Objective To perform laboratory detection and molecular traceability analysis on a case of imported kala-azar in Shenzhen to determine the infection strain. Methods Bone marrow puncture fluid and blood samples from a case of kala-azar in Shenzhen were collected for laboratory tests. The patient's bone marrow puncture fluid smears were stained with Giemsa and examined under a microscope. Blood samples were examined for antibodies using the rk39 visceral leishmania rapid diagnostic reagent. Whole blood DNA was extracted, and the ITS-1 sequence was amplified by PCR, sequenced and aligned, and a phylogenetic tree was constructed based on the ITS-1 sequence. Results Microscopic examination of the patient's bone marrow smears revealed a large number of Leishmania amastigotes without flagella, confirming the diagnosis of kala-azar. The patient's blood was tested positive with the rk39 rapid diagnostic reagent, and PCR amplification yielded an ITS-1 gene product sequence that matched the expected size. Sequence alignment with the NCBI database showed 100% sequence similarity with the ITS-1 gene sequence of Leishmania infantum, confirming the infecting strain as Leishmania infantum. Phylogenetic tree construction of the amplified ITS-1 sequence revealed clustering into a clade with Leishmania infantum , and close to KC347299, one of the reference sequence selected. Conclusions The case of kala-azar in Shenzhen was caused by Leishmania infantum. Kala-azar still occurs in China, so the diagnostic technology of medical personnel in non-epidemic areas should be strengthened so that they can actively use new diagnostic technologies to assist in diagnosis, thus improving their prevention and control ability of Leishmania parasites.

Abstract: Objective　To analyze and understand the mutations of drug resistance genes in imported Plasmodium falciparum in Shenzhen, aiming to assess the efficacy of antimalarial drugs and guide effective drug use. Methods A total of 85 samples from individuals with imported Plasmodium falciparum confirmed by fluorescence quantitative polymerase chain reaction (PCR) in Shenzhen from 2022 to 2023 were collected and genomic DNA was extracted. Nested PCR was used to amplify resistance genes, including Plasmodium falciparum Kelch 13 (PfK13), multidrug resistance gene 1 (Pfmdr1), chloroquine resistance transporter (Pfcrt), dihydrofolate reductase (Pfdhfr), and dihydropteroate synthase (Pfdhps) genes. Bidirectional sequencing was conducted, and mutations in these resistance genes were analyzed using MEGA11.06 software. Results　The study found one missense mutation (S549P) and four synonymous mutations in PfK13. For Pfmdr1, 62.69% of the samples showed Y184F mutation, and no N86Y mutation was detected. No mutations at positions 72 and 73 were detected in the Pfcrt gene, while mutations at M74I, N75E, and K76T accounted for 17.46%, 15.87%, and 15.87%, respectively. The wild-type of Pfcrt gene is dominant (82.54%, 52), followed by the triple mutant I74E75T76 (15.87%, 10). The most common mutation type for Pfdhfr is I51R59N108 (91.78%, 67), followed by the wild type (2.74%, 2). More than half (60.32%, 38) of the Pfdhps samples were wild-type, with single mutation K540E being the most common mutation type. S436A, G437A, K540E, A581G, A613S, I431V, G556K, and G579E site mutations were detected. Among the Pfdhfr-Pfdhps combination mutations, I51R59N108-E540 was the most frequent combination mutation (11.48%), with 59.02% of samples showing solitary Pfdhfr mutations. Conclusions In this study, PfK13 mutation rates were low, with no reported resistance mutations. The Y184F mutation emerged as the dominant Pfmdr1 mutation, with no detection of N86Y. For Pfcrt, the wild-type was dominant, followed by the I74E75T76 triple mutation variant. Triple mutant I51R59N108 of Pfdhfr was very common, and our study did not find Pfdhfr Pfdhps completely resistant and super resistant mutants, but there were other quintuple and septuple mutant types. In the future, it is crucial to continue to strengthen the monitoring of malaria parasite resistance genes and to further integrate in vivo efficacy monitoring to effectively guide clinical drug use.

