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1.
Mayo Clin Proc ; 96(6): 1592-1608, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-34088418

RESUMEN

The coronavirus disease 2019 (COVID-19) pandemic continues its global spread. Coordinated effort on a vast scale is required to halt its progression and to save lives. Electronic health record (EHR) data are a valuable resource to mitigate the COVID-19 pandemic. We review how the EHR could be used for disease surveillance and contact tracing. When linked to "omics" data, the EHR could facilitate identification of genetic susceptibility variants, leading to insights into risk factors, disease complications, and drug repurposing. Real-time monitoring of patients could enable early detection of potential complications, informing appropriate interventions and therapy. We reviewed relevant articles from PubMed, MEDLINE, and Google Scholar searches as well as preprint servers, given the rapidly evolving understanding of the COVID-19 pandemic.


Asunto(s)
COVID-19/epidemiología , Registros Electrónicos de Salud , COVID-19/diagnóstico , COVID-19/prevención & control , Trazado de Contacto/métodos , Reposicionamiento de Medicamentos , Monitoreo Epidemiológico , Humanos , SARS-CoV-2/genética
2.
JMIR Public Health Surveill ; 7(6): e27189, 2021 06 03.
Artículo en Inglés | MEDLINE | ID: mdl-34003761

RESUMEN

BACKGROUND: During the COVID-19 pandemic, swab tests proved to be effective in containing the infection and served as a means for early diagnosis and contact tracing. However, little evidence exists regarding the correct timing for the execution of the swab test, especially for asymptomatic individuals and health care workers. OBJECTIVE: The objective of this study was to analyze changes in the positive findings over time in individual SARS-CoV-2 swab tests during a health surveillance program. METHODS: The study was conducted with 2071 health care workers at the University Hospital of Verona, with a known date of close contact with a patient with COVID-19, between February 29 and April 17, 2020. The health care workers underwent a health surveillance program with repeated swab tests to track their virological status. A generalized additive mixed model was used to investigate how the probability of a positive test result changes over time since the last known date of close contact, in an overall sample of individuals who tested positive for COVID-19 and in a subset of individuals with an initial negative swab test finding before being proven positive, to assess different surveillance time intervals. RESULTS: Among the 2071 health care workers in this study, 191 (9.2%) tested positive for COVID-19, and 103 (54%) were asymptomatic with no differences based on sex or age. Among 49 (25.7%) cases, the initial swab test yielded negative findings after close contact with a patient with COVID-19. Sex, age, symptoms, and the time of sampling were not different between individuals with an initial negative swab test finding and those who initially tested positive after close contact. In the overall sample, the estimated probability of testing positive was 0.74 on day 1 after close contact, which increased to 0.77 between days 5 and 8. In the 3 different scenarios for scheduled repeated testing intervals (3, 5, and 7 days) in the subgroup of individuals with an initially negative swab test finding, the probability peaked on the sixth, ninth and tenth, and 13th and 14th days, respectively. CONCLUSIONS: Swab tests can initially yield false-negative outcomes. The probability of testing positive increases from day 1, peaking between days 5 and 8 after close contact with a patient with COVID-19. Early testing, especially in this final time window, is recommended together with a health surveillance program scheduled in close intervals.


Asunto(s)
Prueba de Ácido Nucleico para COVID-19/estadística & datos numéricos , COVID-19/diagnóstico , Personal de Salud/estadística & datos numéricos , Adulto , COVID-19/epidemiología , COVID-19/transmisión , Trazado de Contacto/métodos , Reacciones Falso Negativas , Femenino , Humanos , Transmisión de Enfermedad Infecciosa de Paciente a Profesional/estadística & datos numéricos , Italia/epidemiología , Masculino , Persona de Mediana Edad , Pandemias , SARS-CoV-2 , Factores de Tiempo
3.
Lancet Digit Health ; 3(6): e383-e396, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-33967002

RESUMEN

Health information technology can support the development of national learning health and care systems, which can be defined as health and care systems that continuously use data-enabled infrastructure to support policy and planning, public health, and personalisation of care. The COVID-19 pandemic has offered an opportunity to assess how well equipped the UK is to leverage health information technology and apply the principles of a national learning health and care system in response to a major public health shock. With the experience acquired during the pandemic, each country within the UK should now re-evaluate their digital health and care strategies. After leaving the EU, UK countries now need to decide to what extent they wish to engage with European efforts to promote interoperability between electronic health records. Major priorities for strengthening health information technology in the UK include achieving the optimal balance between top-down and bottom-up implementation, improving usability and interoperability, developing capacity for handling, processing, and analysing data, addressing privacy and security concerns, and encouraging digital inclusivity. Current and future opportunities include integrating electronic health records across health and care providers, investing in health data science research, generating real-world data, developing artificial intelligence and robotics, and facilitating public-private partnerships. Many ethical challenges and unintended consequences of implementation of health information technology exist. To address these, there is a need to develop regulatory frameworks for the development, management, and procurement of artificial intelligence and health information technology systems, create public-private partnerships, and ethically and safely apply artificial intelligence in the National Health Service.


