-
Categories
-
Pharmaceutical Intermediates
-
Active Pharmaceutical Ingredients
-
Food Additives
- Industrial Coatings
- Agrochemicals
- Dyes and Pigments
- Surfactant
- Flavors and Fragrances
- Chemical Reagents
- Catalyst and Auxiliary
- Natural Products
- Inorganic Chemistry
-
Organic Chemistry
-
Biochemical Engineering
- Analytical Chemistry
- Cosmetic Ingredient
-
Pharmaceutical Intermediates
Promotion
ECHEMI Mall
Wholesale
Weekly Price
Exhibition
News
-
Trade Service
iNature is not yet aware of several mechanisms that drive the spread of SARS-CoV-2.
On March 9, 2021, Hongjie Yu of Fudan University, Marco Ajelli of Indiana University and Gao Lidong of the Hunan Provincial Center for Disease Control and Prevention published a joint newsletter entitled "Infectivity, susceptibility, and risk factors associated with SARS-CoV-2 transmission under" in Nature Communications.
intensive contact tracing in Hunan, China" research paper, based on the personal records of 1,178 potential SARS-CoV-2 infected persons and 15,648 contacts in Hunan Province, the study estimated the key transmission parameters: the estimated average time of occurrence is 5.
7 Infectivity peaked 1.
8 days before the onset of symptoms, and 95% of transmission events occurred between 8.
8 and 9.
5 days before the onset of symptoms.
Most transmission events occurred in the pre-symptomatic stage (59.
2%).
The susceptibility of SARS-CoV-2 to infection increases with age, and there is no significant difference in the transmission ability between different age groups and between symptomatic and asymptomatic individuals.
Family contact and exposure to first-generation cases are associated with a higher probability of transmission.
The findings of the study support the hypothesis that children can effectively transmit SARS-CoV-2 and emphasize how symptomatic and asymptomatic transmission can hinder control efforts.
In short, this study systematically explained the dynamic changes of the transmission dynamics parameters of new coronary pneumonia, revealed the important role of asymptomatic transmission and pre-symptomatic transmission in epidemic transmission and prevention and control, and evaluated the impact of factors such as contact mode, number of passages, and number of contacts.
The impact of the spread of new coronary pneumonia confirms that there are large differences in the susceptibility of people of different ages, and at the same time emphasizes the non-ignorable role of children in the spread of new coronary pneumonia.
The research results prove the necessity and effectiveness of population intervention measures such as case isolation and close tracking, and personal protective measures such as wearing masks, which can provide a scientific basis for the later formulation of more targeted and sustainable prevention and control measures, thereby maximizing To reduce the impact of new coronary pneumonia on global health, society and economy.
In addition, on March 8, 2021, Hongjie Yu's research group at Fudan University published a research paper entitled "Serologicalevidence of human infection with SARS-CoV-2: a systematic review and meta-analysis" online at Lancet Global Health (IF=22).
A comprehensive assessment of the quality of existing SARS-CoV-2 serological studies, suggesting that there is an urgent need for standardized SARS-CoV-2 serological studies in the future, and the research design and laboratory testing methods for SARS-CoV-2 serological studies standardization.
In addition, this study systematically elaborated the serological evidence of global human infection with SARS-CoV-2, suggesting that in most areas, the positive rate of SARS-CoV-2 specific antibodies acquired by the general population through natural infection in the community is low, and the distance from the population is low.
The threshold of immunity is farther (click to read).The research team of Yu Hongjie has systematically studied the epidemiology and transmission dynamics characteristics of new coronary pneumonia in the early stage: 1) clarified the epidemiological characteristics of the early stage of the new coronary pneumonia epidemic outside Hubei Province, and found that the case before or after the symptoms appeared Infectious within a short period of time (Zhang J et al, Lancet Infect Dis 2020); 2) The interaction between age, contact patterns, increased social distance, population susceptibility, and the spread of new coronary pneumonia (Zhang J et al, Lancet Infect Dis 2020); al, Science 2020); 3) quantified the relative contribution of biological factors, behavioral factors, and non-pharmacological interventions to the spread of new coronary pneumonia (Sun K et al, Science 2021).
However, as the new crown pneumonia epidemic progresses and its epidemiology and transmission dynamics research continues to deepen, key epidemiological parameters (including incubation period, series interval, intergenerational interval and infectious period), susceptibility and infectiousness are driving factors Affected by factors such as research time, location, sample size, field survey and its data quality, intergenerational relationships in the communication chain, and the number of contacts.
