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2.
Sci Bull (Beijing) ; 68(23): 3003-3012, 2023 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-37919162

RESUMEN

The continuous evolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in a significant number of variants, particularly with the emergence of Omicron with many sub-variants. These variants have exhibited increased immune escape, leading to reduced efficacy of existing vaccines and therapeutic antibodies. Given the diminished cross-neutralization observed among these variants, it is plausible that SARS-CoV-2 has developed multiple serotypes. As the major antigenic site, the receptor-binding domain (RBD) of viral spike (S) protein was chosen for serotyping. We selected 23 representative variants, including pre-Omicron variants and Omicron sub-variants, and classified them into five serotypes based on systematic evaluation of the antigenicities of their RBDs. Each serotype includes several genetically distinct variants. Serotype-I encompasses all pre-Omicron variants (with two subtypes), while the remaining four serotypes are all comprised of Omicron sub-variants at different stages of evolution. We propose that these serotypes can serve as a foundation for rapid classification of newly emerging SARS-CoV-2 variants, and guide the development of future broad-spectrum vaccines and neutralizing antibodies against the coronavirus disease 2019 (COVID-19).


Asunto(s)
COVID-19 , Vacunas , Humanos , SARS-CoV-2/genética , Serogrupo
3.
Expert Opin Drug Saf ; : 1-8, 2023 Jul 12.
Artículo en Inglés | MEDLINE | ID: mdl-37427985

RESUMEN

BACKGROUND: There are no local or international guidelines or consensus on the use of mAbs against the rabies virus. RESEARCH DESIGN AND METHODS: An expert group in the field of rabies prevention and control formulated the consensus presented in this paper. RESULTS: Class III exposed persons to rabies for the first time; Identify type II exposed persons with immune deficiency; those who are first exposed to Class II and re-exposed to Class III within 7 days. They can use ormutivimab injection after completing the PEP wound treatment. In the case of injection restrictions or a wound that is difficult to detect, it is recommended that the entire Ormutivimab dose be infiltrated close to the wound. For severe multi-wound bites, the recommended dosage of ormutivimab is 20 IU/kg. If the recommended dose cannot meet all of the wound infiltration requirements, appropriate dilution can be conducted at a dilution ratio of 3 ~ 5 times. If the requirements for infiltration cannot be met after dilution, it is recommended that the dosage be increased with caution (maximum dosage, 40 IU/kg). The use of Ormutivimab is safe and effective without any contraindications by all age groups. CONCLUSIONS: This consensus standardizes clinical use of Ormutivimab, improves post-exposure prophylaxis of rabies in China, reduces infection rate.

4.
Clin Chim Acta ; 547: 117415, 2023 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-37271272

RESUMEN

BACKGROUND: Great concerns have been raised on SARS-CoV-2 impact on men's andrological well-being, and many studies have attempted to determine whether SARS-CoV-2 is present in the semen and till now the data are unclear and somehow ambiguous. However, these studies used quantitative real-time (qRT) PCR, which is not sufficiently sensitive to detect nucleic acids in clinical samples with a low viral load. METHODS: The clinical performance of various nucleic acid detection methods (qRT-PCR, OSN-qRT-PCR, cd-PCR, and CBPH) was assessed for SARS-CoV-2 using 236 clinical samples from laboratory-confirmed COVID-19 cases. Then, the presence of SARS-CoV-2 in the semen of 12 recovering patients was investigated using qRT-PCR, OSN-qRT-PCR, cd-PCR, and CBPH in parallel using 24 paired semen, blood, throat swab, and urine samples. RESULTS: The sensitivity and specificity along with AUC of CBPH was markedly higher than the other 3methods. Although qRT-PCR, OSN-qRT-PCR and cdPCR detected no SARS-CoV-2 RNA in throat swab, blood, urine, and semen samples of the 12 patients, CBPH detected the presence of SARS-CoV-2 genome fragments in semen samples, but not in paired urine samples, of 3 of 12 patients. The existing SARS-CoV-2 genome fragments were metabolized over time. CONCLUSIONS: Both OSN-qRT-PCR and cdPCR had better performance than qRT-PCR, and CBPH had the highest diagnostic performance in detecting SARS-CoV-2, which contributed the most improvement to the determination of the critical value in gray area samples with low vrial load, which then provides a rational screening strategy for studying the clearance of coronavirus in the semen over time in patients recovering from COVID-19. Although the presence of SARS-CoV-2 fragments in the semen was demonstrated by CBPH, COVID-19 is unlikely to be sexually transmitted from male partners for at least 3 months after hospital discharge.


