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1.
BMC Infect Dis ; 21(1): 577, 2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-34130652

RESUMO

BACKGROUND: During outbreaks of emerging and re-emerging infections, the lack of effective drugs and vaccines increases reliance on non-pharmacologic public health interventions and behavior change to limit human-to-human transmission. Interventions that increase the speed with which infected individuals remove themselves from the susceptible population are paramount, particularly isolation and hospitalization. Ebola virus disease (EVD), Severe Acute Respiratory Syndrome (SARS), and Middle East Respiratory Syndrome (MERS) are zoonotic viruses that have caused significant recent outbreaks with sustained human-to-human transmission. METHODS: This investigation quantified changing mean removal rates (MRR) and days from symptom onset to hospitalization (DSOH) of infected individuals from the population in seven different outbreaks of EVD, SARS, and MERS, to test for statistically significant differences in these metrics between outbreaks. RESULTS: We found that epidemic week and viral serial interval were correlated with the speed with which populations developed and maintained health behaviors in each outbreak. CONCLUSIONS: These findings highlight intrinsic population-level changes in isolation rates in multiple epidemics of three zoonotic infections with established human-to-human transmission and significant morbidity and mortality. These data are particularly useful for disease modelers seeking to forecast the spread of emerging pathogens.


Assuntos
Controle de Doenças Transmissíveis/métodos , Doenças Transmissíveis Emergentes/epidemiologia , Doenças Transmissíveis Emergentes/prevenção & controle , Surtos de Doenças , Comportamentos Relacionados com a Saúde , Animais , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/prevenção & controle , Epidemias/prevenção & controle , Previsões , Doença pelo Vírus Ebola/epidemiologia , Doença pelo Vírus Ebola/prevenção & controle , Humanos , Saúde Pública , Síndrome Respiratória Aguda Grave/epidemiologia , Síndrome Respiratória Aguda Grave/prevenção & controle , Zoonoses/epidemiologia , Zoonoses/prevenção & controle
2.
BMC Infect Dis ; 21(1): 577, 2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: covidwho-1274542

RESUMO

BACKGROUND: During outbreaks of emerging and re-emerging infections, the lack of effective drugs and vaccines increases reliance on non-pharmacologic public health interventions and behavior change to limit human-to-human transmission. Interventions that increase the speed with which infected individuals remove themselves from the susceptible population are paramount, particularly isolation and hospitalization. Ebola virus disease (EVD), Severe Acute Respiratory Syndrome (SARS), and Middle East Respiratory Syndrome (MERS) are zoonotic viruses that have caused significant recent outbreaks with sustained human-to-human transmission. METHODS: This investigation quantified changing mean removal rates (MRR) and days from symptom onset to hospitalization (DSOH) of infected individuals from the population in seven different outbreaks of EVD, SARS, and MERS, to test for statistically significant differences in these metrics between outbreaks. RESULTS: We found that epidemic week and viral serial interval were correlated with the speed with which populations developed and maintained health behaviors in each outbreak. CONCLUSIONS: These findings highlight intrinsic population-level changes in isolation rates in multiple epidemics of three zoonotic infections with established human-to-human transmission and significant morbidity and mortality. These data are particularly useful for disease modelers seeking to forecast the spread of emerging pathogens.


Assuntos
Controle de Doenças Transmissíveis/métodos , Doenças Transmissíveis Emergentes/epidemiologia , Doenças Transmissíveis Emergentes/prevenção & controle , Surtos de Doenças , Comportamentos Relacionados com a Saúde , Animais , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/prevenção & controle , Epidemias/prevenção & controle , Previsões , Doença pelo Vírus Ebola/epidemiologia , Doença pelo Vírus Ebola/prevenção & controle , Humanos , Saúde Pública , Síndrome Respiratória Aguda Grave/epidemiologia , Síndrome Respiratória Aguda Grave/prevenção & controle , Zoonoses/epidemiologia , Zoonoses/prevenção & controle
3.
Public Health ; 195: 132-134, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34111802

