Coronavirus (COVID-19) Collection
Faster decay of neutralizing antibodies in never infected than previously infected healthcare workers three months after the second BNT162b2 mRNA COVID-19 vaccine dose
The BNT162b2 COVID-19 vaccine is known to induce a rapid production of neutralizing antibodies (Lustig et al., 2021; Vicenti et al., 2021b); however, there are very limited data on their long-term kinetics. Favresse et al. (2021b) described a robust humoral response 90 days after the first dose of vaccine both in previously seropositive and seronegative subjects, but a significant antibody decrease in respect to the higher level reached occurred within this period. Interestingly, the administration of a third dose of the BNT162b2 vaccine, about two months from the second dose, to solid-organ transplant recipients significantly improved the immunogenicity of the vaccine (Kamar et al., 2021).Performance of SARS-CoV-2 rapid antigen test compared with real-time RT-PCR in asymptomatic individuals
Given the increase in cases of SARS-CoV-2 infections worldwide, there is a need for a reliable rapid diagnostic test in addition to existing gold standard real-time RT-PCR. Rapid antigen tests (RAT) for SARS-CoV-2 can be performed onsite in mass testing, are inexpensive compared to real-time RT-PCR, do not require specific and expensive equipment, and the results are available within 15 min (CDC, 2021), which could serve to evaluate chains of infection and their interruption. A recent meta-analysis revealed that the average sensitivity and specificity of RAT for SARS-CoV-2 were 56.2% and 99.5%, respectively (Dinnes et al., 2020).The high prevalence of asymptomatic SARS-CoV-2 infection reveals the silent spread of COVID-19
SARS-CoV-2, the virus causing Coronavirus disease 2019 (COVID-19), has infected more than 92 million people and lead to the death of more than 1.9 million people worldwide since its outbreak in December 2019 (WHO, 2020). The disease has a wide range of presentations, from asymptomatic infection to fever, cough, shortness of breath and the loss of taste and smell. Symptoms normally appear 2–14 days following exposure to the virus and may develop into mild upper respiratory tract infections or progress to severe pneumonia, which can progress to acute respiratory distress, shock, multiorgan failure and death (Huang et al., 2020; Wang et al., 2020).The epidemiological and radiographical characteristics of asymptomatic infections with the novel coronavirus (COVID-19): A systematic review and meta-analysis
COVID-19 was first reported in December 2019 and has spread rapidly worldwide (Chen et al., 2020). The infectivity of COVID-19, which has a basic reproduction number (R0) ranging from 2 to 6.7, was estimated to be much higher than that of influenza, severe acute respiratory syndrome (SARS), and middle east respiratory syndrome (MERS) (Wu et al., 2020; Zhao et al., 2020; Tang et al., 2020). Asymptomatic infections among patients with COVID-19 have been reported, including presymptomatic and covert infections; these are differentiated according to whether related clinical symptoms appear during follow-up (Wu, 2020).High SARS-CoV-2 IgG/IGM seroprevalence in asymptomatic Congolese in Brazzaville, the Republic of Congo
The occurrence of asymptomatic individuals with coronaviruses presents a significant public health issue (Nikolai et al., 2020). As of December 15, 2020, there had been more than 73,557,491 coronavirus disease 2019 (COVID-19) infections world-wide and 1,637,053 deaths (University JH, 2020). The United States had the highest number of infections in the world, with 16,724,753 cases and 303,849 deaths. In Africa, South Africa had the highest number of cases (873,678) and deaths (23,661). The Republic of the Congo, with an estimated population of 5,300,000, had recorded 6200 cases and 100 deaths, as of December 12, 2020 (SITREP 115, Congo).Low-dose and oral exposure to SARS-CoV-2 may help us understand and prevent severe COVID-19
Where efficiently applied, a broad range of restrictive non-pharmaceutical interventions (NPI) has succeeded in preempting or mitigating explosive outbreaks of coronavirus disease 2019 (COVID-19) hospitalizations and deaths in many settings. Elsewhere, it has proven difficult to fully implement, maintain, or reimpose these interventions. Much of the public reluctance lies in their huge social and economic consequences, exacerbated by the failure of political leaders to convincingly advocate for these measures.Asymptomatic COVID-19 in hospital visitors: The underestimated potential of viral shedding
The burden of asymptomatic Coronavirus Disease-2019 (COVID-19) on clinical practice and epidemiological control remains a challenge, particularly due to the high potential of transmission (Al-Sadeq and Nasrallah, 2020; Arons et al., 2020). While several nosocomial outbreaks have been reported (Arons et al., 2020; Roxby et al., 2020), most studies focused on the role of asymptomatic hospitalized patients (Passarelli et al., 2020; Rhee et al., 2020). However, hospital visitors’ impact on viral shedding in healthcare facilities remains underestimated.Antibody responses after COVID-19 infection in patients who are mildly symptomatic or asymptomatic in Bangladesh
