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1.
J. Health Biol. Sci. (Online) ; 10(1): 1-7, 01/jan./2022.
Article in Portuguese | LILACS | ID: biblio-1361634

ABSTRACT

Objetivo: aplicar a modelagem logística da primeira onda da COVID-19, com índice nos países com 20 maiores Produto Interno Bruto (PIB). Métodos: foi utilizada a modelagem matemática de crescimento logístico, considerando os seguintes parâmetros: número cumulativo de casos (C), tamanho final da epidemia na onda única de um surto (K), taxa intrínseca de crescimento (y) e tempo de inflexão (τ). Resultados: o Brasil apresentou maior número de casos e mortalidade, e os Estados Unidos da América (EUA) maior número de casos absolutos. A Coreia do Sul evidenciou o menor ponto de inflexão de 15,3 dias, enquanto o maior foi da Indonésia, com 213,9 dias. Na análise entre o ponto de inflexão e casos acumulados (/100 mil habitantes), observou-se correlação positiva moderada significativa (r=0,629 e p=0,003); (r=0,532 e p=0,016). Conclusão: o reconhecimento do comportamento de uma epidemia por meio da modelagem matemática torna possível determinar a propagação de uma epidemia, visto que, com a possibilidade de captar a dinâmica de uma epidemia, torna-se possível prever a necessidade de medidas públicas antecipadas e, consequentemente, diminuição da mortalidade global.


Objective: to apply logistic modeling of the first wave of COVID-19 in countries with the 20 highest Gross Domestic Product (GDP). Methods: logistic growth mathematical modeling was used, considering the following parameters: cumulative number of cases (C), the final size of the epidemic in the single wave of an outbreak (K), intrinsic growth rate (y), and inflection time (τ). Results: Brazil showed the highest number of cases and mortality, and the United States of America (USA) had the highest number of absolute cases. South Korea showed the lowest inflection point of 15.3 days, while the highest infection point was Indonesia, with 213.9 days. In the analysis between the inflection point and cumulative cases (/100,000 population), a moderate significant positive correlation was observed (r=0.629 and p=0.003); (r=0.532 and p=0.016). Conclusion: the recognition of the behavior of an epidemic through mathematical modeling makes it possible to determine the spread of an epidemic, since, with the possibility of capturing the dynamics of an epidemic, it becomes possible to predict the need for anticipated public measures and, consequently, decrease in overall mortality.


Subject(s)
COVID-19 , Logistic Models , Gross Domestic Product , Epidemics
2.
PLoS One ; 17(8): e0270953, 2022.
Article in English | MEDLINE | ID: mdl-35913926

ABSTRACT

Microblog has become the "first scenario" under which the public learn about the epidemic situation and express their opinions. Public sentiment mining based on microblog data can provide a reference for the government's information disclosure, public sentiment guidance and formulation of epidemic prevention and control policy. In this paper, about 200,000 pieces of text data were collected from Jan. 1 to Feb. 26, 2020 from Sina Weibo, which is the most popular microblog website in China. And a public sentiment analysis framework suitable for Chinese-language scenarios was proposed. In this framework, a sentiment dictionary suitable for Chinese-language scenarios was constructed, and Baidu's Sentiment Analysis API was used to calculate the public sentiment indexes. Then, an analysis on the correlation between the public sentiment indexes and the COVID-19 case indicators was made. It was discovered that there is a high correlation between public sentiments and incidence trends, in which negative sentiment is of statistical significance for the prediction of epidemic development. To further explore the source of public negative sentiment, the topics of the public negative sentiment on Weibo was analyzed, and 20 topics in five categories were got. It is found that there is a strong linkage between the hot spots of public concern and the epidemic prevention and control policies. If the policies cover the hot spots of public concern in a timely and effective manner, the public negative sentiment will be effectively alleviated. The analytical framework proposed in this paper also applies to the public sentiment analysis and policy making for other major public events.