RESUMO

OBJECTIVES: The aim of this study was to trace contacts of coronavirus disease 2019 (COVID-19) hospitalised patients and determine the risk factors of infection in urban areas. STUDY DESIGN: Longitudinal analysis of contacts identified from index cases. METHODS: A contact tracing study was carried out in the Northern Metropolitan area of Barcelona, Spain, during the inter-epidemic lapse of May to July 2020, a period of low SARS-CoV-2 incidence. Index cases were notified from the referral hospital. Contacts were traced and followed up for 14 days. Reverse transcription polymerase chain reaction was performed on day 0 and day 14 for contacts. RESULTS: In total, 368 contacts were identified from 81 index cases (median of seven contacts per index case), from which 308 were traced successfully. The median age of contacts was 28 years, 62% (223 of 368) were men. During the follow-up period, 100 contacts tested positive for COVID-19 (32.5% [95% confidence interval {CI} = 27.3-38.0]), with a secondary infection rate of 48.3% (95% CI = 40.8-55.9) among housemates. Clusters of index and respective contacts tended to aggregate within disadvantaged neighbourhoods (P < 0.001), and non-national index cases (N = 28, 34.1%) resulted in higher secondary infection rates compared with nationals (51.0% [95% CI = 41.0-60.9] vs 22.3% [95% CI = 16.8-28.8]; P < 0.001). CONCLUSIONS: Disadvantaged communities experience a disproportionate burden of COVID-19 and may act as infection reservoirs. Contact tracing with a cross-cutting approach among these communities is required, especially during inter-epidemic periods.


Assuntos
COVID-19/prevenção & controle , Busca de Comunicante , Epidemias/prevenção & controle , Determinantes Sociais da Saúde , Populações Vulneráveis , Adulto , COVID-19/epidemiologia , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Fatores de Risco , SARS-CoV-2 , Espanha/epidemiologia
4.
PLoS One ; 16(6): e0252217, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34138906

RESUMO

INTRODUCTION: There is an evidence gap regarding the duration of SARS-CoV-2 shedding and of its variability across different care settings and by age, sex, income, and co-morbidities. Such evidence is part of understanding of infectivity and reinfection. We examine direct measures of viral shedding using a linked population-based health administrative dataset. METHODS: Laboratory and sociodemographic databases for Ontario, Canada were linked to identify those testing positive (RT-PCR) between Jan. 15 and April 30, 2020 who underwent subsequent testing by May 31, 2020. To maximise use of available data, we computed two shedding duration estimates defined as the time between initial positive and most recent positive (documented shedding) or second of two negative tests (documented resolution). We also report multivariable results using quantile regression to examine subgroup differences. RESULTS: In Ontario, of the 16,595 who tested positive before April 30, 2020, 6604 had sufficient subsequent testing to allow shedding duration calculation. Documented shedding median duration calculated in 4,889 (29% of 16,595) patients was 19 days (IQR 12-28). Documented resolution median duration calculated in 3,219 (19% of the 16,595) patients was 25 days (IQR 18-34). Long-term care residents had 3-5 day longer shedding durations using both definitions. Shorter documented shedding durations of 2-4 days were observed in those living in higher income neighbourhoods. Shorter documented resolution durations of 2-3 days were observed at the 25th% of the distribution in those aged 20-49. Only 11.5% of those with definitive negative test results reverted to negative status by day 14. CONCLUSIONS: Viral shedding continued well beyond 14 days among this large subset of a population-based group with COVID-19, and longer still for long-term care residents and those living in less affluent neighborhoods. Our findings do not speak to duration of infectivity but are useful for understanding the expected duration of RT-PCR positivity and for identifying reinfection.


