ABSTRACT
Objective This study is conducted against a case of positive nucleic acid detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) of environmental samples in a medical institution in Chengdu. Epidemiological investigation methods and laboratory tests are used to investigate the source and analyze the cause of the case, to explore the nucleic acid monitoring mode and the disposal scheme of abnormal conditions of SARS-CoV-2 in the medical institution environment. Methods Chengdu and Shuangliu district CDC jointly investigate A Medical Institution (A refers to a specific anonymous medical institute). Epidemiological surveys were conducted though related influencing factors of the medical institution. SARS-CoV-2 nucleic acid detection kits were used for detection. Sequencing was carried out on a second-generation sequencing platform. Results From Jan.18th 2021 to Jan.20th 2021, a total of 62 smear samples of environment and articles were collected, among which 30 samples were positive for SARS-CoV-2 nucleic acid. 30 positive samples were divided into Gongwei building (9) and Zhonghe building (21) according to the sampling location. The samples' Ct values of ORF1ab gene in Gongwei building were lower than that in Zhonghe building, and the difference was statistically significant (t=2.452, P=0.036). According to the nature of the specimens, they were divided into external environment smear samples (24 samples) and cleaning tool smear samples (6 samples). The N gene Ct values of external environment smear samples were lower than that of cleaning tools, and the difference was statistically significant (Z=-2.204, P=0.028). Through gene sequencing analysis, the sequence of SARS-CoV-2 nucleic acid positive environmental samples detected this time is highly homologous with SARS-CoV-2 vaccine (> 99.9%). Conclusions The positive environmental samples of SARS-CoV-2 nucleic acid in the medical institution are caused by the damage and leakage of COVID-19 vaccine ampoules in the process of vaccination, which led to the contamination of the vaccination room of public health building, and then transmit to the hospital environment of fever clinic and complex building through cleaning tools by cleaning workers. With the progress of COVID-19 vaccine vaccination, there is a high probability of environmental pollution of vaccine liquid in the vaccination area of medical institutions. Therefore, it is necessary in combination with the current normalization monitoring requirements of domestic COVID-19 epidemic situation to refine the specific implementation plan, conduct vaccination in a scientific and orderly manner, and reduce the social impact. © 2022, Publication Centre of Anhui Medical University. All rights reserved.
ABSTRACT
Objective: To describe the COVID-19 epidemic and its characteristics in Heilongjiang province, and provide evidence for the further prevention and control of COVID-19 in the province. Methods: The information of COVID-19 cases and clusters were collected from national notifiable disease report system and management information system for reporting public health emergencies of China CDC. The Software's of Excel 2010 and SPSS 23.0 were applied for data cleaning and statistical analysis on the population, time and area distributions of COVID-19 cases. Results: On January 22, 2020, the first confirmed case of COVID-19 was reported in Heilongjiang. By March 11, 2020, a total of 482 cases domestic case of COVID-19, The incidence rate was 1.28/100 000, the mortality rate was 2.70% (13/482) in 13 municipalities in Heilongjiang. There were 81 clusters of COVID-19, The number of confirmed cases accounted for 79.25% (382/482) of the total confirmed cases and 12 cases of deaths. The family clusters accounted for 86.42% (70/81). Compared with the sporadic cases, the mortality rate, proportion of elderly cases aged 60 or above and severe or critical cases of clinical classification were all higher in the clusters especially the family clusters, but the differences were not significant (P>0.05). There were 34 clusters involving more than 5 confirmed cases accounted for 41.98% (34/81) of the total clusters, the involved cases accounted for 68.31% (261/382) of the total cases of clusters. There were significant differences in age distribution of the cases among the case clusters with different case numbers. In the clusters involving 6-9 cases, the proportion of cases aged 65 years or above was more (26.53%, 39/147). Conclusions: The incidence rate of COVID-19 was relatively high and the early epidemic was serious in Heilongjiang, The number of cases was large in clusters especially family clusters.