Subject(s)
COVID-19 , Epidemics , Social Media , Attitude , COVID-19/epidemiology , COVID-19/prevention & control , Epidemics/prevention & control , Humans , Policy
3.
West Afr J Med ; 39(7): 653-654, 2022 Jul 31.
Article in English | MEDLINE | ID: mdl-35921681
4.
Front Public Health ; 10: 908430, 2022.
Article in English | MEDLINE | ID: mdl-35937208

ABSTRACT

A central issue of public health security and the construction of an early warning system is to establish a set of responsibility-oriented incentives and restraint mechanisms. This is closely related to the accounting transparency of the institutional environment and the fear sentiment of the individual's predicament. This study analyses the relationship between accounting transparency, fear sentiment, and COVID-19 through a VAR model analysis. The results show a significant and negative relationship between accounting transparency and daily new COVID-19 patients. In particular, accounting transparency has a negative impact on the increase in the number of people infected with a two-period lag, while the three-period lag in the number of new epidemics has a negative impact on accounting information. Second, accounting transparency has a positive impact on the increase in the search volume on COVID-19 within a three-period lag. After the three-period lag, the number of new epidemics has a positive impact on accounting information. Third, an increase in fear sentiment can be driven by the fear of COVID-19. Fourth, in the public health early warning system, according to the abovementioned time characteristics, the system arranges the emotional counseling, early warning incentives, and institutional constraints to be dealt with in the first 4 days. In addition, in the early warning target-oriented system setting, the parallel system helps to improve the early warning efficiency.


Subject(s)
COVID-19 , Epidemics , Attitude , COVID-19/epidemiology , Fear , Humans , Public Health
6.
J Biol Dyn ; 16(1): 619-639, 2022 Dec.
Article in English | MEDLINE | ID: mdl-35950789

ABSTRACT

In this paper, we are concerned with an epidemic model with quarantine and distributed time delay. We define the basic reproduction number R0 and show that if R0≤1, then the disease-free equilibrium is globally asymptotically stable, whereas if R0>1, then it is unstable and there exists a unique endemic equilibrium. We obtain sufficient conditions for a Hopf bifurcation that induces a nontrivial periodic solution which represents recurrent epidemic waves. By numerical simulations, we illustrate stability and instability parameter regions. Our results suggest that the quarantine and time delay play important roles in the occurrence of recurrent epidemic waves.


Subject(s)
Epidemics , Quarantine , Basic Reproduction Number , Computer Simulation , Models, Biological
7.
Math Biosci Eng ; 19(9): 9571-9589, 2022 Jul 01.
Article in English | MEDLINE | ID: mdl-35942773

ABSTRACT

When formulating countermeasures to epidemics such as those generated by COVID-19, estimates of the benefits of a given intervention for a specific population are highly beneficial to policy makers. A recently introduced tool, known as the "dynamic-spread" SIR model, can perform population-specific risk assessment. Behavior is quantified by the dynamic-spread function, which includes the mechanisms of droplet reduction using facemasks and transmission control due to social distancing. The spread function is calibrated using infection data from a previous wave of the infection, or other data felt to accurately represent the population behaviors. The model then computes the rate of spread of the infection for different hypothesized interventions, over the time window for the calibration data. The dynamic-spread model was used to assess the benefit of three enhanced intervention strategies - increased mask filtration efficiency, higher mask compliance, and elevated social distancing - in four COVID-19 scenarios occurring in 2020: the first wave (i.e. until the first peak in numbers of new infections) in New York City; the first wave in New York State; the spread aboard the Diamond Princess Cruise Liner; and the peak occurring after re-opening in Harris County, Texas. Differences in the efficacy of the same intervention in the different scenarios were estimated. As an example, when the average outward filtration efficiency for facemasks worn in New York City was increased from an assumed baseline of 67% to a hypothesized 90%, the calculated peak number of new infections per day decreased by 40%. For the same baseline and hypothesized filtration efficiencies aboard the Diamond Princess Cruise liner, the calculated peak number of new infections per day decreased by about 15%. An important factor contributing to the difference between the two scenarios is the lower mask compliance (derivable from the spread function) aboard the Diamond Princess.