Asunto(s)
COVID-19 , SARS-CoV-2 , Humanos , Masculino , SARS-CoV-2/genética , COVID-19/diagnóstico , Semen/química , Prueba de COVID-19 , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , ARN Viral/genética
5.
Trop Med Infect Dis ; 8(6)2023 Jun 20.
Artículo en Inglés | MEDLINE | ID: mdl-37368748

RESUMEN

The Omicron variant is the dominant strain circulating globally, and studies have shown that Omicron cases have milder symptoms than Delta cases. This study aimed to analyze the factors that affect the clinical severity of Omicron and Delta variants, evaluate and compare the effectiveness of COVID-19 vaccines with different technological platforms, and assess the vaccine effectiveness against different variants. We retrospectively collected the basic information of all local COVID-19 cases reported by Hunan Province to the National Notifiable Infectious Disease Reporting System from January 2021 to February 2023, including gender, age, clinical severity, and COVID-19 vaccination history. From 1 January 2021 to 28 February 2023, Hunan Province reported a total of 60,668 local COVID-19 cases, of which, 134 were infected with the Delta variant and 60,534 were infected with the Omicron variant. The results showed that infection with the Omicron variant (adjusted OR (aOR): 0.21, 95% CI: 0.14-0.31), getting vaccinated (booster immunization vs. unvaccinated aOR: 0.30, 95% CI: 0.23-0.39) and being female (aOR: 0.82, 95% CI: 0.79-0.85) were protective factors for pneumonia, while old age (≥60 years vs. <3 years aOR: 4.58, 95% CI: 3.36-6.22) was a risk factor for pneumonia. Being vaccinated (booster immunization vs. unvaccinated aOR: 0.11, 95% CI: 0.09-0.15) and female (aOR: 0.54, 95% CI: 0.50-0.59) were protective factors for severe cases, while older age (≥60 years vs. < 3 years aOR: 4.95, 95% CI: 1.83-13.39) was a risk factor for severe cases. The three types of vaccines had protective effects on both pneumonia and severe cases, and the protective effect on severe cases was better than that on pneumonia. The recombinant subunit vaccine booster immunization had the best protective effect on pneumonia and severe cases, with ORs of 0.29 (95% CI: 0.2-0.44) and 0.06 (95% CI: 0.02-0.17), respectively. The risk of pneumonia from Omicron variant infection was lower than that from Delta. Chinese-produced vaccines had protective effects on both pneumonia and severe cases, with recombinant subunit vaccines having the best protective effect on pneumonia and severe pneumonia cases. Booster immunization should be advocated in COVID-19 pandemic-related control and prevention policies, especially for the elderly, and booster immunization should be accelerated.