Asunto(s)
COVID-19 , Aprendizaje del Sistema de Salud , Informática Médica , Inteligencia Artificial/tendencias , Trazado de Contacto/métodos , Interoperabilidad de la Información en Salud , Humanos , Aplicaciones Móviles , Vigilancia de la Población/métodos , Asociación entre el Sector Público-Privado , Robótica/tendencias , Integración de Sistemas , Reino Unido
4.
Sci Adv ; 7(19)2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33962957

RESUMEN

Nonpharmaceutical interventions to control SARS-CoV-2 spread have been implemented with different intensity, timing, and impact on transmission. As a result, post-lockdown COVID-19 dynamics are heterogeneous and difficult to interpret. We describe a set of contact surveys performed in four Chinese cities (Wuhan, Shanghai, Shenzhen, and Changsha) during the pre-pandemic, lockdown and post-lockdown periods to quantify changes in contact patterns. In the post-lockdown period, the mean number of contacts increased by 5 to 17% as compared to the lockdown period. However, it remains three to seven times lower than its pre-pandemic level sufficient to control SARS-CoV-2 transmission. We find that the impact of school interventions depends nonlinearly on the intensity of other activities. When most community activities are halted, school closure leads to a 77% decrease in the reproduction number; in contrast, when social mixing outside of schools is at pre-pandemic level, school closure leads to a 5% reduction in transmission.


Asunto(s)
COVID-19/epidemiología , COVID-19/transmisión , Trazado de Contacto/estadística & datos numéricos , Pandemias/prevención & control , Cuarentena , SARS-CoV-2 , Adolescente , Adulto , Anciano , COVID-19/virología , Niño , Preescolar , China/epidemiología , Ciudades/epidemiología , Trazado de Contacto/métodos , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad , Encuestas y Cuestionarios , Adulto Joven
5.
PLoS One ; 16(5): e0251867, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33989350

RESUMEN

Contact tracing has historically been used to retard the spread of infectious diseases, but if it is exercised by hand in large-scale, it is known to be a resource-intensive and quite deficient process. Nowadays, digital contact tracing has promptly emerged as an indispensable asset in the global fight against the coronavirus pandemic. The work at hand offers a meticulous study of all the official Android contact tracing apps deployed hitherto by European countries. Each app is closely scrutinized both statically and dynamically by means of dynamic instrumentation. Depending on the level of examination, static analysis results are grouped in two axes. The first encompasses permissions, API calls, and possible connections to external URLs, while the second concentrates on potential security weaknesses and vulnerabilities, including the use of trackers, in-depth manifest analysis, shared software analysis, and taint analysis. Dynamic analysis on the other hand collects data pertaining to Java classes and network traffic. The results demonstrate that while overall these apps are well-engineered, they are not free of weaknesses, vulnerabilities, and misconfigurations that may ultimately put the user security and privacy at risk.


Asunto(s)
COVID-19/epidemiología , COVID-19/prevención & control , Trazado de Contacto/métodos , Aplicaciones Móviles , Pandemias/prevención & control , SARS-CoV-2 , COVID-19/virología , Seguridad Computacional , Europa (Continente)/epidemiología , Humanos , Privacidad
6.
PLoS One ; 16(5): e0251242, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34014947

RESUMEN

The SARS-CoV-2 pandemic led to closure of nearly all K-12 schools in the United States of America in March 2020. Although reopening K-12 schools for in-person schooling is desirable for many reasons, officials understand that risk reduction strategies and detection of cases are imperative in creating a safe return to school. Furthermore, consequences of reclosing recently opened schools are substantial and impact teachers, parents, and ultimately educational experiences in children. To address competing interests in meeting educational needs with public safety, we compare the impact of physical separation through school cohorts on SARS-CoV-2 infections against policies acting at the level of individual contacts within classrooms. Using an age-stratified Susceptible-Exposed-Infected-Removed model, we explore influences of reduced class density, transmission mitigation, and viral detection on cumulative prevalence. We consider several scenarios over a 6-month period including (1) multiple rotating cohorts in which students cycle through in-person instruction on a weekly basis, (2) parallel cohorts with in-person and remote learning tracks, (3) the impact of a hypothetical testing program with ideal and imperfect detection, and (4) varying levels of aggregate transmission reduction. Our mathematical model predicts that reducing the number of contacts through cohorts produces a larger effect than diminishing transmission rates per contact. Specifically, the latter approach requires dramatic reduction in transmission rates in order to achieve a comparable effect in minimizing infections over time. Further, our model indicates that surveillance programs using less sensitive tests may be adequate in monitoring infections within a school community by both keeping infections low and allowing for a longer period of instruction. Lastly, we underscore the importance of factoring infection prevalence in deciding when a local outbreak of infection is serious enough to require reverting to remote learning.


