Challenges to prevent and control the outbreak of Novel Coronavirus Pneumonia (COVID-19) / 中华流行病学杂志

An outbreak of severe pneumonia of unknown cause was reported in December 2019 in Wuhan, Hubei Province, China. The infectious virus was soon identified and named as 2019 novel coronavirus (2019-nCov). The name of the coronavirus infectious disease (COVID-19) was given by WHO on 11 February 2020. It has so far caused about 118 000 cases in 114 countries including China and was characterized as a pandemic by WHO on 11 March. We still face great challenges in control of the epidemic: uncertain initial source of infection, infected populations widely scattered, complex routs of transmission, populations generally susceptible, high contagiousness of the virus, and finally vaccines unlikely available in the near future.

Multi locus sequence typing and antibiotic susceptibility of extended-spectrum beta-lactamases producing Enterobacteriaceae in rural residents in villages with pig-breeding farms in Shandong province / 中华流行病学杂志

Objective@#To analyze the antimicrobial resistance and multilocus sequence typing (MLST) results of extended-spectrum β-lactamase (ESBLs)-producing Escherichia coli in rural residents in villages with pig breeding farms in a county of Shandong province.@*Methods@#Antimicrobial susceptibility testing was performed with agar dilution method by using 360 ESBLs-producing E. coli strains from fresh stool samples of rural residents in villages with pig breeding farms in a county of Shandong. PCR was conducted to amplify the CTX-M, TEM, SHV genes and capillary electrophoresis was used to screen positive strains in July, 2016. MLST was performed for molecular typing analysis, and eBURST v3.0 software was used for cluster analysis.@*Results@#Among 360 strains of ESBLs-producing E. coli, the resistance rates to cefotaxime, tetracycline, trimethoprim-sulfamethoxazole and florfenicol were 100.0% (360/360), 82.2% (296/360), 81.1% (292/360) and 80.3% (289/360), respectively. The positive rate of CTX-M gene was 99.2% (357/360), in which the positive rate of CTX-M-9 was 35.6% (128/360) and the positive rate of CTX-M-1 was 24.4% (88/360). The positive rate of TEM gene was 26.9% (97/360). A total of 132 STs were identified through MLST. The predominant ST was ST10, accounting for 12.5% (45/360). Cluster analysis showed that CC10 was the most important clone group, including 39 ST clones, involving 148 strains (41.1%).@*Conclusions@#The drug resistances of ESBLs-producing E. coli to cefotaxime, tetracycline, trimethoprim-sulfamethoxazole and flurfenicol are serious in this rural area. There is a small-scale clustering of CC10 and transmission mode from animals to humans might exist.

Serotype identification and antibiotic susceptibility of Shiga toxin-producing Escherichia coli in the Weishan area in Shandong Province, China / 中华预防医学杂志

Objective@#To determine the serotypes and drug resistance profiles of Shiga toxin-producing Escherichia coli (STEC) in animal stools from the Weishan area in Shandong Province, China. To provide the basis for further study.@*Methods@#Five hundred animal stool samples (from pigs, cattle, sheep, dogs and birds) were collected from the Weishan area and STEC strains were isolated from these samples. Strains were serotyped by a serum agglutination test, and their drug resistance profiles were determined through antimicrobial sensitivity experiments. In this study, PCR was used to detect tetracycline resistance genes (tetA, tetB, tetC, tetD) and beta-lactam resistance genes (blaSHV-1, blaCTX-M, blaTEM).@*Results@#Sixteen strains of STEC were isolated from animal stool samples. Thirteen strains were isolated from pig stool samples, two from bovine stool samples and one from a sheep stool sample. Two of the strains were identified as E. coli O157:H7, and other 14 strains were non-O157 STEC of different serotypes. Antimicrobial sensitivity experiments showed that 15 of the strains were multidrug resistant. The rates of resistance were as follows: nalidixic acid (12/16 strains), sulfisoxazole (11/16), trimethoprim and sulphame-thoxazole (11/16), doxycycline (9/16), azithromycin (9/16), tetracycline (9/16), chloramphenicol (8/16) and streptomycin (8/16). Therefore, nalidixic acid showed the highest rate of resistance among the strains, followed by trimethoprim and sulphame-thoxazole, and sulfisoxazole. Resistance to cefepime or imipenem was not detected. In total, three types of drug resistance genes (tetA, tetB and tetC) were detected among the 16 strains.@*Conclusion@#The results showed that STEC strains isolated from animals in the Weishan area were of a range of serotypes. The 16 strains of STEC isolated from animal stools in this area were resistant to a number of antibiotics, with many strains displaying multidrug resistance.