In addition, how much do asymptomatic transmission and pre-symptomatic transmission contribute to the spread of new coronary pneumonia? What is the role of children in the spread of new coronary pneumonia? Answering these key scientific questions can help deepen the understanding of the spread of new coronary pneumonia, understand the individual susceptibility and infectivity of new coronary pneumonia, and provide a scientific basis for the prevention and control policies of the new coronary pneumonia pandemic.
To this end, Yu Hongjie’s research team used the investigation and tracking data of 1,178 SARS-CoV-2 infected persons and 15,648 close contacts confirmed in Hunan Province from January 13 to April 2, 2020 to launch an epidemic.
The study of scientific model aims to understand the changes of epidemiological parameters in different epidemic periods, determine the role of asymptomatic transmission and pre-symptomatic transmission, and explore the infectiousness, susceptibility of new coronary pneumonia and the factors affecting its transmission.
The results of the study showed that the average incubation period and intergenerational interval of new coronary pneumonia were 6.
4 days and 5.
7 days, respectively, and the average series interval was 5.
5 days.
Its infectivity peaked 1.
8 days before the onset of symptoms, and 95% of transmission events occurred before the onset of the case.
From 8.
8 days to 9.
5 days after onset, 59.
2% of transmission events occurred before symptoms (Figure 1). Figure 1: Epidemiological parameters of new coronary pneumonia, A: infectious period and series interval; B: incubation period and intergenerational interval.
Before and after the implementation of the first-level public health response, the average series interval (decreased from 7.
0 days to 4.
1 days) and the proportion of pre-symptomatic transmission (increased from 50.
8% to 76.
7%) have undergone major changes, indicating the cases taken in Hunan Province Intervention measures such as isolation and close tracking have restricted most transmission events to the early stages of infection, effectively controlling the further spread of the epidemic.
The study also found evidence of pre-symptomatic transmission and asymptomatic transmission (Figure 2).
Among them, asymptomatic infections caused 3.
5% (15/432) of local transmission events, and there was at least one cluster of asymptomatic infections.
In the epidemic, local transmission incidents caused by asymptomatic infection accounted for 60% (15/25).
Figure 2: There is a cluster of new coronary pneumonia transmission chains with pre-symptomatic or asymptomatic transmission in Hunan Province, A: pre-symptomatic transmission; B: asymptomatic transmission.
The age contact matrix of infected persons and infected persons shows that the risk of infection of close contacts between 15-64 years old is significantly higher than that of close contacts of other age groups.
After adjusting for the impact of the previous generation of cases in the transmission chain and the cluster of epidemics in which they were located, it was found that the infectivity of new coronary pneumonia was not statistically different among people of different ages and genders, asymptomatic infections, and confirmed cases with clinical symptoms; People aged 15-64, those aged 0-14 are less susceptible (OR=0.
58, 95% CI 0.
34-0.
98), and those aged 65 and older are more susceptible (OR=1.
65, 95% CI 1.
03-2.
64) ).
In addition, the risk of transmission of new coronary pneumonia from family contact is significantly higher than that of relatives, social contacts and other contact modes.
It is worth noting that with the increase in the number of passages of cases in the transmission chain and the cumulative number of contacts, the risk of transmission of new coronary pneumonia has been significantly reduced.
This study systematically explained the dynamic changes of the transmission dynamics parameters of new coronary pneumonia, revealed the important role of asymptomatic transmission and pre-symptomatic transmission in the spread and prevention and control of the epidemic, and assessed the influence of factors such as contact mode, number of generations and number of contacts on the new coronary pneumonia The impact of transmission confirms the large differences in the susceptibility of people of different ages, and emphasizes the non-ignorable role of children in the transmission of new coronary pneumonia.
The research results prove the necessity and effectiveness of population intervention measures such as case isolation and close tracking, and personal protective measures such as wearing masks, which can provide a scientific basis for the later formulation of more targeted and sustainable prevention and control measures, thereby maximizing To reduce the impact of new coronary pneumonia on global health, society and economy.
Hu Shixiong, Hunan Provincial Center for Disease Control and Prevention, 2018 PhD student Wang Wei, School of Public Health, Fudan University, 2019 PhD student Wang Yan, and Maria Litvinova, Indiana University School of Public Health, are the co-first authors, professors of Fudan University School of Public Health, affiliated with Fudan University The Department of Infectious Diseases of Huashan Hospital and Shanghai Institute of Major Infectious Diseases and Biosafety double-appointed PI Yu Hongjie, Indiana University School of Public Health Marco Ajelli and Hunan Provincial Center for Disease Control and Prevention Gao Lidong as co-corresponding authors.