6.
Artículo en Inglés | MEDLINE | ID: mdl-36900920

RESUMEN

BACKGROUND: Tuberculosis (TB) is a public health problem worldwide, and the influence of meteorological and air pollutants on the incidence of tuberculosis have been attracting interest from researchers. It is of great importance to use machine learning to build a prediction model of tuberculosis incidence influenced by meteorological and air pollutants for timely and applicable measures of both prevention and control. METHODS: The data of daily TB notifications, meteorological factors and air pollutants in Changde City, Hunan Province ranging from 2010 to 2021 were collected. Spearman rank correlation analysis was conducted to analyze the correlation between the daily TB notifications and the meteorological factors or air pollutants. Based on the correlation analysis results, machine learning methods, including support vector regression, random forest regression and a BP neural network model, were utilized to construct the incidence prediction model of tuberculosis. RMSE, MAE and MAPE were performed to evaluate the constructed model for selecting the best prediction model. RESULTS: (1) From the year 2010 to 2021, the overall incidence of tuberculosis in Changde City showed a downward trend. (2) The daily TB notifications was positively correlated with average temperature (r = 0.231), maximum temperature (r = 0.194), minimum temperature (r = 0.165), sunshine duration (r = 0.329), PM2.5 (r = 0.097), PM10 (r = 0.215) and O3 (r = 0.084) (p < 0.05). However, there was a significant negative correlation between the daily TB notifications and mean air pressure (r = -0.119), precipitation (r = -0.063), relative humidity (r = -0.084), CO (r = -0.038) and SO2 (r = -0.034) (p < 0.05). (3) The random forest regression model had the best fitting effect, while the BP neural network model exhibited the best prediction. (4) The validation set of the BP neural network model, including average daily temperature, sunshine hours and PM10, showed the lowest root mean square error, mean absolute error and mean absolute percentage error, followed by support vector regression. CONCLUSIONS: The prediction trend of the BP neural network model, including average daily temperature, sunshine hours and PM10, successfully mimics the actual incidence, and the peak incidence highly coincides with the actual aggregation time, with a high accuracy and a minimum error. Taken together, these data suggest that the BP neural network model can predict the incidence trend of tuberculosis in Changde City.


Asunto(s)
Contaminantes Atmosféricos , Conceptos Meteorológicos , Tuberculosis , Humanos , China/epidemiología , Ciudades , Incidencia , Tuberculosis/epidemiología , Contaminación del Aire/estadística & datos numéricos
7.
China CDC Wkly ; 5(3): 56-62, 2023 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-36776461

RESUMEN

What is already known about this topic?: Little is known about the epidemiology, natural history, and transmission patterns of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Delta variant. Monitoring the evolution of viral fitness of SARS-CoV-2 in the host population is key for preparedness and response planning. What is added by this report?: We analyzed a successfully contained local outbreak of Delta that took place in Hunan, China, and provided estimates of time-to-key event periods, infectiousness over time, and risk factors for SARS-CoV-2 infection and transmission for a still poorly understood variant. What are the implications for public health practice?: Our findings simultaneously shed light on both the characteristics of the Delta variant, by identifying key age groups, risk factors, and transmission pathways, and planning a future response effort against SARS-CoV-2.

8.
J Cancer Res Clin Oncol ; 149(10): 6901-6916, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-36826593

RESUMEN

PURPOSE: The crucial role of N6-methyladenosine (m6A) methylation in anti-tumor immunity and immunotherapy has been broadly depicted. However, the molecular phenotypic linkages between m6A modification pattern and immunological ecosystem are expected to be disentangled in hepatocellular carcinoma (HCC), for immunotherapeutic unresponsiveness circumvention and combination with promising drug agents. METHODS: Modification patterns of m6A methylation were qualitatively dissected according to the large-scale HCC samples profiling. We then determined the immune phenotypic linkages by systematically evaluating their tumor microenvironment composition, immune/stromal-relevant signature, immune checkpoints correlation, and prognostic value. Individual quantification of m6A methylation pattern was achieved by m6Ascore construction, intensified by longitudinal single-cell analysis of immunotherapy cohort and validated by the transcriptomic profiles of our in-hospital GDPH-HCC cohort. Candidate therapeutic agents were also screened out. RESULTS: Three distinct m6A methylation patterns were determined in high accordance with inflamed-, excluded-, and desert-immunophenotype. To be precise, Immune-inflamed high-m6Ascore group was characterized by activated immunity with favorable prognosis. Stromal activation and absence of immune cell infiltration were observed in low-m6Ascore phenotype, linked to impaired outcome. Patients with low-m6Ascore demonstrated diminished responses and clinical benefits for cohorts receiving immunotherapy. The above credible linkage between m6A methylation pattern and tumor immune microenvironment was robustly validated in our GDPH-HCC cohort. Single-cell dynamic change of m6A methylation level in exhausted CD8 T cell and fibroblast was depicted in immunotherapy cohort fore and art. Derived from m6A methylation pattern, seven potential frontline drug agents were recognized as promising choice for high-m6Ascore patients. CONCLUSION: Our work bridged the credible linkage between epigenetics and anti-tumor immunity in HCC, unraveling m6A modification pattern as immunological indicator and predictor for immunotherapy. Individualized m6Ascore facilitated strategic choices to maximize therapy-responsive possibility.


