RESUMEN
System Dynamics (SD) models have been used to understand complex, multi-faceted dengue transmission dynamics, but a gap persists between research and actionable public health tools for decision-making. Spain is an at-risk country of imported dengue outbreaks, but only qualitative assessments are available to guide public health action and control. We propose a modular SD model combining temperature-dependent vector population, transmission parameters, and epidemiological interactions to simulate outbreaks from imported cases accounting for heterogeneous local climate-related transmission patterns. Under our assumptions, 15 provinces sustain vector populations capable of generating outbreaks from imported cases, with heterogeneous risk profiles regarding seasonality, magnitude and risk window shifting from late Spring to early Autum. Results being relative to given vector-to-human populations allow flexibility when translating outcomes between geographic scales. The model and the framework are meant to serve public health by incorporating transmission dynamics and quantitative-qualitative input to the evidence-based decision-making chain. It is a flexible tool that can easily adapt to changing contexts, parametrizations and epidemiological settings thanks to the modular approach.
Asunto(s)
Dengue , Brotes de Enfermedades , Dengue/epidemiología , Dengue/transmisión , Humanos , España/epidemiología , Animales , Monitoreo Epidemiológico , Medición de Riesgo/métodos , Enfermedades Transmisibles Importadas/epidemiología , Enfermedades Transmisibles Importadas/transmisión , Enfermedades Transmisibles Importadas/virología , Estaciones del Año , Aedes/virología , Análisis de Sistemas , Mosquitos Vectores/virologíaRESUMEN
Dengue fever is a viral illness, mainly transmitted by Aedes aegypti and Aedes albopictus. With climate change and urbanisation, more urbanised areas are becoming suitable for the survival and reproduction of dengue vector, consequently are becoming suitable for dengue transmission in China. Chongqing, a metropolis in southwestern China, has recently been hit by imported and local dengue fever, experiencing its first local outbreak in 2019. However, the genetic evolution dynamics of dengue viruses and the spatiotemporal patterns of imported and local dengue cases have not yet been elucidated. Hence, this study implemented phylogenetic analyses using genomic data of dengue viruses in 2019 and 2023 and a spatiotemporal analysis of dengue cases collected from 2013 to 2022. We sequenced a total of 15 nucleotide sequences of E genes. The dengue viruses formed separate clusters and were genetically related to those from Guangdong Province, China, and countries in Southeast Asia, including Laos, Thailand, Myanmar and Cambodia. Chongqing experienced a dengue outbreak in 2019 when 168 imported and 1,243 local cases were reported, mainly in September and October. Few cases were reported in 2013-2018, and only six were imported from 2020 to 2022 due to the COVID-19 lockdowns. Our findings suggest that dengue prevention in Chongqing should focus on domestic and overseas population mobility, especially in the Yubei and Wanzhou districts, where airports and railway stations are located, and the period between August and October when dengue outbreaks occur in endemic regions. Moreover, continuous vector monitoring should be implemented, especially during August-October, which would be useful for controlling the Aedes mosquitoes. This study is significant for defining Chongqing's appropriate dengue prevention and control strategies.
Asunto(s)
Virus del Dengue , Dengue , Filogenia , Análisis Espacio-Temporal , Dengue/epidemiología , Dengue/transmisión , Dengue/virología , China/epidemiología , Virus del Dengue/genética , Virus del Dengue/clasificación , Humanos , Brotes de Enfermedades , Animales , Aedes/virología , Enfermedades Transmisibles Importadas/epidemiología , Enfermedades Transmisibles Importadas/virología , Enfermedades Transmisibles Importadas/transmisión , Mosquitos Vectores/virología , Ciudades/epidemiologíaRESUMEN
OBJECTIVE: To estimate the numbers of COVID-19-related hospitalisations in Australia after re-opening the international border. DESIGN: Population-level deterministic compartmental epidemic modelling of eight scenarios applying various assumptions regarding SARS-CoV-2 transmissibility (baseline R0 = 3.5 or 7.0), vaccine rollout speed (slow or fast), and scale of border re-opening (mean of 2500 or 13 000 overseas arrivals per day). SETTING: Simulation population size, age structure, and age-based contact rates based on recent estimates for the Australian population. We assumed that 80% vaccination coverage of people aged 16 years or more was reached in mid-October 2021 (fast rollout) or early January 2022 (slow rollout). MAIN OUTCOME MEASURES: Numbers of people admitted to hospital with COVID-19, December 2021 - December 2022. RESULTS: In scenarios assuming a highly transmissible SARS-CoV-2 variant (R0 = 7.0), opening the international border on either scale was followed by surges in both infections and hospitalisations that would require public health measures beyond mask wearing and social distancing to avoid overwhelming the health system. Reducing the number of hospitalisations to manageable levels required several cycles of additional social and mobility restrictions. CONCLUSIONS: If highly transmissible SARS-CoV-2 variants are circulating locally or overseas, large and disruptive COVID-19 outbreaks will still be possible in Australia after 80% of people aged 16 years or more have been vaccinated. Continuing public health measures to restrict the spread of disease are likely to be necessary throughout 2022.
