[Correlation between morphological characteristics of retinal microvessels and diabetic kidney disease in patients with type 2 diabetes mellitus based on a machine learning model].

Objective: To explore the correlation between the morphological characteristics of retinal microvessels and diabetic kidney disease (DKD) in patients with type 2 diabetes mellitus (T2DM). Methods: The clinical data and fundus photography of patients with T2DM treated in the First Affiliated Hospital of Zhengzhou University from January 2018 to December 2020 were retrospectively collected and analyzed. According to the presence of abnormal renal function, the patients were divided into DKD group and control group. The morphology and structure of fundus vessels were digitized by U-Net depth convolution neural network, and the correlation between fundus vascular morphology and DKD was analyzed by multivariate logistic regression. Results: A total of 648 patients with T2DM were enrolled, including 410 males and 238 females, and aged (53±10) years. There were 398 and 250 cases in control and DKD groups, respectively. Meanwhile, 1 296 fundus images were collected. Compared with control group, the male ratio (68.4% vs 60.1%, P=0.032), age [(54±9) vs (52±10) years, P=0.005], blood pressure [(136.8±17.3) vs (130.3±15.4) mmHg（1 mmHg=0.133 kPa）, P<0.001], total cholesterol [(4.5±1.4) vs (4.2±1.0) mmol/L, P=0.009], triglyceride [M (Q1, Q3)][1.7 (1.2, 3.0) vs 1.4 (1.0, 2.3) mmol/L, P<0.001] and Cystatin C [(0.9 (0.8, 1.0) vs 0.8 (0.7, 0.9) mg/L, P<0.001] were higher in the DKD group, while high-density lipoprotein [(1.0±0.3) vs (1.1±0.3) mmol/L, P=0.001] was lower in the DKD group. Multivariate logistic regression analysis showed that the risk of DKD in the third quartile (right eye: OR=1.825, 95%CI: 1.204-2.768, P=0.005) and fourth quartile (left eye: OR=1.929, 95%CI: 1.218-3.055, P=0.005) was higher than that in the lowest quartile of vascular curvature after adjusting for age and gender. The increase of average diameter of retinal vein was associated with the risk of DKD (left eye: OR=1.044, 95%CI: 1.013-1.075, P=0.005). The decrease of vascular fractal dimension (fourth quartile of left eye: OR=0.444, 95%CI: 0.199-0.987, P=0.046) and retinal vascular density (the second and fourth quartile of the right eye: OR=0.639, 95%CI: 0.409-0.998, P=0.049; OR=0.534, 95%CI: 0.331-0.864, P=0.010) were related to the risk of DKD. Conclusions: The abnormal morphological characteristics of retinal microvessels are related to the occurrence of DKD. The increase of retinal vein diameter and the decrease of retinal vessel density correlate with the occurrence of DKD.

[Application of LASSO and its extended method in variable selection of regression analysis].

Multicollinearity is an important issue affecting the results of regression analysis. LASSO developed in recent years has great advantages in selecting explanatory variables, processing high-dimensional data, and solving multicollinearity problems. This method adds a penalty term to the model estimation, which can compress the regression coefficients of some unnecessary variables to zero and then remove them from the model to achieve the purpose of variable screening. This paper focuses on the LASSO method and compares it with optimal subsets, ridge regression, adaptive LASSO, and elastic net results. It is found that both LASSO and adaptive LASSO have good performance in solving independent variable multicollinearity problems and enhancing model interpretation and prediction accuracy.

[Investigation on influenza vaccination policy and vaccination situation during the influenza seasons of 2020-2021 and 2021-2022 in China].