Assuntos
COVID-19/diagnóstico , SARS-CoV-2/genética , Eliminação de Partículas Virais/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , COVID-19/epidemiologia , COVID-19/virologia , Epidemias/prevenção & controle , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Ontário/epidemiologia , RNA Viral/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , SARS-CoV-2/fisiologia , Fatores de Tempo , Adulto Jovem
5.
PLoS One ; 16(6): e0252827, 2021.
Artigo em Inglês | MEDLINE | ID: covidwho-1256046

RESUMO

The novel coronavirus (SARS-CoV-2) has rapidly developed into a global epidemic. To control its spread, countries have implemented non-pharmaceutical interventions (NPIs), such as school closures, bans of small gatherings, or even stay-at-home orders. Here we study the effectiveness of seven NPIs in reducing the number of new infections, which was inferred from the reported cases of COVID-19 using a semi-mechanistic Bayesian hierarchical model. Based on data from the first epidemic wave of n = 20 countries (i.e., the United States, Canada, Australia, the EU-15 countries, Norway, and Switzerland), we estimate the relative reduction in the number of new infections attributed to each NPI. Among the NPIs considered, bans of large gatherings were most effective, followed by venue and school closures, whereas stay-at-home orders and work-from-home orders were least effective. With this retrospective cross-country analysis, we provide estimates regarding the effectiveness of different NPIs during the first epidemic wave.


Assuntos
COVID-19/prevenção & controle , Quarentena/métodos , Quarentena/tendências , Teorema de Bayes , Surtos de Doenças/prevenção & controle , Surtos de Doenças/estatística & dados numéricos , Epidemias/prevenção & controle , Epidemias/estatística & dados numéricos , Humanos , Distanciamento Físico , Estudos Retrospectivos , SARS-CoV-2/patogenicidade
6.
PLoS One ; 16(6): e0252570, 2021.
Artigo em Inglês | MEDLINE | ID: covidwho-1256042

RESUMO

INTRODUCTION: Many countries with weaker health systems are struggling to put together a coherent strategy against the COVID-19 epidemic. We explored COVID-19 control strategies that could offer the greatest benefit in resource limited settings. METHODS: Using an age-structured SEIR model, we explored the effects of COVID-19 control interventions-a lockdown, physical distancing measures, and active case finding (testing and isolation, contact tracing and quarantine)-implemented individually and in combination to control a hypothetical COVID-19 epidemic in Kathmandu (population 2.6 million), Nepal. RESULTS: A month-long lockdown will delay peak demand for hospital beds by 36 days, as compared to a base scenario of no intervention (peak demand at 108 days (IQR 97-119); a 2 month long lockdown will delay it by 74 days, without any difference in annual mortality, or healthcare demand volume. Year-long physical distancing measures will reduce peak demand to 36% (IQR 23%-46%) and annual morality to 67% (IQR 48%-77%) of base scenario. Following a month long lockdown with ongoing physical distancing measures and an active case finding intervention that detects 5% of the daily infection burden could reduce projected morality and peak demand by more than 99%. CONCLUSION: Limited resource settings are best served by a combination of early and aggressive case finding with ongoing physical distancing measures to control the COVID-19 epidemic. A lockdown may be helpful until combination interventions can be put in place but is unlikely to reduce annual mortality or healthcare demand.


Assuntos
COVID-19/prevenção & controle , Controle de Doenças Transmissíveis/métodos , Epidemias/prevenção & controle , Controle de Doenças Transmissíveis/tendências , Busca de Comunicante/métodos , Epidemias/estatística & dados numéricos , Humanos , Modelos Teóricos , Distanciamento Físico , Quarentena/métodos , SARS-CoV-2/patogenicidade
7.
PLoS One ; 16(6): e0252300, 2021.
Artigo em Inglês | MEDLINE | ID: covidwho-1256038

RESUMO

We collected COVID-19 epidemiological and epidemic control measures-related data in mainland China during the period January 1 to February 19, 2020, and empirically tested the practical effects of the epidemic control measures implemented in China by applying the econometrics approach. The results show that nationally, both traffic control and social distancing have played an important role in controlling the outbreak of the epidemic, however, neither of the two measures have had a significant effect in low-risk areas. Moreover, the effect of traffic control is more successful than that of social distancing. Both measures complement each other, and their combined effect achieves even better results. These findings confirm the effectiveness of the measures currently in place in China, however, we would like to emphasize that control measures should be more tailored, which implemented according to each specific city's situation, in order to achieve a better epidemic prevention and control.


