1. Analysis of cerebral gray matter structure in multiple sclerosis and neuromyelitis optica
Xiao-Li LIU ; Ai-Xue WU ; Ru-Hua LI ; An-Ting WU ; Cheng-Chun CHEN ; Lin XU ; Cai-Yun WEN ; Dai-Qian CHEN
Acta Anatomica Sinica 2024;55(1):17-24
Objective The volume and cortical thickness of gray matter in patients with multiple sclerosis (MS) and neuromyelitis optica (NMO) were compared and analyzed by voxel⁃based morphometry (VBM) and surface⁃based morphometry (SBM), and the differences in the structural changes of gray matter in the two diseases were discussed. Methods A total of 21 MS patients, 16 NMO patients and 19 healthy controls were scanned by routine MRI sequence. The data were processed and analyzed by VBM and SBM method based on the statistical parameter tool SPM12 of Matlab2014a platform and the small tool CAT12 under SPM12. Results Compared with the normal control group (NC), after Gaussian random field (GRF) correction, the gray matter volume in MS group was significantly reduced in left superior occipital, left cuneus, left calcarine, left precuneus, left postcentral, left central paracentral lobule, right cuneus, left middle frontal, left superior frontal and left superior medial frontal (P<0. 05). After family wise error (FWE) correction, the thickness of left paracentral, left superiorfrontal and left precuneus cortex in MS group was significantly reduced (P<0. 05). Compared with the NC group, after GRF correction, the gray matter volume in the left postcentral, left precentral, left inferior parietal, right precentral and right middle frontal in NMO group was significantly increased (P<0. 05). In NMO group, the volume of gray matter in left middle occipital, left superior occipital, left inferior temporal, right middle occipital, left superior frontal orbital, right middle cingulum, left anterior cingulum, right angular and left precuneus were significantly decreased (P<0. 05). Brain regions showed no significant differences in cortical thickness between NMO groups after FWE correction. Compared with the NMO group, after GRF correction, the gray matter volume in the right fusiform and right middle frontal in MS group was increased significantly(P<0. 05). In MS group, the gray matter volume of left thalamus, left pallidum, left precentral, left middle frontal, left middle temporal, right pallidum, left inferior parietal and right superior parietal were significantly decreased (P<0. 05). After FWE correction, the thickness of left inferiorparietal, left superiorparietal, left supramarginal, left paracentral, left superiorfrontal and left precuneus cortex in MS group decreased significantly (P<0. 05). Conclusion The atrophy of brain gray matter structure in MS patients mainly involves the left parietal region, while NMO patients are not sensitive to the change of brain gray matter structure. The significant difference in brain gray matter volume between MS patients and NMO patients is mainly located in the deep cerebral nucleus mass.
2.Lycium barbarum miR2911-loaded exosomes promote spermatogenic function recovery in rats with non-obstructive azoospermia by regulating Wnt/β-catenin signaling pathways
Jia TIAN ; Zhi-Yuan XIE ; Cheng-Bin PEI ; Ai-Hua SONG ; Yue ZHOU ; Liang-Hong MA
National Journal of Andrology 2024;30(6):483-492
Objective:To investigate the effect of exosomes loaded with Lycium barbarum miRNA(Lb-miR2911)on spermato-genic function recovery in non-obstructive azoospermia(NOA)rats through cross-regulation of the Wnt/β-catenin signaling pathways.Methods:We established an NOA model in 30 four-week-old male SD rats by intraperitoneal injection of busulfan.At 5 weeks after modeling,we equally randomized the rats into a model control group(MC,untreated),an Lb-miR2911EXO group(Lb-miR2911EXO,treated by intratesticular injection of Lb-miR2911-loaded exosomes),and a sham group(Shame,treated by intratesticular injection of exosomes-empty drug),with another 10 male SD rats taken as normal controls(NC).We observed the uptake and metabolic changes of Lb-miR2911 in the testis tissue of the rats by RNA FISH at 2 and 6 weeks after treatment,detected cell proliferation,spermatogenesis and gene expressions of the Wnt/β-catenin signaling pathways in the testis tissue by Transcriptome sequencing analysis combined with Western blot and RT-PCR at 12 weeks,evaluated the recovery of the spermatogenic function based on the testis tissue morphology and sperm quality,and assessed the organ toxicity of Lb-miR2911 in the tissue and organs of the rats based on histomorphological analysis and the levels of serum TNF-α,IL-1β,Aspartate aminotransferase(AST),Alanine aminotransferase(ALT)and other relevant indi-cators.Results:After 12 weeks of treatment,histomorphological analysis showed regular arrangement of spermatogenic cells at all levels in the testis tissue,with a large number of mature sperm in the tubular lumen,and with significantly higher Johnsen scores,tes-tis weight,testicular index,sperm concentration and sperm motility in the Lb-miR2911EXO than in the sham group(all P<0.05).Compared with the model controls,the Lb-miR2911EXO group exhibited remarkably down-regulated gene expression of DACT3(P<0.05),up-regulated expressions of DVL2 and β-catenin(P<0.05),elevated levels of p-DVL2 and β-catenin(nucleus)proteins(P<0.05),increased expressions of cell proliferation-related genes CCND1,CCNE1 and CCNE2(P<0.05)and spermatogenesis-related genes DMC1,CCR6,JAM2 and KLC3(P<0.05).No pathological changes were observed in the lung,liver and kidney tis-sues of the rats,or in the levels of serum TNF-α,IL-1β,AST,ALT,creatinine and urea nitrogen in the rats treated with Lb-miR2911EXO compared with the normal controls(P>0.05).Conclusion:Lb-miR2911-loaded exosomes promote spermatogenic function recovery in NOA rats through cross-regulation of the DACT3,Wnt and β-catenin signaling pathways.