This research was funded by the National Science Fund for Distinguished Young Scholars of the National Natural Science Foundation of China (81525023) and the Emergency Science and Technology Research Project of the Shanghai Science and Technology Commission (20411950100).
Reference message: https://
On March 9, 2021, Hongjie Yu of Fudan University, Marco Ajelli of Indiana University and Gao Lidong of the Hunan Provincial Center for Disease Control and Prevention published a joint newsletter entitled "Infectivity, susceptibility, and risk factors associated with SARS-CoV-2 transmission under" in Nature Communications.
intensive contact tracing in Hunan, China" research paper, based on the personal records of 1,178 potential SARS-CoV-2 infected persons and 15,648 contacts in Hunan Province, the study estimated the key transmission parameters: the estimated average time of occurrence is 5.
7 Infectivity peaked 1.
8 days before the onset of symptoms, and 95% of transmission events occurred between 8.
8 and 9.
5 days before the onset of symptoms.
Most transmission events occurred in the pre-symptomatic stage (59.
2%).
The susceptibility of SARS-CoV-2 to infection increases with age, and there is no significant difference in the transmission ability between different age groups and between symptomatic and asymptomatic individuals.
Family contact and exposure to first-generation cases are associated with a higher probability of transmission.
The findings of the study support the hypothesis that children can effectively transmit SARS-CoV-2 and emphasize how symptomatic and asymptomatic transmission can hinder control efforts.
In short, this study systematically explained the dynamic changes of the transmission dynamics parameters of new coronary pneumonia, revealed the important role of asymptomatic transmission and pre-symptomatic transmission in epidemic transmission and prevention and control, and evaluated the impact of factors such as contact mode, number of passages, and number of contacts.
The impact of the spread of new coronary pneumonia confirms that there are large differences in the susceptibility of people of different ages, and at the same time emphasizes the non-ignorable role of children in the spread of new coronary pneumonia.
The research results prove the necessity and effectiveness of population intervention measures such as case isolation and close tracking, and personal protective measures such as wearing masks, which can provide a scientific basis for the later formulation of more targeted and sustainable prevention and control measures, thereby maximizing To reduce the impact of new coronary pneumonia on global health, society and economy.
In addition, on March 8, 2021, Hongjie Yu's research group at Fudan University published a research paper entitled "Serologicalevidence of human infection with SARS-CoV-2: a systematic review and meta-analysis" online at Lancet Global Health (IF=22).
A comprehensive assessment of the quality of existing SARS-CoV-2 serological studies, suggesting that there is an urgent need for standardized SARS-CoV-2 serological studies in the future, and the research design and laboratory testing methods for SARS-CoV-2 serological studies standardization.
In addition, this study systematically elaborated the serological evidence of global human infection with SARS-CoV-2, suggesting that in most areas, the positive rate of SARS-CoV-2 specific antibodies acquired by the general population through natural infection in the community is low, and the distance from the population is low.
The threshold of immunity is farther (click to read).The research team of Yu Hongjie has systematically studied the epidemiology and transmission dynamics characteristics of new coronary pneumonia in the early stage: 1) clarified the epidemiological characteristics of the early stage of the new coronary pneumonia epidemic outside Hubei Province, and found that the case before or after the symptoms appeared Infectious within a short period of time (Zhang J et al, Lancet Infect Dis 2020); 2) The interaction between age, contact patterns, increased social distance, population susceptibility, and the spread of new coronary pneumonia (Zhang J et al, Lancet Infect Dis 2020); al, Science 2020); 3) quantified the relative contribution of biological factors, behavioral factors, and non-pharmacological interventions to the spread of new coronary pneumonia (Sun K et al, Science 2021).
However, as the new crown pneumonia epidemic progresses and its epidemiology and transmission dynamics research continues to deepen, key epidemiological parameters (including incubation period, series interval, intergenerational interval and infectious period), susceptibility and infectiousness are driving factors Affected by factors such as research time, location, sample size, field survey and its data quality, intergenerational relationships in the communication chain, and the number of contacts.
In addition, how much do asymptomatic transmission and pre-symptomatic transmission contribute to the spread of new coronary pneumonia? What is the role of children in the spread of new coronary pneumonia? Answering these key scientific questions can help deepen the understanding of the spread of new coronary pneumonia, understand the individual susceptibility and infectivity of new coronary pneumonia, and provide a scientific basis for the prevention and control policies of the new coronary pneumonia pandemic.
