Viral shedding and the durability of IgG antibodies to SARS‐CoV‐2

Abstract Background: Hainan Island, a popular tourist destination, had received many imported cases of Coronavirus disease 2019 (COVID-19), but successfully contained the epidemics in one month. We described epidemiological and clinical characteristics of COVID-19 in Hainan and compared these features between imported and local cases to provide information for other international epidemic areas.Methods: We included 91 patients (56 imported and 35 local cases) from two designed hospitals for COVID-19 in Haikou, China, from January 20 to February 19, 2020. Data on demographic, epidemiological, clinical and laboratory characteristics were extracted from medical records. Patients were followed up until April 21, 2020, the levels of antibodies in the follow-up were also analyzed.Results: Of the 91 patients, 78 (85.7%) patients were diagnosed within the first three weeks after the first case identified (Day 1: Jan 22, 2020), while the number of local cases started to increase from the third week. No new cases occurred after Day 29. Fever and cough were two main clinical manifestations. 15 (16.5%) were severe, 14 (15.4%) had complicated infections, nine (9.9%) were admitted to ICU, and three died. Median duration of viral shedding in feces was longer than that in nasopharyngeal swabs (19 days vs 16 days, P=0.007). Compared with local cases, imported cases were older, have higher incidence of fever and concurrent infections. There was no difference in outcomes between the two groups. IgG was positive in 92.8% patients (77/83) in the follow-up of week 2 after discharge, 88.4% patients (38/43) had a reduction in IgG levels in the follow-up of week 4 after discharge, and the median level was lower than that in the follow-up of week 2 (10.95 S/CO vs 15.02 S/CO, P<0.001)Conclusion: Imported cases were more severe than local cases, but could have similar prognosis. The level of IgG antibodies declined from week 6 to week 8 after onset. The short epidemic period in Hainan suggests that the epidemics could be quickly brought under control if proper timely measures were taken.

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Compare the epidemiological and clinical features of imported and local COVID-19 cases in Hainan, China

Infectious Diseases of Poverty ◽

10.1186/s40249-020-00755-7 ◽

2020 ◽

Vol 9 (1) ◽

Author(s):

Biao Wu ◽

Zi-Ying Lei ◽

Kun-Liang Wu ◽

Jian-Rong He ◽

Hui-Juan Cao ◽

...

Keyword(s):

Clinical Manifestations ◽

Effective Management ◽

Igg Antibodies ◽

Viral Shedding ◽

First Case ◽

Epidemic Period ◽

Imported Cases ◽

Concurrent Infections ◽

And Control

Abstract Background Effective management of imported cases is an important part of epidemic prevention and control. Hainan Province, China reported 168 coronavirus disease 2019 (COVID-19), including 112 imported cases on February 19, 2020, but successfully contained the epidemic within 1 month. We described the epidemiological and clinical characteristics of COVID-19 in Hainan and compared these features between imported and local cases to provide information for other international epidemic areas. Methods We included 91 patients (56 imported and 35 local cases) from two designated hospitals for COVID-19 in Haikou, China, from January 20 to February 19, 2020. Data on the demographic, epidemiological, clinical and laboratory characteristics were extracted from medical records. Patients were followed until April 21, 2020, and the levels of antibodies at the follow-ups were also analysed by the Wilcoxon matched-pairs signed ranks test. Results Of the 91 patients, 78 (85.7%) patients were diagnosed within the first three weeks after the first case was identified (Day 1: Jan 22, 2020), while the number of local cases started to increase during the third week. No new cases occurred after Day 29. Fever and cough were two main clinical manifestations. In total, 15 (16.5%) patients were severe, 14 (15.4%) had complicated infections, nine (9.9%) were admitted to the intensive care unit, and three died. The median duration of viral shedding in feces was longer than that in nasopharyngeal swabs (19 days vs 16 days, P = 0.007). Compared with local cases, imported cases were older and had a higher incidence of fever and concurrent infections. There was no difference in outcomes between the two groups. IgG was positive in 92.8% patients (77/83) in the follow-up at week 2 after discharge, while 88.4% patients (38/43) had a reduction in IgG levels in the follow-up at week 4 after discharge, and the median level was lower than that in the follow-up at week 2 (10.95 S/Cut Off (S/CO) vs 15.02 S/CO, P < 0.001). Conclusion Imported cases were more severe than local cases but had similar prognoses. The level of IgG antibodies declined from week 6 to week 8 after onset. The short epidemic period in Hainan suggests that the epidemic could be quickly brought under control if proper timely measures were taken.

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Epidemiological and clinical features of imported and local patients with coronavirus disease 2019 (COVID-19) in Hainan, China

10.21203/rs.3.rs-39645/v2 ◽

2020 ◽

Author(s):

Biao Wu ◽

Zi-Ying Lei ◽

Kun-Liang Wu ◽

Jian-Rong He ◽

Hui-Juan Cao ◽

...

