Prototypes virus of hand, foot and mouth disease infections and severe cases in Gansu, China: a spatial and temporal analysis.

BACKGROUND: Little research has been conducted on the spatio-temporal relationship between the severe cases and the enteroviruses infections of hand, foot and mouth disease (HFMD). This study aimed to investigate epidemic features and spatial clusters of HFMD incidence rates and assess the relationship between Enterovirus 71 (EV71) and Coxsackievirus A16 (CoxA16) and severe cases of HMFD in Gansu province, China. METHODS: Weekly county-specific data on HFMD between 1st January and 31st December 2018 were collected from the China Infectious Disease Information System (CIDIS), including enterovirus type (EV71 and CoxA16), severe and non-severe cases in Gansu province, China. Temporal risk [frequency index (α), duration index (ß) and intensity index (γ)] and spatial cluster analysis were used to assess epidemic features and identify high-risk areas for HFMD. Time-series cross-correlation function and regression model were used to explore the relationship between the ratios of two types of viruses (i.e. EV71/Cox16) (EC) and severe cases index (i.e. severe cases/non-severe cases) (SI) of HFMD. RESULTS: Some counties in Dingxi City, Gansu were identified as a hot spot for the temporal risk indices. Time-series cross-correlation analysis showed that SI was significantly associated with EC (r = 0.417, P < 0.05) over a 4-week time lag. The regression analysis showed that SI was positively associated with EC (ß = 0.04, 95% confidence interval (CI) 0.02-0.06). CONCLUSION: The spatial patterns of HFMD incidence were associated with enteroviruses in Gansu. The research suggested that the EC could be considered a potential early warning sign for predicting severe cases of HFMD in Gansu province.

Epidemic features of seasonal influenza transmission among eight different climate zones in Gansu, China.

BACKGROUNDS: Seasonal influenza remains epidemic globally with a substantial health burden. Understanding the transmission patterns and epidemic features of influenza may facilitate the improvement of preventive and control measures. This study aims to assess the epidemic features of influenza among different climate zones and identify high-risk zones across Gansu province, China. METHODS: We collected weekly influenza cases at county-level between 1st January 2012 and 31st December 2016, as well as climate zones classification shapefile data from Köppen-Geiger climate map. We compared the epidemic features (Frequency index (α), Duration index (ß) and Intensity index (γ)) of influenza among different climate zones. Spatial cluster analysis was used to examine the high-risk areas of transmission of influenza. RESULTS: The distribution of cases existed significant differences among eight climate zones (F-test: 267.02, p < 0.05). The highest mean weekly incidence rate (per 100,000 population) was 0.59 in snow climate with dry winter and warm summer (Dwb). The primary (relative risk (RR): 3.61, p < 0.001) and secondary (RR: 2.45, p < 0.001) clusters were located in Dwb. The highest values of α, ß and γ were 1.00, 261 and 154.38 in Dwb. The hot spots (high-high clusters) of the epidemic indices were detected in Dwb. CONCLUSIONS: This study found the variability of epidemic features of influenza among eight climate zones. We highlight that Dwb was the high-risk zone where influenza clustered with the highest incidence rate and epidemic temporal indices. This provide further insight into potential improvement of preventive measures by climate zones to minimize the impact of epidemics.

Investigation and source-tracing of an anthrax outbreak in Gansu Province, China.

Anthrax is an endemic disease in China. Cases are reported every year, especially in the northwestern areas. In August 2016, an outbreak of 21 cutaneous anthrax cases was reported in Min County, Gansu Province, China. In this study, the general characteristics of the anthrax outbreak are described. Two molecular typing methods, canonical single-nucleotide polymorphism (canSNP) and multiple-locus variable-number tandem repeat analysis with 15 markers (MLVA15), were used to investigate the possible source of transmission and to identify the genetic relationship among the strains/samples isolated in this outbreak as well as previous isolates. In this outbreak, all patients were infected through contact with diseased livestock or contaminated animal products. Livestock had been introduced into the local area shortly before the outbreak from Gannan Prefecture (in Gansu Province), Sichuan and Qinghai Provinces. In the molecular typing analysis, there were two canSNP subgroups found in Gansu, A.Br.001/002 and A.Br.Ames, and five MLVA15 genotypes were observed. The strains collected from the anthrax outbreak in Min County in 2016 belonged to the A.Br.001/002 canSNP subgroup and the MLVA15-28 and MLVA15-30 genotype. Strains previously isolated from Sichuan, Inner Mongolia and Maqu County (in Gannan Prefecture, Gansu Province) were clustered with these outbreak-related strains/samples according to the MLVA15-30 genotype. The MLVA15-28 genotype was found in strains isolated from Gansu and Xinjiang in previous studies. Combining the epidemiological investigation and molecular typing results, we conclude that the patients in this outbreak were infected by a local pathogen present in the adjoining area of Gansu, Sichuan and Qinghai Provinces.

