Update on SARS-CoV-2 seroprevalence: regional and worldwide.

BACKGROUND: With limited vaccine supplies, an informed position on the status of SARS-CoV-2 infection in people can assist the prioritization of vaccine deployment. OBJECTIVES: We performed a systematic review and meta-analysis to estimate the global and regional SARS-CoV-2 seroprevalences around the world. DATA SOURCES: We systematically searched peer-reviewed databases (PubMed, Embase and Scopus), and preprint servers (medRxiv, bioRxiv and SSRN) for articles published between 1 January 2020 and 30 March 2021. STUDY ELIGIBILITY CRITERIA: Population-based studies reporting the SARS-CoV-2 seroprevalence in the general population were included. PARTICIPANTS: People of different age groups, occupations, educational levels, ethnic backgrounds and socio-economic status from the general population. INTERVENTIONS: There were no interventions. METHODS: We used the random-effects meta-analyses and empirical Bayesian method to estimate the pooled seroprevalence and conducted subgroup and meta-regression analyses to explore potential sources of heterogeneity as well as the relationship between seroprevalence and socio-demographics. RESULTS: We identified 241 eligible studies involving 6.3 million individuals from 60 countries. The global pooled seroprevalence was 9.47% (95% CI 8.99-9.95%), although the heterogeneity among studies was significant (I2 = 99.9%). We estimated that ∼738 million people had been infected with SARS-CoV-2 (as of December 2020). Highest and lowest seroprevalences were recorded in Central and Southern Asia (22.91%, 19.11-26.72%) and Eastern and South-eastern Asia (1.62%, 1.31-1.95%), respectively. Seroprevalence estimates were higher in males, persons aged 20-50 years, in minority ethnic groups living in countries or regions with low income and human development indices. CONCLUSIONS: The present study indicates that the majority of the world's human population was still highly susceptible to SARS-CoV-2 infection in mid-2021, emphasizing the need for vaccine deployment to vulnerable groups of people, particularly in developing countries, and for the implementation of enhanced preventive measures until 'herd immunity' to SARS-CoV-2 has developed.

Investigation of plasma exchange and hemoperfusion effects and complications for the treatment of patients with severe COVID-19 (SARS-CoV-2) disease: A systematic scoping review.

Some previous studies suggested that the plasma exchange (PE) and hemoperfusion (HP) played a cardinal role in the treatment of severe coronavirus disease 2019 (COVID-19) cases by diminishing the cytokine storm. This study aimed to assess the effects of PE and HP on cytokine storms in patients with severe COVID-19 through a systematic scoping review. Four Electronic databases (Medline [accessed from PubMed], Scopus, Science Direct, and Cochrane library) were searched systematically on February 2, 2021, using MESH terms and related keywords in the English language. Considering the titles and abstracts, unrelated studies were excluded. The full texts of the remained studies were evaluated by authors, independently. Then, their findings were assessed and reported. A total of 755 articles were obtained within the first step of searching, and 518 remained after removing the duplications. Through the title and abstract screening, 438 were removed. Of the rest, 59 papers were excluded. Finally, after reading the full text of the remained articles, 21 were included in data extraction. Most of the previously reported evidence were case reports and case series. Findings were summarized in two categories. The first category encompassed nine studies regarding HP and continuous renal replacement therapy, and the second category included twelve studies about PE. The results revealed that HP and PE within the cytokine storm phase would be beneficial with a high probability in the treatment of severely ill COVID-19 patients. Highlights Some studies showed that plasma exchange (PE) and hemoperfusion (HP) played an important role in the treatment of patients with severe COVID-19 disease. The results of this systematic scoping review revealed that HP and PE within the cytokine storm phase would be beneficial with a high probability in the treatment of severely ill COVID-19 patients.

A complementary critical appraisal on systematic reviews regarding the most efficient therapeutic strategies for the current COVID-19 (SARS-CoV-2) pandemic.

BACKGROUND: This critical appraisal aims to clarify which systematic reviews on COVID-19 treatment are based on high-value evidence. Hereby, the most profitable medicines can be suggested. METHODS: The mesh terms of "COVID-19 drug treatment" (Supplementary Concept) and "COVID-19 drug treatment" were sequentially utilized as search strategies in Medline and Science direct on October 18, 2020. Searches were confined to systematic reviews/meta-analyses. The Cochrane database was searched on November 1, 2020 with "COVID." With adding up four articles from other resources, 84 systematic reviews were considered for initial screening. Finally, 22 articles fulfilled the criteria and were assessed using PRISMA guidelines. RESULTS: Increasing number of clinical trials from the onset of the COVID-19 pandemic has revealed that hydroxychloroquine and chloroquine are not only profitable but also deleterious. Lopinavir/ritonavir failed to maintain their initial efficacy in improving clinical symptoms and mortality rate. Steroids and tocilizumab were suggested in patients with intensely severe symptoms. Steroids reduced mechanical ventilation and death in severely ill patients. Plasma or immunoglobulins effects are absolutely controversial. Favorable impressions of remdesivir have been relied on for the early onset of this drug. Hypotension and abnormal liver function tests were realized as its side effects. Favipiravir has resulted in a higher viral clearance than remdesivir. However, this claim needs to be proved with subsequent clinical trials. CONCLUSIONS: Currently, remdesivir and favipiravir are advantageous drugs that should be administered in the early phases. Their side effects are not well known and need to be found in the following research projects. Steroids and tocilizumab have been considered beneficial in the cytokine storm phase.