The Coronavirus disease 2019 (COVID-19) has spread globally. Although mixed liver impairment has been reported in COVID-19 patients, the association of liver injury caused by specific subtype especially chronic hepatitis B (CHB) with COVID-19 has not been elucidated. In this multi-center, retrospective, and observational cohort study, 109 CHB and 327 non-CHB patients with COVID-19 were propensity score matched at an approximate ratio of 3:1 on the basis of age, sex, and comorbidities. Demographic characteristics, laboratory examinations, disease severity, and clinical outcomes were compared. Furthermore, univariable and multivariable logistic and Cox regression models were used to explore the risk factors for disease severity and mortality, respectively. A higher proportion of CHB patients (30 of 109 (27.52%)) developed into severe status than non-CHB patients (17 of 327 (5.20%)). In addition to previously reported liver impairment markers, such as alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and total bilirubin, we identified several novel risk factors including elevated lactate dehydrogenase (⩾ 245 U/L, hazard ratio (HR) = 8.639, 95% confidence interval (CI) = 2.528-29.523; P < 0.001) and coagulation-related biomarker D-dimer (⩾ 0.5 µg/mL, HR = 4.321, 95% CI = 1.443-12.939; P = 0.009) and decreased albumin (< 35 g/L, HR = 0.131, 95% CI = 0.048-0.361; P < 0.001) and albumin/globulin ratio (< 1.5, HR = 0.123, 95% CI = 0.017-0.918; P = 0.041). In conclusion, COVID-19 patients with CHB were more likely to develop into severe illness and die. The risk factors that we identified may be helpful for early clinical surveillance of critical progression.
COVID-19 ; Cohort Studies ; Hepatitis B, Chronic/epidemiology* ; Humans ; Retrospective Studies ; Risk Factors

Objective:To investigate knowledge, attitude and practice intention of medical students on advance care planning (ACP) and to analyze the relevant influencing factors.Methods:This study was a cross-sectional study. From April to May 2019, the convenience sampling method was used to select medical students who were interning in 3 medical schools and affiliated hospitals in Guangdong Province as the research objects. General information questionnaire and self-designed ACP Knowledge, Attitude and Practice Intention Questionnaires were uesd to investigate. Multiple linear regression analysis was used to influencing factors. A total of 276 questionnaires were recovered in this survey, of which 274 were valid, the effective response rate was 99.3%.Results:The average accuracy rate of the ACP Knowledge Questionnaire for medical students was 48.75%. The average score of items of the ACP Attitude Questionnaire was (4.00±0.53) . The average score of items of the ACP Practice Intention Questionnaire for medical students was (3.94±0.59) . The results of multiple linear regression analysis showed that the attitude toward the major they studied, whether they had the part-time social experience, whether they heard of ACP and whether they received ACP training or courses were influencing factors of ACP knowledge for medical students ( P<0.05) . Whether they had clinical practice and whether they had the treatment experience of patients' death were the influencing factors of ACP attitude of medical students ( P<0.05) . Attitudes towards the major they learned and whether they had any experience in the treatment of patients' death were the influencing factors of ACP practice intention of medical students ( P<0.05) . Conclusions:Medical students have a certain acceptance of ACP, but the awareness rate of ACP is generally low. Consideration should be given to improving the relevant education methods and content to prepare for the role adaptation of medical students in future clinical work, improving the humanistic care literacy of medical students and promotion of ACP in the clinical practice.

Objective:To investigate the epidemiological characteristics of dengue fever and genotyping of the epidemic strains of dengue virus in Shenzhen City in 2018.Methods:Descriptive epidemiological analysis was used to analyze dengue fever prevalence in Shenzhen City in 2018. Blood samples of patients with dengue fever were collected. The colloidal gold immunochromatography was used to detect serum specific IgM and IgG antibodies, and real-time fluorescence quantitative polymerase chain reaction (PCR) was used to detect viral nucleic acids and to identify genotypes. The E gene sequence of isolated virus strain was amplified by reverse transcription PCR. Homology comparison and phylogenetic tree of dengue fever epidemic strains in different countries and regions were conducted. Results:A total of 234 cases of dengue fever were reported in Shenzhen City from January 1 to December 31, 2018. The incidence rate was 1.87/100 000. There were 144 (61.54%) local patients and 90 (38.46%) imported patients, who were mainly from Southeast Asia and surrounding cities. Two hundred and two (86.32%) cases were reported during the epidemic peak period from August to November of the year. The patients mainly aged 20 to 50 years old (195 cases, 83.33%). Dengue virus type (DENV)-1 accounted for 86.01%(166/193), DENV-2 accounted for 10.36%(20/193), DENV-3 accounted for 2.59%(5/193), and DENV-4 accounted for 1.04%(2/193). The local cases were all infected with DENV-1. The homologies of nucleotide sequence and the deduced amino acid sequence of E gene of 24 DENV-1 strains with HAWAII45 strain were 93.0% to 94.6% and 96.6% to 97.2%, respectively. The phylogenetic tree of DENV-1 strains revealed that 23 strains belonged to genotypeⅠ, and one strain belonged to genotype Ⅳ which was the first reported imported cases in Shenzhen City. The homologies of nucleotide sequence and the deduced amino acid sequence of E gene of six DENV-2 strains with NGC strain were 93.1%to 93.9% and 97.0% to 97.8%, respectively. The phylogenetic tree of DENV-2 strains showed that two strains belonged to genotype Cosmopolitan and four strains belonged to genotype Asian Ⅰ, which were first reported in Shenzhen City. Conclusions:The epidemic of dengue fever in Shenzhen City in 2018 has the characteristics of coexistence of local and imported transmission. The main epidemic genotype is DENV-1. It infers that the major virus strains may be imported from Southeast Asia countries and surrounding cities. Therefore, attention should be paid to the epidemic trend of local dengue fever.

