Sleeping sickness in West Africa (1906-2006): changes in spatial repartition and lessons from the past

Objective To review the geography and history of sleeping sickness (Human African trypanosomiasis; HAT) over the past 100 years in West Africa, to identify priority areas for sleeping sickness surveillance and areas where HAT no longer seems active. Method History and geography of HAT were summarized based on a review of old reports and recent publications and on recent results obtained from medical surveys conducted in West Africa up to 2006. Results/conclusions Active HAT foci seem to have moved from the North to the South. Endemic HAT presently appears to be limited to areas where annual rainfall exceeds 1200 mm, although the reasons for this remain unknown. There has also been a shift towards the south of the isohyets and of the northern distribution limit of tsetse. Currently, the most severely affected countries are Guinea and Ivory Coast, whereas the northern countries seem less affected. However, many parts of West Africa still lack information on HAT and remain to be investigated. Of particular interest are the consequences of the recent political crisis in Ivory Coast and the resulting massive population movements, given the possible consequences on HAT in neighbouring countries.     

Assessing effect of climate on the incidence of dengue in Tamil Nadu

Incidence of dengue is reported to be influenced by climatic factors. The objective of this study is to assess the association of local climate with dengue incidence, in two geographically distinct districts in Tamil Nadu. The study uses climate data, rainfall and mean maximum and minimum temperature to assess its association if any, with dengue incidence in two districts of Tamil Nadu, South India. According to this study while precipitation levels have an effect on dengue incidence in Tamil Nadu, non-climatic factors such as presence of breeding sites, vector control and surveillance are important issues that need to be addressed.     

Climatic, edaphic and altitudinal factors affecting yield and toxicity of Lathyrus sativus grown at five locations in Ethiopia

A 2 years (2005-2006) data analysis based on agronomic, qualitative, climatic and edaphic factors was carried out using 10 grass pea (Lathyrus sativus L.) genotypes grown at five eco-divergent locations (Alem Tena, Debre Zeit, Denbi, Akaki, Chefe Donsa) in Ethiopia. Crop yield showed considerable variability among locations, years and genotypes. Path coefficient analysis indicated that rainfall and days to maturity have a large positive influence on yield. High level of micronutrients Mn²⁺ and S²⁻ negatively affected yield. Path analysis revealed that Zn²⁺/P, days to maturity, yield and K⁺ were dominant variables affecting the response variable β-ODAP (β-N-oxalyl-L-α,β-diaminopropionic acid), the neuro-excitatory amino acid in grass pea seeds considered as the cause of neurolathyrism. Linear correlation analysis between β-ODAP and the 35 factors considered showed that β-ODAP level was positively correlated (r > 0.70) with K⁺ and sunshine hours (ssh) and negatively correlated (r < 0.70) with soil pH, days to maturity and yield. The strongest correlation of ssh with β-ODAP level was found during the phase of crop maturity. Our results suggest that β-ODAP biosynthesis and its response to environmental stress are maximized during the post-anthesis stage.     

Combined effects of aerobiological pollutants, chemical pollutants and meteorological conditions on asthma admissions and A & E attendances in Derbyshire UK, 1993–96.

BACKGROUND: The effect of outdoor aeroallergen exposure in asthma may be enhanced by air pollutants, including ozone, nitrogen dioxide and particulates, and by certain weather conditions. It is not yet established whether these interactions are important in determining asthma morbidity at the population level. OBJECTIVE: We have investigated the joint effects of aeroallergens, rainfall, thunderstorms and outdoor air pollutants on daily asthma admissions and Accident and Emergency (A & E) attendance using routinely collected data between 1993 and 1996 from Derby in central England. METHODS: Daily counts during the aeroallergen season of grass and birch pollen, basidiospores, Didymella, Alternaria and Cladosporium, maximum 1 hour ozone and nitrogen dioxide and daily average black smoke measurements, all made in the vicinity of the city centre, were categorized in tertiles. Rainfall was classified as dry, light ( 2 mm). The modifying effect of outdoor pollutant levels, and rainfall or the occurrence of a thunderstorm, upon the effects of individual aeroallergens on asthma admissions and A & E attendance were investigated by fitting appropriate interactions in log linear autoregression models with adjustment for potential confounders. RESULTS: We found a significant interaction between the effects of grass pollen and weather conditions upon A & E attendance, such that the increase with grass pollen count was most marked on days of light rainfall (adjusted rate ratio for >/= 50 vs < 10 grains/m3 at lag 2 days = 2.1, 95% CI 1.4, 3.3). Asthma admissions increased with Cladosporium count. We found no statistically significant interactions between effects of any individual aeroallergen and outdoor air pollutant upon either measure of asthma morbidity. CONCLUSIONS: Rainfall and thunderstorms are important effect modifiers in the relation between grass pollen and measures of acute asthma morbidity. Interactions between ambient levels of aeroallergens and chemical pollutants in the Derby area do not play a major role in determining asthma admissions and A & E attendance.     