Assuntos
COVID-19/prevenção & controle , Epidemias/prevenção & controle , Veículos Automotores/estatística & dados numéricos , COVID-19/transmissão , China/epidemiologia , Surtos de Doenças/prevenção & controle , Surtos de Doenças/estatística & dados numéricos , Humanos , Distanciamento Físico , SARS-CoV-2/patogenicidade
8.
PLoS One ; 16(6): e0252827, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34077448

RESUMO

The novel coronavirus (SARS-CoV-2) has rapidly developed into a global epidemic. To control its spread, countries have implemented non-pharmaceutical interventions (NPIs), such as school closures, bans of small gatherings, or even stay-at-home orders. Here we study the effectiveness of seven NPIs in reducing the number of new infections, which was inferred from the reported cases of COVID-19 using a semi-mechanistic Bayesian hierarchical model. Based on data from the first epidemic wave of n = 20 countries (i.e., the United States, Canada, Australia, the EU-15 countries, Norway, and Switzerland), we estimate the relative reduction in the number of new infections attributed to each NPI. Among the NPIs considered, bans of large gatherings were most effective, followed by venue and school closures, whereas stay-at-home orders and work-from-home orders were least effective. With this retrospective cross-country analysis, we provide estimates regarding the effectiveness of different NPIs during the first epidemic wave.


Assuntos
COVID-19/prevenção & controle , Quarentena/métodos , Quarentena/tendências , Teorema de Bayes , Surtos de Doenças/prevenção & controle , Surtos de Doenças/estatística & dados numéricos , Epidemias/prevenção & controle , Epidemias/estatística & dados numéricos , Humanos , Distanciamento Físico , Estudos Retrospectivos , SARS-CoV-2/patogenicidade
9.
PLoS One ; 16(6): e0252570, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34077483

RESUMO

INTRODUCTION: Many countries with weaker health systems are struggling to put together a coherent strategy against the COVID-19 epidemic. We explored COVID-19 control strategies that could offer the greatest benefit in resource limited settings. METHODS: Using an age-structured SEIR model, we explored the effects of COVID-19 control interventions-a lockdown, physical distancing measures, and active case finding (testing and isolation, contact tracing and quarantine)-implemented individually and in combination to control a hypothetical COVID-19 epidemic in Kathmandu (population 2.6 million), Nepal. RESULTS: A month-long lockdown will delay peak demand for hospital beds by 36 days, as compared to a base scenario of no intervention (peak demand at 108 days (IQR 97-119); a 2 month long lockdown will delay it by 74 days, without any difference in annual mortality, or healthcare demand volume. Year-long physical distancing measures will reduce peak demand to 36% (IQR 23%-46%) and annual morality to 67% (IQR 48%-77%) of base scenario. Following a month long lockdown with ongoing physical distancing measures and an active case finding intervention that detects 5% of the daily infection burden could reduce projected morality and peak demand by more than 99%. CONCLUSION: Limited resource settings are best served by a combination of early and aggressive case finding with ongoing physical distancing measures to control the COVID-19 epidemic. A lockdown may be helpful until combination interventions can be put in place but is unlikely to reduce annual mortality or healthcare demand.


Assuntos
COVID-19/prevenção & controle , Controle de Doenças Transmissíveis/métodos , Epidemias/prevenção & controle , Controle de Doenças Transmissíveis/tendências , Busca de Comunicante/métodos , Epidemias/estatística & dados numéricos , Humanos , Modelos Teóricos , Distanciamento Físico , Quarentena/métodos , SARS-CoV-2/patogenicidade
10.
PLoS One ; 16(6): e0252300, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34077487

RESUMO

We collected COVID-19 epidemiological and epidemic control measures-related data in mainland China during the period January 1 to February 19, 2020, and empirically tested the practical effects of the epidemic control measures implemented in China by applying the econometrics approach. The results show that nationally, both traffic control and social distancing have played an important role in controlling the outbreak of the epidemic, however, neither of the two measures have had a significant effect in low-risk areas. Moreover, the effect of traffic control is more successful than that of social distancing. Both measures complement each other, and their combined effect achieves even better results. These findings confirm the effectiveness of the measures currently in place in China, however, we would like to emphasize that control measures should be more tailored, which implemented according to each specific city's situation, in order to achieve a better epidemic prevention and control.


