The West Nile Virus outbreak in Israel (2000) from a new perspective: the regional impact of climate change

The West Nile Virus (WNV) outbreak in Israel in 2000 appeared after medical and climatic warning signs. Re-analysis of the epidemic from a new viewpoint, the regional impact of global warming, especially the worsening in the summers' heat conditions, is presented. The disease appeared averagely at a lag of 3-9 weeks (strongest correlation = lag of 7 weeks). The minimum temperature was found as the most important climatic factor that encourages the disease earlier appearance. Extreme heat is more significant than high air humidity for increasing WNV cases. An early extreme rise in the summer temperature could be a good indicator of increased vector populations. While 93.5% of cases were in the metropolitan areas, the disease was not reported in the sub-arid regions. The outbreak development was comparable to the cases from Romania (1996) and NYC (1999). Each of those epidemics appeared after a long heatwave.     

Climate variation and incidence of Ross river virus in Cairns, Australia: a time-series analysis.

In this study we assessed the impact of climate variability on the Ross River virus (RRv) transmission and validated an epidemic-forecasting model in Cairns, Australia. Data on the RRv cases recorded between 1985 and 1996 were obtained from the Queensland Department of Health. Climate and population data were supplied by the Australian Bureau of Meteorology and the Australian Bureau of Statistics, respectively. The cross-correlation function (CCF) showed that maximum temperature in the current month and rainfall and relative humidity at a lag of 2 months were positively and significantly associated with the monthly incidence of RRv, whereas relative humidity at a lag of 5 months was inversely associated with the RRv transmission. We developed autoregressive integrated moving average (ARIMA) models on the data collected between 1985 to 1994, and then validated the models using the data collected between 1995 and 1996. The results show that the relative humidity at a lag of 5 months (p < 0.001) and the rainfall at a lag of 2 months (p < 0.05) appeared to play significant roles in the transmission of RRv disease in Cairns. Furthermore, the regressive forecast curves were consistent with the pattern of actual values.     

Different responses of Ross River virus to climate variability between coastline and inland cities in Queensland,Australia

Aims: To examine the potential impact of climate variability on the transmission of Ross River virus (RRv) infection, and to assess the difference in the potential predictors of RRv incidence in coastline and inland regions, Queensland, Australia.

Methods: Information on the RRv cases notified between 1985 to 1996 was obtained from the Queensland Department of Health. Climate and population data were supplied by the Australian Bureau of Meteorology and the Australia Bureau of Statistics, respectively. The function of cross correlations was used to compute a series of correlations 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. Time series Poisson regression models were performed to adjust for the autocorrelations of the monthly incidences of RRv disease and the confounding effects of seasonality, the case notification time, and population sizes.

Results: The cross correlation function shows rainfall, maximum temperature, minimum temperature, and relative humidity at a lag of 1–2 months and high tide in the current month were significantly associated with the monthly incidence of RRv in the coastline region. Relative humidity and rainfall at a lag of two months was also significantly associated with the monthly incidence of RRv in the inland region. The results of Poisson regressive models show that the incidence of RRv disease was significantly associated with rainfall, maximum temperature, minimum temperature, relative humidity, and high tide in the coastline region, and with rainfall and relative humidity in the inland region. There was a significant interaction between climate variables and locality in RRv transmission.

Conclusions: Climate variability may have played a significant role in the transmission of RRv. There appeared to be different responses of RRv to climate variability between coastline and inland cities in Queensland, Australia. Maximum temperature appeared to exhibit a greater impact on the RRv transmission in coastline than in inland cities. Minimum temperature and relative humidity at 3 pm inland seemed to affect the RRv transmission more than at the coastline. However, the relation between climate variables and RRv needs to be viewed within a wider context of other social and environmental factors, and further research is needed.