Meta-analysis on epidemiology of iatrogenic-borne methicillin-resistant Staphylococcus aureus / 中华流行病学杂志

Objective To study the molecular-biologic characteristics and epidemiological status of iatrogenic related Community-acquired methicillin-resistant Staphylococcus (S.) aureus (CA-MRSA) in China through Meta-analysis.Methods Data through systematic searching for peer-reviewed articles published before December 3rd,2015 from 4 main electronic databases including China National Knowledge Infrastructure (CNKI),Wanfang Data,PubMed and Web of Science Core Collection was collected,for this Meta-analysis.PRISMA guidelines were followed and the proportion of MRSA,CA-MRSA,hospital-acquired MRSA (HA-MRSA) and panton-valentine leucocidin (PVL) gene in certain populations were quantitatively analyzed by Stata 13.0 software.Results Average proportion of CA-MRSA from S.aureus was 12％ (95％CI:8％-16％).CA-MRSA in MRSA was 18％ (95％CI:12％-24％).42.1％ (95％CI:20.4％-63.7％) of the CA-MRSA carried a PVL gene,and the number was higher than general MRSA (t =-2.99,P=0.011).Conclusion CA-MRSA was in lower proportion than HA-MRSA,both seen in general MRSA and in S.aureu.s,but under higher proportion of carrying the PVL gene.Transmission of CA-MRSA could be prevented within the general population through conducting effective surveillances and preventive programs.

Meta-analysis on epidemiology of iatrogenic-borne methicillin-resistant Staphylococcus aureus / 中华流行病学杂志

Objective To study the molecular-biologic characteristics and epidemiological status of iatrogenic related Community-acquired methicillin-resistant Staphylococcus (S.) aureus (CA-MRSA) in China through Meta-analysis.Methods Data through systematic searching for peer-reviewed articles published before December 3rd,2015 from 4 main electronic databases including China National Knowledge Infrastructure (CNKI),Wanfang Data,PubMed and Web of Science Core Collection was collected,for this Meta-analysis.PRISMA guidelines were followed and the proportion of MRSA,CA-MRSA,hospital-acquired MRSA (HA-MRSA) and panton-valentine leucocidin (PVL) gene in certain populations were quantitatively analyzed by Stata 13.0 software.Results Average proportion of CA-MRSA from S.aureus was 12％ (95％CI:8％-16％).CA-MRSA in MRSA was 18％ (95％CI:12％-24％).42.1％ (95％CI:20.4％-63.7％) of the CA-MRSA carried a PVL gene,and the number was higher than general MRSA (t =-2.99,P=0.011).Conclusion CA-MRSA was in lower proportion than HA-MRSA,both seen in general MRSA and in S.aureu.s,but under higher proportion of carrying the PVL gene.Transmission of CA-MRSA could be prevented within the general population through conducting effective surveillances and preventive programs.

Status of acute upper respiratory infection, influenza-like illness, and influenza vaccination coverage among community residents in Jinan / 中华预防医学杂志

<p><b>OBJECTIVE</b>To analyze the status of acute upper respiratory infection and influenza-like illness (ILI) among community residents in Jinan in 2015, and to make a understand of the patient's medical treatment behavior and influenza vaccination coverage status in 2014.</p><p><b>METHODS</b>Balloting method and convenient sampling method were used to launch a household survey. The residents who had been in Jinan for more than 3 months were selected, to investigate the residents' attack ratio of acute upper respiratory and influenza-like from Jan. 8 to Feb. 7, 2015. Totally, 1 300 persons from 410 families were involved in this survey which recovered 1 241 valid questionnaires with the efficiency of 95.5%. Based on the national age-urban demographic statistics in 2010, the attack rates of acute respiratory infections, influenza-like illness were estimated by the direct standardization method, and the influenza vaccination rates were also calculated in this study. χ(2)-test method was used to compare the different status of incidence and vaccination among residents with different features.</p><p><b>RESULTS</b>The attack rate of acute upper respiratory infection and influenza-like illness in Jinan from January 8, 2015 to February 7, 2015 were 30.2% (375 cases), and 6.1% (76 cases), respectively, with a standardized rate of 29.1% and 5.4%. 5.3% (66 cases) of the residents have vaccinated with the influenza vaccine inoculation, with an adjusted rate of 3.8%. The attack rate difference of acute upper respiratory tract infections was statistically significant between each age group (χ(2)=17.121, P= 0.002). The 0-4 age group had a highest attack rate (45.4%) of acute respiratory infection, while the 15-24 age group got the lowest (26.5%). 38.9% (146 cases) of patients went for a treatment in hospital. Among them, 37.7% (55 cases) of them selected the county level hospitals for treatment, 37.7% (55 cases) selected the community level hospitals, and 24.6% (36 cases) selected the individual clinic. Significant differences of influenza-like illness attack rate between each age group were also found in this study (χ(2)=76.79, P<0.001). 0-4 age group had the highest attack rate (22.7%). 81.6% (62 cases) of the ILI sought treatment in the hospital, of which 53.2% (33 cases) selected county level hospital or above, and 33.9% (21 cases) selected community hospital, and 12.9% (8 cases) selected the individual clinic.</p><p><b>CONCLUSION</b>The attack rate of acute upper respiratory infections among the residents of Jinan was high, whereas that of influenza-like illness was relatively low. 0-4 age group had a higher risk of ILI than other age groups. Most of the cases were likely to take the treatment in large hospitals. In general, the coverage rate of influenza vaccination was relatively low.</p>