Objective: To investigate the policies and coverage of influenza vaccine during the influenza epidemic seasons of 2020-2021 and 2021-2022 in China. Methods: The national influenza vaccination policy and vaccination rate were investigated in counties and districts and described in the two epidemic seasons. Results: In the epidemic seasons of 2020-2021 and 2021-2022, the vaccination coverage of influenza in China was 3.16% and 2.47%, respectively. The free vaccination policy had the highest vaccination coverage (51.75% and 38.32%), followed by the medical insurance reimbursement policy (9.74% and 7.36%). During the epidemic season of 2021-2022, the number of counties and districts implementing the free vaccination policy in China decreased 61 compared with the previous year, but the number of people covered increased by 51.29%. However, the vaccination coverage of the vast population decreased significantly, with the medical staff (75.69% and 40.15% for two epidemic seasons), preschool children (58.86% and 26.15%), and the elderly (45.71% and 32.94%). During the epidemic season of 2021-2022, the number of counties and districts implementing the medical insurance reimbursement policy increased by 6 compared with the previous year, and the number of people covered increased by 11.12%, but the vaccination coverage decreased. Conclusion: The influenza vaccination rate in China is low, and the implementation of cost preferential policy can greatly improve the influenza vaccination rate.

[Thoughts and suggestions on co-administration of seasonal influenza vaccine and COVID-19 vaccine].

In the context of the global pandemic of COVID-19, the epidemic intensity, epidemic characteristics and infection risk of influenza have presented new features. COVID-19 and influenza have simultaneously emerged in many regions of the world. COVID-19 and influenza are similar in terms of transmission mode, clinical symptoms and other aspects. There are also similarities in the mechanism of influenza virus and novel coronavirus on cells. At the same time, it is feasible and significant to do a good job in the prevention and control of COVID-19 and influenza. This paper discusses the relevant strategies and measures for the joint prevention and control of influenza and novel coronavirus from the aspects of influenza vaccination to prevent co-infection, simultaneous vaccination of influenza vaccine and novel coronavirus vaccine, etc., and puts forward corresponding thoughts and suggestions, in order to provide scientific support for the formulation of strategies on seasonal influenza vaccine and novel coronavirus vaccination.

[Pilot surveillance and evaluation of influenza-like illness based on automatic computer analysis of electronic medical record in sentinel hospital].

Objective: To compare the accuracy of influenza-like illness (ILI) surveillance by automatic computer analysis based on electronic medical records and by doctor's report. Methods: A total of 3 542 patients who presented to Yichang Central Hospital fever clinic, respiratory department or emergency department between April to October 2019 with an ICD-10 code for acute respiratory illness (J00-J22) and complete electronic medical information of ILI related syndromes were drawn as the study sample. Taking the classification of the study sample according to the ILI case definition by influenza surveillance professionals as the gold standard, draw the receiver operating characteristic (ROC) curve and calculate sensitivity, specificity, diagnostic consistency to compared the accuracy of ILI surveillance by automatic computer analysis and by doctor's report. Results: Median age of 3 542 cases was 30 (24, 38) years old; 1 179 cases (33.29%) compliance with the case definition, ILI reported by doctors was 1 306 cases (36.87%), and computer automatic identification ILI were 1 150 cases (32.47%); 1 391 (39.27%) cases were men. The results of automatic computer analysis and doctor report consistency of kappa values with gold standard judgment were 0.97 and 0.66 respectively; area under the ROC curve was 0.98 and 0.84, respectively. And the sensitivity and specificity of automatic computer analysis were higher than that of doctor's report (all P values were <0.001), the sensitivity was 96.95% and 82.27%, and the specificity was 99.70% and 85.78%, respectively. Conclusion: The automatic computer analysis based on electronic medical records can identified ILI cases with good sensitivity and specificity in ILI case surveillance.

[Early containment strategies and core measures for prevention and control of novel coronavirus pneumonia in China].

In December 2019, novel coronavirus pneumonia epidemic occurred in Wuhan, Hubei Province, and spread rapidly across the country. In the early stages of the epidemic, China adopted the containment strategy and implemented a series of core measures around this strategic point, including social mobilization, strengthening case isolation and close contacts tracking management, blocking epidemic areas and traffic control to reduce personnel movements and increase social distance, environmental measures and personal protection, with a view to controlling the epidemic as soon as possible in limited areas such as Wuhan. This article summarizes the background, key points and core measures in the country and provinces. It sent prospects for future prevention and control strategies.

Association between IRAK1 rs3027898 and miRNA-499 rs3746444 polymorphisms and rheumatoid arthritis : A case control study and meta-analysis.

