BACKGROUND The B.1.617.2(delta)variant of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)was first discovered in Maharashtra in late 2020 and has rapidly expanded across India and worldwide.It took only 2 ...BACKGROUND The B.1.617.2(delta)variant of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)was first discovered in Maharashtra in late 2020 and has rapidly expanded across India and worldwide.It took only 2 mo for this variant to spread in Indonesia,making the country the new epicenter of the delta variant as of July 2021.Despite efforts made by accelerating massive rollouts of current vaccines to protect against infection,cases of fully-vaccinated people infected with the delta variant have been reported.AIM To describe the demographic statistics and clinical presentation of the delta variant infection after the second dose of vaccine in Indonesia.METHODS A retrospective,single-centre case series of the general consecutive population that worked or studied at Faculty of Medicine,Universitas Indonesia with confirmed Delta Variant Infection after a second dose of vaccine from 24 June and 25 June 2021.Cases were collected retrospectively based on a combination of author recall,reverse transcription-polymerase chain reaction(RT-PCR),and whole genome sequencing results from the Clinical Microbiology Laboratory,Faculty of Medicine,Universitas Indonesia.RESULTS Between 24 June and 25 June 2021,15 subjects were confirmed with the B.1.617.2(delta)variant infection after a second dose of the vaccine.Fourteen subjects were vaccinated with CoronaVac(Sinovac)and one subject with ChAdOx1 nCoV-19(Oxford-AstraZeneca).All of the subjects remained in home isolation,with fever being the most common symptom at the onset of illness(n=10,66.67%).The mean duration of symptoms was 7.73 d(±5.444).The mean time that elapsed from the first positive swab to a negative RT-PCR test for SARS-CoV-2 was 17.93 d(±6.3464).The median time that elapsed from the second dose of vaccine to the first positive swab was 87 d(interquartile range:86-128).CONCLUSION Although this case shows that after two doses of vaccine,subjects are still susceptible to the delta variant infection,currently available vaccines remain the most effective protection.They reduce clinical manifestations of COVID-19,decrease recovery time from the first positive swab to negative swab,and lower the probability of hospitalization and mortality rate compared to unvaccinated individuals.展开更多
Background This study aimed to explore the imaging characteristics,diversity and changing trend in CT scans of pediatric patients infected with Delta-variant strain by studying imaging features of children infected wi...Background This study aimed to explore the imaging characteristics,diversity and changing trend in CT scans of pediatric patients infected with Delta-variant strain by studying imaging features of children infected with Delta and comparing the results to those of children with original COVID-19.Methods A retrospective,comparative analysis of initial chest CT manifestations between 63 pediatric patients infected with Delta variant in 2021 and 23 pediatric patients with COVID-19 in 2020 was conducted.Corresponding imaging features were analyzed.In addition,the changing trend in imaging features of COVID-19 Delta-variant cases were explored by evaluating the initial and follow-up CT scans.Results Among 63 children with Delta-variant COVID-19 in 2021,34(53.9%)showed positive chest CT presentation;and their CT score(1.10±1.41)was signifcantly lower than that in 2020(2.56±3.5)(P=0.0073).Lesion distribution:lung lesions of Delta cases appear mainly in the lower lungs on both sides.Most children had single lobe involvement(18 cases,52.9%),14(41.2%)in the right lung alone,and 14(41.2%)in both lungs.A majority of Delta cases displayed initially ground glass(23 cases,67.6%)and nodular shadows(13 cases,38.2%)in the frst CT scan,with few extrapulmonary manifestations.The 34 children with abnormal chest CT for the frst time have a total of 92 chest CT examinations.These children showed a statistically signifcant diference between the 0-3 day group and the 4-7 day group(P=0.0392)and a signifcant diference between the 4-7 day group and the more than 8 days group(P=0.0003).Conclusions The early manifestations of COVID-19 in children with abnormal imaging are mostly small subpleural nodular ground glass opacity.The changes on the Delta-variant COVID-19 chest CT were milder than the original strain.The lesions reached a peak on CT in 4-7 days and quickly improved and absorbed after a week.Dynamic CT re-examination can achieve a good prognosis.展开更多