Asunto(s)
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Metilación , Carcinoma Hepatocelular/genética , Ecosistema , Neoplasias Hepáticas/genética , Microambiente Tumoral , Fenotipo
9.
Infect Dis Model ; 8(1): 192-202, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36688089

RESUMEN

Background: The current outbreak of novel coronavirus disease 2019 has caused a serious disease burden worldwide. Vaccines are an important factor to sustain the epidemic. Although with a relatively high-vaccination worldwide, the decay of vaccine efficacy and the arising of new variants lead us to the challenge of maintaining a sufficient immune barrier to protect the population. Method: A case-contact tracking data in Hunan, China, is used to estimate the contact pattern of cases for scenarios including school, workspace, etc, rather than ordinary susceptible population. Based on the estimated vaccine coverage and efficacy, a multi-group vaccinated-exposed-presymptomatic-symptomatic-asymptomatic-removed model (VEFIAR) with 8 age groups, with each partitioned into 4 vaccination status groups is developed. The optimal dose-wise vaccinating strategy is optimized based on the currently estimated immunity barrier of coverage and efficacy, using the greedy algorithm that minimizes the cumulative cases, population size of hospitalization and fatality respectively in a certain future interval. Parameters of Delta and Omicron variants are used respectively in the optimization. Results: The estimated contact matrices of cases showed a concentration on middle ages, and has compatible magnitudes compared to estimations from contact surveys in other studies. The VEFIAR model is numerically stable. The optimal controled vaccination strategy requires immediate vaccination on the un-vaccinated high-contact population of age 30-39 to reduce the cumulative cases, and is stable with different basic reproduction numbers ( R 0 ). As for minimizing hospitalization and fatality, the optimized strategy requires vaccination on the un-vaccinated of both aged 30-39 of high contact frequency and the vulnerable older. Conclusion: The objective of reducing transmission requires vaccination in age groups of the highest contact frequency, with more priority for un-vaccinated than un-fully or fully vaccinated. The objective of reducing total hospitalization and fatality requires not only to reduce transmission but also to protect the vulnerable older. The priority changes by vaccination progress. For any region, if the local contact pattern is available, then with the vaccination coverage, efficacy, and disease characteristics of relative risks in heterogeneous populations, the optimal dose-wise vaccinating process will be obtained and gives hints for decision-making.

10.
Infect Dis Model ; 8(1): 203-211, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36694868

RESUMEN

Since the epidemic of the severe acute respiratory syndrome coronavirus 2 (SARS-COV-2), many governments have used reverse transcription polymerase chain reaction (RT-PCR) to detect the virus. However, there are fewer measures of CT values information based on RT-PCR results, and the relationship between CT values and factors from consecutive tests is not clear enough. So in this study, we analyzed the connection between CT values and the factors based on cohort data from Delta variant of SARS-CoV-2 in Hunan Province. Previous studies have showed that the mean age of the cases was 33.34 years (±18.72 years), with a female predominance (55.03%, n = 71), and the greatest proportion of clinical symptoms were of the common type (60.47%, n = 78). There were statistical differences between the N and ORF1ab genes in the CT values for the cases. Based on the analysis of the association between CT values and the factors, the lowest CT values were obtained for the unvaccinated, older and clinically symptomatic group at 3-10 days, the maximum peak of viral load occurred. Therefore, it is recommended to use patient information to focus on older, clinically symptomatic, unvaccinated patients and to intervene promptly upon admission.