Assuntos
COVID-19/prevenção & controle , Epidemias/prevenção & controle , Veículos Automotores/estatística & dados numéricos , COVID-19/transmissão , China/epidemiologia , Surtos de Doenças/prevenção & controle , Surtos de Doenças/estatística & dados numéricos , Humanos , Distanciamento Físico , SARS-CoV-2/patogenicidade
11.
J Res Health Sci ; 21(1): e00505, 2021 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-34024763

RESUMO

BACKGROUND: Since the beginning of the coronavirus disease 2019 (COVID-19) epidemic in Iran, the control and management of the epidemic were headed by the National Headquarter for the Control of COVID-19 Epidemic through setting up different scientific committees, including the COVID-19 National Epidemiology Committee. The present study reviews the missions, structures, achievements, and challenges of the Epidemiology Committee. STUDY DESIGN: A rapid review . METHODS: All relevant reports, documents, guidelines, published literature, and surveillance data related to the establishment, visions, missions, roles, activities, and outputs of the COVID-19 Epidemiology Committee were critically reviewed in this study. RESULTS: The efforts of the committee's working groups may have impacted improvements in data registration/usage, provincial data quality at provincial levels, and perception of the epidemic situation in the provinces. The committees have also played role in informing the policies in different stages of the epidemic through routine or problem-based data/evidence analyses, epidemic investigations, and mathematical modeling. CONCLUSION: The structure and experience gained by the committee can be used in similar situations within and outside the country. To further improve the impacts of our activities, it is essential to have effective interaction, collaboration, and data flow between the committee and a broad range of organizations within and outside the Ministry of Health and Medical Education.


Assuntos
COVID-19/epidemiologia , Epidemias/prevenção & controle , Epidemias/estatística & dados numéricos , Objetivos Organizacionais , Medicina Preventiva/organização & administração , Medicina Preventiva/estatística & dados numéricos , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Irã (Geográfico)/epidemiologia , Masculino , Pessoa de Meia-Idade
13.
Nat Commun ; 12(1): 2586, 2021 05 10.
Artigo em Inglês | MEDLINE | ID: covidwho-1253934

RESUMO

High impact epidemics constitute one of the largest threats humanity is facing in the 21st century. In the absence of pharmaceutical interventions, physical distancing together with testing, contact tracing and quarantining are crucial in slowing down epidemic dynamics. Yet, here we show that if testing capacities are limited, containment may fail dramatically because such combined countermeasures drastically change the rules of the epidemic transition: Instead of continuous, the response to countermeasures becomes discontinuous. Rather than following the conventional exponential growth, the outbreak that is initially strongly suppressed eventually accelerates and scales faster than exponential during an explosive growth period. As a consequence, containment measures either suffice to stop the outbreak at low total case numbers or fail catastrophically if marginally too weak, thus implying large uncertainties in reliably estimating overall epidemic dynamics, both during initial phases and during second wave scenarios.


Assuntos
Teste para COVID-19/estatística & dados numéricos , COVID-19/epidemiologia , COVID-19/prevenção & controle , Surtos de Doenças/estatística & dados numéricos , Epidemias/prevenção & controle , COVID-19/diagnóstico , Busca de Comunicante/estatística & dados numéricos , Surtos de Doenças/prevenção & controle , Epidemias/estatística & dados numéricos , Humanos , Itália/epidemiologia , Modelos Estatísticos , Modelos Teóricos , Distanciamento Físico , Quarentena , Isolamento Social
15.
Mil Med Res ; 8(1): 31, 2021 05 18.
Artigo em Inglês | MEDLINE | ID: covidwho-1232443

RESUMO

In response to an outbreak of coronavirus disease 2019 (COVID-19) within a cluster of Navy personnel in Sri Lanka commencing from 22nd April 2020, an aggressive outbreak management program was launched by the Epidemiology Unit of the Ministry of Health. To predict the possible number of cases within the susceptible population under four social distancing scenarios, the COVID-19 Hospital Impact Model for Epidemics (CHIME) was used. With increasing social distancing, the epidemiological curve flattened, and its peak shifted to the right. The observed or actually reported number of cases was above the projected number of cases at the onset; however, subsequently, it fell below all predicted trends. Predictive modelling is a useful tool for the control of outbreaks such as COVID-19 in a closed community.


