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Objective:To investigate the characteristics of death, tendency and the prediction of Shenzhen residents with adult hematological malignancies from 2017 to 2020.Methods:The surveillance data of hematological malignancies from 2017 to 2020 and the demographic data in Shenzhen were collected from Shenzhen death cause monitoring system and Shenzhen Center for Disease Control and Prevention, respectively. The data of the 7th national demographic data in 2020 were set as the standardized population data. Crude mortality rate (CMR), standardized mortality rate (SMR) and annual percentage change (APC) of mortality were calculated by using Joinpoint software. The grey model GM(1,1) was built to predict the mortality of adult hematological malignancies in Shenzhen between 2021 and 2025.Results:From 2017 to 2022, the male CMR of hematological malignancies was 1.15/100 000 to 1.85/100 000, and the SMR was 2.24/100 000 to 2.44/100 000; the female CMR of hematological malignancies was 0.81/100 000 to 1.75/100 000, and the SMR was 1.67/100 000 to 1.90/100 000. There were no statistically significant differences in the annual CMR and SMR between male and female hematological malignancies (all P > 0.05), and the annual change trend of CMR and SMR was not significant. The APC of male and female CMR was 27.28% and 12.70%, respectively (χ 2 = 0.01, P = 0.939); the APC of male and female SMR was 1.12% and 4.77%, respectively (χ 2 = 0.91, P = 0.318). The death causes of hematological malignancies were successively acute myeloid leukemia (AML), lymphoma, multiple myeloma, acute lymphoblastic leukemia (ALL), myelodysplastic syndrome (MDS) plus chronic myelomonocytic leukemia (CMML), chronic lymphoblastic leukemia (CLL) plus chronic myelogenous leukemia (CML). The CMR of patients with hematological malignancies aged 18-40 years was low, the CMR began to rise in patients above 40 years, especially the rapid increase at the age of 60 years, reaching the peak at the age of 80 years or above. The shortest median time of all kinds of hematological malignancies from the onset of disease to the death was found in AML group (8 months, range 0.1-168 months), the longest time was in CLL+CML group (24 months, range 0.1-300 months). Infection was the most direct cause of death, followed by single organ failure. GM(1,1) model had the better predictive effects and the total SMR would increase from 2021 to 2025 (4.52/100 000, 4.76/100 000, 5.01/100 000, 5.28/100 000 and 5.57/100 000, respectively). Conclusions:The incidence of hematological malignancies in Shenzhen residents over 40 years old is on the increase. The trend of adult hematological malignancies in Shenzhen will rise predicted by GM (1,1) grey model.
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SummaryO_ST_ABSBackgroundC_ST_ABSManaging discharged COVID-19 (DC) patients with recurrent positive (RP) SARS-CoV-2 RNA test results is challenging. We aimed to comprehensively characterize the viral RNA level and serum antibody responses in RP-DC patients and evaluate their viral transmission risk. MethodsA population-based observational cohort study was performed on 479 DC patients discharged from February 1 to May 5, 2020 in Shenzhen, China. We conducted RT-qPCR, antibody assays, neutralisation assays, virus isolation, whole genome sequencing (WGS), and epidemiological investigation of close contacts. FindingsOf 479 DC patients, the 93 (19%) RP individuals, including 36 with multiple RP results, were characterised by young age (median age: 34 years, 95% confidence interval [CI]: 29-38 years). The median discharge-to-RP length was 8 days (95% CI: 7-14 days; maximum: 90 days). After readmission, RP-DC patients exhibited mild (28%) or absent (72%) symptoms, with no disease progression. The viral RNA level in RP-DC patients ranged from 1{middle dot}9-5{middle dot}7 log10 copies/mL (median: 3{middle dot}2, 95% CI: 3{middle dot}1-3{middle dot}5). At RP detection, the IgM, IgG, IgA, total antibody, and neutralising antibody (NAb) seropositivity rates in RP-DC patients were 38% (18/48), 98% (47/48), 63% (30/48), 100% (48/48), and 91% (39/43), respectively. Regarding antibody levels, there was no significant difference between RP-DC and non-RP-DC patients. The antibody level remained constant in RP-DC patients pre- and post-RP detection. Virus isolation of nine representative specimens returned negative results. WGS of six specimens yielded only genomic fragments. No clinical symptoms were exhibited by 96 close contacts of 23 RP-DC patients; their viral RNA (96/96) and antibody (20/20) test results were negative. After full recovery, 60% of patients (n=162, 78 no longer RP RP-DC and 84 non-RP-DC) had NAb titres of [≥]1:32. InterpretationRP may occur in DC patients following intermittent and non-stable excretion of low viral RNA levels. RP-DC patients pose a low risk of transmitting SARS-CoV-2. An NAb titre of [≥] 1:32 may provide a reference indicator for evaluating humoral responses in COVID-19 vaccine clinical trials. FundingSanming Project of Medicine in Shenzhen, China National Science and Technology Major Projects Foundation, Special Foundation of Science and Technology Innovation Strategy of Guangdong Province of China, and Shenzhen Committee of Scientific and Technical Innovation grants.