Molecular types of group A Streptococcus isolated from scarlet fever patients and asymptomatic carriers in Shandong province, 2013 / 中华流行病学杂志

<p><b>OBJECTIVE</b>To describe the molecular characteristics of group A Streptococcus (GAS) isolated from patients and asymptomatic carriers of scarlet fever in Shandong province, 2013, and to explore the relationships between emm types and other molecular types.</p><p><b>METHODS</b>72 strains of GAS were isolated from throat swabs of children with scarlet fever or asymptomatic carriers of GAS. All the strains were typed by emm typing, multilocus sequence typing (MLST), super-antigen (SAg) genes detections and pulsed-field gel electrophoreses (PFGE).</p><p><b>RESULTS</b>Among the 72 strains, emm1 (41.67%) and emm12 (56.94%) were the most common emm types. Two ST types were found, including ST28 (43.06%) and ST36 (56.94%). Additionally, emm1 was also found correlated to ST28, while emm12 was associated with ST36. Eight super-antigen genes were detected, including smeZ (100.00%), ssa (100.00%), speG (97.22%), speC (95.83%), speL (54.17%), speJ (41.67%), speA (38.89%) and speH (38.89%), while speK, speM, speL were not found (0%). Both speA and speJ genes were detected primarily in emm1 strains (all P < 0.05), while speH and speI genes were not detected in emm 1 strains (all P < 0.05). And emm12 strains were inclined to harbor speH and speL (all P < 0.05) but not speA or speJ (all P < 0.05). Twenty different genotypes were identified by PFGE.</p><p><b>CONCLUSION</b>All the emm types of GAS isolated from scarlet fever patients and asymptomatic carriers in Shandong province 2013 were mainly emm1 and emm12 and carrying speC, speG and smeZ, ssa. ST types mainly exsited in ST28 and ST36. In addition, there were correlations between emm types and super-antigen genes, ST types, PFGE types.</p>

Analysis on prevalence states and associated factors of hypertension and prehypertension among adults in Shandong province / 中华预防医学杂志

<p><b>OBJECTIVE</b>To analyze the prevalence states of hypertension and prehypertension and to explore relevant influencing factors among adult residents in Shandong province.</p><p><b>METHODS</b>15 600 residents aged between 18 and 69 from 20 counties in Shandong province were selected by multiple stratified and clustered sampling method from July to September, in 2011, to acquire related information by questionnaire survey and physical measurement. The prevalence of hypertension and prehypertension was estimated by special statistic method used to deal with complex sampling data, and the relevant influencing factors were also analyzed.</p><p><b>RESULTS</b>A total of 15 350 subjects were actually completed the survey, with age at (41.4 ± 14.1) years old. The average systolic blood pressure and diastolic blood pressure were 121.1(95%CI: 119.7-122.4) and 78.8(95%CI: 77.8-79.9) mmHg (1 mmHg = 0.133 kPa) respectively. And also 3776 hypertension patients and 5721 subjects with prehypertension were detected, and the weighting prevalence of hypertension and prehypertension were 23.4% (95%CI: 20.9%-26.0%) and 37.1% (95%CI: 34.7%-39.5%) with adjustive prevalence at 20.7% and 36.5% respectively. The multiple SURVEYLOGISTIC analysis showed that age above 40 years old (OR = 3.24, 95%CI: 2.56-4.10), overweight(OR = 2.22, 95%CI: 1.70-2.89) and obesity(OR = 5.84, 95%CI: 3.54-9.66), smoking history(OR = 1.82, 95%CI: 1.03-3.23), constantly drinking (OR = 1.71, 95%CI: 1.08-2.70), diabetes (OR = 1.99, 95%CI: 1.29-3.07), abnormal TC(OR = 1.64, 95%CI: 1.24-2.17), abnormal TG(OR = 1.75, 95%CI: 1.24-2.48) and high 24 h urine Na/K ratio (OR = 1.05, 95%CI: 1.02-1.08) were risk factors of hypertension, while education equal to or above junior middle school (OR = 0.68, 95%CI: 0.52-0.89) was protective factor of hypertension; age above 40 years old (OR = 1.49, 95%CI: 1.15-1.91), overweight(OR = 1.76, 95%CI: 1.25-2.48) and obesity (OR = 3.50, 95%CI: 2.05-5.97), abnormal TC (OR = 1.54, 95%CI: 1.10-2.14), abnormal TG (OR = 1.79, 95%CI:1.25-2.56) and high 24 h urine Na/K ratio (OR = 1.02, 95%CI: 1.01-1.04) were risk factors of prehypertension, while female (OR = 0.41, 95%CI: 0.31-0.56) and education level equal to or above junior middle school (OR = 0.67, 95%CI: 0.52-0.87) were protective factors.</p><p><b>CONCLUSION</b>The hypertension, especially prehypertension tends to be at high prevalence states currently, which may be affected by many factors.</p>

