Some biological properties of eperythrozoon, such as the influence of low temperature on their viability, their infectivity in different kinds of animals and their changes in amount of organisms in vivo were investigated in the present study. The experimental results showed that the viability of eperythrozoon could be maintained at -20 ℃ for 835 days and at 4 ℃ for 205 days. Small rats could be infected by Eperythrozoon suis, while chickens were not infected. The basic regulation on the changes in amount of organisms in animals was expressed by the fact that the percentages of erythrocytes being infected increased rapidly up to 96-98% 2-4 hours after infection, then it dropped down and followed by dropping and re-rising, attaining its climax up to 8 hours after infection. Finally, it reflected a fluctuating cycle of 14-16 hours. This results showed that eperythrozoons can maintain their viability at -20℃ for a long time and they possess relative species specificity to host with a reproduction cycle of 14-16 hours in animal body.

ObjectiveTo analyze the management and treatment for patients with severe mental disorders in Chengdu from 2016 to 2020， in order to provide references for the relevant authorities to formulate policies and improving the mental health service system. MethodsData relating to 22 districts （cities） and counties in Chengdu from January 1， 2016 to December 31， 2020 were extracted from the National Information System for Severe Mental Disorders. Indicators such as reported prevalence rate， management rate， standardized management rate， medication rate， regular medication rate and stable condition rate of patients with severe mental disorders were analyzed on a yearly basis. ResultsBy the end of 2020， there were 71 899 registered cases of severe mental disorders in Chengdu， with a reported prevalence rate of 0.34%， a standardized management rate of 95.53%， and a regular medication rate of 72.50%. From 2016 to 2020， except the reported prevalence rate （χ²=269.566， P<0.01）， management rate （χ²=384.030， P<0.01）， standardized management rate （χ²=309.742， P<0.01）， medication rate （χ²=414.252， P<0.01）， regular medication rate （χ²=316.172， P<0.01） and stable condition rate （χ²=288.335， P<0.01） had linear trends of increasing with the annual increase. ConclusionFrom 2016 to 2020， the management rate， treatment rate and regular medication rate of patients with severe mental disorders have been increased year by year in Chengdu. Nevertheless， the increase in reported prevalence rate should be accompanied by strengthened management and follow-up to increase the regular medication rate to maintain the stability of patients' conditions.