[Lag effect and influencing factors of temperature on other infectious diarrhea in Zhejiang province].

Objective: To study the lag effect of temperature and the source of heterogeneity on other infectious diarrhea (OID) in Zhejiang province, so as to identify related vulnerable populations at risk. Methods: Data on OID and meteorology in Zhejiang province from 2014 to 2016 were collected. A two-stage model was conducted, including: 1) using the distributed lag non-linear model to estimate the city-specific lag effect of temperature on OID, 2) applying the multivariate Meta- analysis to pool the estimated city-specific effect, 3) using the multivariate Meta-regression to explore the sources of heterogeneity. Results: There were 301 593 cases of OID in Zhejiang province during the study period. At the provincial level, temperature that corresponding to the lowest risk of OID was 16.7 ℃, and the temperature corresponding to the highest risk was 6.2℃ (RR=2.298, 95%CI: 1.527- 3.459). 16.7 ℃ was recognized as the reference temperature. P(5) and P(95) of the average daily temperature represented low and high temperature respectively. When the temperature was cold, the risk was delayed by 2 days, with the highest risk found on the 5(th) day (RR=1.057, 95%CI: 1.030-1.084) before decreasing to the 23(rd) day. When the temperature got hot, the risk of OID occurred on the first day (RR=1.081, 95%CI: 1.045-1.118) and gradually decreasing to the 8(th) day. Differences on heterogeneous sources related to the risks of OID in different regions, presented on urban latitude and the rate of ageing in the population. Conclusions: Both high or low temperature could increase the risk of OID, with a lag effect noticed. Prevention program on OID should be focusing on populations living in the high latitude and the elderly population at the low temperature areas.

[Applications of statistical models on surveillance data in ecological study].

In recent years, with the improvement of various surveillance network, surveillance system has become an important data source for ecological study. Different data types, including cross-sectional data, time series data and panel data, containing abundant information involving exposure, outcome and confoundings. Gradually, some new statistical methods have been developed or improved for the special structural characteristics of surveillance data. In this paper, we summarized the principles of these models, preconditions, as well as their advantages and limitations.

[Influence of diurnal temperature range on influenza incidence in the elderly].

Objective: To understand the influence of diurnal temperature range (DTR) on influenza incidence in the elderly in Beijing and to conduct a subgroup analysis. Methods: The incidence data of daily influenza cases in the elderly and daily meteorological data from 2014 to 2016 in Beijing were collected for this study. A generalized additive model (GAM) was used to explore whether the relationship between daily influenza cases and DTR is a linear one. A distributed lag non-linear model (DLNM) was established to quantify the lagged effect of DTR on daily influenza incidence in the elderly. The model was also used to estimate the effects of DTR on daily influenza incidence among various subgroups. Results: A total of 4 097 influenza cases in the elderly were notified during study period. The mean DTR was 10.153 ℃. A linear relationship between daily influenza incidence and DTR was detected by using GAM. DTR was significantly associated with daily influenza incidence between lag0 and lag5 with a maximal effect at lag0. An 1 ℃ increase of DTR was associated with a 2.0% increase in daily influenza incidence in the elderly (95%CI: 0.9%-3.0%). The RR values of males, females, people aged 60-69 years, people aged ≥70 years were 1.018 (95%CI: 1.005-1.032), 1.021(95%CI: 1.007-1.035), 1.012 (95%CI: 1.002-1.022), 1.025 (95%CI: 1.012-1.039), respectively. The influencing time of DTR on females (lag6) was longer than males (lag2). Conclusions: DTR was associated with increased risk of influenza in the elderly in Beijing. It is necessary to take targeted measures in the elderly to control the incidence of influenza when DTR becomes greater.

[Three-level logistic analysis related to influencing factors on condom use among female sex workers aged 35 years and above in Qingdao].