     

Weather temperatures and sudden infant death syndrome: a regional study over 22 years in New Zealand

STUDY OBJECTIVE: To examine and identify relationships between the sudden infant death syndrome (SIDS) and environmental temperature in Canterbury, New Zealand. DESIGN: A retrospective epidemiological study combining details of regional hourly temperature and reported SIDS cases. SETTING: Canterbury, New Zealand, between 1968 and 1989 inclusively. PARTICIPANTS: All infants reported as dying from SIDS within the Canterbury region. MAIN RESULTS: The SIDS incidence increased after months with prolonged colder minimum temperatures, confirming the seasonality of SIDS. After adjusting for this seasonality, days that showed little change in hourly temperature and days with warmer minimum temperatures recorded were seen to have a significantly increased the incidence of SIDS. No evidence was found for other relationships between the SIDS incidence and various measures of daily temperatures on the day of death, over the preceding eight days or between these days. Infants aged 12 weeks and over were more susceptible to SIDS on days when small hourly temperature changes were recorded than their younger counterparts; no other age differences emerged. CONCLUSIONS: This study confirmed that the incidence of SIDS is affected by seasonality and temperature on the day of death. In particular, after a prolonged period of cold minimum temperatures, infants were most at risk from SIDS on days on which either a warmer minimum temperature or little hourly variation in temperature were recorded. No other daily or lagged daily temperature factor (lagged up to eight days before the day of death) was statistically associated with the SIDS incidence. It is suspected that the inconsistent previously published lag effect findings actually describe some other phenomenon such as parental behaviour or infant thermoregulation.     

Hybrid Vibrio vulnificus

The recent emergence of the human-pathogenic Vibrio vulnificus in Israel was investigated by using multilocus genotype data and modern molecular evolutionary analysis tools. We show that this pathogen is a hybrid organism that evolved by the hybridization of the genomes from 2 distinct and independent populations. These findings provide clear evidence of how hybridization between 2 existing and nonpathogenic forms has apparently led to the emergence of an epidemic infectious disease caused by this pathogenic variant. This novel observation shows yet another way in which epidemic organisms arise.     

Changes in the effects of heat on mortality among the elderly from 1998-2010: results from a multicenter time series study in Italy

ABSTRACT: BACKGROUND: This multicenter study is aimed at estimating changes in the effect of high temperatures on elderly mortality before and after the 2003 heat waves and following the introduction of heat prevention activities. METHODS: A total of sixteen cities were included in the study. City-specific relationships between maximum apparent temperature (MAT) and elderly daily mortality before (1998-2002) and after (2006-2009) intervention were modelled through non-linear distributed lag models and estimates were combined using a random effect meta-analysis. We estimated the percentage change in daily mortality for 3degreesC variations in MAT above the 25th percentile of the June city-specific 1998-2002 distribution. A time-varying analysis was carried out to describe intra-seasonal variations in the two periods. RESULTS: We observed a reduction in high temperatures' effect post intervention; the greatest reduction was for increases in temperature from 9degreesC to 12degreesC above the 25th percentile, with a decrease from +36.7% to +13.3%. A weak effect was observed for temperatures up to 3degreesC above the 25th percentile only after. Changes were month-specific with a reduction in August and an increase in May, June and September in 2006-2010. CONCLUSIONS: A change in the temperature-mortality relationship was observed, attributable to variations in temperature distributions during summer and to the introduction of adaptation measures. The reduction in the effect of high temperature suggests that prevention programs can mitigate the impact. An effect of lower temperature remains, indicating a relevant impact of temperature at the beginning of summer when the population has not yet adapted and intervention activities are not fully operational.     

Spatial and temporal variation in the association between temperature and salmonellosis in NZ

Objective: Modelling the relationship between weather, climate and infectious diseases can help identify high‐risk periods and provide understanding of the determinants of longer‐term trends. We provide a detailed examination of the non‐linear and delayed association between temperature and salmonellosis in three New Zealand cities (Auckland, Wellington and Christchurch). Methods: Salmonella notifications were geocoded to the city of residence for the reported case. City‐specific associations between weekly maximum temperature and the onset date for reported salmonella infections (1997–2007) were modelled using non‐linear distributed lag models, while controlling for season and long‐term trends. Results: Relatively high temperatures were positively associated with infection risk in Auckland (n=3,073) and Christchurch (n=880), although the former showed evidence of a more immediate relationship with exposure to high temperatures. There was no significant association between temperature and salmonellosis risk in Wellington. Conclusions: Projected increases in temperature with climate change may have localised health impacts, suggesting that preventative measures will need to be region‐specific. This evidence contributes to the increasing concern over the public health impacts of climate change.     

