Epidemiological characteristics of COVID-19 epidemic in Ejina banner, Inner Mongolia Autonomous Region, October 2021 / 中华流行病学杂志

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.

The pathogenic spectrum of hand, foot and mouth disease and molecular characterizations of human enterovirus 71 in Inner Mongolia autonomous region in 2010 / 病毒学报

To study the pathogenic spectrum of hand, foot and mouth disease (HFMD) and the molecular characterizations of human enteroviruses 71 (HEV71) isolated from the clinical specimens of HFMD patients in Inner Mongolia in 2010. A total of 921 clinical specimens including stools and throat swabs were collected from HFMD patients in outpatient service in Inner Mongolia and then viral isolation was performed, the positive viral isolates were identified by using the real-time PCR method (detecting EV, HEV71 and CVA16 in a single tube), and VP4 and VP1 coding region amplification and sequencing was performed with the viral isolates that were identified as non-HEV71, non-CVA16 HEVs. A total of 153 viruses were isolated form 921 clinical specimens, the positive rate was 16.61%, of which 61 (39.87%) were HEV71, 82 (53.59%) were CVA16, 7 (6.53%) were other HEVs(6 were CVB4 and 1 was polio vaccine virus type II) and 3 (1.96%) were adenoviruses. Nine viruses were isolated from severe cases, of which 6 were HEV71 and 3 were CVA16. Thirty two HEV71 isolates were selected from the patients presenting mild symptoms and the patients presenting severe symptoms randomly, and the VP1 coding regions of represented HEV71 isolates were amplified and sequenced. Finally the phylogenetic tree was constructed among the VP1 coding regions of the different genotypes and subgenotypes of HEV71 strains. The nucleotide acid and amino acid of 32 represented HEV71 strains in Inner Mongolia were closed to HEV71 strains isolated from mainland China since 2007, especially from Beijing in 2008, and it showed that all HEV71 strains clustered within the C4a evolution branch of C4 subgenotype. There was slight difference in the nucleotide and the amino acid sequence in VP1 region among the 32 Inner Mongolia HEV71 strains, the identity were 96.4%-100% and 98.14%-100%, respectively, and there was a little difference in the nucleotide acid sequence between the HEV71 strains from Inner Mongolia in 2010 and in 2007, the identity was from 96.95% to 97.87%. Thirty two HEV71 strains were in different lineages in the phylogenetic tree, and it indicated that these strains belonged to many different viral transmission chains. HEV71 and CVA16 were the main pathogens of HFMD in Inner Mongolia in 2010 and most severe cases were caused by HEV71. All the HEV71 strains circulated in Inner Mongolia belonged to C4a evolution branch within C4 subgenotype. Phylogenetic analysis revealed that 2010 Inner Mongolia HEV71 strains were located in different lineages, and had more nucleotide identity with 2008 Beijing HEV71 strains than with 2007 Inner Mongolia HEV71 strains. This indicated that Inner Mongolia HEV71 strains had not evolved independently, but co-evolved with the HEV71 strains in other provinces in mainland China.

B1a and b1b evolutionary branch of coxsackie virus A16 co-prevailed in Inner Mongolia Autonomous Region / 病毒学报

To study on the molecular evolution of Coxsackie virus A16 (CVA16)isolated from clinical speci-mens of Hand, foot and mouth Disease( HFMD) patients in Inner Mongolia in 2010. A total of 921 clinical specimens including stools, throat swabs and vesicle fluids were collected from 888 HFMD patients in out-patient service in Inner Mongolia and viral isolation was then performed, the positive viral isolates were identified by using the real-time PCR method detecting CVA16. A total of 50 CVA16 isolates were selected from the patients presenting mild symptoms, severe symptoms and the death patients randomly, and the VP1 coding regions of representative CVA16 isolates were amplified and sequenced. Finally the phylogenetic tree was constructed among the VP1 coding regions of the different genotypes and subgenotypes of CVA16 strains. Eighty two viruses were isolated form 921 clinical specimens, the positive rate was 8. 90%, of which 3 viruses were isolated from severe cases and 1 viruses was from death cases. The nucleotide acid of 50 representative CVA16 strains in Inner Mongolia were closed to CVA16 strains isolated from mainland China since 1998, especially from Beijing in 2009 and from Henan in 2010, the identity were 96. 18% approximately 98. 88% and 94. 94a approximately 98. 76%, respectively. There was a little difference in the nucleotide acid between the CVA16 strains from Inner Mongolia in 2010 and in 2007, the identity were 91. 68% approximately 96. 52% The phylogenetic tree showed that all CVA16 strains clustered within Bla and B1b evolution branch of B1 genotype. There was slight difference in the nucleotide and the amino acid in VP1 region among the 50 Inner Mongolia CVA16 strains, the identity were 89. 99% approximately 100% and 98. 31% approximately 100%, respectively, indicating that these strains belonged to many different viral transmission chains. The CVA16 strains circulated in Inner Mongolia in 2010 were all belong to B1a and B1b evolution branch of B1 genotype, and the two evolutionary branchs of Coxsackie virus A16 were co-evolved and co-prevailed in Inner Mongolia Autonomous Region.