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Coronavirus disease 2019 has led to more than three million cases globally. Since the first family cluster of COVID-19 cases identified in Shenzhen in early January, most of the local transmission occurred within household contacts. Identifying the factors associated with household transmission is of great importance to guide preventive measures.
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Previous studies have demonstrated the characteristics of patients with 2019 novel coronavirus disease (COVID-19). However, the effect of non-pharmaceutical interventions on the epidemic in Shenzhen, China remains unknown. Individual data of 417 cases were extracted from the epidemiological investigations and the National Infectious Disease Information System between January 1, 2020 and February 29, 2020. On the basis of important interventions, the epidemic was divided into four periods (January 1-15, January 16-22, January 23-February 5 and after February 6). We used a susceptible-exposed-infectious-asymptomatic-recovered model to evaluate the effect of interventions. Results suggested that about 53.7% were imported from Wuhan. The median age was 47 years and 52.8% were women. Severity risk increased with age and associated with male and co-existing disorders. The attack rate peaked in the third period and drastically decreased afterwards across sex, age groups and geographic regions. Children younger than 5 years showed a higher attack rate than those aged of 6~19. The effective reproductive number decreased from 1.44 to 0.05 after the highest level emergency response since January 23. Overall, the non-pharmaceutical interventions have effectively mitigated the COVID-19 outbreak in Shenzhen, China. These findings may facilitate the introduction of public health policies in other countries and regions.
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We conducted a retrospective study among 417 confirmed COVID-19 cases from Jan 1 to Feb 28, 2020 in Shenzhen, the largest migrant city of China, to identify the epidemiological and clinical features in settings of high population mobility. We estimated the median incubation time to be 5.0 days. 342 (82.0%) cases were imported, 161 (38.6%) cases were identified by surveillance, and 247 (59.2%) cases were reported from cluster events. The main symptoms on admission were fever and dry cough. Most patients (91.4%) had mild or moderate illnesses. Age of 50 years or older, breathing problems, diarrhea, and longer time between the first medical visit and admission were associated with higher level of clinical severity. Surveillance-identified cases were much less likely to progress to severe illness. Although the COVID-19 epidemic has been contained in Shenzhen, close monitoring and risk assessments are imperative for prevention and control of COVID-19 in future. Article Summary LineWe characterized epidemiological and clinical features of a large population-based sample of COVID-19 cases in the largest migrant city of China, and our findings could provide knowledge of SARS-CoV-2 transmission in the context of comprehensive containment and mitigation efforts in similar settings.