Subject(s)
COVID-19 , Epidemics , COVID-19/epidemiology , COVID-19/prevention & control , Epidemics/prevention & control , Humans , Quarantine
8.
PLoS One ; 17(8): e0272996, 2022.
Article in English | MEDLINE | ID: mdl-35951674

ABSTRACT

BACKGROUND: The influence of human mobility to the domestic spread of COVID-19 in Japan using the approach of effective distance has not yet been assessed. METHODS: We calculated the effective distance between prefectures using the data on laboratory-confirmed cases of COVID-19 from January 16 to August 23, 2020, that were times in the 1st and the 2nd epidemic waves in Japan. We also used the aggregated data on passenger volume by transportation mode for the 47 prefectures, as well as those in the private railway, bus, ship, and aviation categories. The starting location (prefecture) was defined as Kanagawa and as Tokyo for the 1st and the 2nd waves, respectively. The accuracy of the spread models was evaluated using the correlation between time of arrival and effective distance, calculated according to the different starting locations. RESULTS: The number of cases in the analysis was 16,226 and 50,539 in the 1st and 2nd epidemic waves, respectively. The relationship between arrival time and geographical distance shows that the coefficient of determination was R2 = 0.0523 if geographical distance Dgeo and time of arrival Ta set to zero at Kanagawa and was R2 = 0.0109 if Dgeo and Ta set to zero at Tokyo. The relationship between arrival time and effective distance shows that the coefficient of determination was R2 = 0.3227 if effective distance Deff and Ta set to zero at Kanagawa and was R2 = 0.415 if Deff and time of arrival Ta set to zero at Tokyo. In other words, the effective distance taking into account the mobility network shows the spatiotemporal characteristics of the spread of infection better than geographical distance. The correlation of arrival time to effective distance showed the possibility of spreading from multiple areas in the 1st epidemic wave. On the other hand, the correlation of arrival time to effective distance showed the possibility of spreading from a specific area in the 2nd epidemic wave. CONCLUSIONS: The spread of COVID-19 in Japan was affected by the mobility network and the 2nd epidemic wave is more affected than those of the 1st epidemic. The effective distance approach has the impact to estimate the domestic spreading COVID-19.


Subject(s)
COVID-19 , Epidemics , COVID-19/epidemiology , Humans , Japan/epidemiology , Tokyo/epidemiology
9.
J Math Biol ; 85(2): 17, 2022 Aug 01.
Article in English | MEDLINE | ID: mdl-35913603

ABSTRACT

We considered an SIS functional partial differential model cooperated with spatial heterogeneity and lag effect of media impact. The wellposedness including existence and uniqueness of the solution was proved. We defined the basic reproduction number and investigated the threshold dynamics of the model, and discussed the asymptotic behavior and monotonicity of the basic reproduction number associated with the diffusion rate. The local and global Hopf bifurcation at the endemic steady state was investigated theoretically and numerically. There exists numerical cases showing that the larger the number of basic reproduction number, the smaller the final epidemic size. The meaningful conclusion generalizes the previous conclusion of ordinary differential equation.


Subject(s)
Epidemics , Models, Biological , Basic Reproduction Number
10.
Zhonghua Jie He He Hu Xi Za Zhi ; 45(8): 819-825, 2022 Aug 12.
Article in Chinese | MEDLINE | ID: mdl-35927053

ABSTRACT

Based on natural infection or vaccination, the protective barrier for population has been preliminarily established. However, with constant appearances of SARS-CoV-2 variants, breakthrough infection events cannot be completely avoided, and thus the diagnostic strategy is still the key to discovering epidemic sources and blocking the transmission chain. Currently, SARS-CoV-2 diagnosis technologies based on nucleic acid, antigen and antibody detections have developed and extended in diversity. Under the background of work resumption and epidemic-prevention normalization during the later COVID-19 era, it is necessary for us to choose appropriate detection methods to satisfy the need of epidemic prevention and control in various scenarios. We summarized the principles and applicable characteristics of existing SARS-CoV-2 detection technologies in this paper, aimed to provide guidance for clinical and public health personnel to make targeted decisions.