Asunto(s)
COVID-19/transmisión , Trazado de Contacto/métodos , Pandemias , Vigilancia de la Población/métodos , Instituciones Académicas , Adolescente , Niño , Humanos , Modelos Teóricos , Estados Unidos
7.
Nat Commun ; 12(1): 2993, 2021 05 20.
Artículo en Inglés | MEDLINE | ID: mdl-34017008

RESUMEN

Initial COVID-19 containment in the United States focused on limiting mobility, including school and workplace closures. However, these interventions have had enormous societal and economic costs. Here, we demonstrate the feasibility of an alternative control strategy, test-trace-quarantine: routine testing of primarily symptomatic individuals, tracing and testing their known contacts, and placing their contacts in quarantine. We perform this analysis using Covasim, an open-source agent-based model, which has been calibrated to detailed demographic, mobility, and epidemiological data for the Seattle region from January through June 2020. With current levels of mask use and schools remaining closed, we find that high but achievable levels of testing and tracing are sufficient to maintain epidemic control even under a return to full workplace and community mobility and with low vaccine coverage. The easing of mobility restrictions in June 2020 and subsequent scale-up of testing and tracing programs through September provided real-world validation of our predictions. Although we show that test-trace-quarantine can control the epidemic in both theory and practice, its success is contingent on high testing and tracing rates, high quarantine compliance, relatively short testing and tracing delays, and moderate to high mask use. Thus, in order for test-trace-quarantine to control transmission with a return to high mobility, strong performance in all aspects of the program is required.


Asunto(s)
COVID-19/prevención & control , COVID-19/transmisión , Trazado de Contacto/métodos , Cuarentena/métodos , Humanos , SARS-CoV-2/aislamiento & purificación , Estados Unidos
8.
PLoS One ; 16(5): e0252019, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34019589

RESUMEN

Against the current COVID-19 pandemic, governments worldwide have devised a variety of non-pharmaceutical interventions to mitigate it. However, it is generally difficult to estimate the joint impact of different control strategies. In this paper, we tackle this question with an extended epidemic SEIR model, informed by a socio-political classification of different interventions. First, we inquire the conceptual effect of mitigation parameters on the infection curve. Then, we illustrate the potential of our model to reproduce and explain empirical data from a number of countries, to perform cross-country comparisons. This gives information on the best synergies of interventions to control epidemic outbreaks while minimising impact on socio-economic needs. For instance, our results suggest that, while rapid and strong lockdown is an effective pandemic mitigation measure, a combination of social distancing and early contact tracing can achieve similar mitigation synergistically, while keeping lower isolation rates. This quantitative understanding can support the establishment of mid- and long-term interventions, to prepare containment strategies against further outbreaks. This paper also provides an online tool that allows researchers and decision makers to interactively simulate diverse scenarios with our model.


Asunto(s)
COVID-19/epidemiología , Trazado de Contacto/estadística & datos numéricos , Cuarentena/estadística & datos numéricos , COVID-19/prevención & control , COVID-19/transmisión , Trazado de Contacto/métodos , Humanos , Modelos Estadísticos , Distanciamiento Físico , Cuarentena/métodos
9.
JAMA Netw Open ; 4(5): e218824, 2021 05 03.
Artículo en Inglés | MEDLINE | ID: mdl-33938934

RESUMEN

Importance: Schools were closed intermittently across Hong Kong to control the COVID-19 outbreak, which led to significant physical and psychosocial problems among children and youths. Objective: To compare the clinical characteristics and sources of infection among children and youths with COVID-19 during the 3 waves of outbreaks in Hong Kong in 2020. Design, Setting, and Participants: This cross-sectional study involved children and youths aged 18 years or younger with COVID-19 in the 3 waves of outbreaks from January 23 through December 2, 2020. Data were analyzed from December 2020 through January 2021. Main Outcomes and Measures: Demographic characteristics, travel and contact histories, lengths of hospital stay, and symptoms were captured through the central electronic database. Individuals who were infected without recent international travel were defined as having domestic infections. Results: Among 397 children and youths confirmed with COVID-19 infections, the mean (SD) age was 9.95 (5.34) years, 220 individuals (55.4%) were male, and 154 individuals (38.8%) were asymptomatic. There were significantly more individuals who were infected without symptoms in the second wave (59 of 118 individuals [50.0%]) and third wave (94 of 265 individuals [35.5%]) than in the first wave (1 of 14 individuals [7.1%]) (P = .001). Significantly fewer individuals who were infected in the second and third waves, compared with the first wave, had fever (first wave: 10 individuals [71.4%]; second wave: 22 individuals [18.5%]; third wave: 98 individuals [37.0%]; P < .001) or cough (first wave: 6 individuals [42.9%]; second wave: 15 individuals [12.7%]; third wave: 52 individuals [19.6%]; P = .02). Among all individuals, 394 individuals (99.2%) had mild illness. One patient developed chilblains (ie, COVID toes), 1 patient developed multisystem inflammatory syndrome in children, and 1 patient developed post-COVID-19 autoimmune hemolytic anemia. In all 3 waves, 204 patients with COVID-19 (51.4%) had domestic infections. Among these individuals, 186 (91.2%) reported having a contact history with another individual with COVID-19, of which most (183 individuals [90.0%]) were family members. In the third wave, 18 individuals with domestic infections had unknown contact histories. Three schoolmates were confirmed with COVID-19 on the same day and were reported to be close contacts. Conclusions and Relevance: This cross-sectional study found that nearly all children and youths with COVID-19 in Hong Kong had mild illness. These findings suggest that household transmission was the main source of infection for children and youths with domestic infections and that the risk of being infected at school was small.