Asunto(s)
COVID-19/epidemiología , Control de Enfermedades Transmisibles/estadística & datos numéricos , Enfermedades Transmisibles Importadas/epidemiología , Brotes de Enfermedades , Hospitalización/estadística & datos numéricos , Adolescente , Adulto , Anciano , Australia/epidemiología , COVID-19/prevención & control , COVID-19/virología , Control de Enfermedades Transmisibles/métodos , Enfermedades Transmisibles Importadas/virología , Simulación por Computador , Femenino , Humanos , Masculino , Persona de Mediana Edad , SARS-CoV-2 , Cobertura de Vacunación/estadística & datos numéricos , Adulto JovenRESUMEN
The Democratic Republic of the Congo (DRC) declared an Ebola virus disease (EVD) outbreak in North Kivu in August 2018. By June 2019, the outbreak had spread to 26 health zones in northeastern DRC, causing >2,000 reported cases and >1,000 deaths. On June 10, 2019, three members of a Congolese family with EVD-like symptoms traveled to western Uganda's Kasese District to seek medical care. Shortly thereafter, the Viral Hemorrhagic Fever Surveillance and Laboratory Program (VHF program) at the Uganda Virus Research Institute (UVRI) confirmed that all three patients had EVD. The Ugandan Ministry of Health declared an outbreak of EVD in Uganda's Kasese District, notified the World Health Organization, and initiated a rapid response to contain the outbreak. As part of this response, UVRI and the United States Centers for Disease Control and Prevention, with the support of Uganda's Public Health Emergency Operations Center, the Kasese District Health Team, the Superintendent of Bwera General Hospital, the United States Department of Defense's Makerere University Walter Reed Project, and the United States Mission to Kampala's Global Health Security Technical Working Group, jointly established an Ebola Field Laboratory in Kasese District at Bwera General Hospital, proximal to an Ebola Treatment Unit (ETU). The laboratory consisted of a rapid containment kit for viral inactivation of patient specimens and a GeneXpert Instrument for performing Xpert Ebola assays. Laboratory staff tested 76 specimens from alert and suspect cases of EVD; the majority were admitted to the ETU (89.3%) and reported recent travel to the DRC (58.9%). Although no EVD cases were detected by the field laboratory, it played an important role in patient management and epidemiological surveillance by providing diagnostic results in <3 hours. The integration of the field laboratory into Uganda's National VHF Program also enabled patient specimens to be referred to Entebbe for confirmatory EBOV testing and testing for other hemorrhagic fever viruses that circulate in Uganda.
Asunto(s)
Academias e Institutos/organización & administración , Enfermedades Transmisibles Importadas/prevención & control , Enfermedades Transmisibles Importadas/virología , Brotes de Enfermedades/estadística & datos numéricos , Fiebre Hemorrágica Ebola/epidemiología , Fiebre Hemorrágica Ebola/prevención & control , Laboratorios/organización & administración , Laboratorios/normas , Bioensayo , Niño , Preescolar , Enfermedades Transmisibles Importadas/epidemiología , Brotes de Enfermedades/prevención & control , Femenino , Fiebre Hemorrágica Ebola/transmisión , Humanos , Laboratorios/provisión & distribución , Masculino , Persona de Mediana Edad , Viaje , Uganda/epidemiología , Estados Unidos , Universidades , Organización Mundial de la SaludRESUMEN
The appearance of new variants of SARS-CoV-2 has recently challenged public health authorities with respect to tracking transmission and mitigating the impact in the evolving pandemic across countries. B.1.525 is considered a variant under investigation since it carries specific genetic signatures present in P.1, B.1.1.7, and B.1.351. Here we report genomic evidence of the first likely imported case of the SARS-CoV-2 B.1.525 variant, isolated in a traveler returning from Nigeria.