Subject(s)
COVID-19 , Epidemics , COVID-19/diagnosis , COVID-19 Testing , Humans , SARS-CoV-2
11.
Multimedia | Multimedia Resources | ID: multimedia-9871

ABSTRACT

O tema da nossa Live da semana será “Abordagem Homeopática dos Quadros Agudos” Vamos receber os Doutores Cláudio Araújo e Ângela Lanner. Dra. Ângela Augusta Lanner Vieira, médica especialista em Homeopatia, ex-presidente da AMHB, Coordenadora Científica do XXXIV Congresso Brasileiro de Homeopatia; participante da Comissão Brasileira de Gênio Epidêmico para Covid-19. Dr. Claudio Carvalho Araújo, médico Homeopata, Livre Docente em Clínica Médica Homeopática pela UniRio, Pós Graduação e fellow pela Faculty of Homeopathy, London, e segundo ele mesmo descreve, a parte mais difícil, pai de 4 filhos.


Subject(s)
Homeopathy , Epidemics , Risk Factors , COVID-19
12.
Elife ; 112022 07 26.
Article in English | MEDLINE | ID: mdl-35880398

ABSTRACT

Transmission is a driver of tuberculosis (TB) epidemics in high-burden regions, with assumed negligible impact in low-burden areas. However, we still lack a full characterization of transmission dynamics in settings with similar and different burdens. Genomic epidemiology can greatly help to quantify transmission, but the lack of whole genome sequencing population-based studies has hampered its application. Here, we generate a population-based dataset from Valencia region and compare it with available datasets from different TB-burden settings to reveal transmission dynamics heterogeneity and its public health implications. We sequenced the whole genome of 785 Mycobacterium tuberculosis strains and linked genomes to patient epidemiological data. We use a pairwise distance clustering approach and phylodynamic methods to characterize transmission events over the last 150 years, in different TB-burden regions. Our results underscore significant differences in transmission between low-burden TB settings, i.e., clustering in Valencia region is higher (47.4%) than in Oxfordshire (27%), and similar to a high-burden area as Malawi (49.8%). By modeling times of the transmission links, we observed that settings with high transmission rate are associated with decades of uninterrupted transmission, irrespective of burden. Together, our results reveal that burden and transmission are not necessarily linked due to the role of past epidemics in the ongoing TB incidence, and highlight the need for in-depth characterization of transmission dynamics and specifically tailored TB control strategies.


Subject(s)
Epidemics , Mycobacterium tuberculosis , Tuberculosis , Humans , Mycobacterium tuberculosis/genetics , Population Dynamics , Tuberculosis/epidemiology , Whole Genome Sequencing
13.
Washington, D.C.; PAHO; 2022-07-15. (PAHO/PHE/IMS/COVID-19/22-0012).
Non-conventional in English | PAHO-IRIS | ID: phr-56162

ABSTRACT

This publication documents the Pan American Health Organization (PAHO) efforts in 2021 to respond to emerging needs in the Americas Region to detect, track, treat and slow the spread of COVID-19, as well as to facilitate vaccine procurement and deployment within the ten pillars of WHO's Strategic Preparedness and Response Strategy.


Subject(s)
COVID-19 , Betacoronavirus , Pandemics , COVID-19 Vaccines , Epidemics , Disease Outbreaks
14.
Front Public Health ; 10: 915716, 2022.
Article in English | MEDLINE | ID: mdl-35784212

ABSTRACT

Objective: To evaluate epidemiological characteristics of the COVID-19 outbreak that resurged in Yangzhou and to simulate the impact of different control measures at different regional scales. Methods: We collected personal information from 570 laboratory-confirmed cases in Yangzhou from 28 July to 26 August 2021, and built a modified susceptible-exposed-infected-removed (SEIR) model and an agent-based model. Results: The SEIR model showed that for passengers from medium-high risk areas, pre-travel nucleic acid testing within 3 days could limit the total number of infected people in Yangzhou to 50; among elderly persons, a 60% increase in vaccination rates could reduce the estimated infections by 253. The agent-based model showed that when the population density of the chess and card room dropped by 40%, the number of infected people would decrease by 54 within 7 days. A ventilation increase in the chess and card room from 25 to 50% could reduce the total number of infections by 33 within 7 days; increasing the ventilation from 25 to 75% could reduce the total number of infections by 63 within 7 days. Conclusions: The SEIR model and agent-based model were used to simulate the impact of different control measures at different regional scales successfully. It is possible to provide references for epidemic prevention and control work.