Asunto(s)
Infecciones Asintomáticas/epidemiología , COVID-19 , Trazado de Contacto , SARS-CoV-2/aislamiento & purificación , Evaluación de Síntomas , Adolescente , COVID-19/epidemiología , COVID-19/terapia , COVID-19/transmisión , Niño , Trazado de Contacto/métodos , Trazado de Contacto/estadística & datos numéricos , Estudios Transversales , Transmisión de Enfermedad Infecciosa/prevención & control , Transmisión de Enfermedad Infecciosa/estadística & datos numéricos , Composición Familiar , Femenino , Hong Kong/epidemiología , Hospitalización/estadística & datos numéricos , Humanos , Masculino , Índice de Severidad de la Enfermedad , Evaluación de Síntomas/métodos , Evaluación de Síntomas/estadística & datos numéricos , Enfermedad Relacionada con los Viajes
10.
Sci Rep ; 11(1): 9414, 2021 05 03.
Artículo en Inglés | MEDLINE | ID: mdl-33941793

RESUMEN

To combat the COVID-19 pandemic, many countries around the globe have adopted digital contact tracing apps. Various technologies exist to trace contacts that are potentially prone to different types of tracing errors. Here, we study the impact of different proximity detection ranges on the effectiveness and efficiency of digital contact tracing apps. Furthermore, we study a usage stop effect induced by a false positive quarantine. Our results reveal that policy makers should adjust digital contact tracing apps to the behavioral characteristics of a society. Based on this, the proximity detection range should at least cover the range of a disease spread, and be much wider in certain cases. The widely used Bluetooth Low Energy protocol may not necessarily be the most effective technology for contact tracing.


Asunto(s)
COVID-19/transmisión , Trazado de Contacto/métodos , Aplicaciones Móviles , Humanos , Pandemias , Privacidad , Cuarentena , Tecnología
11.
AIDS Educ Prev ; 33(3): 234-248, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-34014111

RESUMEN

We explored interest in disclosing test results through a smartphone app dedicated to self- and partner testing for HIV/syphilis. Fifty-nine cisgender men and transgender women each participated in an in-person survey and interview. We examined their interests in sharing test results by audience (e.g., partners, physicians) and by positive versus negative test result. Participants wanted the ability to share results, with notable interest in disclosing negative results to sexual partners and on social media and forwarding positive results to physicians. Participants envisioned smartphone sharing as a means to normalize testing, to notify partners of results, and to expedite linkage to care. Some questioned the authenticity of results shared by smartphone, while others voiced optimism that a personalized, authenticated app could ensure the security and veracity of results. Smartphone testing apps for HIV/syphilis may facilitate disclosure, partner notification, and linkage to care, but need to address concerns about the security and veracity of results.


Asunto(s)
Trazado de Contacto/métodos , Infecciones por VIH/diagnóstico , Conocimientos, Actitudes y Práctica en Salud , Aplicaciones Móviles , Parejas Sexuales , Teléfono Inteligente , Sífilis/diagnóstico , Revelación de la Verdad , Adulto , Anciano , Femenino , Infecciones por VIH/prevención & control , Infecciones por VIH/psicología , Humanos , Entrevistas como Asunto , Masculino , Persona de Mediana Edad , Percepción , Investigación Cualitativa , Sífilis/prevención & control , Sífilis/psicología , Adulto Joven
12.
Philos Trans R Soc Lond B Biol Sci ; 376(1829): 20200267, 2021 07 19.
Artículo en Inglés | MEDLINE | ID: mdl-34053253

RESUMEN

We explore strategies of contact tracing, case isolation and quarantine of exposed contacts to control the SARS-CoV-2 epidemic using a branching process model with household structure. This structure reflects higher transmission risks among household members than among non-household members. We explore strategic implementation choices that make use of household structure, and investigate strategies including two-step tracing, backwards tracing, smartphone tracing and tracing upon symptom report rather than test results. The primary model outcome is the effect of contact tracing, in combination with different levels of physical distancing, on the growth rate of the epidemic. Furthermore, we investigate epidemic extinction times to indicate the time period over which interventions must be sustained. We consider effects of non-uptake of isolation/quarantine, non-adherence, and declining recall of contacts over time. Our results find that, compared to self-isolation of cases without contact tracing, a contact tracing strategy designed to take advantage of household structure allows for some relaxation of physical distancing measures but cannot completely control the epidemic absent of other measures. Even assuming no imported cases and sustainment of moderate physical distancing, testing and tracing efforts, the time to bring the epidemic to extinction could be in the order of months to years. This article is part of the theme issue 'Modelling that shaped the early COVID-19 pandemic response in the UK'.


