ABSTRACT
Objective:To understand the reported incidence level, change of the trend, epidemic characteristics and spatial clustering of scrub typhus in Nanjing, to explore key seasons, populations and areas for prevention and control, and to guide formulation of scientific and precise prevention and control strategies and measures.Methods:The reported data of scrub typhus in Nanjing from January 1, 2011 to December 31, 2020 were collected in the "Infectious Disease Surveillance System" from Chinese Center for Disease Control and Prevention. The reported incidence level and change of the trend were analyzed, and the seasonal, population and spatial distribution characteristics were described. Global spatial autocorrelation analysis was carried out by ArcGIS 10.3 software, and the spatial clustering scanning was carried out by using FleXScan 3.1.2 software.Results:A total of 192 cases of scrub typhus were reported in Nanjing from 2011 to 2020. Median annual reported incidence was 0.21/100 000 (0.12/100 000 - 0.49/100 000). Totally 87.5% (168/192) of cases were reported from October to November, and the peak occurred in November (57.8%, 111/192). Among these cases, males accounted for 64.1% (123/192); and the median age was 59 years old (6 - 84 years old). The groups ≥60 years old and 45 - 59 years old accounted for 47.9% (92/192) and 31.2% (60/192), respectively, which accounted for 79.2% (152/192) in all groups. Farmers accounted for 43.8% (84/192), household chores and unemployed people accounted for 16.7% (32/192), retired persons accounted for 15.6% (30/192) and workers accounted for 6.8% (13/192), which accounted for 82.8% (159/192) in all occupations. The top four areas in the total number of reported cases were Jiangning District (23.4%, 45/192), Luhe District (22.9%, 44/192), Gulou District (10.4%, 20/192) and Jiangbei New Area (8.9%, 17/192), which accounted for 65.6% (126/192) in all districts. According to global spatial autocorrelation analysis, Moran's I = 0.34 ( Z = 5.90, P < 0.001). FlexScan 3.1.2 software scanned and detected two spatial clusters areas, the first-class of cluster area covered three streets in Jiangning District, one street in Yuhuatai District and two streets in Pukou District [restricted log likelihood ratio ( RLLR) = 26.91, P < 0.001]. The second-class of cluster area included six townships/streets in Luhe District and four streets in Jiangbei New Area ( RLLR = 26.48, P < 0.001). All the cluster areas were agriculture-related. Conclusions:The reported incidence level of scrub typhus in Nanjing is low and stable which belongs to a typical autumn epidemic area. The middle-aged and elderly population is the key population and the agriculture-related area is key area. It is suggested that scrub typhus should be included in the management of statutory or regional key infectious diseases in Nanjing. Additionally, training on diagnosis and treatment technology and information report management of scrub typhus need to be carried out, and comprehensive prevention and control interventions such as health education, personal protection, rodent prevention and control and vector control should be strengthened and implemented in the high incidence season.
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Objective To analyze the substitutions at amino acid residues of neuraminidases ( NAs) in influenza B virus strains isolated in Jiangsu province from 2010 to 2012 and to further understand the genetic evolution of NAs in those influenza B virus strains .Methods Forty strains of influenza B virus isolated in Jiangsu province from 2010 to 2012 were screened out for this study .A two-step reverse transcrip-tion PCR ( RT-PCR) was performed to amply the gene fragments encoding the neuraminidases of influenza B virus strains.The PCR products were purified and then sequenced in an ABI 3730XL Genetic Analyzer.The evolutionary characteristics of NA gene were analyzed by using DNAStar , Bioedit, MEGA 5.0 and BEAST 1.8.0 softwares.Results The phylogenetic tree analysis of the NA genes showed that the NAs of 28 Vic-toria strains were derived from the Yamagata lineage .There were reassortments between the Victoria lineage-HA and theYamagata lineage-NA.Some of the strains added a glycosylation site at position 462.No substitu-tion was found in important enzyme active sites and neuraminidase inhibitor resistant sites .The Bayesian MCMC analysis showed that the estimated mean evolutionary rate for NA gene was 1.74×10-3(95%HPD:1.46×10-3-2.06×10-3) substitutions/site/year.The dN/dS ratio (ω), an indicator of selective pressure, was 0.24.Conclusion The important amino acid sites of NA were relatively conservative and the evolution -ary rate for NA gene was low .The dN/dS ratio was less than one , indicating that the NA gene was under pu-rifying selection .
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Objective To explore the controlling level of fasting blood glucose(FBG) and glucosylated hemoglobin(GH) in order to stop occurrence of nephropathy in diabetic mellitus.Methods Data was collected by retrospective study,analyzed by non-conditional Logistic regression.Then the controlling levels of blood glucose and glucosylated hemoglobin were studied by regression equation.Results It was regarded that under 6.8 mmol/L of FBG and 5.9% of GH,diabetic nephropathy can be prevented;while under 6.0 mmol/L of FBG and 5.3% of GH,the onset of diabetic nephropathy was strictly controlled.Conclusion it is more important to control strictly on the threshold of fasting blood glucose and glucosylated hemoglobin for prevention of diabetic nephropathy.