ABSTRACT
Background: To control the imported risks brought by all international arrivals, China Customs has implemented strict closed-loop health management policy called "three checks, three screenings and one transfer". This study provides epidemiological evidence for prevention and control measures on imported cases of asymptomatic infections and describes the current COVID-19 prevention and control system on imported risks in China. Methods: We retrospectively analyzed an imported incident of three asymptomatic carriers. Serum SARS-CoV-2 IgM and IgG antibodies were detected by chemiluminescence and gold immnnochromatography(GICA). Results: Three cases were reported positive for SARS-CoV-2 nucleic acid on their arrival, total antibodies and IgG, but negative for IgM. The Ct values of cases A, B and C were 34/36/36, 32/33/32 and 25/31/29, respectively. There were 10726434 pair-end reads sequenced for case C, and approximate 80% reads were aligned to the hCoV-19/Wuhan/IVDC-HB-01/2019 genome (EPI_ISL_402119). The viruses of case A and C were homologous and came from the SARS-CoV-2 variant. Conclusion: Serum antibody IgM and IgG tests are recommended for international travelers from epidemic areas. The "three checks, three screenings and one transfer" policy implemented at custom's entry points was effective in COVID-19 prevention and control.
ABSTRACT
With the outbreak of coronavirus disease (COVID-19) in China and even the world, people are paying Close attention 10 the source of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), Clinical symptoms of being infected, and treatment Options. Whether the new coronavirus Will be transmitted to pets has also lead to discussion and concern. Due to the short period of time, there is a lack of direct research on domestic pets of SARS-CoV-2, so there is no strong evidence that pets can act as intermediate hosts or communicators to spread SARS-CoV-2 in the natural environment. Meanwhile, SARS-CoV-2 share high similarity With SARS-CoV that broke out in 2003 in terms of binding to functional receptors. Therefore, based on the theoretical research of SARS-CoV on this issue, this report analyzes the possibility transmission in animals of SARS-CoV-2, and relevant suggestions and treatment measures are put forward for existing problems. At the same time, further research is needed to prove this possibility.
ABSTRACT
Since July 2020, nucleic acids of novel coronavirus SARS-CoV-2 were frequently detected in cold chain food imported to China, making imported food being a potential risk to the COVID-19 outbreak. Based on the epidemiological characteristics of SARS-CoV-2, imported cold-chain food and their packaging may become the carriers of SARS-CoV-2 in long-distance cross-border transportation. In each aspect of stakeholders including governmental supervision, manufacturers and consumers, China should strengthen the risk management of imported cold-chain food to ensure the safety, especially pay attention to the health protection of industry workers in close contact with cold -chain food.
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The coronavirus disease 2019 (COVID-19) outbreak initiated in Wuhan, China and has spread rapidly all around the world and labeled as a pandemic with almost 168,000 infected cases and 6,500 deaths globally up to March 16, 2020. It is believed that children are less likely than adults to be infected with COVID-19. In this review, we discuss different aspects of COVID-19 infection in pediatrics. COVID-19 in pediatrics occurs in the early stages of its outbreak at a high rate with a family cluster pattern mainly. Children infected with COVID-19 are mostly asymptomatic carriers and the main potential causes of the spread and transmission of the disease in communities. Asymptomatic children with no underlying disease or red flags should follow home isolation protocols. Children with red flags, comorbidities and risk factors or those with severe pneumonia must be admitted to the hospitals. Children's hospitals should be equipped with the acute respiratory diseases ward, quarantine rooms, and intensive care unit to protect other patients and health care staff during the COVID-19 outbreak.
ABSTRACT
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to spread worldwide as a severe pandemic, and a significant portion of the infected population may remain asymptomatic. Given this, five surveys were carried out between May and September 2020 with a total of 3585 volunteers in the municipality of Foz do Igua..u, State of Paran.., a triple border region between Brazil/Argentina/Paraguay. Five months after the first infection, volunteers were re-analysed for the production of IgG anti-Spike and anti-RBD-Spike, in addition to analyses of cellular immunity. Seroconversion rates ranged from 4.4% to a peak of 37.21% followed by a reduction in seroconversion to 21.1% in September, indicating that 25% of the population lost their circulating anti-SARS-CoV-2 antibodies 3 months after infection. Analyses after 5 months of infection showed that only 17.2% of people still had anti-RBD-Spike antibodies, however, most volunteers had some degree of cellular immune response. The strategy of letting people become naturally infected with SARS-CoV-2 to achieve herd immunity is flawed, and the first contact with the virus may not generate enough immunogenic stimulus to prevent a possible second infection.