Asunto(s)
COVID-19/virología , Enfermedades Transmisibles Importadas/virología , SARS-CoV-2/genética , SARS-CoV-2/aislamiento & purificación , Anciano , Brasil/epidemiología , COVID-19/diagnóstico , COVID-19/epidemiología , Enfermedades Transmisibles Importadas/diagnóstico , Enfermedades Transmisibles Importadas/epidemiología , Femenino , Genoma Viral/genética , Humanos , Mutación , Nigeria/epidemiología , Enfermedad Relacionada con los ViajesRESUMEN
Despite the high number of coronavirus disease-19 (COVID-19) cases from India, there are few reports from India describing the clinical epidemiology of COVID-19. This study aimed to describe the clinical/epidemiological characteristics and outcomes of asymptomatic vs. symptomatic COVID-19 patients. This was a retrospective chart review of all admitted patients with COVID-19 above 18 years with a history of travel within one month of the admission. The patients were categorized into asymptomatic and symptomatic. The symptomatic patients were further classified into mild, moderate and severe. The demographic profile, risk factors, clinical features, laboratory parameters, treatment details and outcome of all patients were recorded. The clinical and laboratory parameters were compared between symptomatic patients and asymptomatic patients. Of the 127 recruited patients, 75 were asymptomatic. Of the 52 symptomatic patients, 41 patients were classified as a mild illness. The mean age of the patients was 44.5 ± 15 years. A total of 73 patients had one or more risk factors. The male patients were more commonly found to be symptomatic compared to female patients. Neutrophil-lymphocyte ratio, C-reactive protein and lactate dehydrogenase were significantly elevated in symptomatic patients. A total of five individuals required supplemental oxygen therapy, and one of them required mechanical ventilation. All the patients had favourable outcomes. Asymptomatic and mild illness form a significant proportion of positive patients and have excellent outcomes without therapeutic interventions.
Asunto(s)
Infecciones Asintomáticas/epidemiología , COVID-19/epidemiología , COVID-19/terapia , Enfermedades Transmisibles Importadas/epidemiología , Enfermedades Transmisibles Importadas/terapia , Adulto , Proteína C-Reactiva/metabolismo , COVID-19/sangre , Enfermedades Transmisibles Importadas/sangre , Enfermedades Transmisibles Importadas/virología , Femenino , Hospitalización/estadística & datos numéricos , Humanos , India/epidemiología , L-Lactato Deshidrogenasa/sangre , Recuento de Linfocitos , Masculino , Persona de Mediana Edad , Neutrófilos/metabolismo , Terapia por Inhalación de Oxígeno , Pronóstico , Respiración Artificial , Estudios Retrospectivos , Enfermedad Relacionada con los Viajes , Adulto JovenRESUMEN
ABSTRACT: Wenzhou had the highest number of confirmed novel coronavirus 2019 (COVID-19) cases outside the Hubei province. The aim of this study was to identify the difference in clinical features and viral RNA shedding between the imported and local COVID-19 cases in Wenzhou.All patients with confirmed COVID-19 admitted to Wenzhou Sixth People's Hospital, Wenzhou Central Hospital Medical Group, from January 17 to February 11, 2020, were enrolled in this study. Data was analyzed and compared for the imported and local cases with regard to epidemiological, demographic, clinical, radiological features, and laboratory findings. Outcomes for the enrolled participants were followed up until May 7, 2020.Of the 136 cases, 50 were imported from Wuhan. The median age was 45âyears and 73 (53.7%) were men. The most common symptoms at onset were fever (104 [76.5%]) and cough (85[62.5%]). Pleural effusion was more common among imported cases compared to local cases. The white blood cell count, neutrophil count, lymphocyte count and platelet count of the imported cases were significantly lower than those of the local cases, while the prothrombin time was significantly longer than that of the local cases. Severe and critically ill patients accounted for 15.4% and 2.9%, respectively. The median duration of SARS-CoV-2 RNA shedding from symptom onset was 26âdays (IQR 17-32.3âdays) and there were no significant differences in duration of viral RNA shedding between the two groups.The study findings suggest that imported cases from Wuhan were more likely to be severe compared to the local cases in Wenzhou. However, there was no difference between imported and local cases on the viral shedding among the COVID patients.