11.
Commun Biol ; 5(1): 1419, 2022 12 27.
Artículo en Inglés | MEDLINE | ID: mdl-36575240

RESUMEN

The strong suppression of Aedes albopictus on two Guangzhou islands in China has been successfully achieved by releasing males with an artificial triple-Wolbachia infection. However, it requires the use of radiation to sterilize residual females to prevent population replacement. To develop a highly effective tool for dengue control, we tested a standalone incompatible insect technique (IIT) to control A. albopictus in the urban area of Changsha, an inland city where dengue recently emerged. Male mosquitoes were produced in a mass rearing facility in Guangzhou and transported over 670 km under low temperature to the release site. After a once-per-week release with high numbers of males (phase I) and a subsequent twice-per-week release with low numbers of males (phase II), the average numbers of hatched eggs and female adults collected weekly per trap were reduced by 97% and 85%, respectively. The population suppression caused a 94% decrease in mosquito biting at the release site compared to the control site. Remarkably, this strong suppression was achieved using only 28% of the number of males released in a previous trial. Despite the lack of irradiation to sterilize residual females, no triple-infected mosquitoes were detected in the field post release based on the monitoring of adult and larval A. albopictus populations for two years, indicating that population replacement was prevented. Our results support the feasibility of implementing a standalone IIT for dengue control in urban areas.


Asunto(s)
Aedes , Dengue , Animales , Masculino , Femenino , Control de Mosquitos/métodos , Dinámica Poblacional , Larva , Dengue/prevención & control
12.
China CDC Wkly ; 4(44): 986-989, 2022 Nov 04.
Artículo en Inglés | MEDLINE | ID: mdl-36483987

RESUMEN

Introduction: The objective of this paper was to assess the epidemiology of rabies in Hunan Province, analyze the associated factors, understand the status of prevention and treatment after rabies exposure, evaluate the effectiveness of prevention and treatment, and provide a scientific basis for formulating effective prevention and control measures. Methods: The surveillance data of rabies in Hunan Province in 2020 were collected and analyzed by descriptive epidemiological method. Results: In 2020, a total of 59 cases of rabies were reported in Hunan Province, with an incidence rate of 0.09/100,000. Overall, 42 cases (71.19%) were due to animal bites and 43 cases (72.88%) were of grade III. The proportion of hand and combined injury of hand was the highest (40.68%). A total of 603,261 cases of rabies exposure were reported from the rabies post-exposure prophylaxis (PEP) clinic in Hunan Province. Dogs were the main animal causing injuries, accounting for 74.21%. Only 83,418 (13.84%) of the animals had a clear immune history, and a total of 11 dog attacks were reported in Hunan Province. The average immunity rate of dogs in the whole province was 30.98%. In 2020, 554 dogs were sampled in the whole province; 20 of them were positive for a positivity rate of 3.61%. Conclusions: Rabies in Hunan Province in 2020 had a relatively low prevalence. Failure to treat wounds, immunoglobulin injections, and vaccination after exposure were the main causes of rabies. Therefore, post-exposure management of rabies should be further strengthened to reduce the risk of rabies for high-risk populations.

13.
Nat Commun ; 13(1): 7280, 2022 11 26.
Artículo en Inglés | MEDLINE | ID: mdl-36435844

RESUMEN

Enterovirus A71 (EV-A71)-related hand, foot, and mouth disease (HFMD) imposes a substantial clinical burden in the Asia Pacific region. To inform policy on the introduction of the EV-A71 vaccine into the National Immunization Programme, we investigated the seroepidemiological characteristics of EV-A71 in two prospective cohorts of children in southern China conducted between 2013 and 2018. Our results show that maternal antibody titres declined rapidly in neonates, with over half becoming susceptible to EV-A71 at 1 month of age. Between 6 months and 2 years of age, over 80% of study participants were susceptible, while one third remained susceptible at 5 years old. The highest incidence of EV-A71 infections was observed in children aged 5-6 months. Our findings support EV-A71 vaccination before 6 months for birth cohorts in southern China, potentially with a one-time catch-up vaccination for children 6 months-5 years old. More regionally representative longitudinal seroepidemiological studies are needed to further validate these findings.