3.Identification of an LDLR variant in a Chinese familial hypercholesterolemia and its relation to ROS/NLRP3-Mediated pyroptosis in hepatic cells.
Wen-Zhuo CHENG ; Wei-Hua WANG ; Ai-Ping DENG ; Xiao DANG ; Chao LIU ; Xian-Can WANG ; Ju-Yi LI ; Si JIN
Journal of Geriatric Cardiology 2023;20(5):341-349
BACKGROUND:
Familial hypercholesterolemia (FH) is a common autosomal dominant hereditary disease. Its early diagnosis and intervention significantly improve the patient's quality of life. However, there are few types of research on the FH pathogenic genes in China.
METHODS:
In this study, we recruited a family diagnosed with FH and used whole exome sequencing (WES) to analyze the proband variants. Intracellular cholesterol level, reactive oxygen species (ROS) level, and the expression of pyroptosis-related genes were detected after overexpression of wild-type or variant LDLR in L02 cells.
RESULTS:
A heterozygous missense variant predicted to be deleterious to LDLR (c.1879G > A, p.Ala627Thr) was identified in the proband. Mechanistically, intracellular cholesterol level, ROS level, and the expression of pyroptosis-related genes, nucleotide-binding oligomerization domain-like receptor family protein 3 (NLRP3) inflammasome and components (caspase 1, apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) and NLRP3), gasdermin D (GSDMD), interleukin (IL) -18, IL-1β was elevated in the variant LDLR group, which was attenuated by inhibition of ROS.
CONCLUSIONS
FH is associated with a variant (c.1879G>A, p.Ala627Thr) in the LDLR gene. Regarding the mechanism, the ROS/NLRP3-mediated pyroptosis in hepatic cells may contribute to the pathogenesis of the LDLR variant.
4.Clinical tolerability and pharmacokinetics of troxacitabine.
Yan SONG ; Cheng Xu CUI ; Wen ZHANG ; Yong Kun SUN ; Lin YANG ; Hua ZHOU ; Hai Feng LIU ; Ai Ping ZHOU
Chinese Journal of Oncology 2023;45(6):519-524
Objective: To investigate the safety and efficacy of troxatabine in advanced or relapsed malignant tumors resistant to standard therapy in China. Methods: This is a phase Ⅰ prospective study. During dose escalation, patients in Cancer Hospital, Chinese Academy of Medical Sciences received a single-dose intravenous infusion of troxacitabine. The planned dosing groups were 1.8, 3.6, 4.8, 6.4 and 8.0 mg/m(2) on days 1 and 8 every 3 weeks. The data of all patients were collected for safety analyses. Safety and tolerability were evaluated by monitoring adverse events. Results: Nineteen patients were enrolled from April 2018 to May 2019. The major adverse events were fatigue (89.5%, 17/19), leukopenia (84.2%, 16/19) and neutropenia (78.9%, 15/19). The dose limiting toxicity was neutropenia. The maximum tolerated dose was 6.4 mg/m(2). The best effect was stable disease (43.8%). The half-life of elimination phase from 15.91 hours to 76.63 hours in each dose group. Conclusions: The toxicity of troxacitabine is well tolerant. We recommend that the dose for Phase Ⅱ clinical trial should be 6.4 mg/m(2).