During the two-year pandemic of coronavirus disease 2019(COVID-19), its causative agent, severe acute respiratory syndrome coronavirus 2(SARS-CoV-2), has been evolving. SARS-CoV-2 Delta, a variant of concern, has beco...During the two-year pandemic of coronavirus disease 2019(COVID-19), its causative agent, severe acute respiratory syndrome coronavirus 2(SARS-CoV-2), has been evolving. SARS-CoV-2 Delta, a variant of concern, has become the dominant circulating strain worldwide within just a few months. Here, we performed a comprehensive analysis of a new B.1.617.2 Delta strain(Delta630) compared with the early WIV04 strain(WIV04) in vitro and in vivo, in terms of replication, infectivity, pathogenicity, and transmission in hamsters. When inoculated intranasally, Delta630 led to more pronounced weight loss and more severe disease in hamsters. Moreover, 40%mortality occurred about one week after infection with 10^(4)PFU of Delta630, whereas no deaths occurred even after infection with 10^(5)PFU of WIV04 or other strains belonging to the Delta variant. Moreover, Delta630outgrew over WIV04 in the competitive aerosol transmission experiment. Taken together, the Delta630 strain showed increased replication ability, pathogenicity, and transmissibility over WIV04 in hamsters. To our knowledge, this is the first SARS-CoV-2 strain that causes death in a hamster model, which could be an asset for the efficacy evaluation of vaccines and antivirals against infections of SARS-CoV-2 Delta strains. The underlying molecular mechanisms of increased virulence and transmission await further analysis.展开更多
Background The aim of this study was to analyze the clinical characteristics of 66 pediatric patients with B.l.617.2(Delta)variant of coronavirus disease 2019(COVID-19).Methods Sixty-six pediatric patients with B.1.61...Background The aim of this study was to analyze the clinical characteristics of 66 pediatric patients with B.l.617.2(Delta)variant of coronavirus disease 2019(COVID-19).Methods Sixty-six pediatric patients with B.1.617.2(Delta)variant of COVID-19 admitted to the hospital from July to August 2021 were classified into mild(n=41)and moderate groups(n=25).Clinical characteristics,laboratory data and dynamic trends in different time periods were analyzed retrospectively.Results There were no statistically significant differences in age,gender ratios and clinical symptoms between the mild group and the moderate group.All the patients in the moderate group had clusters of onsets,and the incubation period was shorter than that of the mild group.Within 24 hours of admission,the levels of erythrocyte sedimentation rate,cardiac troponin I,D-dimer in the moderate group were higher than that in the mild group(P<0.05).The titers of immunoglobulin(Ig)G and IgM antibodies gradually increased after disease onset.Thirty-five(53.03%)children were tested positive for antibodies in 4-12 days.IgG increased gradually,while IgM decreased obviously in about 15 days after disease onset.The cycle threshold values of open reading frame lab and nucleocapsid protein gene in the severe acute respiratory syndrome coronavirus 2 genomes in creased gradually on the 3rd,6th,9th,and 12th days after disease onset,compared with those in day 0.Conclusions The symptoms of children with B.l.617.2(Delta)variant of COVID-19 were mild.The description and analysis of the clinical characteristics and laboratory data can help medical stafiF to evaluate the condition of children with COVID-19 and to accumulate more clinical experience.展开更多
文摘BACKGROUND The B.1.617.2(delta)variant of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)was first discovered in Maharashtra in late 2020 and has rapidly expanded across India and worldwide.It took only 2 mo for this variant to spread in Indonesia,making the country the new epicenter of the delta variant as of July 2021.Despite efforts made by accelerating massive rollouts of current vaccines to protect against infection,cases of fully-vaccinated people infected with the delta variant have been reported.AIM To describe the demographic statistics and clinical presentation of the delta variant infection after the second dose of vaccine in Indonesia.METHODS A retrospective,single-centre case series of the general consecutive population that worked or studied at Faculty of Medicine,Universitas Indonesia with confirmed Delta Variant Infection after a second dose of vaccine from 24 June and 25 June 2021.Cases were collected retrospectively based on a combination of author recall,reverse transcription-polymerase chain reaction(RT-PCR),and whole genome sequencing results from the Clinical Microbiology Laboratory,Faculty of Medicine,Universitas Indonesia.RESULTS Between 24 June and 25 June 2021,15 subjects were confirmed with the B.1.617.2(delta)variant infection after a second dose of the vaccine.Fourteen subjects were vaccinated with CoronaVac(Sinovac)and one subject with ChAdOx1 nCoV-19(Oxford-AstraZeneca).All of the subjects remained in home isolation,with fever being the most common symptom at the onset of illness(n=10,66.67%).The mean duration of symptoms was 7.73 d(±5.444).The mean time that elapsed from the first positive swab to a negative RT-PCR test for SARS-CoV-2 was 17.93 d(±6.3464).The median time that elapsed from the second dose of vaccine to the first positive swab was 87 d(interquartile range:86-128).CONCLUSION Although this case shows that after two doses of vaccine,subjects are still susceptible to the delta variant infection,currently available vaccines remain the most effective protection.They reduce clinical manifestations of COVID-19,decrease recovery time from the first positive swab to negative swab,and lower the probability of hospitalization and mortality rate compared to unvaccinated individuals.
基金This study was supported by the China Postdoctoral Science Foundation 2020M681674(to Xuhua Ge)The Nanjing Medical Science and Technique Development Foundation(No.YKK20130)(to Zhuo Li)This work was reviewed and approved by the Medical Ethical Committee of Second Hospital of Nanjing(approval number 2020-LS-ky003).