Asunto(s)
Enterovirus Humano A , Infecciones por Enterovirus , Enterovirus , Enfermedad de Boca, Mano y Pie , Niño , Recién Nacido , Humanos , Preescolar , Enfermedad de Boca, Mano y Pie/epidemiología , Estudios Prospectivos , Estudios Seroepidemiológicos , Infecciones por Enterovirus/epidemiología , China/epidemiología , Antígenos Virales
14.
Front Cell Infect Microbiol ; 12: 1010683, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36389149

RESUMEN

The outbreak of the novel coronavirus disease 2019 (COVID-19) has had an unprecedented impact worldwide, and it is of great significance to predict the prognosis of patients for guiding clinical management. This study aimed to construct a nomogram to predict the prognosis of COVID-19 patients. Clinical records and laboratory results were retrospectively reviewed for 331 patients with laboratory-confirmed COVID-19 from Huangshi Hospital of Traditional Chinese Medicine (TCM) (Infectious Disease Hospital) and Third Affiliated Hospital of Sun Yat-sen University. All COVID-19 patients were followed up for 80 days, and the primary outcome was defined as patient death. Cases were randomly divided into training (n=199) and validation (n=132) groups. Based on baseline data, we used statistically significant prognostic factors to construct a nomogram and assessed its performance. The patients were divided into Death (n=23) and Survival (n=308) groups. Analysis of clinical characteristics showed that these patients presented with fever (n=271, 81.9%), diarrhea (n=20, 6.0%) and had comorbidities (n=89, 26.9.0%). Multivariate Cox regression analysis showed that age, UREA and LDH were independent risk factors for predicting 80-day survival of COVID-19 patients. We constructed a qualitative nomogram with high C-indexes (0.933 and 0.894 in the training and validation groups, respectively). The calibration curve for 80-day survival showed optimal agreement between the predicted and actual outcomes. Decision curve analysis revealed the high clinical net benefit of the nomogram. Overall, our nomogram could effectively predict the 80-day survival of COVID-19 patients and hence assist in providing optimal treatment and decreasing mortality rates.


Asunto(s)
COVID-19 , Humanos , COVID-19/diagnóstico , Análisis Multivariante , Nomogramas , Pronóstico , Estudios Retrospectivos
15.
Immunity ; 55(8): 1501-1514.e3, 2022 08 09.
Artículo en Inglés | MEDLINE | ID: mdl-35777362

RESUMEN

SARS-CoV-2 Omicron variant has presented significant challenges to current antibodies and vaccines. Herein, we systematically compared the efficacy of 50 human monoclonal antibodies (mAbs), covering the seven identified epitope classes of the SARS-CoV-2 RBD, against Omicron sub-variants BA.1, BA.1.1, BA.2, and BA.3. Binding and pseudovirus-based neutralizing assays revealed that 37 of the 50 mAbs lost neutralizing activities, whereas the others displayed variably decreased activities against the four Omicron sub-variants. BA.2 was found to be more sensitive to RBD-5 antibodies than the other sub-variants. Furthermore, a quaternary complex structure of BA.1 RBD with three mAbs showing different neutralizing potencies against Omicron provided a basis for understanding the immune evasion of Omicron sub-variants and revealed the lack of G446S mutation accounting for the sensitivity of BA.2 to RBD-5 mAbs. Our results may guide the application of the available mAbs and facilitate the development of universal therapeutic antibodies and vaccines against COVID-19.