The relationship between salt consumption and blood pressure among residents in Shandong province, China / 中华预防医学杂志

<p><b>OBJECTIVE</b>To study the relationship between salt consumption and blood pressure among residents in Shandong province, and to provide basic information for guiding people to prevent hypertension by reducing salt intake.</p><p><b>METHODS</b>Using multi-stage stratified cluster random sampling method, 2 184 residents aged 18 to 69 were selected as the research subjects, which were extracted randomly from 20 counties in Shandong province in June, 2011. The blood pressure of the subjects were measured and weighted. Based on 72 h dietary recalls and weighing measurement, and according to the distribution of salt intake, the grouping cut-off points were 10, 14 and 18 g. The difference of subjects with different characteristics and systolic blood pressure, diastolic blood pressure and prevalence of hypertension by grouping salt intake and other characteristics were analyzed, and the relationship between salt intake and prevalence of hypertension were analyzed.</p><p><b>RESULTS</b>The total of 2 133 residents were involved finally, the completion rate was 97.7%. After the complex weighted, the systolic and diastolic blood pressure's means (95%CI value) of the subjects were 121.0 (119.5-122.5) mmHg (1 mmHg = 0.133 kPa) and 78.5(77.4-79.6) mmHg respectively, which were all elevated with increasing of salt consumption. The blood pressure of the subjects with salt intake <10 g was the lowest, which were 119.6 (116.9-122.4) mmHg and 77.5(76.2-78.7) mmHg respectively. The blood pressure of the subjects with salt intake ≥ 18 g was the highest, which were 122.3(120.1-124.5) mmHg and 79.6(78.2-80.9) mmHg respectively. The analysis results showed that, among residents with normal waistline, the prevalence of hypertension of people with salt intake ≥ 18 g was 1.70(95%CI:1.04-2.76) times compared to that of people who consumed less than 10 g salt per day.</p><p><b>CONCLUSION</b>The hypertension prevalence of Shandong province is quite high, and there is a relationship between salt consumption and blood pressure.</p>

Molecular characteristics and antibiotic resistance of Vibrio cholerae O139 in Shandong province / 中华预防医学杂志

<p><b>OBJECTIVE</b>To investigate the molecular epidemiological characteristics and antibiotic resistance profiles of Vibrio cholerae O139 in Shandong province.</p><p><b>METHODS</b>A total of 13 strains of V. cholerae O139 (9 clinical strains and 4 environmental strains) isolated from cholera epidemics in Shandong province since 1997 were recovered and confirmed with serum agglutination and biochemical reaction. Pulsed-field gel electrophoresis (PFGE) was carried out for molecular subtyping. Virulence genes and drug resistance related genes were detected by PCR. Antibiotic susceptibility tests were performed using micro-broth dilution method.</p><p><b>RESULTS</b>Thirteen strains of V. cholerae O139 were differentiated into seven pulsetypes. One clinical strain and two environmental strains isolated from Jining in 2013 were clustered into the pulsetype namely KZGN11O139. CN0077, and an identical PFGE pattern of KZGN11O139. CN0002 was found among three clinical strains from Jinan in 2005, Jining in 2005 and Heze in 2009. Other pulsotypes were unique in China and found only in Shandong province. Because of deletion of ctxAB and tcpI, the PFGE patterns of two strains isolated from Yantai in 2000 and 2004 were different from other 11 strains which harbored ctxAB, tcpA, tcpI, rtxA, hlyA and toxR. All strains contained one or more drug resistance related genes such as intI 1, intI 4 and sxt, and were resistant to two kinds of antibiotics at least. Among the 12 kinds of antibiotics, the resistant ratioes to kamamycin, trimethoprim-sulfamethoxazole, ampicillin and gentamicin were 11/13, 9/13, 7/13 and 7/13, respectively.</p><p><b>CONCLUSION</b>Molecular subtyping indicates possible epidemiological links among V.cholerae O139 in Shandong province, and almost all strains were toxigenic and drug resistant.</p>