ABSTRACT
Objective: To understand the epidemiological characteristics of COVID-19 epidemic in Ejina banner, Inner Mongolia, in October 2021 and provide evidence for the improvement of COVID-19 prevention and control. Methods: The information about the time, area and population distributions of COVID-19 cases in Ejina before November 13, 2021 and the gene sequencing result of the isolates were collected for a statistical descriptive analysis. Results: The first COVID-19 case in Ejina occurred on 7 October, 2021. A total of 164 COVID-19 cases were reported from October 19 to November 12. Most cases were distributed in 6 communities in Darahub (156 cases, 95.12%). The result of full gene sequencing of the isolates indicted that the pathogen was Delta variant (B.1.617.2). The male to female ratio of the cases was 1.3∶1. The age of cases ranged from 1 to 85 years, and the cases aged 20-59 years accounted for 78.66%. The main clinical symptoms were sore throat (91 cases, 91.92%), cough (49 cases, 49.49%) and fever (23 cases, 23.23%). Most cases were ordinary ones (81 cases, 49.39%) and mild ones (68 cases, 41.46%). The cases were mainly detected at the isolation points (84 cases, 51.22%) and through population based nucleic acid testing (62 cases, 37.80%). The basic reproduction number (R0) of COVID-19 was 5.3, the average incubation period was 3.9 days. The local government rapidly started Ⅳ level emergency response and conducted 10 rounds of nucleic acid tests. The transferring of travelers reduced the risk for the further spread of COVID-19 in Ejina. Conclusions: The epidemic of COVID-19 in Ejina characterized by strong transmission, short incubation period, herd susceptibility and case clustering. Delta variant (B.1.617.2) was the pathogen, which might be imported from Zeke port. Comprehensive prevention and control measures, such as closed-loop management and vaccination, should be continued. The successful transferring of the patients and travelers provided evidence for the effective and precise prevention and control of COVID-19 in a routine manner.
Subject(s)
Adolescent , Adult , Aged , Aged, 80 and over , Child , Child, Preschool , Female , Humans , Infant , Male , Middle Aged , Young Adult , COVID-19 , China/epidemiology , Epidemics , SARS-CoV-2ABSTRACT
Objective To master of the characteristics of development and variation in plague natural foci of Marmota sibirica, and to analyze the plague monitoring results from 2004 to 2008. Methods From May to September every year, we monitored plague in Manzhouli, Chenbaerhuqi, Xinbaerhuzuoqi, Xinbaerhuyouqi,Ewenkeqi and Yakeshi city. The monitored area was 20 000 - 40 000 hm2 in every county. The density of Marmota,ground squirrel and moonlighting rats was surveyed by path method, one-day bow-clip method and a clamp was placed every five meters, respectively. The classification and identification of ectoparasite fleas were done by using low power lens. The fleas in the ground squirrel hole were collected by flannel rubber stick, then classified and identified. According to National Standard of Plague Diagnostic Criteria(GB 15991-1995), the collected rats and fleas were detected by isolation and cultured Yersinia pestis, the serums of collected rats were tested by indirect hemagglutination test. Results In five years, the density of Marmota and ground squirrel was 0.010/hm2 and 0.602/hm2, respectively. The capture rate of moonlighting rats was 2.69％ (258/9600). The flea infection rate of Marmota was 17.54％(10/57) and the fleas index was 2.54. The fleas infection rate of ground squirrel was 28.40％(213/750) and the fleas index was 1.01. Flea infection rat of ground squirrel hole was 5.60％(46/822) and the fleas index was 0.17. The total number of various hosts of Yersinia pestis detected was 1351, the groups number of the variety of cultured fleas was 127, and the pathogen test results were negative. The number of serum tested was 1064, positive number was 43, and the detection rate was 4.04％(43/1064). The highest positive titer was 1 : 1280. Other than 2006, the remaining four years were found positive for blood clotting material; positive serum was found in a total of three regions, they were Manzhouli, Xinbaerhuzuoqi, and Xinbaerhuyouqi; and 30, 12 and 1 copies of hemagglutination-positive sera were detected. Conclusions The epidemic of plague natural foci of Marmota sibirica is in a active state, and gradually expands the scope. We must continue to strengthen the inspection of the bacteria, bearing in mind the replacement of the region's main host, make every effort to prevent and control of human plague.