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BackgroundRapid spread of SARS-CoV-2 in Wuhan prompted heightened surveillance in Shenzhen and elsewhere in China. The resulting data provide a rare opportunity to measure key metrics of disease course, transmission, and the impact of control. MethodsThe Shenzhen CDC identified 391 SARS-CoV-2 cases from January 14 to February 12, 2020 and 1286 close contacts. We compare cases identified through symptomatic surveillance and contact tracing, and estimate the time from symptom onset to confirmation, isolation, and hospitalization. We estimate metrics of disease transmission and analyze factors influencing transmission risk. FindingsCases were older than the general population (mean age 45) and balanced between males (187) and females (204). Ninety-one percent had mild or moderate clinical severity at initial assessment. Three have died, 225 have recovered (median time to recovery is 21 days). Cases were isolated on average 4.6 days after developing symptoms; contact tracing reduced this by 1.9 days. Household contacts and those travelling with a case where at higher risk of infection (ORs 6 and 7) than other close contacts. The household secondary attack rate was 15%, and children were as likely to be infected as adults. The observed reproductive number was 0.4, with a mean serial interval of 6.3 days. InterpretationOur data on cases as well as their infected and uninfected close contacts provide key insights into SARS-CoV-2 epidemiology. This work shows that heightened surveillance and isolation, particularly contact tracing, reduces the time cases are infectious in the community, thereby reducing R. Its overall impact, however, is uncertain and highly dependent on the number of asymptomatic cases. We further show that children are at similar risk of infection as the general population, though less likely to have severe symptoms; hence should be considered in analyses of transmission and control.
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BackgroundOn December 31, 2019, an outbreak of COVID-19 in humans was reported in Wuhan, and then spread fast to other provinces, China. We analyzed data from field investigations and genetic sequencing to describe the evidence and characteristics of human-to-human transmission in Guangdong Province. MethodsA confirmed COVID-19 case was defined if a suspected case was verified with positive of SARS-CoV-2 in throat swabs, nasal swabs, bronchoalveolar lavage fluid (BALF), or endotracheal aspirates by real-time reverse transcriptase polymerase chain reaction assay (RT-PCR) or genetic sequencing. Field investigations were conducted for each confirmed case. Clinical and demographic data of confirmed cases were collected from medical records. Exposure and travel history were obtained by interview. ResultsA total of 1,151 confirmed cases were identified as of February 10, 2020 in Guangdong Province, China. Of them, 697 (60.1%) cases were from 234 cluster infections. Two hundred and fourteen (18.6%) were secondary cases, in which 144 cases were from family cluster infections. With the epidemic continuing, although familial cluster events were dominated, community cluster events increased with a nosocomial event. The whole genomes within the same family cluster infections were identical, and presented a few unique single nucleotide variants (SNVs) compared with SARS-CoV-2 identified on December 2019 in Wuhan. ConclusionsWe observed evident human-to-human transmissions of SARS-CoV-2 in Guangdong, China. Although most of them were from family cluster infections, community and nosocomial infections were increasing. Our findings indicate that human-to-human transmission risks are transferring from family to community in Guangdong Province.
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Objective@#To investigate the epidemiological characteristics of norovirus outbreaks in Shenzhen during 2005 to 2017 in order to provide reference for disease control and prevention.@*Methods@#Monitoring data of norovirus outbreaks in Shenzhen from January 1, 2005 to December 31, 2017 were collected from Shenzhen Communicable Disease Information System and China Information System for Disease Control and Prevention. Descriptive epidemiological methods were used for data analysis.@*Results@#From January 2005 to December 2017, 346 norovirus outbreaks (five or more cases in one community within one week) were reported in Shenzhen, of which 6.36% (22/346) were public health emergency events. Fewer outbreaks were reported during 2006 to 2013 and they were mainly caused by GⅡ.4 genotype, but the number increased sharply since 2014 with 57.80% (200/346) occurred in 2016—2017 and the epidemic genotype changed from GⅡ.4 to GⅡ.17 and GⅡ.2. The outbreaks peaked during November to March (76.88%, 266/346). There were 63.87% (221/346) reported in urban areas, 67.05% (232/346) in nurseries and 23.70% (82/346) in primary/middle schools. Among the 22 public health emergency events, 40.91% (10/22) were caused by person-to-person contacts, 40.91% (10/22) by foodborne transmission and 13.64% (3/22) by waterborne transmission. Moreover, 75.80% (238/314) of the outbreaks in nurseries and primary/middle schools were confined to one classroom and most were due to contact transmission.@*Conclusions@#Norovirus outbreaks increased obviously since 2014, which might be related to the changes of the predominant genotype from GⅡ.4 to GⅡ.17 and GⅡ.2. It is necessary to strengthen a comprehensive prevention and control in key units such as nurseries and primary/middle schools in winter and spring.