BACKGROUND: The IRAK1 and miR-499 polymorphisms play an important role in the etiology of rheumatoid arthritis (RA). Several studies have been carried out to estimate the association between IRAK1 rs3027898 and miR-499 rs3746444 and RA risk; however, the results were inconsistent. AIM: A case control study was carried out to explore the association between IRAK1 rs3027898 and miR-499 rs3746444 and the RA risk in a Chinese population. Meta-analyses combining present with previous studies were conducted to further explore the association. MATERIAL AND METHODS: A total of 386 RA patients were enrolled along with 576 matched healthy controls. Genotyping was performed by using TaqMan genotyping assays on Fluidigm 192.24 system. For the meta-analysis, a systematic literature search was conducted to identify all relevant studies. RESULTS: This case control study showed that the IRAK1 rs3027898 C allele was associated with increased risk of RA with an odds ratio (OR) = 1.4 and 95 % confidence intervals (CI) = 1.093-1.793, P = 0.008 but miR-499 rs3746444 polymorphisms were not significantly associated with the risk for RA. The meta-analyses included a total of 4 case control studies on IRAK1 rs3027898 and 4 studies on miR-499 rs3746444. The IRAK1 rs3027898 C allele had an overall OR of 1.268 (95 % CI = 1.130-1.424, P < 0.001). After stratification by ethnicity the C allele had an OR of 1.238 (95 % CI = 1.096-1.398, P = 0.001) in Asians. No association between miR-499 rs3746444 polymorphism and RA was found in the overall and Asian populations. CONCLUSION: The results from our case control study and the meta-analyses indicate that the IRAK1 rs3027898 C allele is significantly associated with an increased risk of RA, especially in Asians.

[Clinical effects of early rehabilitation treatment after repair surgery of skin and soft tissue defects accompanied by extensor tendon injury on the back of hand].

Objective: To explore the clinical effects of early rehabilitation treatment after repair surgery of skin and soft tissue defects accompanied by extensor tendon injury on the back of hand. Methods: This study was a retrospective non-randomized controlled study. From February 2015 to February 2023, 24 patients (15 males and 9 females, aged 12-55 years) with skin and soft tissue defects accompanied by extensor tendon injury on the back of hand, who met the inclusion criteria and were repaired with flap transplantation and tendon grafting or tendon anastomosis, were admitted to the First Affiliated Hospital of Air Force Medical University. According to different intervention time for postoperative rehabilitation treatment of patients, the patients were divided into conventional rehabilitation group and early rehabilitation group, with 12 cases in each group. Patients in early rehabilitation group received rehabilitation treatment immediately after surgery under the rehabilitation guidance of specialized rehabilitation physicians based on the characteristics of different postoperative periods. Patients in conventional rehabilitation group began rehabilitation treatment from the third week after surgery, and their rehabilitation treatment was the same as that of patients in early rehabilitation group from the second week after surgery. The patients in 2 groups were treated in the hospital until the sixth week after surgery. The occurrence of flap vascular crisis and tendon rupture were observed within 6 weeks after surgery. After 6 weeks of surgery, the manual muscle test was used to measure the pinching force between the index finger and thumb, lateral pinching force, three-point pinching force, and grip force of the affected hand; the total action motion method was used to evaluate the finger joint range of motion of the affected hand, and the excellent and good ratio was calculated; the Carroll upper extremity function test was used to score and rate the function of the affected hand. Results: Within 6 weeks after surgery, only 1 patient in conventional rehabilitation group suffered from venous crisis, and the flap survived after the second surgical exploration and anastomosis of blood vessels; there was no occurrence of tendon rupture in patients of 2 groups. After 6 weeks of surgery, there were no statistically significant differences in pinching force between the index finger and thumb, lateral pinching force, three-point pinching force, or grip force of the affected hand between the two groups of patients (P>0.05); the excellent and good ratio of the finger joint range of motion of the affected hand of patients in early rehabilitation group was 11/12, which was higher than 7/12 in conventional rehabilitation group, but there was no statistically significant difference (P>0.05); the affected hand function score of patients in early rehabilitation group was 90±6, which was significantly higher than 83±8 in conventional rehabilitation group (t=2.41, P<0.05); the function rating of the affected hand of patients in early rehabilitation group was obviously better than that in conventional rehabilitation group (Z=2.04, P<0.05). Conclusions: Early rehabilitation treatment for patients with skin and soft tissue defects accompanied by extensor tendon injury on the back of hand after repair surgery can improve hand function, but it would not increase surgery related complications, which is worthy of clinical promotion and application.

