key: cord-0717883-z5oyi1ej authors: da Silva, F. L.; A. Gomes, M. D.; Lelis da Silva, A. P.; de Sousa, S. C.; Serafim de Souza, M. F.; P. da Silva, G. L. title: Correlation between meteorological factors and COVID-19 infection in the Belem Metropolitan Region date: 2020-06-12 journal: nan DOI: 10.1101/2020.06.10.20127506 sha: 739203f5f4bc3d17162a508336a1d9030b23bb85 doc_id: 717883 cord_uid: z5oyi1ej Many factors can influence then spread of viruses and respiratory infections. Studies have suggested that there is a direct relationship between environmental issues and population density with cases of COVID-19. In this sense, this research aims to analyze, through correlational study and Krigagem, the relationship of meteorological and demographic variables with cases of COVID-19 in regions of subtropical climate in Brazil. The results suggest that population and demographic density (hab/km2) are risk factors for the spread of SAR-CoV-2 and an increase in the daily case record of COVID-19. The distribution of cases according to age group did not present a significant disparity between men and women. Relative humidity (RH)%, average temperature Celsius, minimum temperature Celsius, maximum temperature Celsius, wind speed m/s and daily precipitation (rain) mm show negative relationships with cases of COVID-19 in regions of humid equatorial climate. Analysis between associations of environmental factors, wind, temperature and HR in a region is extremely important to understand the dynamics of SARS-CoV-2 in the environment. In the northern region of Brazil, low wind speed, high temperatures and high RH are observed, environmental factors that, when associated, reduce the transmission process because it hinders the movement of the virus in the environment. In this sense, it is suggested that the transmission of SARS-CoV-2 in this region is disseminated through fluids in the air between man/man and by contact between objects/men. Therefore, strategic public policies to combat the pandemic must consider the environmental factors of the regions involved and control and/or blocking the transit of people. The descriptive analyzes of the variables were expressed as mean and number 160 (%). Cases without identification for age and gender were imputed. The proportions and 161 mean between gender were analyzed using the Chi-square test of adherence and the 162 Independence T test considering homogeneity of variance of the data with a significance 163 alpha level 5%. 164 The distribution of cases within genders was assessed using boxplot diagrams. 165 The occurrences of cases and the mean age of the infected were analyzed using the Chi-166 square test and the Independence T test. The correlations between number of cases and 167 environmental variables were analyzed using the Spearman test. 168 Spearman's nonparametric test was applied due to the monotonic relationship 169 between ordinal variables and non-compliance with the assumption of normality. It was 170 used to assess the association between the number of COVID-19 cases and 171 environmental factors. Spearman's coefficient (Eq.1) was calculated according to 172 (Sahin, 2020 . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review) The copyright holder for this preprint this version posted June 12, 2020. . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review) The copyright holder for this preprint this version posted June 12, 2020. worth mentioning that these municipalities are located on the margins of the BR 223 . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review) The copyright holder for this preprint this version posted June 12, 2020. . Table 1 , the Spearrman test (rho = 0.987) was applied to assess the 229 relationship between population and density in the occurrence of cases of COVID-19. 230 The results show that there is a high positive correlation between the number of 231 registered cases and the total population of these regions. However, demographic 232 density and cases of infection by COVID-19 with (rho = 0.393) show a moderate 233 correlation. Similar results were obtained by Sahin (2020), considering that urban 234 centers with large agglomerations are closely linked to high infections by COVID-19. 235 The Chi-square test to assess the existence of a significant difference between 236 cases occurring by gender in the municipalities in the region (Table 1) infections. Therefore, sex is not associated with a risk factor for COVID-19. 242 The Independence T tests, applied to compare the average ages of those affected 243 by the virus by gender within the municipalities, were not significant at 5%. These tests 244 demonstrate that there are no significant differences between the mean ages and that 245 there is no difference in the behavior of the distribution of cases by age group between 246 men and women. 247 . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review) The copyright holder for this preprint this version posted June 12, 2020. . municipal regions, which make up the BMR, the age group factor is not the COVID-19 250 is a risk factor. However, the economically active population aged 20 to 60 years is the 251 most affected by the disease. 252 . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this preprint this version posted June 12, 2020. Turkey according to (Sahin, 2020), concluded that the temperature is closely related , 294 because at high temperatures a reduction in case records was observed. 295 . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this preprint this version posted June 12, 2020. For multiple associations between temperature variations (minimum and 335 maximum) and cases of COVID-19, identified daily, it is noted that with temperatures 336 between 24 to 34ºC, minimum temperatures in the 24ºC range, associated with RH 337 between 85 to 95% and temperatures around 24ºC and speed between 0.5 to 2.0 m/s, the 338 lowest average daily records of COVID-19 were observed in the municipality of Santa 339 Barbara (Fig.4) . is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this preprint this version posted June 12, 2020. . These results suggest that regions of low density hab/km 2 have lower records of 346 COVID-19 cases. However, urban centers with a population density of more than 150 347 inhabitants per square kilometer recorded the highest number of infections in the region. 348 In Castanhal and Santa Izabel, significant negative correlations were found 349 between the number of cases and relative humidity ( Table 2 ). Multiple spatial 350 correlation analysis was performed considering RH as the main factor for these regions. 351 There are associations between RH/wind speed and RH/rain, suggesting that when the 352 RH is between 85 to 100% and the wind speed in the range of 0 to 1 m/s, in Castanhal, 353 smaller cases were registered of COVID-19. However, for higher winds of 2 m/s and 354 daily rainfall above 60 mm, the highest numbers of infected cases were identified. 355 Similar results, from lower occurrences of COVID-19 cases, were found in 356 Santa Izabel when the RH varied between 85 to 100% and rainfall levels from 0 to 30 357 mm average/day. 358 In Belém city, the combination of RH between 80 and 95% and rainfall between 359 0 and 30 mm/day was the lowest number of cases of SARS-CoV-2 infections. For RH 360 less than 85% and daily rainfall greater than 60 mm favored the number of cases of 361 COVID-19. Combination of RH in the 80 to 95% range, with an average temperature 362 index between 26 and 32 ºC, the lowest numbers of SARS-CoV-2 infected individuals 363 were registered in the municipality of Ananindeua (Fig. 4) . 364 Correlational studies aim to subsidize intervention measures, as they have implications 366 for the structuring of health policies and the containment of disease progress and the 367 . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this preprint this version posted June 12, 2020. . is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this preprint this version posted June 12, 2020. is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this preprint this version posted June 12, 2020. . https://doi.org/10.1101/2020.06.10.20127506 doi: medRxiv preprint suggests a reduction in SARS-CoV-2 infections with increasing temperature. And 417 therefore, in warmer periods in the region, it is expected that temperature is not a risk 418 factor for infections. 419 Relative Humidity in the regions of Ananindeua and Castanhal showed a 420 negative and relevant correlation with the cases of COVID-19, which suggests that RH 421 is not a risk factor in the region, the spread of SARS-CoV-2, since the Relative 422 Humidity recorded is always high. 423 It is noteworthy that in the northern region of Brazil the seasons of higher 424 temperatures correspond to the period from June to December. As demonstrated in this 425 study, high temperatures, despite the low negative correlation, were not statistically 426 significant indicating that they reduce contamination and the registration of new daily 427 cases. Likewise, there is no evidence to affirm that high temperatures are risk factors for 428 the increase in cases of Covid-19. However, the significant negative correlation between 429 number of cases and minimum temperature leads us to infer that high temperatures in 430 the northern region will not favor the progress of SARS-CoV-2. 431 The multiple correlation of variables shows that high relative humidity 432 associated with the phenomenon of precipitation, low wind speed and temperature 433 above 26 ° C favors a lower incidence of new cases of COVID-19 in the study region. 434 However, low relative humidity provides an increase in the number of cases and may be 435 related to the drier environment. For, as the RH lowers, the environment becomes dry 436 and facilitates the air transport of particles in the environment, enabling the transmission 437 of the SARS-CoV-2 virus. 438 . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this preprint this version posted June 12, 2020. . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this preprint this version posted June 12, 2020. CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this preprint this version posted June 12, 2020. CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this preprint this version posted June 12, 2020. . B e l é m A n a n i n d e u a B e n e v i d e s S t ª B a r b a r a C a s t a n h a l M a r i t u b a S t ª I z a b e l . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this preprint this version posted June 12, 2020. . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this preprint this version posted June 12, 2020. CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this preprint this version posted June 12, 2020. . Note: in the analyzes (Chi-square and mean test) 78 cases were disregarded due to the lack of identification in the records for gender/sex and age of the infected person. . It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this preprint this version posted June 12, 2020. is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this preprint this version posted June 12, 2020. is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this preprint this version posted June 12, 2020. A 491 PRISMA-compliant systematic review A 495 PRISMA-compliant systematic review World Health Organization. Coronavirus disease (COVID-19) outbreak situation Association between ambient temperature and covid-19 infection in 122 615 cities from China A pneumonia outbreak associated with a new 619 coronavirus of probable bat origin. 2020 A novel coronavirus from patients with 623 pneumonia in China