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Objective To investigate the epidemiological characteristics of norovirus outbreaks in Shenzhen during 2005 to 2017 in order to provide reference for disease control and prevention. Methods Monitoring data of norovirus outbreaks in Shenzhen from January 1, 2005 to December 31, 2017 were col-lected from Shenzhen Communicable Disease Information System and China Information System for Disease Control and Prevention. Descriptive epidemiological methods were used for data analysis. Results From January 2005 to December 2017, 346 norovirus outbreaks (five or more cases in one community within one week) were reported in Shenzhen, of which 6. 36％ (22/346) were public health emergency events. Fewer outbreaks were reported during 2006 to 2013 and they were mainly caused by GⅡ. 4 genotype, but the num-ber increased sharply since 2014 with 57. 80％ (200/346) occurred in 2016—2017 and the epidemic geno-type changed from GⅡ. 4 to GⅡ. 17 and GⅡ. 2. The outbreaks peaked during November to March (76. 88％, 266/346). There were 63. 87％ (221/346) reported in urban areas, 67. 05％ (232/346) in nurseries and 23. 70％ ( 82/346 ) in primary/middle schools. Among the 22 public health emergency events, 40. 91％ (10/22) were caused by person-to-person contacts, 40. 91％ (10/22) by foodborne trans-mission and 13. 64％ (3/22) by waterborne transmission. Moreover, 75. 80％ (238/314) of the outbreaks in nurseries and primary/middle schools were confined to one classroom and most were due to contact trans-mission. Conclusions Norovirus outbreaks increased obviously since 2014, which might be related to the changes of the predominant genotype from GⅡ. 4 to GⅡ. 17 and GⅡ. 2. It is necessary to strengthen a com-prehensive prevention and control in key units such as nurseries and primary/middle schools in winter and spring.
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Objective To identify the species of Biomphalaria snails collected in Shenzhen reservoir,based on the mitochondrial 16S rDNA sequences.Methods The 16S rDNA fragments were amplified by PCR from the genome DNA of Biomphalaria snails,and inserted in plasmid pMD-18T for sequencing.The sequence of 16S rDNA fragment and its phylogenetic relationships with those of other species of Biomphalaria snails were analyzed with BLAST and MEGA4 software.Results The amplified 16S rDNA fragment of the Biomphalaria snails was about 466 bp in length.As aligned with the corresponding sequences of the related Biomphalaria species,the identity of nucleotides was 99％ with 1 isolate of Biomphaltria straminea (B.straminea),98％ with 3 isolates of B.kuhniana,95％ with 1 isolate of B.intermedia,and 94％ with 1 isolate of B.edisoni.Based on the 16S rDNA sequence,the results of phylogenetic analysis with neighbor-joining (NJ) and unweighted pair-group method with arithmetic means (UPGMA) indicated that the snails had close genetic relationships with the B.straminea isolate (Genbank accession NO.AY030213.1) Conclusion The Biomphalaria snails collected in Shenzhen reservoir could be classified as B.straminea based on the characteristics of 16S rDNA sequence.
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<p><b>OBJECTIVE</b>To study the potential association of DNA oxidation and DNA methylation, in vitro cultured cells were exposed to different doses of H2O2, 8-oxo-dG formation, cell DNA 5-mC contents were analyzed to explore the time- dose-response relationship of DNA oxidation and DNA methylation.</p><p><b>METHODS</b>A549 cells were exposed to different doses of H2O2, 8-oxo-dG formation and cell genomic DNA 5-mC contents were analyzed by a high-performance liquid chromatography system and high performance capillary electrophoresis (HPCE), respectively.</p><p><b>RESULTS</b>H2O2 induced the formation of 8-oxo-dG and 5-mC in different characteristics, it need at least 10 days for significant changes in the level of DNA methylation, whereas under the same conditions, changes in the level of DNA oxidation cast only 12 hours. H2O2 induced decreased levels of DNA methylation in A549 cells in a dose-dependent manner. In a certain range of time and dose, it showed a negative correlation between DNA oxidation and DNA methylation.</p><p><b>CONCLUSION</b>The study suggests that oxidative DNA could lead to reduced levels of DNA methylation, DNA oxidation may affect the regulation of cellular methylation mechanisms, in the course of chemical mutagenesis, DNA oxidation may be an earlier important molecule event than DNA methylation.</p>