Humans
;
Antineoplastic Agents/adverse effects*
;
Maximum Tolerated Dose
;
Neoplasms/drug therapy*
;
Neutropenia/chemically induced*
;
Prospective Studies
5.Leonurine inhibits ferroptosis in renal tubular epithelial cells by activating p62/Nrf2/HO-1 signaling pathway.
Ai-Jun WU ; Nai-Qing CHEN ; Li-Hua HUANG ; Ran CHENG ; Xiao-Wan WANG ; Chuang LI ; Wei MAO ; Qing-Ming HUANG ; Peng XU ; Rui-Min TIAN
China Journal of Chinese Materia Medica 2023;48(8):2176-2183
To investigate the protective effect and the potential mechanism of leonurine(Leo) against erastin-induced ferroptosis in human renal tubular epithelial cells(HK-2 cells), an in vitro erastin-induced ferroptosis model was constructed to detect the cell viability as well as the expressions of ferroptosis-related indexes and signaling pathway-related proteins. HK-2 cells were cultured in vitro, and the effects of Leo on the viability of HK-2 cells at 10, 20, 40, 60, 80 and 100 μmol·L~(-1) were examined by CCK-8 assay to determine the safe dose range of Leo administration. A ferroptosis cell model was induced by erastin, a common ferroptosis inducer, and the appropriate concentrations were screened. CCK-8 assay was used to detect the effects of Leo(20, 40, 80 μmol·L~(-1)) and positive drug ferrostatin-1(Fer-1, 1, 2 μmol·L~(-1)) on the viability of ferroptosis model cells, and the changes of cell morphology were observed by phase contrast microscopy. Then, the optimal concentration of Leo was obtained by Western blot for nuclear factor erythroid 2-related factor 2(Nrf2) activation, and transmission electron microscope was further used to detect the characteristic microscopic morphological changes during ferroptosis. Flow cytometry was performed to detect reactive oxygen species(ROS), and the level of glutathione(GSH) was measured using a GSH assay kit. The expressions of glutathione peroxidase 4(GPX4), p62, and heme oxygenase 1(HO-1) in each group were quantified by Western blot. RESULTS:: showed that Leo had no side effects on the viability of normal HK-2 cells in the concentration range of 10-100 μmol·L~(-1). The viability of HK-2 cells decreased as the concentration of erastin increased, and 5 μmol·L~(-1) erastin significantly induced ferroptosis in the cells. Compared with the model group, Leo dose-dependently increased cell via-bility and improved cell morphology, and 80 μmol·L~(-1) Leo promoted the translocation of Nrf2 from the cytoplasm to the nucleus. Further studies revealed that Leo remarkably alleviated the characteristic microstructural damage of ferroptosis cells caused by erastin, inhibited the release of intracellular ROS, elevated GSH and GPX4, promoted the nuclear translocation of Nrf2, and significantly upregulated the expression of p62 and HO-1 proteins. In conclusion, Leo exerted a protective effect on erastin-induced ferroptosis in HK-2 cells, which might be associated with its anti-oxidative stress by activating p62/Nrf2/HO-1 signaling pathway.
Humans
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Ferroptosis
;
Reactive Oxygen Species/metabolism*
;
NF-E2-Related Factor 2/metabolism*
;
Sincalide/pharmacology*
;
Signal Transduction
;
Epithelial Cells/metabolism*
;
Glutathione
6.Effects and mechanisms of ferroptosis on high glucose-induced retinal pigment epithelial cells injury
Jin ZHANG ; Ai-Hua JIA ; Yan GAO ; Cheng-Xiu LIU ; Tao LIANG
International Eye Science 2023;23(6):894-899
AIM: To observe the effects and mechanisms of ferroptosis on high glucose(HG)-induced retinal pigment epithelium(RPE)cells injury, and to provide new ideas for the treatment of diabetic retinopathy(DR).METHODS: The ARPE-19 cell lines cultured in vitro were divided into normal control group(NC group), high glucose group(HG group), and high glucose+Ferrostatin-1 group(Fer-1 group). The cell viability of each group was detected by CCK-8 assay. The expressions of interleukin 6(IL-6), IL-1β and monocyte chemotactic protein-1(MCP-1)were detected using ELISA kits. The levels of malondialdehyde(MDA), glutathione(GSH), glutathione peroxidase 4(GPX4)and iron content were detected using the corresponding assay kits. The mitochondrial changes in ARPE-19 cells were observed by transmission electron microscopy. The expressions of ferroptosis-related proteins including long-chain lipoyl CoA synthase 4(ACSL4)and GPX4, as well as vascular endothelial growth factor(VEGF)were detected by Western blotting and immunofluorescence staining.RESULTS: Compared with NC group, the cell viability of HG group decreased significantly, the expression levels of inflammatory factors in cell supernatant increased, the contents of MDA and iron significantly increased, GSH and GPX4 significantly decreased(all P<0.01), the mitochondria of ARPE-19 cells shrunk, the expression of proteins ACSL4 and VEGF increased, while the expression of GPX4 decreased(all P<0.01). Compared with HG group, the cell viability of Fer-1 group significantly increased, the expression levels of inflammatory factors in cell supernatant decreased, MDA and iron contents significantly decreased, GSH contents and GPX4 viability significantly increased(all P<0.05), the morphology of mitochondria in ARPE-19 cells improved, the expression of ACSL4 and VEGF decreased, while the expression of GPX4 increased(all P<0.05).CONCLUSION: Ferroptosis is involved in the injury of RPE induced by HG. Inhibiting ferroptosis can improve cell viability, reduce inflammation and oxidative stress, and alleviate HG-induced RPE cells injury.