Coronavirus disease-2019 (COVID-19), the disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was first identified in December 2019 in Wuhan, China (Guo et al., 2020). The World Health Organization (WHO) declared a Public Health Emergency on January 30, 2020, after COVID-19 had spread to other countries (Cascella et al., 2020) and declared COVID-19 a pandemic in March 2020 (2020, WHO, 2020). The first case of COVID-19 in Bangladesh was confirmed on March 8, 2020. As of August 27, 2020, according to the Institute of Epidemiology, Disease Control and Research (IEDCR), there have been 302,147 confirmed COVID-19 cases in Bangladesh, including 4082 related deaths for a case fatality rate of 1.38%.(Anon, 2020b)Asymptomatic SARS Coronavirus 2 infection: Invisible yet invincible
Transmission of SARS-CoV-2, the agent causing COVID-19, is driven by virus-containing droplets released from the upper airways and aerosols that can float, dependent on the airflow, for a prolonged period in the environment (Meselson, 2020). Aerosols can be spread by just breathing, while droplets originate from speaking, shouting, sneezing, and coughing as well as from singing and playing wind instruments (Zhang et al., 2020; Zhen-Dong et al., 2020; Asadi et al., 2019). Of great importance are super-spreading events, which are infection clusters constituting effective chains of SARS-CoV-2 transmission.Clinical Characteristics of Asymptomatic Patients with COVID-19: A Nationwide Cohort Study in South Korea
In South Korea, the first coronavirus disease 2019 (COVID-19) case was confirmed on January 20, 2020 (Korea Ministry of Health and Welfare and Center for Disease Control and Prevention, 2020). With proactive containment efforts, comprehensive contact tracing, and extensive testing of symptomatic or high risk individuals for COVID-19, South Korea was able to flatten the curve of new COVID-19 infections by mid-March (Korea Ministry of Health and Welfare and Center for Disease Control and Prevention, 2020; Song et al., 2020).Patterns of viral clearance in the natural course of asymptomatic COVID-19: Comparison with symptomatic non-severe COVID-19
The first cases of coronavirus disease 2019 (COVID-19) were reported in Wuhan, China in December 2019 (Chen et al., 2020; Huang et al., 2020). The pathogen has been identified as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (Lu et al., 2020; Zhu et al., 2020). COVID-19 has rapidly become widespread across the world. In March 2020, the World Health Organization declared the COVID-19 outbreak a pandemic. From the end of February through March 2020, Daegu—the fourth largest city in South Korea—was emerging as an epicenter of COVID-19 in South Korea.Asymptomatic infection by SARS-CoV-2 in healthcare workers: A study in a large teaching hospital in Wuhan, China
Coronavirus Disease 2019 (COVID-19) has caused a large number of related deaths and multiple healthcare-associated outbreaks (Zhu et al., 2019; Wang et al., 2020a; Huang et al., 2020; Chen et al., 2020a). Investigators have summarised the clinical characteristics of initial onset in cases (Huang et al., 2020; Chen et al., 2020a): some had atypical clinical manifestations (e.g. severe cases only had moderate or low fever or even no fever), while some mild cases did not have pneumonia and only had low fever or mild fatigue (NHC, 2020; Guan et al., 2020).Asymptomatic patients as a source of COVID-19 infections: A systematic review and meta-analysis
Coronavirus Disease 2019 (COVID-19), caused by severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2), emerged as a global threat; it was declared a pandemic by the WHO on 11 March 2020. As of 12 June 2020, over 7,200,000 infected cases and 400,000 deaths have been reported by the World Health Organization (WHO).Duration of viral shedding in asymptomatic or mild cases of novel coronavirus disease 2019 (COVID-19) from a cruise ship: A single-hospital experience in Tokyo, Japan
The novel coronavirus (severe acute respiratory syndrome coronavirus 2; SARS-CoV-2), which is the cause of novel coronavirus disease 2019 (COVID-19), first reported in Wuhan, China, has spread across the world and has been characterized by the World Health Organization as a global pandemic (Bedford et al., 2020). In February 2020, at the port of Yokohama, Japan, an outbreak of COVID-19 among passengers and crew of the Diamond Princess cruise ship occurred, with approximately 700 confirmed cases.The proportion of COVID-19 cases that are asymptomatic in South Korea: Comment on Nishiura et al.
In a recent paper, Nishiura et al. (2020) estimated the asymptomatic rate of COVID-19 cases among Japanese nationals who were tested upon returning to Japan from abroad. The authors estimated the proportion of positive COVID-19 cases that were asymptomatic to be 30.8% (95% confidence interval: 7.7%, 53.8%).