Clinical Characteristics and Molecular Subtyping of Vibrio vulnificus Illnesses, Israel

During 1996–1997, a new Vibrio vulnificus biotype 3, which caused severe soft tissue infection after fishbone injury, emerged in Israel. We conducted a follow-up study from 1998 through 2005 to assess changing trends, outcomes, and molecular relatedness of the implicated strains. A total of 132 cases (71% confirmed and 29% suspected) of V. vulnificus biotype 3 infection were found. Most infections (95%) were related to percutaneous fish exposure, mainly tilapia (83%) or common carp (13%). Bacteremia, altered immune status, and history of ischemic heart disease were identified as independent risk factors for death, which reached a prevalence of 7.6%. Pulsed-field gel electrophoresis patterns of strains from 1998 through 2005 and from 1996 through 1997 showed a high degree of homogeneity and were distinct from those of V. vulnificus biotype 1. Infections caused by V. vulnificus biotype 3 continue affect the public’s health in Israel.     

Relationship between climate change and determinant factors of mortality among the elderly in the municipality of São Carlos (São Paulo, Brazil) over a period of ten years

The aim of this study was to identify the correlation between the number of deaths of elderly people and climate change in the district of S?o Carlos (SP) over a period of 10 years (1997-2006). Records of deaths were obtained from DATASUS for people aged over 60 who died between 1997 and 2006 in S?o Carlos. The average monthly maximum and minimum temperature data and relative air humidity in S?o Carlos were provided by the National Institute of Meteorology. The mortality coefficient of the district was calculated by gender and age and the resulting data were analyzed using t test, one-way ANOVA, the Bonferroni test and the Pearson correlation coefficient test. There were 8,304 deaths which predominantly occurred among males aged over 80, and diseases of the circulatory system were the main cause of death. There was a positive correlation between mortality by infectious disease and minimum humidity, and a negative correlation between mortality by infectious diseases and minimum temperatures, between mortality caused by respiratory disease and minimum humidity, between mortality caused by endocrine disease and minimum and maximum temperature. Thereby, it was possible to conclude that there was a correlation between climate change and mortality among elderly individuals in S?o Carlos.     

Daily mortality in Madrid community 1986–1992: Relationship with meteorological variables

Daily mortality displays a seasonal pattern linked to weather, air pollution, photoperiod length, influenza incidence and diet, among which temperature ranks as a leading cause. This study thus sought to assess the relationship between temperature, relative humidity, wind speed and mortality in the Madrid Autonomous Region (Spain) for the period January 1986–December 1992, controlling for the effects of air pollution and influenza incidence. Daily data on maximum, minimum and 24-hour mean temperature, relative humidity and wind speed were matched against daily mortality. Transfer function was identified using the Box–Jenkins pre-whitening method. Multivariate time series regression models were used to control for the confounding effects of air pollution and influenza incidence. Separate seasonal analyses were carried out for winter and summer periods. A J-shaped relationship between outdoor temperature, relative humidity and daily mortality was found. Mortality proved to be inversely related to cold temperature (4- to 11-day lag) and directly related to warm temperature (1-day lag). High relative humidity during summer periods was negatively related to mortality. Thermal variation ascribable to Madrid's mesothermal Mediterranean climate was strongly related to daily mortality, even where air pollution and influenza incidence were controlled for.     

Septicaemia secondary to Vibrio vulnificus cellulitis

Vibrio vulnificus is a naturally occurring, salt-water bacteria found in estuarine and coastal waters worldwide. It prefers low salinity and warm water temperatures for optimum growth. Infection from Vibrio vulnificus is uncommon, although it has been reported from many locations (e.g. southern United States of America, Israel, Republic of Korea, Japan, Taiwan, Spain, Turkey). It can be serious and life threatening, causing septicaemia and wound infections. This paper reports a case of septicaemia secondary to Vibrio vulnificus cellulitis in an elderly woman. The infection was acquired after wading in a coastal lagoon with a pre-existing superficial leg wound.     

