Weather variability and the incidence of cryptosporidiosis: comparison of time series poisson regression and SARIMA models

PURPOSE: Few studies have examined the relationship between weather variables and cryptosporidiosis in Australia. This paper examines the potential impact of weather variability on the transmission of cryptosporidiosis and explores the possibility of developing an empirical forecast system. METHODS: Data on weather variables, notified cryptosporidiosis cases, and population size in Brisbane were supplied by the Australian Bureau of Meteorology, Queensland Department of Health, and Australian Bureau of Statistics for the period of January 1, 1996-December 31, 2004, respectively. Time series Poisson regression and seasonal auto-regression integrated moving average (SARIMA) models were performed to examine the potential impact of weather variability on the transmission of cryptosporidiosis. RESULTS: Both the time series Poisson regression and SARIMA models show that seasonal and monthly maximum temperature at a prior moving average of 1 and 3 months were significantly associated with cryptosporidiosis disease. It suggests that there may be 50 more cases a year for an increase of 1 degrees C maximum temperature on average in Brisbane. Model assessments indicated that the SARIMA model had better predictive ability than the Poisson regression model (SARIMA: root mean square error (RMSE): 0.40, Akaike information criterion (AIC): -12.53; Poisson regression: RMSE: 0.54, AIC: -2.84). Furthermore, the analysis of residuals shows that the time series Poisson regression appeared to violate a modeling assumption, in that residual autocorrelation persisted. CONCLUSIONS: The results of this study suggest that weather variability (particularly maximum temperature) may have played a significant role in the transmission of cryptosporidiosis. A SARIMA model may be a better predictive model than a Poisson regression model in the assessment of the relationship between weather variability and the incidence of cryptosporidiosis.     

铊暴露与出生结局的关联研究

目的 研究铊暴露与出生结局关联的相关性。方法 以2013年5月至2014年9月在马鞍山市妇幼保健院纳入的3 236名孕妇作为研究对象,采用电感耦合等离子质谱法检测孕妇外周血及新生儿脐血中的铊浓度,运用多元线性回归方法分析研究铊暴露与出生结局关联的相关性。结果 孕妇孕早、中期外周血和新生儿脐血中铊浓度分别为61.7（50.8~77.0）、60.3（50.8~75.2）和38.5（33.6~44.1）ng/L。调整混杂因素后,孕早期外周血铊浓度与新生儿出生头围呈负相关（β=-0.41,95%CI：-0.76~-0.06）;脐血中铊浓度与新生儿出生身长呈负相关（β=-0.65,95%CI：-1.25~-0.05）;而孕中期外周血铊浓度与新生儿出生体重、身长、头围均无统计学关联（P>0.05）。性别差异分析显示：孕早期外周血铊浓度与女婴出生头围呈负相关（β=-0.53,95%CI：-1.05~-0.01）;脐血中铊浓度与女婴出生体重（β=-277.08,95%CI：-485.13~-69.03）、身长（β=-1.39,95%CI：-2.26~-0.53）呈负相关;孕早期和孕中期外周血及脐血中铊浓度与男婴出生体重、身长、头围均无统计学关联（P>0.05）。结论 铊暴露对新生儿出生结局的影响存在性别差异,孕早期外周血铊浓度与女婴出生头围呈负相关,脐血中铊浓度与女婴出生体重、身长均呈负相关。     

白细胞介素-9在胃癌前病变中的表达及意义

目的观察白细胞介素-9(IL-9)在胃良性病变、胃癌前病变及胃癌中的表达及临床意义。方法回顾性分析12例胃良性病变、38例胃癌前病变、46例胃癌患者的临床病理资料。采用免疫组化法检测上述标本中IL-9的表达水平,分析其与临床病理资料的关系。结果胃良性病变组、胃癌前病变组、胃癌组中IL-9表达差异有统计学意义(P0.01),且胃癌前病变中IL-9表达显著高于胃癌组(P0.01)。胃癌前病变组幽门螺旋杆菌(Hp)(+)患者IL-9表达显著高于Hp(-)患者,且组织炎症、萎缩、肠化程度越高,IL-9表达随之增加,差异具有统计学意义(P0.05)。结论 IL-9在胃癌前病变组织中高表达并与临床病理资料密切相关,推测IL-9及其介导的免疫反应参与胃癌前病变的发生及进展。     