Objective: To analyze the influencing factors on condom use among 35-years-or-older female sex workers (OFSWs) in Qingdao by using the three-level logistic model. Methods: From March to June 2014, OFSWs were recruited in Qingdao, using respondent-driven sampling. Related information on OFSWs and their recent five sexual partners (not including husband) were obtained by conducting a questionnaire survey on OFSWs. A Three-level logistic regression model was conducted to analyze the influencing factors of condom use between OFSWs and their sexual partners. Results: A total of 420 OFSWs participated the survey as well as information on 2 100 sexual partners. Results from the empty model showed that the use of condoms among OFSWs having an aggregation that related to the levels of working sites and their own behaviors. Results from the three-levels of logistic model analysis showed that, OFSWs that having had junior middle school education (OR=1.450, 95%CI: 1.054-1.994)/high school education or above (OR=2.264, 95%CI: 1.215-4.222), knowing the function of condom use (OR=2.004, 95%CI: 1.273-3.154) would have higher rates of condom use. OFSWs with higher score of attitude on condom use (OR=0.796, 95%CI: 0.745-0.849), having had syphilis infections in the past (OR=0.657, 95%CI: 0.478-0.902) would have lower rate of condom use. For the sexual partners, the rate of condom use among OFSWs' regular partners were higher than that of OFSWs' boyfriends (OR=15.291, 95%CI: 8.441-27.700; OR=29.032, 95%CI: 15.413-54.682). Conclusion: Condom use of OFSWs was affected by behaviors of both OFSWs themselves and their sexual partners. Prevention and control programs should focus on OFSWs and their sexual partners at the same time. The key intervention contents should include target populations as: OFSWs with low level of education, having had infections of syphilis, those who do not use condoms with their trusted partners.

[Meta-analysis on partial risk factors of full-term infants with low birth weight].

Objective: To evaluate the risk factors of full-term infants with low birth weight. Methods: All related Chinese and English literatures published from 1980 to February 25, 2016 were collected from CBM, CNKI, Wang Fang Data, Medline and Embase databases, and screened with inclusion and exclusion criteria and Stata13.0 software was used in this Meta-analysis. Results: Twenty three studies were included and there were 278 020 subjects. Female infants (pooled OR=1.60, 95%CI: 1.49-1.72), less antenatal care visits (pooled OR=1.81, 95%CI: 1.54-2.11), maternal passive smoking (pooled OR=1.49, 95% CI: 1.08-2.06), pregnancy-induced hypertension (pooled OR=2.96, 95% CI: 1.85-4.74) and hypamnion (pooled OR=2.71, 95%CI: 1.87-3.93) were the risk factors for full-term infants with low birth weight. Conclusion: Departments of maternal and health care should encourage pregnant women to have antenatal care visits to find and treat their pregnancy complications, and avoid passive smoking actively through health education for the purpose to prompt the birth quality of infants.

[Study on influence of floods on bacillary dysentery incidence in Liaoning province, 2004 -2010].

OBJECTIVE: To understand the influence of floods on bacillary dysentery in Liaoning province. METHODS: The monthly surveillance data of bacillary dysentery, floods, meteorological and demographic data in Liaoning from 2004 to 2010 were collected. Panel Poisson regression analysis was conducted to evaluate the influence of floods on the incidence of bacillary dysentery in Liaoning. RESULTS: The mean monthly morbidity of bacillary dysentery was 2.17 per 100 000 during the study period, the bacillary dysentery cases mainly occurred in during July-September. Spearman correlation analysis showed that no lagged effect was detected in the influence of floods on the incidence of bacillary dysentery. After adjusting the influence of meteorological factors, panel data analysis showed that the influence of floods on the incidence of bacillary dysentery existed and the incidence rate ratio was 1.439 4(95%CI: 1.408 1-1.471 4). CONCLUSION: Floods could significantly increase the risk of bacillary dysentery for population in Liaoning.

[Characteristics of social supportive network serving the older female sex workers in Qingdao].