Asunto(s)
COVID-19/virología , ARN Viral , SARS-CoV-2 , Esparcimiento de Virus , Adolescente , Adulto , Anciano , COVID-19/diagnóstico , COVID-19/epidemiología , Niño , Preescolar , China/epidemiología , Enfermedades Transmisibles Importadas/epidemiología , Enfermedades Transmisibles Importadas/virología , Tos/virología , Enfermedad Crítica , Femenino , Fiebre/virología , Humanos , Hipertensión/epidemiología , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Adulto JovenAsunto(s)
COVID-19/virología , SARS-CoV-2/genética , COVID-19/transmisión , Enfermedades Transmisibles Importadas/transmisión , Enfermedades Transmisibles Importadas/virología , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , India , Mutación , Salud Pública , SARS-CoV-2/aislamiento & purificación , Sudáfrica , TanzaníaRESUMEN
Dengue fever should be included in the differential diagnosis of febrile illness even if another infection such as COVID-19 has been found in returning travellers from tropical and sub-tropical area where dengue virus circulates epidemically. We describe a 40-year-old man diagnosed with laboratory-confirmed COVID-19 and dengue fever during the COVID-19 outbreak in Milan, Italy.
Asunto(s)
COVID-19/diagnóstico , Coinfección/diagnóstico , Dengue/diagnóstico , Anamnesis , SARS-CoV-2 , Adulto , Coinfección/virología , Enfermedades Transmisibles Importadas/diagnóstico , Enfermedades Transmisibles Importadas/virología , Virus del Dengue , Diagnóstico Diferencial , Humanos , Masculino , ViajeRESUMEN
Low pathogenic avian influenza (LPAI) caused by H5 and H7 viruses is considered a threatening disease for poultry production due to the possibility of prolonged undetected virus circulation in a poultry flock and its potential to mutate to highly pathogenic avian influenza (HPAI). The occurrence of HPAI may have devastating impact on the poultry industry and has serious economic consequences. The possibility of LPAI virus (LPAIV) being introduced into Poland via import of live poultry from EU countries was considered. The main aim of the study was to quantitatively assess the probability of LPAIV H5 and H7 introduction into Poland (PLPAI) via this pathway, to evaluate the relative contribution of exporting countries and species of poultry to this probability and to present the spatial distribution of the introduction probability in Poland. To this end, a stochastic multilevel binomial risk model, taking into account uncertainty and variability of input parameter values, was developed. The results of this model indicate that the mean annual probability of LPAIV H5 or H7 introduction into Poland is 0.088 [95 % uncertainty interval: 0.0575, 0.128], which corresponds to, on average, one outbreak every 11 years. The countries contributing most to this probability are Germany, Czech Republic and Denmark. Importations of ducks, chickens and turkeys contribute most to PLPAI, whereas importations of geese and guinea fowl represent a minor risk. The probability of LPAIV introduction is not equally distributed across Poland with the majority of counties having a high probability of LPAIV introduction being located in the Western part of the country. The results of this study can be used to support decision makers on targeted prevention or risk-based surveillance strategies for LPAI.
Asunto(s)
Enfermedades Transmisibles Importadas/veterinaria , Gripe Aviar , Enfermedades de las Aves de Corral , Animales , Pollos , Comercio , Enfermedades Transmisibles Importadas/virología , Gripe Aviar/epidemiología , Polonia/epidemiología , Aves de Corral , Enfermedades de las Aves de Corral/epidemiología , Medición de RiesgoAsunto(s)
COVID-19/virología , Enfermedades Transmisibles Importadas/virología , SARS-CoV-2/genética , COVID-19/diagnóstico , COVID-19/epidemiología , Enfermedades Transmisibles Importadas/diagnóstico , Enfermedades Transmisibles Importadas/epidemiología , Genes Virales/genética , Humanos , Mutación , Pakistán/epidemiología , Filogenia , SARS-CoV-2/clasificación , SARS-CoV-2/aislamiento & purificaciónRESUMEN
We report an imported case of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant P.1 detected in an asymptomatic traveler who arrived in Italy on an indirect flight from Brazil. This case shows the risk for introduction of SARS-CoV-2 variants from indirect flights and the need for continued SARS-CoV-2 surveillance.