Asunto(s)
COVID-19/epidemiología , Modelos Teóricos , Pandemias , SARS-CoV-2/patogenicidad , COVID-19/transmisión , COVID-19/virología , Trazado de Contacto/métodos , Composición Familiar , Humanos , Cuarentena/métodos
13.
Sci Rep ; 11(1): 10952, 2021 05 26.
Artículo en Inglés | MEDLINE | ID: mdl-34040093

RESUMEN

The rapid early spread of COVID-19 in the US was experienced very differently by different socioeconomic groups and business industries. In this study, we study aggregate mobility patterns of New York City and Chicago to identify the relationship between the amount of interpersonal contact between people in urban neighborhoods and the disparity in the growth of positive cases among these groups. We introduce an aggregate spatiotemporal contact density index (CDI) to measure the strength of this interpersonal contact using mobility data collected from mobile phones, and combine it with social distancing metrics to show its effect on positive case growth. With the help of structural equations modeling, we find that the effect of CDI on case growth was consistently positive and that it remained consistently higher in lower-income neighborhoods, suggesting a causal path of income on case growth via CDI. Using the CDI, schools and restaurants are identified as high contact density industries, and the estimation suggests that implementing specific mobility restrictions on these point-of-interest categories is most effective. This analysis can be useful in providing insights for government officials targeting specific population groups and businesses to reduce infection spread as reopening efforts continue to expand across the nation.


Asunto(s)
COVID-19/epidemiología , Trazado de Contacto/métodos , SARS-CoV-2/fisiología , Factores Socioeconómicos , Población Urbana , COVID-19/transmisión , Control de Enfermedades Transmisibles , Biología Computacional , Conjuntos de Datos como Asunto , Programas de Gobierno , Humanos , Modelos Estadísticos , Estados Unidos
14.
An. pediatr. (2003. Ed. impr.) ; 94(5): 318-326, mayo 2021. tab
Artículo en Español | IBECS | ID: ibc-196939

RESUMEN

INTRODUCCIÓN: Ante la posible coexistencia de la infección por el virus SARS-CoV-2 con otras infecciones estacionales, se pretende identificar síntomas diferenciales. Se ha estudiado el papel de los niños en el contagio intrafamiliar y la sensibilidad de la reacción en cadena de la polimerasa con transcriptasa inversa (RT-PCR) en un área con baja transmisión comunitaria. MATERIAL Y MÉTODOS: Estudio observacional transversal. Pacientes entre 0-15 años estudiados por técnica RT-PCR por sospecha clínica de infección por virus SARS-CoV-2 en los meses de marzo-mayo del 2020. Encuesta sobre síntomas y contactos. Determinación de anticuerpos anti-SARS-CoV-2 al menos 21 días después del test RT- PCR. RESULTADOS: Se incluyó a 126 pacientes, 33 con infección confirmada y edad media 8,4 años (IC del 95%, 6,8-10,0) superior a los no infectados. La fiebre fue el síntoma más común y con mayor sensibilidad. Las diferencias encontradas fueron una mayor frecuencia de anosmia (p = 0,029) y cefalea (p = 0,009) entre los niños infectados con una especificidad del 96,7 y el 81,5% respectivamente. No hubo diferencias en la duración de los síntomas. Un 81,8% de los infectados fue probablemente contagiado en el núcleo familiar, en un 85,2% por un progenitor que trabajaba fuera del hogar. La sensibilidad de RT-PCR fue 70,9% y su valor predictivo negativo 91,1%. CONCLUSIONES: El cuadro clínico es inespecífico y los síntomas más específicos difíciles de detectar en niños más pequeños. Los niños tuvieron un papel reducido en la transmisión intrafamiliar. La sensibilidad de la RT-PCR podría estar relacionada con una menor contagiosidad infantil tras una semana de infección