ABSTRACT
The effect of COVID-19 on the male reproductive tract has been sparsely studied. This exploratory study was designed to determine the presence of SARS-CoV-2 in the semen of men recovering from COVID-19. A systematic literature review was also performed as per PRISMA guidelines to gather perspective on this topic. The prospective study included men 21 years and older recovering from COVID-19 with nasopharyngeal swab negative for SARS-CoV-2 or at least two weeks from the last COVID RT-PCR positivity. After clinical evaluation, freshly ejaculated semen sample by masturbation was collected in a sterile container. Samples were processed for the detection of SARS-CoV-2 by RT-PCR. Twenty-one patients were contacted for the study, 11 of which consented to provide a semen sample. The mean age of the cohort was 29.72 ± 4.52 years. None of the patients gave a history of epididymo-orchitis or sexual dysfunction at the time of assessment. None of the semen samples demonstrated SARS-CoV-2 on RT-PCR. Median duration of semen sample collection from the COVID positivity was 44 days (Range 19-59 days). Detailed literature review revealed that SARS-CoV-2 is not found in patients recovering from COVID-19 infection. We conclude that SARS-CoV-2 is not found in the semen of patients recovering from COVID-19.
Subject(s)
COVID-19 , SARS-CoV-2 , Adult , Humans , Male , Prospective Studies , RNA, Viral , SemenABSTRACT
Information regarding the infectivity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in asymptomatic carriers is scarce. In order to determine the duration of infectivity and its correlation with reverse transcription-PCR (RT-PCR) results and time since initial positive PCR test in this population, we evaluated SARS-CoV-2 cell infectivity in nasopharyngeal samples longitudinally obtained from asymptomatic carriers who disembarked from a cruise ship during a COVID-19 outbreak. Of 166 nasopharyngeal samples collected from 39 asymptomatic carriers every 48 h until two consecutive negative PCR test results were obtained, SARS-CoV-2 was successfully isolated from 9 PCR-positive samples which were obtained from 7 persons (18%; 7/39). Viable viruses were isolated predominantly within 7 days after the initial positive PCR test, except for one person who shed viable virus until day 15. The median crossing point (Cp) value of RT-PCR of culture-positive samples was 24.6 (interquartile range [IQR], 20.4 to 25.8; range, 17.9 to 30.3), and Cp values were significantly associated with isolation of viable virus (odds ratio, 0.496; 95% confidence interval [CI], 0.329 to 0.747; P value, 0.001), which was consistent with existing data for symptomatic patients. Genome sequence analysis of SARS-CoV-2 samples consecutively obtained from a person who shed viable virus for 15 days identified the emergence of two novel single nucleotide variants (C8626T transition and C18452T transition) in the sample collected on day 15, with the latter corresponding to an amino acid substitution in nonstructural protein 14. The impact of these mutations on prolonged viable-virus shedding is unclear. These findings underscore the potential role of asymptomatic carriers in transmission.IMPORTANCE A growing number of studies suggest the potential role of asymptomatic SARS-CoV-2 carriers as a major driver of the COVID-19 pandemic; however, virological assessment of asymptomatic infection has largely been limited to reverse transcription-PCR (RT-PCR), which can be persistently positive without necessarily indicating the presence of viable virus (e.g., replication-competent virus). Here, we evaluated the infectivity of asymptomatic SARS-CoV-2 carriers by detecting SARS-CoV-2-induced cytopathic effects on Vero cells using longitudinally obtained nasopharyngeal samples from asymptomatic carriers. We show that asymptomatic carriers can shed viable virus until 7 days after the initial positive PCR test, with one outlier shedding until day 15. The crossing point (Cp) value of RT-PCR was the leading predictive factor for virus viability. These findings provide additional insights into the role of asymptomatic carriers as a source of transmission and highlight the importance of universal source control measures, along with isolation policy for asymptomatic carriers.