Different responses of weather factors on hand, foot and mouth disease in three different climate areas of Gansu, China.

BACKGROUND: To determine the linear and non-linear interacting relationships between weather factors and hand, foot and mouth disease (HFMD) in children in Gansu, China, and gain further traction as an early warning signal based on weather variability for HFMD transmission. METHOD: Weekly HFMD cases aged less than 15 and meteorological information from 2010 to 2014 in Jiuquan, Lanzhou and Tianshu, Gansu, China were collected. Generalized linear regression models (GLM) with Poisson link and classification and regression trees (CART) were employed to determine the combined and interactive relationship of weather factors and HFMD in both linear and non-linear ways. RESULTS: GLM suggested an increase in weekly HFMD of 5.9% [95% confidence interval (CI): 5.4%, 6.5%] in Tianshui, 2.8% [2.5%, 3.1%] in Lanzhou and 1.8% [1.4%, 2.2%] in Jiuquan in association with a 1 °C increase in average temperature, respectively. And 1% increase of relative humidity could increase weekly HFMD of 2.47% [2.23%, 2.71%] in Lanzhou and 1.11% [0.72%, 1.51%] in Tianshui. CART revealed that average temperature and relative humidity were the first two important determinants, and their threshold values for average temperature deceased from 20 °C of Jiuquan to 16 °C in Tianshui; and for relative humidity, threshold values increased from 38% of Jiuquan to 65% of Tianshui. CONCLUSION: Average temperature was the primary weather factor in three areas, more sensitive in southeast Tianshui, compared with northwest Jiuquan; Relative humidity's effect on HFMD showed a non-linear interacting relationship with average temperature.

Socio-ecological factors and hand, foot and mouth disease in dry climate regions: a Bayesian spatial approach in Gansu, China.

The influence of socio-ecological factors on hand, foot and mouth disease (HFMD) were explored in this study using Bayesian spatial modeling and spatial patterns identified in dry regions of Gansu, China. Notified HFMD cases and socio-ecological data were obtained from the China Information System for Disease Control and Prevention, Gansu Yearbook and Gansu Meteorological Bureau. A Bayesian spatial conditional autoregressive model was used to quantify the effects of socio-ecological factors on the HFMD and explore spatial patterns, with the consideration of its socio-ecological effects. Our non-spatial model suggests temperature (relative risk (RR) 1.15, 95 % CI 1.01-1.31), GDP per capita (RR 1.19, 95 % CI 1.01-1.39) and population density (RR 1.98, 95 % CI 1.19-3.17) to have a significant effect on HFMD transmission. However, after controlling for spatial random effects, only temperature (RR 1.25, 95 % CI 1.04-1.53) showed significant association with HFMD. The spatial model demonstrates temperature to play a major role in the transmission of HFMD in dry regions. Estimated residual variation after taking into account the socio-ecological variables indicated that high incidences of HFMD were mainly clustered in the northwest of Gansu. And, spatial structure showed a unique distribution after taking account of socio-ecological effects.

[Spatial-temporal distribution of hepatitis B in Gansu province, 2009-2014].

OBJECTIVE: To understand the hot/cold spots and the spatial-temporal clustering of hepatitis B in Gansu province during 2009-2014 by using spatial statistics, and provide scientific evidence for the prevention and control of hepatitis B. METHODS: The spatial hot/cold spots and its trend, and the time frame and areas of its spatial-temporal clustering of hepatitis B in Gansu were analyzed by using the county specific incidence of hepatitis B from 2009 to 2014 and spatial statistical software GeoDa and SatScan. RESULTS: The incidences of hepatitis B from 2009 to 2014 in Gansu were spatial autocorrelated respectively. Local G scan statistics indicated that the number of hot spots was in decline in Hexi area, while the hot spots was in increase in Linxia Hui autonomous prefecture and Gannan Tibetan autonomous prefecture. There was no obvious pattern in cold spots. Temporal-spatial scan statistics showed that the areas with high hepatitis B incidence most likely clustered in Hexi area during 2009-2011, and the areas with low hepatitis B incidence most likely clustered in eastern Gansu during 2012-2014. CONCLUSIONS: The spatial and temporal clustering of hepatitis B was observed in Gansu from 2009 to 2014. The number of hot spots in Hexi area was in decline, while the numbers of hot spots in Linxia and Gannan were in increase, suggesting that the hepatitis B control and prevention in these areas should be strengthened.

[Time-space study on viral hepatitis C in Gansu province, from 2009 to 2013].