自来水中总放射性比活度及其与降雨量相关的探讨

[目的 ]了解自来水中总 α、总 β放射性水平 ,探讨其与降雨量的关系。 [方法 ]总 α、总 β比活度测定采用蒸发法 (GB85 38.5 6 .5 7- 87)高灵敏度 α、β测量仪测量 ,用 SPSS统计软件包进行曲线拟合。 [结果 ]自来水中总 α放射性比活度为 15 .0～ 95 .7Bq·m- 3(均值 4 4 .6 8± 19.34) Bq· m- 3;总 β放射性比活度为 15 .0～ 130 .0 Bq· m- 3(均值5 9.74± 13.88) Bq· m- 3;总 α、总 β放射性比活度与降雨量的最佳曲线拟合模型均为三次曲线方程 ,前者呈正相关 ,后者呈负相关。 [结论 ]福州市区 6个自来水厂 10年 30 0个样品的总α、总β放射性比活度均低于 GB 5 789- 85《生活饮用水卫生标准》中规定的限值 ,总α、总β放射性比活度与降雨量的最佳曲线拟合模型均为三次曲线方程。     

Incidence of Farmer's Lung Leading to Hospitalization and Its Relation to Meteorological Observations in Finland

ABSTRACT The standardized annual incidence of farmer's lung (FL) leading to hospitalization during 1980 in Finland was 50 per 100 000 persons employed in farming. Using preset uniform criteria, data were collected from all pulmonary disease units in the country. There were 186 new cases of FL in 1980. The mean age was 46 years, and 64% were women. Using the national population in 1975 as standard, the rates were standardized for age and sex. There were differences both in the incidence and in the sex ratio of FL among the farming population of the six districts of Finland. These differences are closely related to prevalent proportions of cattle raising among farmers and local cultural traditions in the various districts. Seasonal variation in the incidence of FL was statistically significant (Roger's test, p<0.001), the peak occurring in April. This confirms an earlier observation. The incidence rates were statistically significantly correlated with the sum and the mean of daily rainfall during the haymaking period preceding the diagnosis of FL.     

Regional Differences in the Growing Incidence of Dengue Fever in Vietnam Explained by Weather Variability

Dengue fever is a major health problem in Vietnam, but its incidence differs from province to province. To understand this at the local level, we assessed the effect of four weather components (humidity, rainfall, temperature and sunshine) on the number of dengue cases in nine provinces of Vietnam. Monthly data from 1999 to 2009 were analysed by time-series regression using negative binomial models. A test for heterogeneity was applied to assess the weather-dengue association in the provinces. Those associations were significantly heterogeneous (for temperature, humidity, and sunshine: P < 0.001 heterogeneity test; for rainfall: P = 0.018 heterogeneity test). This confirms that weather components strongly affect dengue transmission at a lag time of 0 to 3 months, with considerable variation in their influence among different areas in Vietnam. This finding may promote the strategic prevention of dengue disease by suggesting specific plans at the local level, rather than a nationally unified approach.     

The microbiological quality of seven large commercial private water supplies in the United Kingdom

Some 1% of the UK population derives their potable water from 140,000 private water supplies (PWSs) regulated by Local Authorities. The overwhelming majority of these are very small domestic supplies serving a single property or a small number of properties. Treatment for such supplies is rudimentary or non-existent and their microbiological quality has been shown to be poor in every published study to date. Private water supplies serving commercial enterprises such as hotels, restaurants, food production premises and factories are more frequently treated and subject to closer regulation in the United Kingdom. As a result, it has been assumed that these larger commercial supplies are less likely to experience elevated faecal indicator and pathogen concentrations at the consumer tap which have been observed at small domestic supplies.     

Epidemiological survey of Vibrio vulnificus infection in Japan between 1999 and 2003

The frequency of Vibrio vulnificus infection is very rare and there are many questions regarding its epidemiology in Japan. To investigate the clinical course and epidemiology of V. vulnificus infection in Japan, we performed a retrospective questionnaire survey in which 1693 hospitals from all over Japan were surveyed, including advanced life saving emergency centers and dermatology institutions. Of the 1693 hospitals, we received answers from 1045. Ninety-four cases were confirmed as V. vulnificus infections during 1999 and 2003. Sixty-eight (72.3%) of the 94 patients had the septic type infection with a mortality rate of 75.0% (51/68 patients died). The prognosis of patients with the septic type was worse than that of the wound type (P < 0.001). V. vulnificus infections occurred from June to November and none occurred in winter. Many infections occurred in western Japan with the majority of infections (50/94) occurring in Kyushu. In particular, 43 infections occurred in marine coastal areas of the Ariake and Yatsushiro Seas, which have many tidelands. Seventy-seven of 89 patients (86.5%) had liver function impairment as an underlying disease, and 53 (59.6%) had liver cirrhosis, of whom nine (10.1%) suffered from liver cancer. The incidence of V. vulnificus infection was different according to districts. Geographic and climatic factors also contributed to the occurrence of V. vulnificus infection.