Vulnerability of eco-environmental health to climate change: the views of government stakeholders and other specialists in Queensland,Australia

Background  

There is overwhelming scientific evidence that human activities have changed and will continue to change the climate of the Earth. Eco-environmental health, which refers to the interdependencies between ecological systems and population health and well-being, is likely to be significantly influenced by climate change. The aim of this study was to examine perceptions from government stakeholders and other relevant specialists about the threat of climate change, their capacity to deal with it, and how to develop and implement a framework for assessing vulnerability of eco-environmental health to climate change.     

Challenges for epidemiologic research on the verge of a new era

Although risk factor epidemiology has achieved much, it has its limitations (e.g., a failure to reveal causal mechanisms at multiple levels). To illustrate contemporary challenges for epidemiological research, we present a dialog with examples and argue for incorporating a “systems thinking through a life course” paradigm in epidemiological research. There is an increasing interest in moving part of public health from a discipline concerned primarily with risk factors at the individual level toward one concerned with complex causal patterns which often operate across different levels in time and space (e.g., from the molecular to the population, from the past to the future, and from the distal to the proximal). However, the methodology for discovering these complex and dynamic relationships remains to be improved. We propose strategies for taking up this challenge.     

Air pollution and sudden infant death syndrome: a literature review

Although the rate of sudden infant death syndrome (SIDS) has been reduced with the 'Back to Sleep' campaign, SIDS is still a common cause of death in infancy. A range of environmental factors may interact to contribute to the adverse health conditions conducive to SIDS. Nine studies have evaluated the association between exposure to air pollution and the incidence of SIDS. The available evidence is inadequate to come to any conclusion about a relationship between air pollution and SIDS, although the body of evidence appears to suggest that air pollution (especially particles and some gaseous pollutants) may play a certain role in the occurrence of SIDS. We suggest that future studies should focus on the research design, role of indoor air quality and the effect of smaller particles, particularly those in the ultrafine range.     

Maternal smoking and childhood respiratory illnesses: A seven year cohort study

In this prospective cohort study of 723 young children in South Australia, there was a strong dose‐response relationship between postnatal exposure to maternal smoking and increased incidence of respiratory illness in early childhood. Compared with children whose mothers did not smoke, the odds ratios were 1.58 (95% confidence interval (CI)): 0.83–2.93; p<0.10) and 2.67 (95% CI: 0.96–6.66; p < 0.10) for lower respiratory tract infections in children aged 0–2 years whose mothers smoked 1–20, or more than 20 cigarettes per day, respectively. The odds ratios for middle ear infections in 0–2 year‐old children whose mothers smoked 1–20, or more than 20 cigarettes per day were 2.43 (95% CI: 1.56–3.79; p< 0.01) and 3.50 (95% CI: 1.55–8.28; p< 0.01), respectively, and for children aged 2–4 years were 1.58 (95% CI: 1.02–2.46; p<0.05) and 2.56 (95% CI: 1.04–6.89; p < 0.05), respectively. Multiple logistic regression analysis yielded adjusted odds ratios consistent with the results of simple analysis. The findings from this prospective study confirm earlier evidence that postnatal exposure to maternal smoking is a major risk factor for respiratory illness in early childhood.     

Climate variability and Ross River virus transmission in Townsville Region, Australia, 1985-1996

BACKGROUND: How climate variability affects the transmission of infectious diseases at a regional level remains unclear. We assess the impact of climate variation on the Ross River virus (RRv) transmission in the Townsville region, Queensland, north-east Australia. METHODS: We obtained population-based information on monthly variations in RRv cases, climatic factors, sea level, and population growth between 1985 and 1996. Cross-correlations were computed for a series of associations between climate variables (rainfall, maximum temperature, minimum temperature, relative humidity and high tide) and the monthly incidence of RRv disease over a range of time lags. We assessed the impact of climate variability on RRv transmission using the seasonal auto-regressive integrated moving average (SARIMA) model. RESULTS: There were significant correlations of the monthly incidence of RRv to rainfall, maximum temperature, minimum temperature and relative humidity, all at a lag of 2 months, and high tide in the current month. The results of SARIMA models show that monthly average rainfall (beta = 0.0007, P = 0.01) and high tide (beta = 0.0089, P = 0.04) were significantly associated with RRv transmission and maximum temperature was also marginally significantly associated with monthly incidence of RRv (beta = 0.0412, P = 0.07), although relative humidity did not seem to have played an important role in the Townsville region. CONCLUSIONS: Rainfall, high tide and maximum temperature were likely to be key determinants of RRv transmission in the Townsville region.     