OBJECTIVE: To study the time-space distribution of viral hepatitis C in Gansu province during 2009-2013, using the time-space statistics. METHODS: Using Geoda to analysis the univariate Moran's I and univariate local Moran's I while using SaTScan to detect the time-space gathering areas. RESULTS: There was spatial autocorrelation on incidence of hepatitis C noticed in Gansu during 2009-2013. The hot spots areas were counties as Jinchang, Wuwei, Zhangye and Lanzhou. Cold spot areas would include counties as Dingxi, Longnan, Pingliang, Gannan, Jiuquan, Qingyang, Baiyin and Tianshui. There were time-space gathering areas nitoced, during 2009-2010. Qinzhou and Maiji counties belonged to high incidence gathering areas. Lintao and Linxia were of low incidence gathering areas. In 2011-2013, high incidence gathering area would include counties as Zhangye, Jinchang, Wuwei Lanzhou and Baiyin while low incidence gathering areas would include counties as Dingxi, Tianshui, Pingliang, Longnan and Qingyang. CONCLUSION: There appeared time-space gathering of hepatitis C in Gansu province during 2009-2013. High and low gathering areas varied with time and high incidence gathering area mainly distributed in the western and central areas of Gansu province.

Histone Methylation in Nickel-Smelting Industrial Workers.

BACKGROUND: Nickel is an essential trace metal naturally found in the environment. It is also common in occupational settings, where it associates with various levels of both occupational and nonoccupational exposure In vitro studies have shown that nickel exposure can lead to intracellular accumulation of Ni2+, which has been associated with global decreases in DNA methylation, increases in chromatin condensation, reductions in H3K9me2, and elevated levels of H3K4me3. Histone modifications play an important role in modulating chromatin structure and gene expression. For example, tri-methylation of histone H3k4 has been found to be associated with transcriptional activation, and tri-methylation of H3k27 has been found to be associated with transcriptional repression. Aberrant histone modifications have been found to be associated with various human diseases, including cancer. The purpose of this work was to identify biomarkers for populations with occupational nickel exposure and to examine the relationship between histone methylation and nickel exposure. This may provide a scientific indicator of early health impairment and facilitate exploration of the molecular mechanism underlying cancer pathogenesis. METHODS: One hundred and forty subjects with occupational exposure to Ni and 140 referents were recruited. H3K4 and H3K27 trimethylation levels were measured in subjects' blood cells. RESULTS: H3K4me3 levels were found to be higher in nickel smelting workers (47.24±20.85) than in office workers (22.65±8.81; P = 0.000), while the opposite was found for levels of H3K27me3(nickel smelting workers, 13.88± 4.23; office workers, 20.67± 5.96; P = 0.000). H3K4me3 was positively (r = 0.267, P = 0.001) and H3K27 was negatively (r = -0.684, P = 0.000) associated with age and length of service in smelting workers. CONCLUSION: This study indicated that occupational exposure to Ni is associated with alterations in levels of histone modification.

[Spatial-temporal specific incidence of pulmonary tuberculosis in Gansu, 2009-2013].

OBJECTIVE: To understand the spatial-temporal specific incidence of pulmonary tuberculosis (TB) in Gansu. METHODS: The county-based incidence of pulmonary TB in Gansu from 2009 to 2013 was used to calculate Moran's I and G statistics, and analyze the spatial-temporal distribution of areas with different pulmonary TB incidences. RESULTS: The spatial correlation in incidence of pulmonary TB was found in Gansu from 2009 to 2013 (P<0.001), and the hot spot areas were mainly in Hexi area, Linxia, part of Dingxi, while the cold spot areas were in Lanzhou, part of Dingxi, Tianshui, Pingliang and Qingyang. Spatial-temporal analysis showed that the clustering of high pulmonary TB incidence areas were most likely in the Hexi area during 2009-2010 (LLR=3,031.10, RR=2.27, P<0.001), and the clustering of low pulmonary TB incidence areas were most likely in Lanzhou during 2011-2013 (LLR=1,545.52, RR=0.37, P<0.001). CONCLUSION: The analysis on spatial and spatial-temporal specific incidences of pulmonary TB in Gansu from 2009 to 2013 indicated that Hexi area is the key area in pulmonary TB prevention and control in Gansu.

[Spatial temporal distribution of mumps in Gansu, 2009-2013].

OBJECTIVE: To detect the spatial temporal distribution of mumps in Gansu by means of spatial statistics. METHODS: The county-based incidence of mumps from 2009 to 2013 was used to calculate the global Moran's I and local G statistics, and analyze its spatial temporal distribution characteristics. RESULTS: The incidence of mumps in Gansu were spatial auto-correlated from 2009 to 2013 respectively (P<0.001), and the hot spots were mainly distributed in Hexi area, while the cold spots were distributed in Tianshui, Longnan and Qingyang. Spatial temporal analysis showed that the high incidence of mumps was most likely to be detect in Hexi area (RR=3.05, LLR=4 670.995, P<0.001), and the low incidence was most likely to be detect in Longdong area (RR=0.36, LLR=1 980.686, P<0.001). CONCLUSION: The spatial and spatial temporal clustering of mumps existed in Gansu from 2009 to 2013, the results can be used in the development of mumps prevention and control measure in Gansu.