Subject(s)
COVID-19 , Epidemics , Aged , COVID-19/epidemiology , China/epidemiology , Computer Simulation , Disease Outbreaks/prevention & control , Humans
15.
Theor Popul Biol ; 146: 71-85, 2022 08.
Article in English | MEDLINE | ID: mdl-35842054

ABSTRACT

In classical epidemic theory, behavior is assumed to be stationary. In recent years, epidemic models have been extended to include behaviors that transition in response to the current state of the epidemic. However, it is widely known that human behavior can exhibit strong history-dependence as a consequence of learned experiences. This history-dependence is similar to hysteresis phenomena that have been well-studied in control theory. To illustrate the importance of history-dependence for epidemic theory, we study dynamics of a variant of the SIRS model where individuals exhibit lazy-switch responses to prevalence dynamics, based on the Preisach hysteresis operator. The resulting model can possess a continuum of endemic equilibrium states characterized by different proportions of susceptible, infected and recovered populations. We consider how the limit point of the epidemic trajectory and the infection peak along this trajectory depend on the degree of heterogeneity of the response. Our approach supports the argument that public health responses during the emergence of a new disease can have fundamental long-term consequences for subsequent management efforts.


Subject(s)
Epidemics , Epidemiological Models , Humans , Models, Biological , Policy , Prevalence
16.
J Law Med Ethics ; 50(S1): 8-23, 2022.
Article in English | MEDLINE | ID: mdl-35902089

ABSTRACT

The U.S. has the tools to end the HIV epidemic, but progress has stagnated. A major gap in U.S. efforts to address HIV is the under-utilization of medications that can virtually eliminate acquisition of the virus, known as pre-exposure prophylaxis (PrEP). This document proposes a financing and delivery system to unlock broad access to PrEP for those most vulnerable to HIV acquisition and bring an end to the HIV epidemic.


Subject(s)
Epidemics , HIV Infections , Pre-Exposure Prophylaxis , HIV Infections/epidemiology , HIV Infections/prevention & control , Humans
17.
Article in English | MEDLINE | ID: mdl-35805660

ABSTRACT

African swine fever (ASF) is a severe infectious disease affecting domestic and wild suids. Spatiotemporal dynamics analysis of the ASF is crucial to understanding its transmission. The ASF broke out in Vietnam in February 2019. The research on the spatiotemporal evolution characteristics of ASF in Vietnam is lacking. Spatiotemporal statistical methods, including direction analysis, spatial autocorrelation analysis, and spatiotemporal scan statistics were used to reveal the dynamics of the spatial diffusion direction and spatiotemporal aggregation characteristics of ASF in Vietnam. According to the cessation of the epidemic, it was divided into three phases: February to August 2019 (phase 1), April to December 2020 (phase 2), and January 2021 to March 2022 (phase 3). The ASF showed a significant spread trend from north to south in phase 1. The occurrence rate of the ASF aggregated spatially in phase 1 and became random in phases 2 and 3. The high-high ASF clusters (the province was a high cluster and both it and its neighbors had a high ASF occurrence rate) were concentrated in the north in phases 1 and 2. Four spatiotemporal high-risk ASF clusters were identified with a mean radius of 121.88 km. In general, there were significant concentrated outbreak areas and directional spread in the early stage and small-scale, high-frequency, and randomly scattered outbreaks in the later stage. The findings could contribute to a deeper understanding of the spatiotemporal spread of the ASF in Vietnam.


