Food Sources Affects the Symptom Rates of COVID-19, a Case Study Based on the Public Data in Gansu Province, China, during the Summer Epidemic Cycle in 2022.

According to the public data collected from the Health Commission of Gansu Province, China, regarding the COVID-19 pandemic during the summer epidemic cycle in 2022, the epidemiological analysis showed that the pandemic spread stability and the symptom rate (the number of confirmed cases divided by the sum of the number of asymptomatic cases and the number of confirmed cases) of COVID-19 were different among three main epidemic regions, Lanzhou, Linxia and Gannan; both the symptom rate and the daily instantaneous symptom rate (daily number of confirmed cases divided by the sum of daily number of asymptomatic cases and daily number of confirmed cases) in Lanzhou were substantially higher than those in Linxia and Gannan. The difference in the food sources due to the high difference of the population ethnic composition in the three regions was probably the main driver for the difference of the symptom rates among the three regions. This work provides potential values for prevention and control of COVID-19 in different regions.