Keyword(s):

Clinical Manifestations ◽

Hainan Island ◽

Igg Antibodies ◽

Tourist Destination ◽

Viral Shedding ◽

First Case ◽

Epidemic Period ◽

Imported Cases ◽

Concurrent Infections

Abstract Background: Hainan Island, which is a popular tourist destination, received many imported cases of Coronavirus disease 2019 (COVID-19) but successfully contained the epidemic within one month. We described the epidemiological and clinical characteristics of COVID-19 in Hainan and compared these features between imported and local cases to provide information for other international epidemic areas.Methods: We included 91 patients (56 imported and 35 local cases) from two designated hospitals for COVID-19 in Haikou, China, from January 20 to February 19, 2020. Data on the demographic, epidemiological, clinical and laboratory characteristics were extracted from medical records. Patients were followed until April 21, 2020, and the levels of antibodies at the follow-ups were also analyzed.Results: Of the 91 patients, 78 (85.7%) patients were diagnosed within the first three weeks after the first case was identified (Day 1: Jan 22, 2020), while the number of local cases started to increase during the third week. No new cases occurred after Day 29. Fever and cough were two main clinical manifestations. In total, 15 (16.5%) patients were severe, 14 (15.4%) had complicated infections, nine (9.9%) were admitted to the ICU, and three died. The median duration of viral shedding in feces was longer than that in nasopharyngeal swabs (19 days vs 16 days, P=0.007). Compared with local cases, imported cases were older and had a higher incidence of fever and concurrent infections. There was no difference in outcomes between the two groups. IgG was positive in 92.8% patients (77/83) in the follow-up at week 2 after discharge, while 88.4% patients (38/43) had a reduction in IgG levels in the follow-up at week 4 after discharge, and the median level was lower than that in the follow-up at week 2 (10.95 S/CO vs 15.02 S/CO, P<0.001).Conclusion: Imported cases were more severe than local cases but had similar prognoses. The level of IgG antibodies declined from week 6 to week 8 after onset. The short epidemic period in Hainan suggests that the epidemic could be quickly brought under control if proper timely measures were taken.

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Presymptomatic viral shedding and infective ability of SARS-CoV-2; a case report.

10.21203/rs.3.rs-36269/v2 ◽

2021 ◽

Author(s):

Karolina Nissen ◽

Marie Hagbom ◽

Janina Krambrich ◽

Dario Akaberi ◽

Sumit Sharma ◽

...

Keyword(s):

Health Care ◽

Case Report ◽

Health Care Worker ◽

Symptom Onset ◽

Cytopathic Effect ◽

Case Reports ◽

Igg Antibodies ◽

Double Stranded Rna ◽

Viral Shedding ◽

Care Worker

Abstract Reports of possible pre- or asymptomatic transmission have been reported, both from SARS-CoV and from MERS-CoV outbreaks, although this appears to be uncommon. In contrast, during the COVID-19 pandemic, an increasing number of studies and case reports indicate that pre- or asymptomatic transmission of SARS-CoV-2 is not only possible but also occurs frequently. We report repeated rRT-PCR detection of SARS-CoV-2 in a health care worker and demonstrate infective ability up to three days prior to mild COVID-19 symptoms. rRT-PCR indicated high viral levels approximately three days after exposure. Viral samples collected one and three days prior to symptoms exhibited infectivity on Vero E6 cells, confirmed by detection of double-stranded RNA by immunofluorescence, assessment of cytopathic effect (CPE) and rRT-PCR. SARS-CoV-2 specific IgM and IgG antibodies were detected by day 9 and 15, respectively, after symptom onset. We propose that this provides evidence for potential early presymptomatic transmission of SARS-CoV-2 and that infectivity may be manifest shortly after exposure.

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The Application of Protein A-Gold Immunocytochemistry to Studies of Protein Secretion

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100118989 ◽

1985 ◽

Vol 43 ◽

pp. 426-429

Author(s):

George H. Herbener ◽

Antonio Nanci ◽

Moise Bendayan

Keyword(s):

Tissue Section ◽

Colloidal Gold ◽

Unit Area ◽

Protein A ◽

Extracellular Proteins ◽

Gold Complex ◽

Second Step ◽

Igg Antibodies ◽

Tissue Sections ◽

Antigenic Sites

Protein A-gold immunocytochemistry is a two-step, post-embedding labeling procedure which may be applied to tissue sections to localize intra- and extracellular proteins. The key requisite for immunocytochemistry is the availability of the appropriate antibody to react in an immune response with the antigenic sites on the protein of interest. During the second step, protein A-gold complex is reacted with the antibody. This is a non- specific reaction in that protein A will combine with most IgG antibodies. The ‘label’ visualized in the electron microscope is colloidal gold. Since labeling is restricted to the surface of the tissue section and since colloidal gold is particulate, labeling density, i.e., the number of gold particles per unit area of tissue section, may be quantitated with ease and accuracy.

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