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1.
Rev. bras. promoç. saúde (Impr.) ; 34(1): 1-9, 17/02/2021.
Article in Spanish | WHO COVID, LILACS (Americas) | ID: covidwho-2202501

ABSTRACT

Objetivo: Este artículo de investigación busca conocer la influencia de la propagación del virus COVID-19 a través de la temperatura y de la humedad en España y Brasil. Métodos: Para el cálculo de la variación mensual del índice de propagación del virus COVID-19 por provincias en España se han utilizado, en primer lugar, las series climáticas de la AEMET de España e INMETRO de Brasil. Se han extraído las medias correspondientes y después se han sometido los datos a un proceso de homogenización, para posteriormente poder calcular el incremento mensual de temperatura y de humedad por provincias y estados. Este proceso metodológico establece una relación directamente proporcional entre el aumento de la temperatura y de la humedad con el índice de propagación del virus COVID-19. Resultados: En España, las condiciones climáticas favorecerán la disminución o aumento del índice reproductivo del virus. En Brasil las condiciones climáticas no favorecerán la disminución del índice reproductivo del virus y, climatológicamente, no existe un periodo óptimo para una desescalada y vuelta a la normalidad. Las variaciones de las condiciones climáticas en Brasil no son significativas, por lo que el clima de Brasil no influye en la disminución de propagación del virus. Conclusión: El clima influye en la propagación del virus. Descriptores: COVID-19; Transmisión de Enfermedad Infecciosa; Clima; Temperatura; Humedad.


Objetivo: Este artigo de pesquisa busca conhecer a influência da propagação do vírus COVID-19 através da temperatura e umidade na Espanha e no Brasil. Métodos: Para calcular a variação mensal do índice de propagação do vírus COVID-19 por províncias da Espanha, primeiramente, utilzaram-se as séries climáticas da AEMET da Espanha e do INMETRO do Brasil. Extraíram-se as médias correspondentes, para posterior submissão dos dados a um processo de homogeneização, com o intuito de calcular o aumento mensal de temperatura e umidade por províncias e estados. Esse processo metodológico estabeleceu uma relação diretamente proporcional entre o aumento da temperatura e da umidade com a taxa de disseminação do vírus COVID-19. Resultados: Na Espanha, as condições climáticas favoreceram a diminuição ou aumento do índice reprodutivo do vírus. No Brasil, entretanto, as condições climáticas não favorecem a diminuição do índice reprodutivo do virus, comprovando que climatologicamente não existe um período ideal para uma desaceleração e retorno à normalidade. As variações nas condições climáticas no Brasil não são significativas, portanto o clima não influencia na diminuição da propagação do vírus neste país. Conclusão: O clima influencia a disseminação do vírus. Descritores: COVID-19; Transmissão de Doença Infecciosa; Clima; Temperatura; Umidade.


Objective: This research article seeks to know the influence of the spread of the COVID-19 virus through temperature and humidity in Spain and Brazil. Methods: In order to calculate the monthly variation in the COVID-19 virus spread index by provinces in Spain, at first, the climatic series of the AEMET of Spain and INMETRO of Brazil were used. The corresponding means have been extracted and then the data have been subjected to a homogenization process, to later be able to calculate the monthly increase in temperature and humidity by provinces and states. This methodological process establishes a directly proportional the climatic conditions favored the decrease or increase of the reproductive index of the virus. In Brazil, however, the climatic conditions do not favor the decrease in the reproductive index of the virus, proving that climatologically there is no optimal period for de-escalation and return to normality. The variations in climatic conditions in Brazil are not significant, so the climate does not influence the decrease in the spread of the virus. Conclusion: Climate influences the spread of the virus. Descriptors: COVID-19; Disease Transmission, Infectious; Climate; Temperature; Humidity. relationship between the increase in temperature and humidity with the spread rate of the COVID-19 virus. Results: In Spain the climatic conditions favored the decrease or increase of the reproductive index of the virus. In Brazil, however, the climatic conditions do not favor the decrease in the reproductive index of the virus, proving that climatologically there is no optimal period for de-escalation and return to normality. The variations in climatic conditions in Brazil are not significant, so the climate does not influence the decrease in the spread of the virus. Conclusion: Climate influences the spread of the virus.