Cytolethal distending toxin is essential for Helicobacter hepaticus colonization in outbred Swiss Webster mice

Helicobacter hepaticus, which induces chronic hepatitis and typhlocolitis in susceptible mouse strains, produces a cytolethal distending toxin (CDT) consisting of CdtA, CdtB, and CdtC. A cdtB-deficient H. hepaticus isogenic mutant (HhcdtBm7) was generated and characterized for colonization parameters in four intestinal regions (jejunum, ileum, cecum, and colon) of outbred Swiss Webster (SW) mice. Inactivation of the cdtB gene abolished the ability of HhcdtBm7 to colonize female mice at both 8 and 16 weeks postinfection (wpi), whereas HhcdtBm7 colonized all of four intestinal regions of three of five males at 8 wpi and then was eliminated by 16 wpi. Wild-type (WT) H. hepaticus was detected in the corresponding intestinal regions of both male and female mice at 8 and 16 wpi; however, colonization levels of WT H. hepaticus in the cecum and colon of male mice were approximately 1,000-fold higher than in females (P < 0.0079) at 16 wpi. Infection with WT H. hepaticus, but not HhcdtBm7, at 8 wpi was associated with significantly increased mRNA level of ileal and cecal gamma interferon (IFN-gamma) in females (P < 0.016 and 0.031 between WT H. hepaticus-infected and sham-dosed females, respectively). In contrast, the mRNA levels of IFN-gamma were significantly higher in the colon (P < 0.0079) and trended to be higher in the cecum (P < 0.15) in the HhcdtBm7-colonized male mice versus the sham-dosed controls at 8 wpi. In addition, mRNA levels of ileal IFN-gamma were significantly higher in the control females than males at 8 wpi (P < 0.016). There were significantly higher Th1-associated immunoglobulin G2a (IgG2a), Th2-associated IgG1 and mucosal IgA (P < 0.002, 0.002, 0.002, respectively) responses in the mice infected with WT H. hepaticus when compared to HhcdtBm7 at 16 wpi. Colonic interleukin-10 (IL-10) expressions at 16 wpi were significantly lower in both female and male mice colonized by WT H. hepaticus or in males transiently colonized through 8 wpi by HhcdtBm7 versus control mice (P < 0.0159). These lines of evidence indicate that (i) H. hepaticus CDT plays a crucial role in the persistent colonization of H. hepaticus in SW mice; (ii) SW female mice are more resistant to H. hepaticus colonization than male mice; (iii) there was persistent colonization of WT H. hepaticus in cecum, colon, and jejunum but only transient colonization of H. hepaticus in the ileum of female mice; (iv) H. hepaticus colonization was associated with down-regulation of colonic IL-10 production.     

Knowledge, attitude and intentions related to colorectal cancer screening using faecal occult blood tests in a rural Australian population

A telephone survey with 604 men and women without history of colorectal cancer (CRC) (age 50-74 years) explored knowledge of, attitudes toward, and intention to screen for CRC using faecal occult blood tests (FOBT) in a rural Australian population. Overall, 53% intended to participate in and 86% would follow a doctor's recommendation for FOBT screening. In contrast, only 18% had ever had a FOBT, and fewer than 60% of those with high-risk family history had undergone appropriate screening for CRC. Prior use of FOBT (OR=3.2), high perceived susceptibility to CRC (OR=2.4), belief in the importance of screening despite the absence of symptoms (OR=2.1) were positively and older age (OR = 0.5) was negatively related to screening intention in multivariate logistic regression analysis. A doctor's recommendation improved screening intention among those who never tested for CRC before but believe in the importance of early treatment. This study highlights the lack of compliance with standard CRC screening recommendations in Australia and provides evidence for the importance of continued educational efforts, with the particular emphasis on older adults and the medical community.