7.Modified strict sperm morphology threshold aids in the clinical selection of conventional in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI).
Yong ZHU ; Feng ZHANG ; Hua CHENG ; Xiao-Xi SUN ; Feng JIANG
Asian Journal of Andrology 2022;24(1):62-66
For infertility treatment, the selection of in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) is decided by multiplying indicators (including fallopian tube factors, semen count, and semen motility), except for sperm morphology. In this study, we conducted a retrospective analysis, from implantation to birth, over a period of 5 years. A total of 1873 couples with primary or secondary fallopian tube factors and an increased defective sperm morphology rate (DSMR) were divided into different groups to receive IVF or ICSI cycles. By comparing the outcomes, we found that the F1 group (DSMR <96%, IVF group 1) had higher cleavage rate, biochemical pregnancy rate, clinical pregnancy rate, and live birth rate than the F3 group (DSMR >98%, IVF group 3; P < 0.05). In contrast, there was no significant difference in the ICSI subgroups. Furthermore, a comparison of the outcomes between IVF and ICSI showed that the S3 group (DSMR >98%, ICSI group 3) had higher cleavage rate (P < 0.001), biochemical pregnancy rate (P < 0.05), clinical pregnancy rate (P < 0.05) and live birth rate (P < 0.05) than the F3 group. However, the ICSI subgroup had a lower two pronuclei fertilization rate than the IVF subgroup (P < 0.05). Our data suggest that the sperm morphology should also be considered when selecting IVF or ICSI combined with other semen parameters before the first assisted reproductive technologies (ART) cycle, especially for males with severe sperm defects.
Female
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Fertilization in Vitro
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Humans
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Male
;
Pregnancy
;
Pregnancy Rate
;
Reproductive Techniques, Assisted
;
Retrospective Studies
;
Sperm Injections, Intracytoplasmic
;
Spermatozoa
8.Analysis on the epidemic characteristics and genetic characteristics of varicella in Beijing from 2019 to 2021.
Ai Hua LI ; Dan ZHAO ; Xiao Jing WEN ; Fang HUANG ; Li LU ; Meng CHEN ; Cheng GONG
Chinese Journal of Preventive Medicine 2022;56(8):1118-1122
The reported incidence of varicella in Beijing from 2019 to 2021 were 63.8/100 000, 32.2/100 000 and 38.6/100 000, respectively. There were two VZV epidemics in Beijing each year, one peaked in May and the other in November. However, the first VZV epidemic almost disappeared in 2020. Among the cases involved in the varicella outbreaks in school, the proportion of the students with no history of vaccine immunization, 1 dose of immunization and 2 doses of immunization were 33.12%, 44.79% and 22.08%, respectively. The major body of VZV breakthrough cases was children aged 6-14 years (523/755, 69.27%). The proportion of moderate- or severe-rash were 55.32%, 39.06%, 29.96% in the three groups of cases with no immunization history, 1 dose of immunization and 2 doses of immunization, respectively (P<0.001). A total of 1 089 varicella samples were collected, and 837 (76.86%) were confirmed to be PCR-positive for VZV and were identified as VZV wild strains. 311 VZV strains were sequenced successfully, and 307 strains were clade 2 (98.72%), 1 clade 3 (0.32%) and 3 Clade 5 (0.96%). Compared with the representative strains, the nucleotide similarities of ORF22 fragments were between 99.4% and 100%, and amino acid similarities were between 99.4% and 100%.
