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 study the molecular mechanisms of ampicillin- resistant haemophilius influenzae (Hi)in Nanjing. Methods One hundred and fifty- eight strains of Hi isolated from children were collected to detect bata-lactamase. TEM and ROB bata- lacta-mase genes were detected by polymerase chain reaction (PCR) ,and cloned into T vector for sequencing. Results The rate of ampicillin resistance was 41. 77% in Hi isolated from children in Nanjing,40.51 % was found to be bata-lactamase production. Eighty-nine strain were TEM positives, 1 strain was ROB positive,63 strains bata - lactamase positive ampicillin- resistant Hi were identified. The resistance mechanism of ampicillin resistant Hi was production of bata - lactamase , mainly TEM - type enzyme. Two bata - lactamase negative ampicillin - resistant Hi were identified , predicts the other mechanisms of ampicillin - resistant Hi was occuered yet . One strain of non -TEM - type,and non - ROB - type bata - lactamase - producing Hi was identified. Conclusions Ampicillin - resisitant in Hi isolated from children in this region is challenging. TEM bata - lactamase is the principal mechanism of ampicillin - resistant of Hi.