Asunto(s)
COVID-19 , Enfermedades Transmisibles Importadas , Programas de Detección Diagnóstica , SARS-CoV-2 , Glicoproteína de la Espiga del Coronavirus/genética , Adulto , Brasil/epidemiología , COVID-19/diagnóstico , COVID-19/epidemiología , COVID-19/inmunología , COVID-19/virología , Prueba Serológica para COVID-19/métodos , Portador Sano/diagnóstico , Portador Sano/epidemiología , Enfermedades Transmisibles Importadas/diagnóstico , Enfermedades Transmisibles Importadas/epidemiología , Enfermedades Transmisibles Importadas/virología , Programas de Detección Diagnóstica/organización & administración , Programas de Detección Diagnóstica/normas , Humanos , Italia/epidemiología , Masculino , Mutación , SARS-CoV-2/genética , SARS-CoV-2/aislamiento & purificación , Viaje/estadística & datos numéricos , Enfermedad Relacionada con los ViajesRESUMEN
Multiple severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants with higher transmission potential have been emerging globally, including SARS-CoV-2 variants from the United Kingdom and South Africa. We report 4 travelers from Brazil to Japan in January 2021 infected with a novel SARS-CoV-2 variant with an additional set of mutations.
Asunto(s)
Tratamiento Farmacológico de COVID-19 , Enfermedades Transmisibles Importadas , SARS-CoV-2 , Adulto , Número Básico de Reproducción , Brasil/epidemiología , COVID-19/epidemiología , COVID-19/terapia , COVID-19/transmisión , COVID-19/virología , Enfermedades Transmisibles Importadas/epidemiología , Enfermedades Transmisibles Importadas/fisiopatología , Enfermedades Transmisibles Importadas/terapia , Enfermedades Transmisibles Importadas/virología , Hospitalización , Humanos , Japón/epidemiología , Masculino , Mutación , Cuarentena/métodos , SARS-CoV-2/genética , SARS-CoV-2/aislamiento & purificación , Evaluación de Síntomas/métodos , Enfermedad Relacionada con los Viajes , Resultado del TratamientoAsunto(s)
COVID-19/virología , Enfermedades Transmisibles Importadas/virología , SARS-CoV-2/genética , Adulto , COVID-19/diagnóstico , Enfermedades Transmisibles Importadas/diagnóstico , Femenino , Genoma Viral/genética , Humanos , Masculino , Mutación , Filogenia , SARS-CoV-2/clasificación , SARS-CoV-2/aislamiento & purificación , Vietnam/epidemiologíaRESUMEN
The United Kingdom's COVID-19 epidemic during early 2020 was one of world's largest and was unusually well represented by virus genomic sampling. We determined the fine-scale genetic lineage structure of this epidemic through analysis of 50,887 severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) genomes, including 26,181 from the UK sampled throughout the country's first wave of infection. Using large-scale phylogenetic analyses combined with epidemiological and travel data, we quantified the size, spatiotemporal origins, and persistence of genetically distinct UK transmission lineages. Rapid fluctuations in virus importation rates resulted in >1000 lineages; those introduced prior to national lockdown tended to be larger and more dispersed. Lineage importation and regional lineage diversity declined after lockdown, whereas lineage elimination was size-dependent. We discuss the implications of our genetic perspective on transmission dynamics for COVID-19 epidemiology and control.