[Theoretical models for influenza vaccination behavior at the individual level].

Influenza imposes a significant disease burden on society and individuals annually, and influenza vaccination is considered a significant public health measure to prevent influenza and reduce influenza-related severe disease and death. The low influenza vaccination rate in China is partly due to certain factors affecting the willingness and behavior of individuals to receive them. Scientific research and targeted interventions on these factors can effectively improve the vaccination situation. Commonly used individual-level theoretical models for influenza vaccination behavior include the health belief model, protection motivation theory, and theory of planned behavior. This study reviews theoretical models commonly employed in researching influenza vaccination willingness and behavior. An overview of these practical applications and challenges models is presented to provide references for relevant research and intervention programs in China.

The association between lysosomal protein glucocerebrosidase and Parkinson's disease.

BACKGROUND: In recent years, mutations in glucocerebrosidase gene (GBA), which encodes the lysosomal enzyme glucocerebrosidase (GCase) deficient in Gaucher disease (GD), were found to be the most widespread genetic for the development of Parkinson disease. AIM: In this work, we investigated the possibility of a biological linkage between GCase and alpha-synuclein. MATERIALS AND METHODS: siRNA was used to knockdown the GBA, then the related proteins such as alpha-synuclein were detected, additionally, the mutations of GBA were also detected. We also provide evidence that a mouse model of Gaucher disease (GBAD409H/D409H) to detect the gene types of GBA. RESULTS: The results showed functional knockdown (KD) of GBA in neuroblastoma cells culture causes a significant accumulation of alpha-synuclein and alpha-synuclein-mediated neurotoxicity. Furthermore, KD of GBA in rat primary neurons expressing the A53T mutation of alpha-synuclein, decreases cell viability. In addition, we observed that overexpression of several GBA mutants (N370S, L444P, D409H, D409V) significantly raised human alpha-syn levels of vector control. Glucosylceramide (GlcCer), the GCase substrate, influenced formation of purified a-syn by stabilizing soluble oligomeric intermediates. We also provide evidence that a mouse model of Gaucher disease (GBAD409H/D409H) exhibited alpha-syn aggregates in substantia nigra, cortex and hippocampus regions. ELISA analysis showed a significant rise in membrane-associated α-syn and western blot analysis showed that two forms of alpha-syn oligomers were present in brain homogenates from the hippocampus D409H mice. CONCLUSIONS: These studies support the contention that both WT and mutant GBA can cause Parkinson disease-like alpha-synuclein pathology.

[Curative effects of medial plantar free flap in reconstructing electric burn wound and scar contracture in the palm].

