ABSTRACT
Prompt detection and isolation of COVID-19 cases is vital for preventing further viral transmission, and lateral flow or rapid antigen tests have been an important diagnostic tool in this pandemic. However, concerns have emerged regarding the sensitivity of these devices for the new BA.1, BA.2, and BA.4/5 omicron variants, which have greater transmissibility and extensive mutations in its spike (S) and nucleocapsid (N) proteins. N protein is an important target protein for existing lateral flow devices. This paper therefore aimed to provide a rapid review of available literature on the performance of the lateral flow tests for detecting the omicron coronavirus variant. A systematic literature search of PubMed, EMBASE, OVID Medline, and Google Scholar found six published studies and four preprints investigating the performance of existing lateral flow devices for the omicron variant, as compared to the B.1.617.2 (Delta) variant. Overall, it appears that the devices have poorer performance for the omicron variant and when testing samples with cycle threshold (Ct) values greater than 25 and in asymptomatic individuals. As most available data were preliminary and had small sample sizes, it is recommended that these data be further studied to better inform and adapt our public health responses.
ABSTRACT
Background: Since the first case reported in December 2019, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused an outbreak of coronavirus disease 2019 (COVID-19) worldwide. The global case count continued to rise and the WHO declared a Public Health Emergency of International Concern (PHEIC), causing a growing risk of imported COVID-19 infection. This study aimed to provide descriptive and quantitative epidemiological characteristics of imported COVID-19 cases in China. Methods: This cross-sectional study examined all imported COVID-19 cases in Mainland China from 22 January to 21 April 2020. Ratios, Median and percentile were used for descriptive analysis. Spearman's correlation analysis was performed between daily new imported cases in Mainland China and the country of origin. The chi-square test was used to evaluate the difference between home quarantine and compulsory centralized quarantine on native transmission. Results: A total of 1,610 cases of COVID-19 were imported from 49 countries to 27 provincial administrative regions in China; 79.8% were from European countries and the United States of America (the USA). Before 29 March 2020, the imported cases were mainly from the USA (27.7%) and United Kingdom (UK; 42.6%). After 29 March 2020, the daily newly imported cases from Russia rapidly grew. After 12 April 2020, the number of daily newly imported cases gradually decreased and remained at a low level (12±7 cases per day). Airport entry was encouraged, and ground border crossing was limited. Among the 1,610 cases, 54.0% were in the asymptomatic incubation period on arrival in Mainland China. Conclusions: The transmissions by imported COVID-19 were gradually and effectively curbed in Mainland China, despite a disproportionally high number of cases worldwide. Entry screening measures must be implemented universally to all inbound travelers at a point of entry or targeted to specific travel routes or to specific travelers. Compulsory centralized quarantine should be recommended in the prevention of the imported COVID-19 epidemic.
ABSTRACT
Despite numerous technological and medical advances, out-of-hospital cardiac arrests (OHCAs) still suffer from suboptimal survival rates and poor subsequent neurological and functional outcomes amongst survivors. Multiple studies have investigated the implementation of high-quality prehospital resuscitative efforts, and across these studies, different terms describing high-quality resuscitative efforts have been used, such as high-performance CPR (HP CPR), multi-tiered response (MTR) and minimally interrupted cardiac resuscitation (MICR). There is no universal definition for HP CPR, and dissimilar designs have been employed. This systematic review thus aimed to review current evidence on HP CPR implementation and examine the factors that may influence OHCA outcomes. Eight studies were systematically reviewed, and seven were included in the final meta-analysis. Random-effects meta-analysis found a significantly improved likelihood of prehospital return of spontaneous circulation (pooled odds ratio (OR) = 1.46, 95% CI: 1.16 to 1.82, p < 0.001), survival-to-discharge (pooled OR = 1.32, 95% CI: 1.16 to 1.50, p < 0.001) and favourable neurological outcomes (pooled OR = 1.24, 95% CI: 1.11 to 1.39, p < 0.001) with HP CPR or similar interventions. However, the studies had generally high heterogeneity (I2 greater than 50%) and overall moderate-to-severe risk for bias. Moving forward, a randomised, controlled trial is necessary to shed light on the subject.