Effects of temperature and ozone on daily mortality during the August 2003 heat wave in France

During the summer of 2003, Europe experienced a heat wave that lasted almost 2 weeks in which high temperatures were accompanied by exceptionally high ozone levels. Unfortunately, few studies have examined the effects of temperature and ozone simultaneously. The authors use constrained distributed lag models to estimate the effects of daily temperature and peak ozone on mortality in 12 French cities during the heat wave and to estimate the deaths attributable to each component. Elevated minimum and maximum temperature and peak ozone all increase mortality, with substantial interaction effects between temperature and ozone. Researchers expect extreme weather events, along with elevated ozone levels and temperatures, to become more common. Our results suggest that ozone will be an important contributor to the adverse health effects of such events.     

Positive changes in sun-related behavior in Israel (1994-1998)

BACKGROUND: Current preventive measures against skin cancer focus on individual sun protection and early detection. Solar radiation in Israel is powerful, and about one-half of its population is fair skinned. We investigated whether public awareness efforts yielded changes in sun-related behaviors in Israel from 1994 to 1998. METHODS: The Department of Health Promotion in the Ministry of Health in Israel has been conducting an ongoing research on health knowledge, attitude, and practice, including six closed questions about sun-related behaviors in a general questionnaire. Independent samples of about 3,000 people representing the adult Jewish population (18 years old and above) were surveyed in 1994, 1996, and 1998. Response rates in 1994 and 1996 were about 85 and 80% in 1998. RESULTS: The number of people reporting sun protection behaviors increased from 34% in 1994 to 41% in 1996 and to 46% in 1998. Periodic medical skin examination increased from 9% of the responders in 1994, to 13% in 1996 and to 16% in 1998. The number of people reporting having fair skin increased from 28% in 1994 to 41% in 1996 and to 43% in 1998. CONCLUSIONS: There were positive changes in sun-related awareness and behaviors in Israel between 1994 and 1998. These findings support the conclusion that positive gains were associated with the health promotion efforts conducted by the Israel Cancer Society, Ministry of Health, and other Israeli organizations throughout these years.     

Predicting the risk of bluetongue through time: climate models of temporal patterns of outbreaks in Israel

Determining the temporal relationship between climate and epidemics of Culicoides-borne viral disease may allow control and surveillance measures to be implemented earlier and more efficiently. In Israel, outbreaks of bluetongue (BT) have occurred almost annually since at least 1950, with severe episodes occurring periodically. In this paper, the authors model a twenty-year time-series of BT outbreaks in relation to climate. Satellite-derived correlates of low temperatures and high moisture levels increased the number of outbreaks per year. This is the first study to find a temporal relationship between the risk of Culicoides-borne disease and satellite-derived climate variables. Climatic conditions in the year preceding a BT episode, between October and December, coincident with the seasonal peak of vector abundance and outbreak numbers, appeared to be more importantthan spring or early summer conditions in the same year as the episode. Since Israel is an arid country, higher-than-average moisture levels during this period may increase the availability of breeding sites and refuges for adult Culicoides imicola vectors, while cooler-than-average temperatures will increase fecundity, offspring size and survival through adulthood in winter, which, in turn, increases the size of the initial vector population the following year. The proportion of variance in the annual BT outbreak time-series resulting from climate factors was relatively low, at around 20%. This was possibly due to temporal variation in other factors, such as viral incursions from surrounding countries and levels of herd immunity. Alternatively, since most BT virus (BTV) circulation in this region occurs silently, in resistant breeds of local sheep, the level of transmission is poorly correlated with outbreak notification so that strong relationships between BTV circulation and climate, if they exist, are obscured.     