Objective: To explore the curative effects of medial plantar free flap in reconstructing electric burn wound and scar contracture in the palm. Methods: A retrospective observational study was conducted. From January 2020 to January 2023, 6 patients with electric burn wounds or scar contracture in the palm who met the inclusion criteria were admitted to the First Affiliated Hospital of Air Force Medical University, including 5 males and 1 female, aged 35 to 55 years. The wound area was 5.0 cm×3.0 cm-8.0 cm×7.0 cm after the debridement of electric burn wounds or resection of scar in the palm. The medial plantar free flap anastomosed with cutaneous nerve was used for wound reconstruction, with flap area of 5.5 cm×3.5 cm-8.5 cm×7.5 cm. The wound in the donor site was repaired with transplantation of abdominal full-thickness skin graft. After surgery, the survival of flaps and skin grafts were observed, the shape and texture of flap and the recovery of donor site of flap were observed, and the holding function of the affected hand was assessed. At the last follow-up, the two-point discrimination distance of flap was measured, the sensory recovery of flap was evaluated with the trial standard for the evaluation of the functions of the upper limbs of the Hand Surgery Society of the Chinese Medical Association, and the function recovery of flap was evaluated by post-surgery flap function evaluation scale. Results: After surgery, 5 flaps survived well, while the distal part of 1 flap was partially necrotic, which was repaired by medium-thickness skin graft from lateral thigh after debridement. All the skin grafts at the donor sites survived well. During follow-up of 3 to 24 months, the flap was not bloated, the texture and color were good, the match with the surrounding tissue was high, with no obvious scar contracture occurred at the donor site. The affected hand had good holding function. At the last follow-up, the two-point discrimination distance of flap was 6-8 mm, the flap sensation recovery was as follows: 5 flaps recovered to grade S3+, 1 flap recovered to grade S3, and the functional evaluation of flaps was excellent in 5 cases and good in 1 case. The patients basically returned to normal life and work. Conclusions: The medial plantar free flap with cutaneous nerve anastomosis has many advantages, such as high matching degree of appearance, good sensory recovery, and holding function of the affected hand. It is an ideal choice for the reconstruction of the electric burn wound and scar contracture in the palm.

[Progress in research of influenza vaccination in pregnant women].

Influenza is an acute respiratory infectious disease caused by influenza virus. Pregnancy is associated with physiologic and immunological changes that may increase the risk for influenza virus infection and influenza-related complications. Influenza vaccination is the most effective way to prevent influenza virus infection. WHO and many countries have classified pregnant women as a priority population for influenza vaccination, however, there are still many challenges for promoting influenza vaccination in pregnant women in China, influenza vaccination coverage in pregnant women remains low and some influenza vaccine package inserts list pregnancy as an absolute contraindication. In this paper, we summarize the research progress in the effects of influenza infection and influenza vaccination during pregnancy both at home and abroad, then discuss the strategies to promote influenza vaccination in pregnancy for the purpose of providing reference for the related research and policy development in China.

[Clinical experience of free superficial temporal fascia flap/anterolateral femoral fascial flap combined with skin grafting in repairing deep tissue defects of special parts of extremities].

The deep tissue defects of extremities are prone to cause the exposure of tendons, blood vessels, nerves, and bones, which are commonly repaired with free flaps in clinical practice. However, for special parts such as fingers, toes, posterior ankles, anterior tibias, and dorsum of feet, the appearances are usually bulky after being repaired with free flaps and need lipectomy operations, which bring great physiological, psychological, and economic burden to patients. As the fascia flap is soft and thin with reliable blood supply and strong anti-infection ability, the free fascia flap combined with skin grafting offers some advantages in repairing the above-mentioned wounds. However, its clinical application is severely limited due to the complexity of surgical operation and the difficulty in observing blood supply after operation. In recent years, our team has carried out a lot of work and accumulated rich experience in repairing deep tissue defects of special parts of extremities with free superficial temporal fascia flap/anterolateral femoral fascial flap combined with skin grafting. From the clinical perspective, this paper mainly introduces the anatomy and harvesting method of free superficial temporal fascia flap/anterolateral femoral fascial flap, as well as the advantages, difficulties, and precautions of clinical application, for reference of peers.

[Application of target trail emulation in real world: a case study of effect of statins on mortality in diabetes patients].

Target trail emulation is an observational research method, which can use real-world data (such as observational data and historical data) to carry out research design according to the design principles of randomized controlled trials (RCT) when RCT cannot be carried out. The intervention group and the control group were classified by simulating random grouping. Finally a high-reliable conclusion similar to RCT can be obtained. This paper summarizes the basic concepts and application process of target trail emulation based on the effect of statins on the prognosis of myocardial infarction in diabetic patients to provide reference for the application of this method in real world.

[Performance of screening of contacts of COVID-19 cases in same flight].

