunum and ileum, between 1 and 5 h post-ingestion. We speculate that C3G uses phloroglucinaldehyde and protocatechuic acid metabolic pathways in its metabolism in vivo.

Behavioral study of a rat model of migraine induced by CGRP.

Migraine is a debilitating disorder characterized by recurrent headache arising from neurovascular dysfunction. Despite recent progress in migraine research, the exact mechanisms underpinning migraine are poorly understood. Furthermore, it is difficult to develop an animal model of migraine that resembles all symptoms of patients. In this study, we established a novel animal model of migraine induced by epidural injection of calcitonin gene-related peptide (CGRP), and examined climbing hutch behavior, facial-grooming behavior, body-grooming behavior, freezing behavior, resting behavior, and ipsilateral hindpaw facial grooming behavior of rats following CGRP injection. CGRP significantly reduced climbing hutch behavior, and face-grooming behavior, and increased immobile behavior. We also found that the P15 and P85 percentile range of behavioral data exhibited a high positive rate (83.3%) for establishing the model with less false positive rate. Our results verified that the rat model of migraine induced by CGRP featured many behaviors of migraine patients demonstrated during migraine attacks. Our findings suggest that this new model can be a useful tool for understanding the pathophysiology of migraine and studying novel therapeutic strategies for the treatment of migraine.