Objective: To observe the effects of oxymatrine(OM) on the expression and release of high mobility group box 1(HMGB1) in rat pancreatic acinar cell line AR42J stimulated by hydrogen peroxide. Methods: MTT method was used to detect the effects of H₂O₂ in different concentrations on the survival of AR42J cells. AR42J cells cultured in vitro were divided into control group, H₂O₂ group and H₂O₂+ OM group. An equal volume of H₂O₂(final concentration 0.16 mmol/L) was added in H₂O₂ group and H₂O₂+ OM group, respectively, while an equal volume of triple distilled water was added in control group. In H₂O₂+ OM group, OM(final concentration 0.5 g/L)was added 0.5 h before the addition of H₂O₂, and cell samples and supernatant were collected after 24 h culture. The expression of HMGB1 protein was detected by Western blotting, the level of HMGB1 protein in cell supernatant was detected by enzyme-linked immunosorbent assay, and the intracellular distribution of HMGB1 protein was detected by immunofluorescence. Results: In the H₂O₂ group, the expression of HMGB1, the secretion of HMGB1 in the supernatant and the proportion of cytoplasmic HMGB1 in the total HMGB1 were significantly higher than those in the control group[1.04±0.04 vs 0.69±0.02, (4.84±0.13)μg/L vs (2.68±0.07)μg/L, (35.7±2.5)% vs (10.7±1.9)%], and all the differences were statistically significant (all P<0.05). After OM intervention, HMGB1 protein expression, secretion and cytoplasmic proportion were [0.82±0.02, (3.97±0.10)μg/L and (27.3±1.7)%], respectively, which were obviously lower than those in the H₂O₂ group, and all the differences were statistically significant (all P<0.05). Conclusions H₂O₂ can induce the expression and release of HMGB1 in rat pancreatic acinar cells; OM treatment could alleviate the severity of oxidative stress injuries induced by H₂O₂ in AR42J cells.

Objective:To test whether the constructed intervention model of advance care planning (ACP) for patients with advanced cancer can be successfully implemented and the preliminary intervention effect, which provides reference for empirical research.Methods:32 cases of advanced cancer patients and 25 cases of their families at the Fifth Affiliated Hospital of Zunyi Medical University, Zhuhai were selected. The patients were subdivided into the experimental group and the control group by random number table method. The control group received routine nursing, while the experimental group adopted the intervention model of "VIP for future care" on the basis of customary nursing. We measured the main outcome indicators: enrollment rate, consent rate, completion rate and loss of follow-up rate and secondary outcome indicators: decision-making certainty, end-of-life care preference and post-intervention satisfaction of patients and their families, within 1 week and 1 month after intervention.Results:The enrollment rate, consent rate and loss of follow-up rate were 74.6% (206/276), 36.9% (76/151)and 15.6% (5/32), respectively. After intervention, the completion rates of the experimental group and the control group were 16/16 and 15/16 within one week, and 14/16 and 13/16 within one month. All of the family members were conducted during the follow-up period. The intervention mode of "VIP for future care" had a statistically significant difference in decision-making certainty between the two groups of patients ( β=0.63, 95% CI 0.08-1.18, P<0.05), no statistically significant difference in end-of-life care preference between the two groups of patients and their families ( P>0.05), and had a statistically significant difference in "whether to recommend this project to others" between the two groups ( χ2 value was 4.167 , P<0.05). Conclusions:On the premise of sufficient preparation, the "VIP for future care" intervention mode can be successfully implemented in advanced cancer patients in mainland China, can improve the decision-making certainty of patients and the satisfaction of patients and their families, and it is recommended. And should be applied to ACP intervention for patients with advanced cancer.