OBJECTIVE: To overview the status of social support on older female sex workers (OFSWs) in Qingdao and to better understand the characteristics of this egocentric social support networks. METHODS: Ucinet 6 software was used to analyze the characteristics of egocentric social networks which involving 400 OFSWs who were recruited by respondent-driven sampling (RDS) method in Qingdao during March 2014 to June. Structural equation model (SEM) was used for data analysis, fitted test and estimation. RESULTS: A total of 400 OFSWs of Qingdao nominated 1 617 social supportive members, and the average size of egocentric social networks of OFSWs was (4.0 ± 1.5). Among all the alter egos (social support network members of the egos), 613 were female sex workers fellows, accounted for the most important part of all the social ties (37.91%). Characteristics of small size and non-relative relationships were seen more obviously among OFSWs with non-local registration and the ratings of emotional support (4.42±2.38) was significantly lower than the tangible support (5.73 ± 1.69) (P<0.05). Result of the SEM showed that homogeneity, joint strength and the network structure were significantly related to the ratings of average support. The total standard effects of which were 0.110, 0.925 and -0.069 respectively. It seemed that homogeneity can affect the degree of support, both directly and indirectly. CONCLUSION: OFSWs in Qingdao tended to ask for social support from friends who were also female sex workers. Stronger the joint strength between egos and alters, greater the homogeneity between the two was seen. Tighter relations among the alter egos, higher degree of average social support of the egos were acquired.

Multilocus variable-number tandem-repeat analysis of Neisseria meningitidis serogroup C in China.

This study characterized Neisseria meningitidis serogroup C strains in China in order to establish their genetic relatedness and describe the use of multilocus variable-number tandem-repeat (VNTR) analysis (MLVA) to provide useful epidemiological information. A total of 215 N. meningitidis serogroup C strains, obtained from 2003 to 2012 in China, were characterized by MLVA with different published schemes as well as multilocus sequence typing. (i) Based on the MLVA scheme with a combination of five highly variable loci, 203 genotypes were identified; this level of discrimination supports its use for resolving closely related isolates. (ii) Based on a combination of ten low variable loci, clear phylogenetic relationships were established within sequence type complexes. In addition, there was evidence of microevolution of VNTR loci over the decade as strain lineages spread from Anhui to other provinces, the more distant the provinces from Anhui, the higher the genetic variation.

Effects of meteorological factors on scrub typhus in a temperate region of China.

Scrub typhus is emerging and re-emerging in many areas: climate change may affect its spread. To explore the effects of meteorological factors on scrub typhus, monthly cases of scrub typhus from January 2006 to December 2012 in the Laiwu district of temperate northern China were analysed. We examined the correlations between scrub typhus and meteorological factors (and their delayed effects). We built a time-series adjusted negative binomial model to reflect the relationships between climate variables and scrub typhus cases. The key determinants of scrub typhus transmission were temperature, relative humidity and precipitation. Each 1°C increase in monthly average temperature in the previous 3 months, each 1% increase in monthly relative humidity in the previous 2 months and each 1 mm increase in monthly precipitation in the previous 3 months induced 15·4%, 12·6% and 0·7% increases in the monthly number of cases, respectively. In conclusion, scrub typhus is affected by climate change in temperate regions.

NAT2 polymorphisms and susceptibility to anti-tuberculosis drug-induced liver injury: a meta-analysis.

BACKGROUND AND OBJECTIVE: Although a series of studies have evaluated the potential association between N-acetyltransferase 2 (NAT2) polymorphisms and the risk of anti-tuberculosis drug-induced liver injury (ATLI), the results have generally been controversial and inadequate, mainly due to limited power. The present meta-analysis sought to resolve this problem. DESIGN: PubMed, Embase and Web of Science were searched using the following key words: 'N-acetyltransferase 2' or 'NAT2' and 'polymorphism' and 'tuberculosis' or 'TB' and 'hepatotoxicity' or 'liver injury'. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were summarised in forest plots and set out in a table. RESULTS: A total of 14 studies, comprising 474 cases and 1446 controls, were included in the meta-analysis. A significant association was observed between NAT2 slow acetylators and the risk of ATLI. The OR for NAT2 slow acetylators compared with rapid acetylators was 4.697 (95%CI 3.291-6.705, P < 0.001). Subgroup analyses indicate that both Asian and non-Asian cases with slow acetylators develop ATLI more frequently, which is similar to patients with slow acetylators receiving first-line combination treatment. On comparing NAT2 intermediate acetylators with rapid acetylators, the OR for ATLI was 1.261 (95%CI 0.928-1.712, P = 0.138). CONCLUSIONS: This meta-analysis showed that tuberculosis patients with slow acetylators had a higher risk of ATLI than other acetylators. Screening of patients for the NAT2 genetic polymorphisms will be useful for the clinical prediction and prevention of ATLI.