INTRODUCTION: Given the possible coexistence of infection by the SARS-CoV-2 with other seasonal infections, the aim is to identify differential symptoms. I know has studied the role of children in intrafamily contagion and the sensitivity of reverse transcriptase polymerase chain reaction (RT-PCR) in an area with low community transmission. MATERIAL AND METHODS: Cross-sectional observational study. Patients between 0-15 years studied by RT-PCR technique due to clinical suspicion of infection by SARS-CoV-2 virus in the months of March-May 2020. Survey on symptoms and contacts. Determination of Anti-SARS-CoV-2 antibodies at least 21 days after the RT-PCR test. RESULTS: 126 patients were included, 33 with confirmed infection and age mean 8.4 years (95% CI 6.8-10,5) higher than not infected. Fever was the most common and with greater sensitivity. The differences found were a greater frequency of anosmia (P = 0.029) and headache (P = .009) among children infected with a specificity of 96.7% and 81.5% respectively. There were no differences in the duration of the symptoms. 81.8% of those infected were probably infected in the nucleus 85.2% by a parent who worked outside the home. The sensitivity of RT-PCR was 70.9% and its negative predictive value 91.1%. CONCLUSIONS: The clinical picture is nonspecific and the symptoms more specific difficult to detect in younger children. Children had a reduced role in the intrafamily transmission. The sensitivity of RT-PCR could be related to a less contagiousness in children after one week of infection


Asunto(s)
Humanos , Masculino , Femenino , Recién Nacido , Lactante , Preescolar , Trazado de Contacto/métodos , Trazado de Contacto/estadística & datos numéricos , Infecciones por Coronavirus/transmisión , Neumonía Viral/transmisión , Infecciones por Coronavirus/diagnóstico , Neumonía Viral/diagnóstico , Pandemias , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Sensibilidad y Especificidad , Diagnóstico Diferencial , Estudios Transversales
15.
PLoS Med ; 18(4): e1003585, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33930019

RESUMEN

BACKGROUND: Test-trace-isolate programs are an essential part of coronavirus disease 2019 (COVID-19) control that offer a more targeted approach than many other nonpharmaceutical interventions. Effective use of such programs requires methods to estimate their current and anticipated impact. METHODS AND FINDINGS: We present a mathematical modeling framework to evaluate the expected reductions in the reproductive number, R, from test-trace-isolate programs. This framework is implemented in a publicly available R package and an online application. We evaluated the effects of completeness in case detection and contact tracing and speed of isolation and quarantine using parameters consistent with COVID-19 transmission (R0: 2.5, generation time: 6.5 days). We show that R is most sensitive to changes in the proportion of cases detected in almost all scenarios, and other metrics have a reduced impact when case detection levels are low (<30%). Although test-trace-isolate programs can contribute substantially to reducing R, exceptional performance across all metrics is needed to bring R below one through test-trace-isolate alone, highlighting the need for comprehensive control strategies. Results from this model also indicate that metrics used to evaluate performance of test-trace-isolate, such as the proportion of identified infections among traced contacts, may be misleading. While estimates of the impact of test-trace-isolate are sensitive to assumptions about COVID-19 natural history and adherence to isolation and quarantine, our qualitative findings are robust across numerous sensitivity analyses. CONCLUSIONS: Effective test-trace-isolate programs first need to be strong in the "test" component, as case detection underlies all other program activities. Even moderately effective test-trace-isolate programs are an important tool for controlling the COVID-19 pandemic and can alleviate the need for more restrictive social distancing measures.


Asunto(s)
COVID-19/prevención & control , Trazado de Contacto , Brotes de Enfermedades/prevención & control , Modelos Teóricos , COVID-19/diagnóstico , Trazado de Contacto/métodos , Humanos , Cuarentena , SARS-CoV-2/patogenicidad
16.
J Med Internet Res ; 23(5): e25447, 2021 05 19.
Artículo en Inglés | MEDLINE | ID: mdl-33882016

RESUMEN

BACKGROUND: To combat the global COVID-19 pandemic, contact tracing apps have been discussed as digital health solutions to track infection chains and provide appropriate information. However, observational studies point to low acceptance in most countries, and few studies have yet examined theory-based predictors of app use in the general population to guide health communication efforts. OBJECTIVE: This study utilizes established health behavior change and technology acceptance models to predict adoption intentions and frequency of current app use. METHODS: We conducted a cross-sectional online survey between May and July 2020 in a German convenience sample (N=349; mean age 35.62 years; n=226, 65.3% female). To inspect the incremental validity of model constructs as well as additional variables (privacy concerns, personalization), hierarchical regression models were applied, controlling for covariates. RESULTS: The theory of planned behavior and the unified theory of acceptance and use of technology predicted adoption intentions (R2=56%-63%) and frequency of current app use (R2=33%-37%). A combined model only marginally increased the predictive value by about 5%, but lower privacy concerns and higher threat appraisals (ie, anticipatory anxiety) significantly predicted app use when included as additional variables. Moreover, the impact of perceived usefulness was positive for adoption intentions but negative for frequency of current app use. CONCLUSIONS: This study identified several theory-based predictors of contact tracing app use. However, few constructs, such as social norms, have a consistent positive effect across models and outcomes. Further research is required to replicate these observations, and to examine the interconnectedness of these constructs and their impact throughout the pandemic. Nevertheless, the findings suggest that promulgating affirmative social norms and positive emotional effects of app use, as well as addressing health concerns, might be promising strategies to foster adoption intentions and app use in the general population.