Objectives:This study aimed to evaluate the effect of the strategies on COVID-19 outbreak control in Shenzhen, and to clarify the feasibility of these strategies in metropolitans that have high population density and strong mobility.Methods:The epidemic feature of COVID-19 was described by different phases and was used to observe the effectiveness of intervention. Hierarchical spot map was drawn to clarify the distribution and transmission risk of infection sources at different time points. The Susceptible-Exposed-Infectious-Asymptomatic-Recovered model was established to estimate case numbers without intervention and compare with the actual number of cases to determine the effect of intervention. The positive rate of the nucleic acid test was used to reflect the risk of human exposure. A survey on COVID-19 related knowledge, attitude and behaviors were used to estimate the abilities of personal protection and emergency response.Results:The epidemic of COVID-19 in Shenzhen experienced the rising, plateau and decline stage. The case number increased rapidly at the beginning, with short duration of peak period. Although the epidemic curve showed human-to-human transmission, the "trailing" was not obvious. From the spot map, during the intervention period, the source of infection was widely distributed. More cases and higher transmission risk were observed in areas with higher population density. After the effective intervention measures, both infection sources and the risk of transmission decreased. After compared with the estimated case numbers without intervention, actual number proved the COVID-19 control strategies were effective. The positive rate of nucleic acid test for high risk populations decreased and no new cases reported since February 16. Shenzhen citizens had high knowledge, attitude and behavior level, and high protection ability and emergency response.Conclusions:Although the response initiated by the health administration department played a key role at the early stage of the epidemic, it was not enough to contain the outbreak of COVID-19. The first-level emergency response initiated by provincial and municipal government was effective and ensured the start of work resumption after the Spring Festival. Metropolitans like Shenzhen can also achieve the goals of strategies and measures for containment and mitigation of COVID-19.

Objective To analyze the genetic characteristics of VP1-VP4 genes carried by cox-sackievirus A6 (CVA6) strains isolated from severe cases of hand, foot, and mouth disease (HFMD) in Shenzhen during 2012 to 2015. -ethods The VP1-VP4 genes of CVA6 strains isolated from severe HFMD cases in Shenzhen during 2012 to 2015 were amplified and sequenced. Phylogenetic analysis was performed to analyze the VP1-VP4 genes of CVA6 isolates and sequences downloaded from GenBank by using DNASTAR6. 0 and MEGA6. 02 software packages. Results Four cases of severe HFMD were caused by CVA6 in Shenzhen during 2012 to 2015. All of the patients had the symptom of fever, skin rash and aseptic encephalitis. The CVA6 strain causing severe HFMD in 2013 shared 98. 8％-98. 9％ homology in nucleotide sequences and 99. 3％-99. 8％ in amino acid sequences with the strains isolated in 2012. Two amino acid mutations were found in the CVA6 strain isolated in 2013, which were G73E in VP2 region and S13G in VP1 region. However, the CVA6 strain isolated in 2015 only shared 95. 0％ homology in nucleotide sequences and 99. 3％ homology in amino acid sequences with the strain isolated in 2013. Six amino acid mutations were identified including E73G in VP2 region and T5A, S27N, A30V, N137S and V242I in VP1 region. The phylogenetic analysis revealed that the four CVA6 strains belong to D3 sub-genotype. The CVA6 strains causing severe cases in 2012 had the nearest genetic relationship with the strain isolated in Changsha in 2012 (KJ156349). The CVA6 strain isolated in Shenzhen in 2013 had the nearest genetic relationship with the strain isolated in Shanghai in 2013 (KJ612513). The Shenzhen CVA6 isolate in 2015 showed high similarity to Weifang CVA6 isolate in 2014 (KX752785). Conclusions All CVA6 strains causing severe HFMD ca-ses in Shenzhen during 2012 to 2015 belongs to D3 sub-genotype. Mutations of S27N and A30V in the VP1 region of the CVA6 isolate in 2015 are located in the B cell epitopes. In addition, the VP1-V242I mutation in the CVA6 strain isolated in 2015 is located in the binding site of PSGL-1 receptor. These mutations may affect the binding of CVA6 strains to the cellular receptors and their infectivity to people.

Objective: To study the epidemiology and the etiology characteristics of first imported severe fever with thrombocytopenia syndrome (SFTS) case reported in Shenzhen city in 2017. Methods: Data on descriptive epidemiology was collected to study the characteristics to the epidemic. The serum sample collected from the suspect SFTS case was detected for IgM, IgG by ELISA and severe fever with thrombocytopenia syndrome bunyavirus (SFTSV) nucleic acid by real-time RT-PCR. The samples were further inoculated in Vero cell for virus isolation. The partial fragements of L and S gene were amplified by RT-PCR and sequenced to construct homology comparison and phylogenetic tree with the strains isolated from other areas. Results: The case was laboratory confirmed imported SFTS case in Shenzhen on May 2017. IgM antibody and RNA of SFTSV were detected in the serum sample. SFTSV named GDSZ01/2017/China was successfully isolated from the serum sample. The high nucleotide homology of L and S genome segments were found at 95.3%-98.2% and 93.8%-98.8% with other representative strains from the popular provinces, respectively. The phylogenetic tree indicated that GDSZ01 was most close to SDTA_3 strain, next to strains in Hubei procince. The isolated SFTSV belonged to genotype C3 with HB29, HB154. Conclusions The virological, serological and molecular features showed that the imported case of SFTS in 2017 was caused by SFTSV C3 genotype.