Beijing/epidemiology*
;
Chickenpox/epidemiology*
;
Chickenpox Vaccine
;
Child
;
Herpesvirus 3, Human/genetics*
;
Humans
;
Schools
;
Vaccination
9.A multicenter epidemiological study of acute bacterial meningitis in children.
Cai Yun WANG ; Hong Mei XU ; Jiao TIAN ; Si Qi HONG ; Gang LIU ; Si Xuan WANG ; Feng GAO ; Jing LIU ; Fu Rong LIU ; Hui YU ; Xia WU ; Bi Quan CHEN ; Fang Fang SHEN ; Guo ZHENG ; Jie YU ; Min SHU ; Lu LIU ; Li Jun DU ; Pei LI ; Zhi Wei XU ; Meng Quan ZHU ; Li Su HUANG ; He Yu HUANG ; Hai Bo LI ; Yuan Yuan HUANG ; Dong WANG ; Fang WU ; Song Ting BAI ; Jing Jing TANG ; Qing Wen SHAN ; Lian Cheng LAN ; Chun Hui ZHU ; Yan XIONG ; Jian Mei TIAN ; Jia Hui WU ; Jian Hua HAO ; Hui Ya ZHAO ; Ai Wei LIN ; Shuang Shuang SONG ; Dao Jiong LIN ; Qiong Hua ZHOU ; Yu Ping GUO ; Jin Zhun WU ; Xiao Qing YANG ; Xin Hua ZHANG ; Ying GUO ; Qing CAO ; Li Juan LUO ; Zhong Bin TAO ; Wen Kai YANG ; Yong Kang ZHOU ; Yuan CHEN ; Li Jie FENG ; Guo Long ZHU ; Yan Hong ZHANG ; Ping XUE ; Xiao Qin LI ; Zheng Zhen TANG ; De Hui ZHANG ; Xue Wen SU ; Zheng Hai QU ; Ying ZHANG ; Shi Yong ZHAO ; Zheng Hong QI ; Lin PANG ; Cai Ying WANG ; Hui Ling DENG ; Xing Lou LIU ; Ying Hu CHEN ; Sainan SHU
Chinese Journal of Pediatrics 2022;60(10):1045-1053
Objective: To analyze the clinical epidemiological characteristics including composition of pathogens , clinical characteristics, and disease prognosis acute bacterial meningitis (ABM) in Chinese children. Methods: A retrospective analysis was performed on the clinical and laboratory data of 1 610 children <15 years of age with ABM in 33 tertiary hospitals in China from January 2019 to December 2020. Patients were divided into different groups according to age,<28 days group, 28 days to <3 months group, 3 months to <1 year group, 1-<5 years of age group, 5-<15 years of age group; etiology confirmed group and clinically diagnosed group according to etiology diagnosis. Non-numeric variables were analyzed with the Chi-square test or Fisher's exact test, while non-normal distrituction numeric variables were compared with nonparametric test. Results: Among 1 610 children with ABM, 955 were male and 650 were female (5 cases were not provided with gender information), and the age of onset was 1.5 (0.5, 5.5) months. There were 588 cases age from <28 days, 462 cases age from 28 days to <3 months, 302 cases age from 3 months to <1 year of age group, 156 cases in the 1-<5 years of age and 101 cases in the 5-<15 years of age. The detection rates were 38.8% (95/245) and 31.5% (70/222) of Escherichia coli and 27.8% (68/245) and 35.1% (78/222) of Streptococcus agalactiae in infants younger than 28 days of age and 28 days to 3 months of age; the detection rates of Streptococcus pneumonia, Escherichia coli, and Streptococcus agalactiae were 34.3% (61/178), 14.0% (25/178) and 13.5% (24/178) in the 3 months of age to <1 year of age group; the dominant pathogens were Streptococcus pneumoniae and the detection rate were 67.9% (74/109) and 44.4% (16/36) in the 1-<5 years of age and 5-<15 years of age . There were 9.7% (19/195) strains of Escherichia coli producing ultra-broad-spectrum β-lactamases. The positive rates of cerebrospinal fluid (CSF) culture and blood culture were 32.2% (515/1 598) and 25.0% (400/1 598), while 38.2% (126/330)and 25.3% (21/83) in CSF metagenomics next generation sequencing and Streptococcus pneumoniae antigen detection. There were 4.3% (32/790) cases of which CSF white blood cell counts were normal in etiology confirmed group. Among 1 610 children with ABM, main intracranial imaging complications were subdural effusion and (or) empyema in 349 cases (21.7%), hydrocephalus in 233 cases (14.5%), brain abscess in 178 cases (11.1%), and other cerebrovascular diseases, including encephalomalacia, cerebral infarction, and encephalatrophy, in 174 cases (10.8%). Among the 166 cases (10.3%) with unfavorable outcome, 32 cases (2.0%) died among whom 24 cases died before 1 year of age, and 37 cases (2.3%) had recurrence among whom 25 cases had recurrence within 3 weeks. The incidences of subdural effusion and (or) empyema, brain abscess and ependymitis in the etiology confirmed group were significantly higher than those in the clinically diagnosed group (26.2% (207/790) vs. 17.3% (142/820), 13.0% (103/790) vs. 9.1% (75/820), 4.6% (36/790) vs. 2.7% (22/820), χ2=18.71, 6.20, 4.07, all P<0.05), but there was no significant difference in the unfavorable outcomes, mortility, and recurrence between these 2 groups (all P>0.05). Conclusions: The onset age of ABM in children is usually within 1 year of age, especially <3 months. The common pathogens in infants <3 months of age are Escherichia coli and Streptococcus agalactiae, and the dominant pathogen in infant ≥3 months is Streptococcus pneumoniae. Subdural effusion and (or) empyema and hydrocephalus are common complications. ABM should not be excluded even if CSF white blood cell counts is within normal range. Standardized bacteriological examination should be paid more attention to increase the pathogenic detection rate. Non-culture CSF detection methods may facilitate the pathogenic diagnosis.
Adolescent
;
Brain Abscess
;
Child
;
Child, Preschool
;
Escherichia coli
;
Female
;
Humans
;
Hydrocephalus
;
Infant
;
Infant, Newborn
;
Male
;
Meningitis, Bacterial/epidemiology*
;
Retrospective Studies
;
Streptococcus agalactiae
;
Streptococcus pneumoniae
;
Subdural Effusion
;
beta-Lactamases
10.Course of disease and related epidemiological parameters of COVID-19: a prospective study based on contact tracing cohort.
Yan ZHOU ; Wen Jia LIANG ; Zi Hui CHEN ; Tao LIU ; Tie SONG ; Shao Wei CHEN ; Ping WANG ; Jia Ling LI ; Yun Hua LAN ; Ming Ji CHENG ; Jin Xu HUANG ; Ji Wei NIU ; Jian Peng XIAO ; Jian Xiong HU ; Li Feng LIN ; Qiong HUANG ; Ai Ping DENG ; Xiao Hua TAN ; Min KANG ; Gui Min CHEN ; Mo Ran DONG ; Hao Jie ZHONG ; Wen Jun MA
Chinese Journal of Preventive Medicine 2022;56(4):474-478
Objective: To analyze the course of disease and epidemiological parameters of COVID-19 and provide evidence for making prevention and control strategies. Methods: To display the distribution of course of disease of the infectors who had close contacts with COVID-19 cases from January 1 to March 15, 2020 in Guangdong Provincial, the models of Lognormal, Weibull and gamma distribution were applied. A descriptive analysis was conducted on the basic characteristics and epidemiological parameters of course of disease. Results: In total, 515 of 11 580 close contacts were infected, with an attack rate about 4.4%, including 449 confirmed cases and 66 asymptomatic cases. Lognormal distribution was fitting best for latent period, incubation period, pre-symptomatic infection period of confirmed cases and infection period of asymptomatic cases; Gamma distribution was fitting best for infectious period and clinical symptom period of confirmed cases; Weibull distribution was fitting best for latent period of asymptomatic cases. The latent period, incubation period, pre-symptomatic infection period, infectious period and clinical symptoms period of confirmed cases were 4.50 (95%CI:3.86-5.13) days, 5.12 (95%CI:4.63-5.62) days, 0.87 (95%CI:0.67-1.07) days, 11.89 (95%CI:9.81-13.98) days and 22.00 (95%CI:21.24-22.77) days, respectively. The latent period and infectious period of asymptomatic cases were 8.88 (95%CI:6.89-10.86) days and 6.18 (95%CI:1.89-10.47) days, respectively. Conclusion: The estimated course of COVID-19 and related epidemiological parameters are similar to the existing data.
COVID-19
;
Cohort Studies
;
Contact Tracing
;
Humans
;
Incidence
;
Prospective Studies

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