Asunto(s)
Anticuerpos Neutralizantes , COVID-19 , Anticuerpos Monoclonales , Anticuerpos Antivirales , Vacunas contra la COVID-19 , Humanos , Glicoproteínas de Membrana , SARS-CoV-2 , Glicoproteína de la Espiga del Coronavirus , Proteínas del Envoltorio Viral
16.
Build Environ ; 207: 108414, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34629689

RESUMEN

Uncertainty remains on the threshold of ventilation rate in airborne transmission of SARS-CoV-2. We analyzed a COVID-19 outbreak in January 2020 in Hunan Province, China, involving an infected 24-year-old man, Mr. X, taking two subsequent buses, B1 and B2, in the same afternoon. We investigated the possibility of airborne transmission and the ventilation conditions for its occurrence. The ventilation rates on the buses were measured using a tracer-concentration decay method with the original driver on the original route. We measured and calculated the spread of the exhaled virus-laden droplet tracer from the suspected index case. Ten additional passengers were found to be infected, with seven of them (including one asymptomatic) on B1 and two on B2 when Mr. X was present, and one passenger infected on the subsequent B1 trip. B1 and B2 had time-averaged ventilation rates of approximately 1.7 and 3.2 L/s per person, respectively. The difference in ventilation rates and exposure time could explain why B1 had a higher attack rate than B2. Airborne transmission due to poor ventilation below 3.2 L/s played a role in this two-bus outbreak of COVID-19.

17.
J Hazard Mater ; 425: 128051, 2022 03 05.
Artículo en Inglés | MEDLINE | ID: mdl-34910996

RESUMEN

The number of people infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to increase worldwide, but despite extensive research, there remains significant uncertainty about the predominant routes of SARS-CoV-2 transmission. We conducted a mechanistic modeling and calculated the exposure dose and infection risk of each passenger in a two-bus COVID-19 outbreak in Hunan province, China. This outbreak originated from a single pre-symptomatic index case. Some human behavioral data related to exposure including boarding and alighting time of some passengers and seating position and mask wearing of all passengers were obtained from the available closed-circuit television images/clips and/or questionnaire survey. Least-squares fitting was performed to explore the effect of effective viral load on transmission risk, and the most likely quanta generation rate was also estimated. This study reveals the leading role of airborne SARS-CoV-2 transmission and negligible role of fomite transmission in a poorly ventilated indoor environment, highlighting the need for more targeted interventions in such environments. The quanta generation rate of the index case differed by a factor of 1.8 on the two buses and transmission occurred in the afternoon of the same day, indicating a time-varying effective viral load within a short period of five hours.


Asunto(s)
Microbiología del Aire , COVID-19 , Fómites/virología , Vehículos a Motor , SARS-CoV-2 , COVID-19/transmisión , Brotes de Enfermedades , Humanos
18.
Zhongguo Dang Dai Er Ke Za Zhi ; 23(11): 1141-1148, 2021 Nov 15.
Artículo en Inglés, Chino | MEDLINE | ID: mdl-34753546

RESUMEN

OBJECTIVES: To investigate the epidemic situation of hand-foot-mouth disease (HFMD) in Hunan Province, China, from 2008 to 2019, as well as its spatial autocorrelation characteristics and spatial-temporal clustering, and to provide a reference for the prevention and control of HFMD in Hunan Province. METHODS: Spatial autocorrelation and spatial-temporal clustering analyses were used to analyze the monitoring data of HFMD in Hunan Province from 2008 to 2019. RESULTS: The epidemic situation of HFMD in Hunan Province from 2008 to 2019 showed obvious seasonal distribution, with a low incidence rate in January to March and a high incidence rate in April to July. As for population distribution, children aged 0-5 years had the highest number of HFMD cases and accounted for 95.89% (1 460 391/1 522 910) of all cases, with a mean annual incidence rate of 2 197.784/100 000, and scattered children had the highest number of cases and accounted for 82.59% (1 257 739/1 522 910) of all cases. The global spatial autocorrelation analysis showed that the onset of HFMD in Hunan Province showed a significant clustering distribution, and the local spatial autocorrelation analysis showed that the high clustering areas of HFMD were mainly the districts and counties of Changsha, Zhuzhou, and Yueyang cities. Time-space scanning showed that clustering time was mainly April to July; the cases were clustered in the northeast of Hunan Province from 2008 to 2010 and in the central part of Hunan Province from 2011 to 2019. CONCLUSIONS: The high incidence rate of HFMD is observed in April to July in Hunan Province. Children under 5 years of age are at a high risk of this disease. Spatial-temporal clustering is observed for the epidemic of HFMD, mainly clustered in the northeastern and central areas of Hunan Province. It is suggested that the results may be used as guidance to determine the key areas for HFMD prevention and control in Hunan Province and optimize the allocation of health resources.


