Impact of climate change on SARS-CoV-2 epidemic in China

and no areas of HH clustering were discovered. The number of confirmed cases in Hubei Province was much higher than the average number among all regions in China. The number of surrounding sections was lower than the number of confirmed cases in Hubei, indicating significant HL clustering (P-value < 0.05). The northern region of China, with a relatively small population and few confirmed infection cases, showed LL clustering. Three provinces (Anhui, Hunan, and Jiangxi) are adjacent to Hubei Province and are connected. The number of confirmed cases in these three immediate provinces was higher than that in Hubei Province, indicating significant LH clustering. The Hu Line segregates the level of population from the social and economic pattern in China, from Heihe City, Heilongjiang Province, to Tengchong City, Yunnan Province, where approximately 44% of the country’s territory southeast of the line is inhabited by approxi- mately 94% of the population [36]. In general, it delineates the urbanization levels, with most of the southeastern provinces and cities along this line exhibiting urbanization levels higher than the national average. Generally, both the GR and confirmed spatial distribution charac- teristics were consistent with the Hu Line, which indicates that the SARS-CoV-2 epidemic was more severe in cities with higher population concentrations and urbanization levels. SARS-CoV-2 temporal variation characteristics. The average GR of all provinces (GR = 5.15%) showed an overall logarithmic distribution with a significant downward trend

(P-value < 0.05), with 84,385 confirmed cases as of April 30 and an average of 833 new cases per day (Fig 5). The highest GR was recorded on January 23, 2020 (GR = 68.47%), with 870 confirmed cases and 290 new confirmed cases, and the average GR for eight days from January 23 to January 31 was 37.43%. From January 27 to February 18, the number of newly confirmed cases exceeded 1,000 per day, with an average GR of 14.32%. The highest GR values were recorded from January 20 to January 27 (eight days), as shown in S3 Fig. For most provinces, the maximum GR was recorded within two days of the first con- firmed case, i.e., the first and second days of the outbreak; subsequently, it decreased for the three provinces (Hubei, Jiangxi, and Xinjiang). These effects appeared only after the outbreak. For Hubei and Jiangxi, the severity of the epidemic was indirectly demonstrated by the prox- imity of the two provinces and the intense population circulation. Xinjiang indirectly Fig 5. Distribution characteristics of number of confirmed SARS CoV-2 cases and its growth rate in China. (a) Temporal variation; (b) spatial distribution. https://doi.org/10.1371/journal.pone.0285179.g005 PLOS ONE Impact of climate change on SARS-CoV-2 epidemic in China PLOS ONE | https://doi.org/10.1371/journal.pone.0285179 July 27, 2023 9 / 21