To this end, Yu Hongjie’s research team used the investigation and tracking data of 1,178 SARS-CoV-2 infected persons and 15,648 close contacts confirmed in Hunan Province from January 13 to April 2, 2020 to launch an epidemic.
The study of scientific model aims to understand the changes of epidemiological parameters in different epidemic periods, determine the role of asymptomatic transmission and pre-symptomatic transmission, and explore the infectiousness, susceptibility of new coronary pneumonia and the factors affecting its transmission.
The results of the study showed that the average incubation period and intergenerational interval of new coronary pneumonia were 6.
4 days and 5.
7 days, respectively, and the average series interval was 5.
5 days.
Its infectivity peaked 1.
8 days before the onset of symptoms, and 95% of transmission events occurred before the onset of the case.
From 8.
8 days to 9.
5 days after onset, 59.
2% of transmission events occurred before symptoms (Figure 1). Figure 1: Epidemiological parameters of new coronary pneumonia, A: infectious period and series interval; B: incubation period and intergenerational interval.
Before and after the implementation of the first-level public health response, the average series interval (decreased from 7.
0 days to 4.
1 days) and the proportion of pre-symptomatic transmission (increased from 50.
8% to 76.
7%) have undergone major changes, indicating the cases taken in Hunan Province Intervention measures such as isolation and close tracking have restricted most transmission events to the early stages of infection, effectively controlling the further spread of the epidemic.
The study also found evidence of pre-symptomatic transmission and asymptomatic transmission (Figure 2).
Among them, asymptomatic infections caused 3.
5% (15/432) of local transmission events, and there was at least one cluster of asymptomatic infections.
In the epidemic, local transmission incidents caused by asymptomatic infection accounted for 60% (15/25).
Figure 2: There is a cluster of new coronary pneumonia transmission chains with pre-symptomatic or asymptomatic transmission in Hunan Province, A: pre-symptomatic transmission; B: asymptomatic transmission.
The age contact matrix of infected persons and infected persons shows that the risk of infection of close contacts between 15-64 years old is significantly higher than that of close contacts of other age groups.
After adjusting for the impact of the previous generation of cases in the transmission chain and the cluster of epidemics in which they were located, it was found that the infectivity of new coronary pneumonia was not statistically different among people of different ages and genders, asymptomatic infections, and confirmed cases with clinical symptoms; People aged 15-64, those aged 0-14 are less susceptible (OR=0.
58, 95% CI 0.
34-0.
98), and those aged 65 and older are more susceptible (OR=1.
65, 95% CI 1.
03-2.
64) ).
In addition, the risk of transmission of new coronary pneumonia from family contact is significantly higher than that of relatives, social contacts and other contact modes.
It is worth noting that with the increase in the number of passages of cases in the transmission chain and the cumulative number of contacts, the risk of transmission of new coronary pneumonia has been significantly reduced.
This study systematically explained the dynamic changes of the transmission dynamics parameters of new coronary pneumonia, revealed the important role of asymptomatic transmission and pre-symptomatic transmission in the spread and prevention and control of the epidemic, and assessed the influence of factors such as contact mode, number of generations and number of contacts on the new coronary pneumonia The impact of transmission confirms the large differences in the susceptibility of people of different ages, and emphasizes the non-ignorable role of children in the transmission of new coronary pneumonia.
The research results prove the necessity and effectiveness of population intervention measures such as case isolation and close tracking, and personal protective measures such as wearing masks, which can provide a scientific basis for the later formulation of more targeted and sustainable prevention and control measures, thereby maximizing To reduce the impact of new coronary pneumonia on global health, society and economy.
Hu Shixiong, Hunan Provincial Center for Disease Control and Prevention, 2018 PhD student Wang Wei, School of Public Health, Fudan University, 2019 PhD student Wang Yan, and Maria Litvinova, Indiana University School of Public Health, are the co-first authors, professors of Fudan University School of Public Health, affiliated with Fudan University The Department of Infectious Diseases of Huashan Hospital and Shanghai Institute of Major Infectious Diseases and Biosafety double-appointed PI Yu Hongjie, Indiana University School of Public Health Marco Ajelli and Hunan Provincial Center for Disease Control and Prevention Gao Lidong as co-corresponding authors.
This research was funded by the National Science Fund for Distinguished Young Scholars of the National Natural Science Foundation of China (81525023) and the Emergency Science and Technology Research Project of the Shanghai Science and Technology Commission (20411950100).
Reference message: https://