文摘Background This study aimed to explore the imaging characteristics,diversity and changing trend in CT scans of pediatric patients infected with Delta-variant strain by studying imaging features of children infected with Delta and comparing the results to those of children with original COVID-19.Methods A retrospective,comparative analysis of initial chest CT manifestations between 63 pediatric patients infected with Delta variant in 2021 and 23 pediatric patients with COVID-19 in 2020 was conducted.Corresponding imaging features were analyzed.In addition,the changing trend in imaging features of COVID-19 Delta-variant cases were explored by evaluating the initial and follow-up CT scans.Results Among 63 children with Delta-variant COVID-19 in 2021,34(53.9%)showed positive chest CT presentation;and their CT score(1.10±1.41)was signifcantly lower than that in 2020(2.56±3.5)(P=0.0073).Lesion distribution:lung lesions of Delta cases appear mainly in the lower lungs on both sides.Most children had single lobe involvement(18 cases,52.9%),14(41.2%)in the right lung alone,and 14(41.2%)in both lungs.A majority of Delta cases displayed initially ground glass(23 cases,67.6%)and nodular shadows(13 cases,38.2%)in the frst CT scan,with few extrapulmonary manifestations.The 34 children with abnormal chest CT for the frst time have a total of 92 chest CT examinations.These children showed a statistically signifcant diference between the 0-3 day group and the 4-7 day group(P=0.0392)and a signifcant diference between the 4-7 day group and the more than 8 days group(P=0.0003).Conclusions The early manifestations of COVID-19 in children with abnormal imaging are mostly small subpleural nodular ground glass opacity.The changes on the Delta-variant COVID-19 chest CT were milder than the original strain.The lesions reached a peak on CT in 4-7 days and quickly improved and absorbed after a week.Dynamic CT re-examination can achieve a good prognosis.
基金supported by China Natural Science Foundation (82150201)
文摘During the two-year pandemic of coronavirus disease 2019(COVID-19), its causative agent, severe acute respiratory syndrome coronavirus 2(SARS-CoV-2), has been evolving. SARS-CoV-2 Delta, a variant of concern, has become the dominant circulating strain worldwide within just a few months. Here, we performed a comprehensive analysis of a new B.1.617.2 Delta strain(Delta630) compared with the early WIV04 strain(WIV04) in vitro and in vivo, in terms of replication, infectivity, pathogenicity, and transmission in hamsters. When inoculated intranasally, Delta630 led to more pronounced weight loss and more severe disease in hamsters. Moreover, 40%mortality occurred about one week after infection with 10^(4)PFU of Delta630, whereas no deaths occurred even after infection with 10^(5)PFU of WIV04 or other strains belonging to the Delta variant. Moreover, Delta630outgrew over WIV04 in the competitive aerosol transmission experiment. Taken together, the Delta630 strain showed increased replication ability, pathogenicity, and transmissibility over WIV04 in hamsters. To our knowledge, this is the first SARS-CoV-2 strain that causes death in a hamster model, which could be an asset for the efficacy evaluation of vaccines and antivirals against infections of SARS-CoV-2 Delta strains. The underlying molecular mechanisms of increased virulence and transmission await further analysis.
基金supported by the China Postdoctoral Science Foundation(No.2020M681674,to GXH)the Nanjing Medical Science and Technique Development Foundation(No.YKK20130,to LZ).
文摘Background The aim of this study was to analyze the clinical characteristics of 66 pediatric patients with B.l.617.2(Delta)variant of coronavirus disease 2019(COVID-19).Methods Sixty-six pediatric patients with B.1.617.2(Delta)variant of COVID-19 admitted to the hospital from July to August 2021 were classified into mild(n=41)and moderate groups(n=25).Clinical characteristics,laboratory data and dynamic trends in different time periods were analyzed retrospectively.Results There were no statistically significant differences in age,gender ratios and clinical symptoms between the mild group and the moderate group.All the patients in the moderate group had clusters of onsets,and the incubation period was shorter than that of the mild group.Within 24 hours of admission,the levels of erythrocyte sedimentation rate,cardiac troponin I,D-dimer in the moderate group were higher than that in the mild group(P<0.05).The titers of immunoglobulin(Ig)G and IgM antibodies gradually increased after disease onset.Thirty-five(53.03%)children were tested positive for antibodies in 4-12 days.IgG increased gradually,while IgM decreased obviously in about 15 days after disease onset.The cycle threshold values of open reading frame lab and nucleocapsid protein gene in the severe acute respiratory syndrome coronavirus 2 genomes in creased gradually on the 3rd,6th,9th,and 12th days after disease onset,compared with those in day 0.Conclusions The symptoms of children with B.l.617.2(Delta)variant of COVID-19 were mild.The description and analysis of the clinical characteristics and laboratory data can help medical stafiF to evaluate the condition of children with COVID-19 and to accumulate more clinical experience.