Asunto(s)
COVID-19/epidemiología , Trazado de Contacto/métodos , Conductas Relacionadas con la Salud/fisiología , Aplicaciones Móviles/estadística & datos numéricos , Adulto , Estudios Transversales , Femenino , Humanos , Masculino , Modelos Estadísticos , Pandemias , SARS-CoV-2/aislamiento & purificación , Encuestas y Cuestionarios
17.
PLoS One ; 16(4): e0249394, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33852588

RESUMEN

INTRODUCTION: The reporting of Coronavirus Disease 19 (COVID-19) mortality among healthcare workers highlights their vulnerability in managing the COVID-19 pandemic. Some low- and middle-income countries have highlighted the challenges with COVID-19 testing, such as inadequate capacity, untrained laboratory personnel, and inadequate funding. This article describes the components and implementation of a healthcare worker surveillance programme in a designated COVID-19 teaching hospital in Malaysia. In addition, the distribution and characteristics of healthcare workers placed under surveillance are described. MATERIAL AND METHODS: A COVID-19 healthcare worker surveillance programme was implemented in University Malaya Medical Centre. The programme involved four teams: contact tracing, risk assessment, surveillance and outbreak investigation. Daily symptom surveillance was conducted over fourteen days for healthcare workers who were assessed to have low-, moderate- and high-risk of contracting COVID-19. A cross-sectional analysis was conducted for data collected over 24 weeks, from the 6th of March 2020 to the 20th of August 2020. RESULTS: A total of 1,174 healthcare workers were placed under surveillance. The majority were females (71.6%), aged between 25 and 34 years old (64.7%), were nursing staff (46.9%) and had no comorbidities (88.8%). A total of 70.9% were categorised as low-risk, 25.7% were moderate-risk, and 3.4% were at high risk of contracting COVID-19. One-third (35.2%) were symptomatic, with the sore throat (23.6%), cough (19.8%) and fever (5.0%) being the most commonly reported symptoms. A total of 17 healthcare workers tested positive for COVID-19, with a prevalence of 0.3% among all the healthcare workers. Risk category and presence of symptoms were associated with a positive COVID-19 test (p<0.001). Fever (p<0.001), cough (p = 0.003), shortness of breath (p = 0.015) and sore throat (p = 0.002) were associated with case positivity. CONCLUSION: COVID-19 symptom surveillance and risk-based assessment have merits to be included in a healthcare worker surveillance programme to safeguard the health of the workforce.


Asunto(s)
Prueba de COVID-19/métodos , COVID-19/prevención & control , Brotes de Enfermedades/prevención & control , Adulto , COVID-19/diagnóstico , Prueba de COVID-19/tendencias , Comorbilidad , Trazado de Contacto/métodos , Estudios Transversales , Monitoreo Epidemiológico , Femenino , Personal de Salud , Hospitales de Enseñanza , Humanos , Malasia/epidemiología , Masculino , Pandemias , SARS-CoV-2/aislamiento & purificación
18.
JAMA Netw Open ; 4(4): e218184, 2021 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-33929521

RESUMEN

Importance: Digital contact tracing (DCT) apps have been released in several countries to help interrupt SARS-CoV-2 transmission chains. However, the effect of DCT on pandemic mitigation remains to be demonstrated. Objective: To estimate key populations and performance indicators along the exposure notification cascade of the SwissCovid DCT app in a clearly defined regional and temporal context. Design, Setting, and Participants: This comparative effectiveness study was based on a simulation informed by measured data from issued quarantine recommendations and positive SARS-CoV-2 test results after DCT exposure notifications in the canton of Zurich. A stochastic model was developed to re-create the DCT notification cascade for Zurich. Population sizes at each cascade step were estimated using triangulation based on publicly available administrative and observational research data for the study duration from September 1 to October 31, 2020. The resultant estimates were checked for internal consistency and consistency with upstream or downstream estimates in the cascade. Stochastic sampling from data-informed parameter distributions was performed to explore the robustness of results. Subsequently, key performance indicators were evaluated to assess the potential contribution of DCT compared with manual contact tracing. Main Outcomes and Measures: Receiving a voluntary quarantine recommendation and/or a positive SARS-CoV-2 test result after exposure notification. Results: In September 2020, 537 app users received a positive SARS-CoV-2 test result in Zurich, 324 of whom received and entered an upload authorization code. This code triggered an app notification for an estimated 1374 (95% simulation interval [SI], 932-2586) proximity contacts and led to 722 information hotline calls, with an estimated 170 callers (95% SI, 154-186) receiving a quarantine recommendation. An estimated 939 (95% SI, 720-1127) notified app users underwent testing for SARS-CoV-2, of whom 30 (95% SI, 23-36) had positive results after an app notification. Key indicator evaluations revealed that the DCT app triggered quarantine recommendations for the equivalent of 5% of all exposed contacts placed in quarantine by manual contact tracing. For every 10.9 (95% SI, 7.6-15.6) upload authorization codes entered in the app, 1 contact had positive test results for SARS-CoV-2 after app notification. Longitudinal indicator analyses demonstrated bottlenecks in the notification cascade, because capacity limits were reached owing to an increased incidence of SARS-CoV-2 infection in October 2020. Conclusions and Relevance: In this simulation study of the notification cascade of the SwissCovid DCT app, receipt of exposure notifications was associated with quarantine recommendations and identification of SARS-CoV-2-positive cases. These findings in notified proximity contacts reflect important intermediary steps toward transmission prevention.