Objective: To understand the performance of 2019-nCoV nucleic acid detection in screening of contacts of COVID-19 cases in same flights and provide evidence for the effective screening of persons at high risk for the infection in domestic flights. Methods: The information of passengers who took same domestic flights with COVID-19 cases in China from April 1, 2020 to April 30, 2022 were retrospectively collected,and χ2 test was used to analyze positive nucleic acid detection rates in the passengers in different times before the onsets of the index cases, in different seat rows and in epidemic periods of different 2019-nCoV variants. Results: During the study period, a total of 433 index cases were identified among 23 548 passengers in 370 flights. Subsequently, 72 positive cases of 2019-nCoV nucleic acid were detected in the passengers, in whom 57 were accompanying persons of the index cases. Further analysis of the another 15 passengers who tested positive for the nucleic acid showed that 86.67% of them had onsets or positive detections within 3 days after the diagnosis of the index cases, and the boarding times were all within 4 days before the onsets of the index cases. The positive detection rate in the passengers who seated in first three rows before and after the index cases was 0.15% (95%CI: 0.08%-0.27%), significantly higher than in the passengers in other rows (0.04%, 95%CI: 0.02%-0.10%, P=0.007),and there was no significant difference in the positive detection rate among the passengers in each of the 3 rows before and after the index cases (P=0.577). No significant differences were found in the positive detection rate in the passengers, except the accompanying persons, among the epidemics caused by different 2019-nCoV variants (P=0.565). During the Omicron epidemic period, all the positive detections in the passengers, except the accompanying persons, were within 3 days before the onset of the index cases. Conclusions: The screening test of 2019-nCoV nucleic acid can be conducted in the passengers took the same flights within 4 days before the onsets of the index cases on board. Passengers who seated within 3 rows from the index cases can considered as the close contacts at high risk for 2019-nCoV, for whom screening should be conducted first and special managements are needed. The passengers in other rows can be classified as general risk persons for screening and management.

[Time distribution of positive nucleic acid detection in imported cases infected with SARS-CoV-2 in China].

Objective: To analyze the time distribution of the first positive nucleic acid detection in imported cases infected with SARS-CoV-2 reported nationwide in China and provide references for further improvement of the prevention and control of COVID-19 in international travelers. Methods: The data of imported cases infected with SARS-CoV-2 reported by provinces from 24 July 2020 and 23 July 2021 were collected for the analysis on the time distribution of the first positive nucleic acid detection after entering China. Results: A total of 7 199 imported cases infected with SARS-CoV-2 were reported in 28 provinces during 24 July 2020 to 23 July 2021. The median interval (Q1, Q3) from the entry to the first positive nucleic acid detection of SARS-CoV-2 was 1 (0, 5) day. The imported cases who had the first positive nucleic acid detections within 14 days and 14 days later after the entry accounted for 95.15% (6 850/7 199) and 4.85% (349/7 199) respectively. Among these cases, 3.65% (263/7 199), 0.88% (63/7 199) and 0.32% (23/7 199) had the first positive nucleic acid detections within 15-21 days, 22-28 days and 28 days later after the entry respectively. The proportion of asymptomatic infections were 47.24% (3 236/6 850) and 63.61% (222/349) among the cases who had the first positive nucleic acid detections within 14 days and 14 days later after the entry respectively. A total of 39.54% (138/349) of cases infected with SARS-CoV-2 with the first positive nucleic acid detections 14 days later after the entry had inter-provincial travel after the discharge of entry point isolation. Conclusions: About 5% of the imported cases infected with SARS-CoV-2 were first positive 14 days later after the entry. In order to effectively reduce the risk of domestic COVID-19 secondary outbreaks caused by imported cases, it is suggested to add a nucleic acid test on 8th -13th day after the entry.

[Investigation of incidence of acute respiratory infection and healthcare-seeking behavior in period of COVID-19 epidemic].