Asunto(s)
Enfermedad de Boca, Mano y Pie , Niño , Preescolar , China/epidemiología , Análisis por Conglomerados , Enfermedad de Boca, Mano y Pie/epidemiología , Humanos , Incidencia , Lactante , Análisis Espacio-Temporal
19.
Front Med (Lausanne) ; 8: 735779, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34650998

RESUMEN

Objectives: To data, no patients with obvious epidemiological relationship co-infected with SARS-CoV-2 and other pathogens have been reported. Here, we investigated 10 patients caused by co-infection with SARS-CoV-2 and human adenovirus (HAdV), resulting in third-generation transmission. Materials and Methods: From Jan 15, 2020, we enrolled 10 patients with pneumonia in Hunan Province, China. Epidemiological, clinical, and laboratory investigation results from these patients were analyzed. An epidemiological investigation was performed to assess whether patient infections were linked using conventional methods and metagenomic sequencing. Results: The presence of co-infection with SARS-CoV-2 and HAdV was determined via RT-PCR and metagenomic sequencing. Phylogenetic analysis revealed that SARS-CoV-2 and HAdV genomes clustered together, with similar genetic relationships. The first patient likely became co-infected during meetings or travel in Wuhan. The patient transmitted the virus via dinners and meetings, which resulted in four second-generation cases. Then, a second-generation case transmitted the virus to her family members or relatives via presymptomatic transmission. Conclusions: This study described an example of co-infection with SARS-CoV-2 and HAdV in pneumonia patients, which caused third-generation cases and inter-regional transmission via meetings, household interactions, and dinner parties. We also observed the persistent and presymptomatic transmission of co-infection, which has the potential to make the continued control of the COVID-19 pandemic challenging. Continuous surveillance is needed to monitor the prevalence, infectivity, transmissibility, and pathogenicity of SARS-CoV-2 co-infection with other pathogens to evaluate its real risk.

20.
Virol Sin ; 36(6): 1484-1491, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34403037

RESUMEN

The sudden emergence of severe acute respiratory syndrome coronavirus (SARS-CoV) has caused global panic in 2003, and the risk of SARS-CoV outbreak still exists. However, no specific antiviral drug or vaccine is available; thus, the development of therapeutic antibodies against SARS-CoV is needed. In this study, a nanobody phage-displayed library was constructed from peripheral blood mononuclear cells of alpacas immunized with the recombinant receptor-binding domain (RBD) of SARS-CoV. Four positive clones were selected after four rounds of bio-panning and subjected to recombinant expression in E. coli. Further biological identification demonstrated that one of the nanobodies, S14, showed high affinity to SARS-CoV RBD and potent neutralization activity at the picomole level against SARS-CoV pseudovirus. A competitive inhibition assay showed that S14 blocked the binding of SARS-CoV RBD to either soluble or cell-expressed angiotensin-converting enzyme 2 (ACE2). In summary, we developed a novel nanobody targeting SARS-CoV RBD, which might be useful for the development of therapeutics against SARS.


Asunto(s)
COVID-19 , Coronavirus Relacionado al Síndrome Respiratorio Agudo Severo , Anticuerpos Neutralizantes , Anticuerpos Antivirales/metabolismo , Escherichia coli/metabolismo , Humanos , Leucocitos Mononucleares/metabolismo , Unión Proteica , Coronavirus Relacionado al Síndrome Respiratorio Agudo Severo/metabolismo , SARS-CoV-2 , Glicoproteína de la Espiga del Coronavirus/metabolismo
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