Objective:To investigate the molecular epidemiological characteristics of HIV-1 infection among men who have sex with men (MSM) in Jiaxing city, and provide methods and ideas for the prevention and control of HIV-1 infection.Methods:This study retrospectively collected the blood samples from all newly reported cases of HIV-1 infection among MSM without antiviral treatment from 2020 to 2022. HIV-1 pol genes in the blood samples were amplified and sequenced. MEGA v6.0 software was used to analyze nucleic acid sequences. A phylogenetic tree was constructed to analyze HIV-1 subtypes. The calibrated population resistance program (CPR) was used to detect drug-resistant mutations. After calculating the genetic distance between gene sequences, molecular transmission networks were constructed using Cytoscape v3.6.0 software. Results:A total of nine genetic subtypes were identified, with CRF07_BC (43.3%) and CRF01_AE (36.9%) accounting for the most. The recombinant forms that were not clustered with the reference subtype accounted for 5.0%. Drug-resistant mutations were identified in 21 cases (7.0%), and the mutation rates among strains of CRF07_BC and CRF01_AE subtypes were 8.2% and 7.8%, respectively. The detection rates of drug-resistant mutations to protease inhibitors, nucleoside reverse transcriptase inhibitors and non-nucleoside reverse transcriptase inhibitors were 1.7%, 0.7% and 4.7%, respectively. The optimal genetic distance threshold of the molecular network was 0.018. At this genetic distance, the molecular network access rate was 43.3%, and 38 molecular clusters (ranging from 2 to 26 nodes per cluster) were included. Cases with ≥6 homosexual partners and a degree value of ≥4 were more likely to access the active molecular cluster. The population of high-risk transmission cases with TNS>0.75 were mainly nonlocal residents and commercial service providers. The recombinant forms showed high similarity in sequences with the strains from other provinces.Conclusions:The distribution of HIV-1 subtypes in MSM in Jiaxing city was complex. Given the increasing detection rate of recombinant forms, the high transmission rate of drug-resistant mutations, and the active molecular clusters and high-risk transmission clusters mainly detected in nonlocal residents and commercial service providers, strengthened surveillance and intervention are needed.

Objective To investigate the epidemiological characteristics of COPD in people over 60 years old in Chaohu City, Anhui Province, and explore the risk factors affecting the occurrence and development of COPD, and to provide a data basis for formulating prevention and control measures of COPD. Methods Permanent residents over 60 years old in Chaohu City were selected as the research subjects. The subjects were selected by multi-stage stratified cluster random sampling method. All research subjects were divided into two different groups according to the diagnostic criteria of COPD and received questionnaire survey and pulmonary function tests. The differences in epidemiological distribution of the two groups were compared by χ² test. Logistics regression was used to analyze the risk factors affecting COPD. Results A total of 1722 cases were investigated in this study. The prevalence of COPD in people over 60 years old was 13.47%. The average age and body mass index of all research subjects were 70.4±7.5 years old and 20.4±3.5kg/m², respectively. Among them, 49.25% were males, 20.96% had college degree or above, and 63.88% lived in cities and towns. 23.11% of the subjects still smoked, 32.58% had quit smoking, and 28.16% had a history of passive smoking or were still receiving passive smoking. 16.20% of the subjects had an occupational exposure to dust and particulate matter as coal miners and painters. 51.34% of the subjects had a family history of respiratory diseases. 83.57% of the subjects had other chronic diseases, including coronary heart disease, hypertension, and diabetes. There were 232 cases diagnosed as COPD in this study. All subjects were divided into the COPD group and control group according to the diagnostic criteria of COPD. There were no significant differences between the two groups in body mass index, marital status, education, residence, type of fuel used and family history of respiratory diseases. However, there were significant differences in age, gender, smoking status, occupational dust exposure and chronic disease complications between the two groups. Multivariate logistic regression analysis showed that age (OR70~79 vs. 60~69=2.578, P=0.024; OR≥80 vs. 60~69=4.258, P=0.018), smoking status (OR_{passive smoking vs. Active smoking}=0.683, P=0.073; OR_{quit smoking vs. active smoking}=0.365, P=0.020; OR_{Non-smoking vs. active smoking}=0.252, P=0.008) and occupational dust exposure (OR=0.158, P=0.010) were the major risk factors for COPD. Conclusion Advanced age, active or passive smoking and occupational dust exposure are important risk factors for COPD.