Objective: To analyze the incidence of acute respiratory infection (ARI) and related healthcare seeking behaviors in population in the period of COVID-19 epidemic in China. Methods: According to the province specific cumulative incidence rates of COVID-19 reported as of March 31, 2020, the low, medium and high-risk areas were classified. In these areas, a stratified two stage cluster random sampling method was used to select participants for face-to-face questionnaire surveys. Data on the incidence of ARI and related healthcare seeking behaviors in community residents during COVID-19 epidemic period were collected to calculate the attack rate of ARI and related healthcare seeking rate. Logistic regression method was used to explore the influencing factors for ARI incidence and healthcare seeking behavior. Results: A total of 34 857 community residents were surveyed, in whom 647 (1.9%) reported that they had ARI symptoms during the COVID-19 epidemic period, and 241 (37.2%) had healthcare seeking behaviors. In terms of the incidence of COVID-19-related ARI, in high-risk area, the risk of COVID-19-related ARI was 1.36 times (95%CI: 1.12-1.65) than that in low-risk area; among different age groups, the risk of COVID-19-related ARI in age groups 20-39 years, ≥60 years was 1.80 times (95%CI: 1.29-2.59) and 1.63 times (95%CI: 1.14-2.40) than that in age group 1-9 years; the risk of COVID-19-related ARI in people with underlying diseases was 1.53 times (95%CI: 1.23-1.89) than that in those without underlying diseases; the risk of COVID-19-related ARI in people with contacts with confirmed cases of COVID-19 and people with fever or respiratory symptoms was 1.53 times (95%CI: 1.01-2.27) and 6.60 times (95%CI: 5.05-8.53) than those in people without these contacts. The healthcare seeking rate in COVID-19-related ARI patients with exposures to those with fever or respiratory symptoms was 1.68 times (95%CI: 1.05-2.70) than that in such patients without the exposures. Conclusions: The attack rate of COVID-19-related ARI was affected by the local epidemic level of COVID-19, and in high-risk area, the attack rate of COVID-19-related ARI was also high. The healthcare seeking rate in patients with COVID-19-related ARI was low. Therefore, it is necessary to encourage the healthcare seeking in people with ARI in COVID-19 pandemic period.

[Advance on the infectivity of SARS-CoV-2 infection at different stages].

The studies on infectiousness of person infected with SARS-CoV-2 at different stages of illness are an important basis for making effective prevention and control measures such as investigating the infectious source, determining the scope of close contacts and the timing of case isolation. This review discusses the infectiousness of cases infected with SARS-CoV-2 in the incubation period, symptomatic period and convalescent period by reviewing national and international literatures, technical and professional guidelines. Existing researches suggest that the infectious viruses could be isolated at the end of the incubation period as well as since illness onset, and viral load in upper respiratory tract swabs reached the peak on day 4-6 after illness onset and thereafter began to decline, implying the infectiousness was relatively strong at the end of incubation period and within one week after illness onset. Although there were a few cases who tested positive for SARS-CoV-2 after recovery, no evidence was found to indicate these cases can cause the transmission.

[Analysis on prevention and control of some infectious diseases in the elderly aged 60 years and above in China and countermeasure recommendation].

As the progress of population aging in China, the proportion of elderly population is increasing. Both chronic diseases and infectious diseases can threaten the health of the elderly. There are many kinds of infectious diseases, including vaccine preventable infectious diseases affecting the health of adults, such as influenza, pneumococcal diseases and herpes zoster. In addition, the newly emerged COVID-19 has caused a pandemic in the world, resulting the highest proportion of deaths occurred in the elderly and posing a serious threat to the health of the elderly. This paper mainly summarizes the prevention and control of vaccine preventable diseases and COVID-19 to which the elderly are susceptible, analyzes the infectious disease problems affecting the health of elderly population, and recommends countermeasures for the prevention and control of these diseases in elderly population.

[Progress in research of specific antibody dynamic characteristics in patients with COVID-19].

COVID-19 is an emerging infectious disease caused by SARS-CoV-2. After the infection of the virus, the host immune system is stimulated to produce multifarious specific antibodies to decrease or eliminate effects of the pathogen. Study of the specific antibodies dynamic characteristics in patients with COVID-19 is very important for the understanding and diagnosis of the disease, research and development of vaccine, and planning of prevention and control strategy. This paper reviews and summarizes the domestic and oversea research on dynamic characteristics of specific antibodies of COVID-19 patients, including the antibody producing, duration and level, and its possible influencing factors in order to improve the understanding of the immunological characteristics of COVID-19.