Assuntos
COVID-19/prevenção & controle , Militares , Modelos Estatísticos , COVID-19/transmissão , Controle de Doenças Transmissíveis/métodos , Controle de Doenças Transmissíveis/estatística & dados numéricos , Biologia Computacional , Epidemias/prevenção & controle , Humanos , SARS-CoV-2 , Sri Lanka
16.
J Res Health Sci ; 21(1): e00505, 2021 Mar 07.
Artigo em Inglês | MEDLINE | ID: covidwho-1158971

RESUMO

BACKGROUND: Since the beginning of the coronavirus disease 2019 (COVID-19) epidemic in Iran, the control and management of the epidemic were headed by the National Headquarter for the Control of COVID-19 Epidemic through setting up different scientific committees, including the COVID-19 National Epidemiology Committee. The present study reviews the missions, structures, achievements, and challenges of the Epidemiology Committee. STUDY DESIGN: A rapid review . METHODS: All relevant reports, documents, guidelines, published literature, and surveillance data related to the establishment, visions, missions, roles, activities, and outputs of the COVID-19 Epidemiology Committee were critically reviewed in this study. RESULTS: The efforts of the committee's working groups may have impacted improvements in data registration/usage, provincial data quality at provincial levels, and perception of the epidemic situation in the provinces. The committees have also played role in informing the policies in different stages of the epidemic through routine or problem-based data/evidence analyses, epidemic investigations, and mathematical modeling. CONCLUSION: The structure and experience gained by the committee can be used in similar situations within and outside the country. To further improve the impacts of our activities, it is essential to have effective interaction, collaboration, and data flow between the committee and a broad range of organizations within and outside the Ministry of Health and Medical Education.


Assuntos
COVID-19/epidemiologia , Epidemias/prevenção & controle , Epidemias/estatística & dados numéricos , Objetivos Organizacionais , Medicina Preventiva/organização & administração , Medicina Preventiva/estatística & dados numéricos , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Irã (Geográfico)/epidemiologia , Masculino , Pessoa de Meia-Idade
17.
Nat Commun ; 12(1): 2586, 2021 05 10.
Artigo em Inglês | MEDLINE | ID: mdl-33972522

RESUMO

High impact epidemics constitute one of the largest threats humanity is facing in the 21st century. In the absence of pharmaceutical interventions, physical distancing together with testing, contact tracing and quarantining are crucial in slowing down epidemic dynamics. Yet, here we show that if testing capacities are limited, containment may fail dramatically because such combined countermeasures drastically change the rules of the epidemic transition: Instead of continuous, the response to countermeasures becomes discontinuous. Rather than following the conventional exponential growth, the outbreak that is initially strongly suppressed eventually accelerates and scales faster than exponential during an explosive growth period. As a consequence, containment measures either suffice to stop the outbreak at low total case numbers or fail catastrophically if marginally too weak, thus implying large uncertainties in reliably estimating overall epidemic dynamics, both during initial phases and during second wave scenarios.


Assuntos
Teste para COVID-19/estatística & dados numéricos , COVID-19/epidemiologia , COVID-19/prevenção & controle , Surtos de Doenças/estatística & dados numéricos , Epidemias/prevenção & controle , COVID-19/diagnóstico , Busca de Comunicante/estatística & dados numéricos , Surtos de Doenças/prevenção & controle , Epidemias/estatística & dados numéricos , Humanos , Itália/epidemiologia , Modelos Estatísticos , Modelos Teóricos , Distanciamento Físico , Quarentena , Isolamento Social
18.
Mil Med Res ; 8(1): 31, 2021 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-34001251

RESUMO

In response to an outbreak of coronavirus disease 2019 (COVID-19) within a cluster of Navy personnel in Sri Lanka commencing from 22nd April 2020, an aggressive outbreak management program was launched by the Epidemiology Unit of the Ministry of Health. To predict the possible number of cases within the susceptible population under four social distancing scenarios, the COVID-19 Hospital Impact Model for Epidemics (CHIME) was used. With increasing social distancing, the epidemiological curve flattened, and its peak shifted to the right. The observed or actually reported number of cases was above the projected number of cases at the onset; however, subsequently, it fell below all predicted trends. Predictive modelling is a useful tool for the control of outbreaks such as COVID-19 in a closed community.