Subject(s)
Temperature , Disease Transmission, Infectious , Basic Reproduction Number , COVID-19 , Humidity
18.
PLoS Biol ; 20(6): e3001685, 2022 06.
Article in English | MEDLINE | ID: covidwho-1902597

ABSTRACT

Historically, emerging and reemerging infectious diseases have caused large, deadly, and expensive multinational outbreaks. Often outbreak investigations aim to identify who infected whom by reconstructing the outbreak transmission tree, which visualizes transmission between individuals as a network with nodes representing individuals and branches representing transmission from person to person. We compiled a database, called OutbreakTrees, of 382 published, standardized transmission trees consisting of 16 directly transmitted diseases ranging in size from 2 to 286 cases. For each tree and disease, we calculated several key statistics, such as tree size, average number of secondary infections, the dispersion parameter, and the proportion of cases considered superspreaders, and examined how these statistics varied over the course of each outbreak and under different assumptions about the completeness of outbreak investigations. We demonstrated the potential utility of the database through 2 short analyses addressing questions about superspreader epidemiology for a variety of diseases, including Coronavirus Disease 2019 (COVID-19). First, we found that our transmission trees were consistent with theory predicting that intermediate dispersion parameters give rise to the highest proportion of cases causing superspreading events. Additionally, we investigated patterns in how superspreaders are infected. Across trees with more than 1 superspreader, we found preliminary support for the theory that superspreaders generate other superspreaders. In sum, our findings put the role of superspreading in COVID-19 transmission in perspective with that of other diseases and suggest an approach to further research regarding the generation of superspreaders. These data have been made openly available to encourage reuse and further scientific inquiry.


Subject(s)
COVID-19 , Decision Trees , COVID-19/epidemiology , Disease Outbreaks , Disease Transmission, Infectious , Humans
20.
Sci Rep ; 12(1): 212, 2022 01 07.
Article in English | MEDLINE | ID: covidwho-1890215

ABSTRACT

In response to the COVID19 pandemic, many countries have implemented lockdowns in multiple phases to ensure social distancing and quarantining of the infected subjects. Subsequent unlocks to reopen the economies started next waves of infection and imposed an extra burden on quarantine to keep the reproduction number ([Formula: see text]) < 1. However, most countries could not effectively contain the infection spread, suggesting identification of the potential sources weakening the effect of lockdowns could help design better informed lockdown-unlock cycles in the future. Here, through building quantitative epidemic models and analyzing the metadata of 50 countries from across the continents we first found that the estimated value of [Formula: see text], adjusted w.r.t the distribution of medical facilities and virus clades correlates strongly with the testing rates in a country. Since the testing capacity of a country is limited by its medical resources, we investigated if a cost-benefit trade-off can be designed connecting testing rate and extent of unlocking. We present a strategy to optimize this trade-off in a country specific manner by providing a quantitative estimate of testing and quarantine rates required to allow different extents of unlocks while aiming to maintain [Formula: see text]. We further show that a small fraction of superspreaders can dramatically increase the number of infected individuals even during strict lockdowns by strengthening the positive feedback loop driving infection spread. Harnessing the benefit of optimized country-specific testing rates would critically require minimizing the movement of these superspreaders via strict social distancing norms, such that the positive feedback driven switch-like exponential spread phase of infection can be avoided/delayed.


Subject(s)
COVID-19/prevention & control , Contact Tracing , Disease Transmission, Infectious/prevention & control , Physical Distancing , Quarantine , SARS-CoV-2/growth & development , Virus Replication , COVID-19/epidemiology , COVID-19/transmission , COVID-19/virology , COVID-19 Testing , Carrier State , Humans , Metadata , SARS-CoV-2/pathogenicity , Time Factors
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