Asunto(s)
COVID-19 , Simulación por Computador , Trazado de Contacto , Notificación de Enfermedades , Transmisión de Enfermedad Infecciosa , Aplicaciones Móviles , Adulto , COVID-19/diagnóstico , COVID-19/epidemiología , COVID-19/prevención & control , COVID-19/transmisión , Control de Enfermedades Transmisibles/métodos , Control de Enfermedades Transmisibles/organización & administración , Trazado de Contacto/métodos , Trazado de Contacto/estadística & datos numéricos , Notificación de Enfermedades/métodos , Notificación de Enfermedades/estadística & datos numéricos , Transmisión de Enfermedad Infecciosa/prevención & control , Transmisión de Enfermedad Infecciosa/estadística & datos numéricos , Femenino , Humanos , Masculino , Cuarentena , SARS-CoV-2/aislamiento & purificación , Suiza/epidemiología
19.
PLoS One ; 16(4): e0250826, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33914810

RESUMEN

We report on the results of a measurement study carried out on a commuter bus in Dublin, Ireland using the Google/Apple Exposure Notification (GAEN) API. This API is likely to be widely used by Covid-19 contact tracing apps. Measurements were collected between 60 pairs of Android handset locations and are publicly available. We find that the attenuation level reported by the GAEN API need not increase with distance between handsets, consistent with there being a complex radio environment inside a bus caused by the metal-rich environment. Changing the people sitting in a pair of seats can cause variations of ±10dB in the attenuation level reported by the GAEN API. Applying the rule used by the Swiss Covid-19 contact tracing app to trigger an exposure notification to our bus measurements we find that no exposure notifications would have been triggered despite the fact that all pairs of handsets were within 2m of one another for at least 15 mins. Applying an alternative threshold-based exposure notification rule can somewhat improve performance to a detection rate of 5% when an exposure duration threshold of 15 minutes is used, increasing to 8% when the exposure duration threshold is reduced to 10 mins. Stratifying the data by distance between pairs of handsets indicates that there is only a weak dependence of detection rate on distance.


Asunto(s)
Trazado de Contacto , Aplicaciones Móviles , Transportes , COVID-19/epidemiología , Teléfono Celular , Trazado de Contacto/métodos , Humanos , Irlanda/epidemiología
20.
Travel Med Infect Dis ; 41: 102044, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33838318

RESUMEN

BACKGROUND: Imported COVID-19 cases, if unchecked, can jeopardize the effort of domestic containment. We aim to find out what sustainable border control options for different entities (e.g., countries, states) exist during the reopening phases, given their own choice of domestic control measures. METHODS: We propose a SUIHR model, which has built-in imported risk and (1-tier) contact tracing to study the cross-border spreading and control of COVID-19. Under plausible parameter assumptions, we examine the effectiveness of border control policies, in combination with internal measures, to confine the virus and avoid reverting back to more restrictive life styles again. RESULTS: When the basic reproduction number R0 of COVID-19 exceeds 2.5, even 100% effective contact tracing alone is not enough to contain the spreading. For an entity that has completely eliminated the virus domestically, and resumes "normal", without mandatory institutional quarantine, even very strict border control measures combined with effective contact tracing can only delay another outbreak by 6 months. For entities employing a confining domestic control policy, non-increasing net imported cases is sufficient to remain open. CONCLUSIONS: Extremely strict border control in entities, where domestic spreading is currently eliminated (e.g., China), is justifiable. However such harsh measure are not necessary for other places. Entities successfully confining the virus by internal measures can open up to similar entities without additional border controls so long as the imported risk stays non-increasing. Opening the borders to entities lacking sufficient internal control of the virus should be exercised in combination with pre-departure screening and tests upon arrival.


Asunto(s)
COVID-19/prevención & control , Control de Enfermedades Transmisibles/métodos , Política Pública , Viaje , Número Básico de Reproducción , COVID-19/epidemiología , COVID-19/transmisión , Enfermedades Transmisibles Importadas/epidemiología , Enfermedades Transmisibles Importadas/prevención & control , Enfermedades Transmisibles Importadas/transmisión , Trazado de Contacto/métodos , Brotes de Enfermedades/prevención & control , Gobierno , Humanos , Modelos Teóricos , Pandemias/prevención & control , Cuarentena/métodos , SARS-CoV-2
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