开封地区急性脑血管病与季节气候关联性研究

目的 观察急性脑血管病与季节气候的相关性,以期在急性脑血管疾病的高发期进行预报,使人们做好防护,降低急性脑血管病的发病率和死亡率.方法 将开封地区2008年1月～2011年9月收治的急性脑血管患者按季节进行分类计数,运用卡方检验不同的季节和气候因素条件下脑血管病发病率及不同年龄段发病率.一年按春、夏、秋、冬四个季节划分,12、1、2月为冬季,3、4、5月为春季,6、7、8月为夏季,9、10、11月为秋季.年龄段划分：30～80岁以上,10岁为1个年龄段,共划分6个年龄组.结果 不同季节脑血管病发病率差异有统计学意义（P＜0.01）,其中冬季和夏季发病率高,冬季与春季比较差异有统计学意义（P＜0.01）;夏季与秋季相比较差异有统计学意义（P＜0.05）;冬季发病率高于夏季发病率,但无明显的统计学意义（P＞0.05）.春、秋季节脑血管病发病率差异无统计学意义（P＞0.05）.从年龄分布来看,不同年龄脑血管病发病率有显著差异（P＜0.01）,其中51岁～60岁是脑出血高发年龄段（P＜0.05）;71岁～80岁是脑梗死高发年龄段（P＜0.05）.结论 开封地区急性脑血管病发病与季节气温有一定的相关性,急性脑血管病在冬季和夏季发病率高,脑出血受季节气候变换因素影响更大.人们要注意适应季节气候变化,冬天注意保暖,夏天多饮水,养成良好生活习惯,并注意基础病的治疗.     

Effects of climatic elements on Campylobacter-contaminated chicken products in Japan

Japanese weather data for areas that produced Campylobacter spp.-positive chicken products were compared with those for areas producing negative samples. Regarding samples produced during the period of rising temperature (spring and summer), the mean weekly air temperatures for Campylobacter-positive samples were higher than those for negative samples for the period of the week in which the samples were purchased (18.7 °C vs. 13.1 °C, P = 0.006) to a 12-week lag (12 weeks before purchasing samples; 7.9 °C vs. 3.4 °C, P = 0.009). Significant differences in weekly mean minimum humidity and sunshine duration per day were also observed for 1- and 2-week lag periods. We postulated that the high air temperature, high humidity and short duration of sunshine for the chicken-rearing period increased Campylobacter colonization in chickens during the period of rising temperature. Consequently, the number of Campylobacter-contaminated chicken products on the market in Japan may fluctuate because of the climatic conditions to which reared chickens are exposed.     

Climate variability and Ross River virus transmission

OBJECTIVES: (1) To examine the feasibility to link climate data with monthly incidence of Ross River virus (RRv). (2) To assess the impact of climate variability on the RRv transmission. DESIGN: An ecological time series analysis was performed on the data collected between 1985 to 1996 in Queensland, Australia. METHODS: Information on the notified RRv cases was obtained from the Queensland Department of Health. Climate and population data were supplied by the Australian Bureau of Meteorology and the Australian Bureau of Statistics, respectively. Spearman's rank correlation analyses were performed to examine the relation between climate variability and the monthly incidence of notified RRv infections. The autoregressive integrated moving average (ARIMA) model was used to perform a time series analysis. As maximum and minimum temperatures were highly correlated with each other (r(s)=0.75), two separate models were developed. RESULTS: For the eight major cities in Queensland, the climate-RRv correlation coefficients were in the range of 0.12 to 0.52 for maximum and minimum temperatures, -0.10 to 0.46 for rainfall, and 0.11 to 0.52 for relative humidity and high tide. For the whole State, rainfall (partial regression coefficient: 0.017 (95% confidence intervals 0.009 to 0.025) in Model I and 0.018 (0.010 to 0.026) in Model II), and high tidal level (0.030 (0.006 to 0.054) in Model I and 0.029 (0.005 to 0.053) in Model II) seemed to have played significant parts in the transmission of RRv in Queensland. Maximum temperature was also marginally significantly associated with the incidence of RRv infection. CONCLUSION: Rainfall, temperature, and tidal levels may be important environmental determinants in the transmission cycles of RRv disease.     

Weather and the transmission of bacillary dysentery in Jinan, northern China: a time-series analysis

OBJECTIVES: This article aims to quantify the relationship between weather variations and bacillary dysentery in Jinan, a city in northern China with a temperate climate, to reach a better understanding of the effect of weather variations on enteric infections. METHODS: The weather variables and number of cases of bacillary dysentery during the period 1987-2000 has been studied on a monthly basis. The Spearman correlation between each weather variable and dysentery cases was conducted. Seasonal autoregressive integrated moving average (SARIMA) models were used to perform the regression analyses. RESULTS: Maximum temperature (one-month lag), minimum temperature (one-month lag), rainfall (one-month lag), relative humidity (without lag), and air pressure (one-month lag) were all significantly correlated with the number of dysentery cases in Jinan. After controlling for the seasonality, lag time, and long-term trend, the SARIMA model suggested that a 1 degree C rise in maximum temperature might relate to more than 10% (95% confidence interval 10.19, 12.69) increase in the cases of bacillary dysentery in this city. CONCLUSIONS: Weather variations have already affected the transmission of bacillary dysentery in China. Temperatures could be used as a predictor of the number of dysentery cases in a temperate city in northern China. Public health interventions should be undertaken at this stage to adapt and mitigate the possible consequences of climate change in the future.     