Asunto(s)
COVID-19/epidemiología , COVID-19/virología , Genoma Viral , SARS-CoV-2/genética , COVID-19/prevención & control , COVID-19/transmisión , Cadena de Infección , Control de Enfermedades Transmisibles , Enfermedades Transmisibles Importadas/epidemiología , Enfermedades Transmisibles Importadas/virología , Epidemias , Humanos , Filogenia , Viaje , Reino Unido/epidemiologíaRESUMEN
As with many countries around the world, Thailand is currently experiencing restrictions to daily life as a consequence of the worldwide transmission of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). SARS-CoV-2 is the third respiratory syndrome coronavirus to be introduced into Thailand, following previous importation of cases of the severe acute respiratory syndrome coronavirus (SARS) and the Middle East respiratory syndrome coronavirus (MERS). Unlike SARS and MERS, SARS-CoV-2 was able to establish local transmission in Thailand. In addition to the imported coronaviruses, Thailand has a number of endemic coronaviruses that can affect livestock and pet species, can be found in bats, as well as four human coronaviruses that are mostly associated with the common cold. This article seeks to review what is known on both the endemic and imported coronaviruses in Thailand.
Asunto(s)
Infecciones por Coronavirus , Animales , Enfermedades Transmisibles Importadas/virología , Infecciones por Coronavirus/epidemiología , Infecciones por Coronavirus/virología , Enfermedades Endémicas , Humanos , Tailandia/epidemiologíaRESUMEN
As the COVID-19 pandemic continues, there is growing concordance and persisting conflicts on the virus and the disease process. We discuss limited transmissibility of the virus by asymptomatic and mild cases of COVID-19 patients in Bhutan. We followed up the secondary transmission of SARS-CoV-2 in the contacts of asymptomatic and mild COVID-19 patients in Bhutan. Bhutan had 33 confirmed COVID-19 cases in the country as of May 29, 2020. Of these, 22 (67%) were females. Except the first two cases (American tourists), the rest were Bhutanese living outside the country. The mean age of the Bhutanese patients was 26.3 (range 16-33) years. Close contacts of 27 of the 33 cases were followed up for signs and symptoms and COVID-19 positivity. The first two cases had 73 and 97 primary contacts, respectively, and equal number of secondary contacts (224). From the third case, a mandatory 21-day facility quarantine was instituted, all primary contacts were facility quarantined, and there were no secondary contacts. In total, the 27 cases had 1,095 primary contacts and 448 secondary contacts. Of these, 75 individuals were categorized as definite high-risk contacts. Secondary transmission occurred in seven high-risk contacts. Therefore, the overall secondary transmission was 9.0% (7/75) and 0.6% (7/1,095) among the high-risk and primary contacts, respectively. No transmission occurred in the secondary contacts. In contrast to several reports indicating high transmissibility of SARS-CoV-2 in contacts of confirmed cases, the mostly young, asymptomatic, and mild cases of COVID-19 in Bhutan showed limited secondary transmission.
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COVID-19/transmisión , Portador Sano/virología , Enfermedades Transmisibles Importadas/transmisión , Enfermedades Transmisibles Importadas/virología , Adolescente , Adulto , Anciano , Bután/epidemiología , COVID-19/epidemiología , COVID-19/prevención & control , Enfermedades Transmisibles Importadas/epidemiología , Trazado de Contacto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Cuarentena , Factores de Riesgo , SARS-CoV-2/patogenicidad , Enfermedad Relacionada con los Viajes , Adulto JovenRESUMEN
Objectives: A clinical case caused by Chikungunya virus (CHIKV) was introduced into Tianjin, China from Myanmar. The current study is aimed to phylogenetically analyzing this imported strain and to reveal the relationship between this virus and other circulating CHIKV strains. Methods: RNA was extracted from serum of the suspected patient presenting with symptoms compatible with CHIKV infections. Real-time reverse transcription PCR (RT-PCR) assay was used for diagnoses of the patient. For phylogenetic analysis, envelope glycoprotein 1 (E1) gene of CHIKV was amplified by two-step RT-PCR and the products were sequenced. Results: The phylogenetic analyses revealed that the imported CHIKV belong to Indian Ocean Lineage (IOL) derived from ECSA genotype and sharing the same cluster with the Aede albopitus-adapted strains that triggered the outbreaks in Pakistan (2016), Italy (2017) and Bangladesh (2017). Conclusion: The imported CHIKV strain has the potential to cause explosive outbreaks in China and this event happened in Tianjin calls for strengthening the monitoring programs on mosquito-borne diseases in China.