Assuntos
COVID-19/prevenção & controle , Militares , Modelos Estatísticos , COVID-19/transmissão , Controle de Doenças Transmissíveis/métodos , Controle de Doenças Transmissíveis/estatística & dados numéricos , Biologia Computacional , Epidemias/prevenção & controle , Humanos , SARS-CoV-2 , Sri Lanka
19.
Nat Commun ; 12(1): 2991, 2021 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-34016992

RESUMO

Influenza forecasting in the United States (US) is complex and challenging due to spatial and temporal variability, nested geographic scales of interest, and heterogeneous surveillance participation. Here we present Dante, a multiscale influenza forecasting model that learns rather than prescribes spatial, temporal, and surveillance data structure and generates coherent forecasts across state, regional, and national scales. We retrospectively compare Dante's short-term and seasonal forecasts for previous flu seasons to the Dynamic Bayesian Model (DBM), a leading competitor. Dante outperformed DBM for nearly all spatial units, flu seasons, geographic scales, and forecasting targets. Dante's sharper and more accurate forecasts also suggest greater public health utility. Dante placed 1st in the Centers for Disease Control and Prevention's prospective 2018/19 FluSight challenge in both the national and regional competition and the state competition. The methodology underpinning Dante can be used in other seasonal disease forecasting contexts having nested geographic scales of interest.


Assuntos
Epidemias/prevenção & controle , Monitoramento Epidemiológico , Previsões/métodos , Influenza Humana/epidemiologia , Modelos Estatísticos , Teorema de Bayes , Epidemias/estatística & dados numéricos , Geografia , Humanos , Estudos Retrospectivos , Estações do Ano , Análise Espaço-Temporal , Estados Unidos/epidemiologia
20.
Nat Commun ; 12(1): 2619, 2021 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-33976183

RESUMO

After the Zika virus (ZIKV) epidemic in the Americas in 2016, both Zika and dengue incidence declined to record lows in many countries in 2017-2018, but in 2019 dengue resurged in Brazil, causing ~2.1 million cases. In this study we use epidemiological, climatological and genomic data to investigate dengue dynamics in recent years in Brazil. First, we estimate dengue virus force of infection (FOI) and model mosquito-borne transmission suitability since the early 2000s. Our estimates reveal that DENV transmission was low in 2017-2018, despite conditions being suitable for viral spread. Our study also shows a marked decline in dengue susceptibility between 2002 and 2019, which could explain the synchronous decline of dengue in the country, partially as a result of protective immunity from prior ZIKV and/or DENV infections. Furthermore, we performed phylogeographic analyses using 69 newly sequenced genomes of dengue virus serotype 1 and 2 from Brazil, and found that the outbreaks in 2018-2019 were caused by local DENV lineages that persisted for 5-10 years, circulating cryptically before and after the Zika epidemic. We hypothesize that DENV lineages may circulate at low transmission levels for many years, until local conditions are suitable for higher transmission, when they cause major outbreaks.


Assuntos
Vírus da Dengue/imunologia , Dengue/epidemiologia , Suscetibilidade a Doenças/imunologia , Epidemias/estatística & dados numéricos , Infecção por Zika virus/imunologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Antivirais/imunologia , Brasil/epidemiologia , Criança , Pré-Escolar , Dengue/imunologia , Dengue/transmissão , Dengue/virologia , Vírus da Dengue/genética , Vírus da Dengue/isolamento & purificação , Epidemias/prevenção & controle , Monitoramento Epidemiológico , Feminino , Genoma Viral/genética , Humanos , Imunidade Heteróloga , Incidência , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Tipagem Molecular , Mosquitos Vetores/virologia , Filogeografia , Sorotipagem , Adulto Jovem , Zika virus/imunologia , Infecção por Zika virus/epidemiologia
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