The effect of temperature on mortality in Stockholm 1998--2003: a study of lag structures and heatwave effects

AIMS: To describe seasonal patterns of natural mortality in Stockholm as well as the temperature-mortality relationship and the lag structure for effects of high and low temperatures; to describe the impact of high temperatures on cardiovascular and respiratory mortality, and the general effect of high temperatures in different age groups; and to investigate whether there is any indication of an additional heatwave or cold spell effect. METHODS: Generalized additive Poisson regression models were fitted to mortality and temperature data from Stockholm from the period 1998-2003, controlling for influenza, season, time trends, week day, and holidays. RESULTS: The mortality in Stockholm followed a seasonal pattern, with a peak in the winter season. The ;;optimal temperature' was around 11-12 degrees C. Above this temperature, the cumulative general relative risk (RR) corresponded to a 1.4% (95% confidence interval (CI)=0.8-2.0) increase per degrees C, and below this temperature the cumulative RR corresponded to a 0.7% (95% CI=0.5-0.9) decrease per degrees C. Age-specific RRS were estimated above the threshold for age <65 years, age 65-74 years, and age >74 years, with estimated increases of 0.5% (not significant), 1.5% (not significant) and 1.6% (95% CI=0.9-2.3) per degrees C, respectively. The RRs for cardiovascular and respiratory causes were studied above the breakpoint, and estimated to be 1.1% (95% CI=0.3-2.0) and 4.3% (95% CI=2.2-6.5) per degrees C, respectively. The lag structures from moving averages and polynomial distributed lag models coincided with a rather direct effect during summer (lag 0 and 1) and a more prolonged effect during winter, covering about a week. The inclusion of an indicator of heatwaves added an increase in daily mortality of 3.1-7.7%, depending on the threshold. CONCLUSIONS: These results show that the predicted increase in heat events must also be taken seriously in Scandinavia, whatever the extent of the decreasing cold related mortality. The relative risks associated with heat and heatwaves seem stronger than the cold effects and thus a larger public health threat, since northern populations have not yet adapted to heat as have been done over a long time for the cold periods. The pressure on the healthcare sector will probably increase in the warm season, periodically it may become even greater than the pressure due to cold weather, which will be a new phenomenon for the healthcare sector to cope with. We need to be prepared for these kind of events by developing adaptation and education strategies to handle the consequences that a warmer climate will have for public health and the healthcare sector.     

Seasonal variation of mortality from cerebro-cardiovascular diseases--effect of ambient temperature on death]

A study to clarify the relationship between seasonal variations in mortality from cerebro-cardiovascular diseases and ambient temperature (maximum/minimum temperature and daily range) was performed using time series analysis, and the role of ambient temperature as an associated factor in cerebro-cardiovascular disease caused death was discussed. The following results were obtained: 1) The seasonality factor associated with the monthly variation for mortality was of greater magnitude for heart diseases more than for cerebral diseases. There was a tendency for mortality from cardiac diseases to decline gradually from February/March to July/August, and to increase in October/November, with a maximum peak in the curve of seasonal variation observed in January/February. 2) The seasonal factor associated with maximum/minimum temperature and daily temperature range showed a stable variation in magnitude from January to December, with temperatures displaying a single peak in August. Daily temperature range was lowest during summer and highest during the late fall, winter or early spring. 3) A statistically significant negative correlation was seen between mortality from cerebro-cardiovascular diseases and seasonality and temperature, while a positive correlation was seen between mortality and daily temperature range, suggesting that low environmental temperatures may operate indirectly as a factor that affects cerebro-cardiovascular disease mortality.