Subject(s)
African Swine Fever Virus , African Swine Fever , Epidemics , African Swine Fever/epidemiology , Animals , Disease Outbreaks/veterinary , Sus scrofa , Swine , Vietnam/epidemiology
18.
Acta Biomed ; 93(3): e2022262, 2022 Jul 01.
Article in English | MEDLINE | ID: mdl-35775780

ABSTRACT

BACKGROUND AND AIM: On January 9, 2020, the World Health Organization (WHO) declared that Chinese health authorities had identified a new coronavirus strain never before isolated in humans, the 2019-nCoV later redefined SARS-CoV-2, that still today represent a public health problem. The present survey started on 10 February 2020 with the aim of a) assessing the risk perception in healthcare workers and young students, following the evolution of attitudes, perception and knowledge over time, b) provide useful information to the general population during survey. RESULTS: A study sample consisting of 4116 Italian individuals of both sexes was enrolled. High levels of risk perception, low perception of self-efficacy and low levels of knowledge scores (24.55 ± 5.76 SD) were obtained indicating the need for continuous population monitoring as well as further communication strategies carried out at institution levels. CONCLUSION: The results of the present study could help public health authorities in carrying out informative campaigns for general population and could be an important tool in evaluating public knowledge and misperceptions during the management of the COVID-19. (www.actabiomedica.it).


Subject(s)
COVID-19 , Epidemics , Attitude , Female , Humans , Male , Public Health , SARS-CoV-2
19.
Int J Mol Sci ; 23(13)2022 Jun 30.
Article in English | MEDLINE | ID: mdl-35806320

ABSTRACT

The epidemic curve of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is silently rising again. Worldwide, the dominant SARS-CoV-2 variant of concern (VOC) is Omicron, and its virological characteristics, such as transmissibility, pathogenicity, and resistance to both vaccine- and infection-induced immunity as well as antiviral drugs, are an urgent public health concern. The Omicron variant has five major sub-lineages; as of February 2022, the BA.2 lineage has been detected in several European and Asian countries, becoming the predominant variant and the real antagonist of the ongoing surge. Hence, although global attention is currently focused on dramatic, historically significant events and the multi-country monkeypox outbreak, this new epidemic is unlikely to fade away in silence. Many aspects of this lineage are still unclear and controversial, but its apparent replication advantage and higher transmissibility, as well as its ability to escape neutralizing antibodies induced by vaccination and previous infection, are rising global concerns. Herein, we review the latest publications and the most recent available literature on the BA.2 lineage of the Omicron variant.


Subject(s)
COVID-19 , Epidemics , COVID-19/epidemiology , Disease Outbreaks , Humans , SARS-CoV-2
20.
PLoS One ; 17(7): e0270740, 2022.
Article in English | MEDLINE | ID: mdl-35776716

ABSTRACT

BACKGROUND: Disease surveillance using adequate case definitions is very important. The objective of the study was to compare the performance of influenza case definitions and influenza symptoms in the first two epidemic weeks with respect to other epidemic weeks. METHODS: We analysed cases of acute respiratory infection detected by the network of sentinel primary care physicians of Catalonia for 10 seasons. We calculated the diagnostic odds ratio (DOR) and 95% confidence intervals (CI) for the first two epidemic weeks and for other epidemic weeks. RESULTS: A total of 4,338 samples were collected in the epidemic weeks, of which 2,446 (56.4%) were positive for influenza. The most predictive case definition for laboratory-confirmed influenza was the WHO case definition for influenza-like illness (ILI) in the first two epidemic weeks (DOR 2.10; 95% CI 1.57-2.81) and in other epidemic weeks (DOR 2.31; 95% CI 1.96-2.72). The most predictive symptom was fever. After knowing that epidemic threshold had been reached, the DOR of the ILI WHO case definition in children aged <5 years and cough and fever in this group increased (190%, 170% and 213%, respectively). CONCLUSIONS: During influenza epidemics, differences in the performance of the case definition and the discriminative ability of symptoms were found according to whether it was known that the epidemic threshold had been reached or not. This suggests that sentinel physicians are stricter in selecting samples to send to the laboratory from patients who present symptoms more specific to influenza after rather than before an influenza epidemic has been declared.


Subject(s)
Epidemics , Influenza, Human , Respiratory Tract Infections , Child , Fever/epidemiology , Humans , Influenza, Human/diagnosis , Influenza, Human/epidemiology , Respiratory Tract Infections/diagnosis , Respiratory Tract Infections/epidemiology , Seasons , Sentinel Surveillance
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