Asunto(s)
Fiebre Chikungunya , Virus Chikungunya , Enfermedades Transmisibles Importadas , Brotes de Enfermedades , Fiebre Chikungunya/epidemiología , Fiebre Chikungunya/virología , Virus Chikungunya/genética , China/epidemiología , Enfermedades Transmisibles Importadas/epidemiología , Enfermedades Transmisibles Importadas/virología , Genotipo , Humanos , Mianmar/etnologíaRESUMEN
Full genome sequences are increasingly used to track the geographic spread and transmission dynamics of viral pathogens. Here, with a focus on Israel, we sequence 212 SARS-CoV-2 sequences and use them to perform a comprehensive analysis to trace the origins and spread of the virus. We find that travelers returning from the United States of America significantly contributed to viral spread in Israel, more than their proportion in incoming infected travelers. Using phylodynamic analysis, we estimate that the basic reproduction number of the virus was initially around 2.5, dropping by more than two-thirds following the implementation of social distancing measures. We further report high levels of transmission heterogeneity in SARS-CoV-2 spread, with between 2-10% of infected individuals resulting in 80% of secondary infections. Overall, our findings demonstrate the effectiveness of social distancing measures for reducing viral spread.
Asunto(s)
Betacoronavirus/genética , Enfermedades Transmisibles Importadas/virología , Infecciones por Coronavirus/transmisión , Genoma Viral/genética , Neumonía Viral/transmisión , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Secuencia de Bases , Número Básico de Reproducción/estadística & datos numéricos , COVID-19 , Niño , Preescolar , Enfermedades Transmisibles Importadas/epidemiología , Infecciones por Coronavirus/epidemiología , Infecciones por Coronavirus/prevención & control , Femenino , Humanos , Lactante , Recién Nacido , Israel/epidemiología , Masculino , Persona de Mediana Edad , Pandemias/prevención & control , Filogenia , Neumonía Viral/epidemiología , Neumonía Viral/prevención & control , Distancia Psicológica , ARN Viral/genética , SARS-CoV-2 , Análisis de Secuencia de ARN , Estados Unidos , Adulto JovenRESUMEN
BACKGROUND: Effective management of imported cases is an important part of epidemic prevention and control. Hainan Province, China reported 168 coronavirus disease 2019 (COVID-19), including 112 imported cases on February 19, 2020, but successfully contained the epidemic within 1 month. We described the epidemiological and clinical characteristics of COVID-19 in Hainan and compared these features between imported and local cases to provide information for other international epidemic areas. METHODS: We included 91 patients (56 imported and 35 local cases) from two designated hospitals for COVID-19 in Haikou, China, from January 20 to February 19, 2020. Data on the demographic, epidemiological, clinical and laboratory characteristics were extracted from medical records. Patients were followed until April 21, 2020, and the levels of antibodies at the follow-ups were also analysed by the Wilcoxon matched-pairs signed ranks test. RESULTS: Of the 91 patients, 78 (85.7%) patients were diagnosed within the first three weeks after the first case was identified (Day 1: Jan 22, 2020), while the number of local cases started to increase during the third week. No new cases occurred after Day 29. Fever and cough were two main clinical manifestations. In total, 15 (16.5%) patients were severe, 14 (15.4%) had complicated infections, nine (9.9%) were admitted to the intensive care unit, and three died. The median duration of viral shedding in feces was longer than that in nasopharyngeal swabs (19 days vs 16 days, P = 0.007). Compared with local cases, imported cases were older and had a higher incidence of fever and concurrent infections. There was no difference in outcomes between the two groups. IgG was positive in 92.8% patients (77/83) in the follow-up at week 2 after discharge, while 88.4% patients (38/43) had a reduction in IgG levels in the follow-up at week 4 after discharge, and the median level was lower than that in the follow-up at week 2 (10.95 S/Cut Off (S/CO) vs 15.02 S/CO, P < 0.001). CONCLUSION: Imported cases were more severe than local cases but had similar prognoses. The level of IgG antibodies declined from week 6 to week 8 after onset. The short epidemic period in Hainan suggests that the epidemic could be quickly brought under control if proper timely measures were taken.