Application of the WHO alert level framework to cyanobacterial monitoring of Lake Champlain, Vermont

The increasing incidence of toxic cyanobacteria blooms worldwide has created a need for practical and efficient monitoring in order to protect public health. We developed a monitoring and alert framework based on World Health Organization (WHO) recommendations and applied it on Lake Champlain during the summers of 2002-2004. The protocol began with collection of net samples of phytoplankton in order to maximize the chance of finding potential toxin-producing cyanobacteria. Samples were collected lake-wide in partnership with ongoing monitoring efforts, but because open water sample sites did not capture conditions along the shoreline, we added near-shore and shoreline stations in problem areas. Samples were examined qualitatively until potential toxin-producing taxa were found. Then quantitative analyses began, using a rapid screening method to estimate cell density based on colony size. A final cell density of 4000 cells/mL triggered toxin analyses. Primary analysis was for microcystins using ELISA methods. Cell densities, locations of colonies, and toxin concentrations were reported weekly to public health officials. We found that screening for potential toxin-producing cyanobacteria and then measuring toxin concentrations when cell densities reached critical levels worked well to identify problem locations. Although the WHO recommends using chlorophyll a concentration, it was not a good indicator of problem densities of potential toxin-producing cyanobacteria. Our cell density screening method missed no developing blooms but produced less precise density estimates at high cell counts. Overall, our framework appears to provide an efficient and effective method for monitoring cyanotoxin risks.     

SARS诊断和鉴别诊断的几个问题

传染性非典型肺炎(SARS)是一种新出现的、具有明显传染性、可累及多个脏器和系统的特殊肺炎,对它的病原学、流行病学、发病机制、临床特征、影响预后等因素有待更进一步深入研究.虽然经过2003年的临床实践,中华医学会、中华中医药学会颁布的诊疗方案日趋完善,但由于人们对它的认识不深刻,绝大多数医务人员尚未接触到实际病例,疾病的临床表现不具特征性,加之其他因素的影响,给临床诊断带来了一定困难,甚至有的还出现误诊漏诊的现象.     

格林巴利综合征相关研究近况

<正>格林-巴利综合征(Guillian-Barre syndrome,GBS),是一种神经系统自身免疫性疾病,以神经根、外周神经损害为主,伴有脑脊液中蛋白-细胞分离,是一种最常见的脊神经和周围神经的脱髓鞘疾病。最初1916年由Guillian和Barre两位     

The global research trend of porcine reproductive and respiratory syndrome virus (PRRSV): A mini review

The Porcine reproductive and respiratory syndrome (PRRS) is a significantly harmful illness in swine causing respiratory problems and reproductive failure in sows, gilts, and pneumonia in young pigs. PRRS is often diagnosed with available test methods to identify disease agent or to detect the immune response of virus. In spite of many extensive researches, there are still no specific treatments and many unknown relationships between this virus and other diseases in swine. Virus isolation and molecular techniques are possible to identify PRRS virus or its acid nucleic but the high genetic diversity of virus results to unwanted false-negative results. Although PRRS has spreads throughout the world, many researches still focus on updating the methods to quickly diagnose PRRSV and to generate an effective fast treatment. This review highlights the current global PRRS research trend, its detection and diagnosis.     

严重急性呼吸道综合征的流行病学与临床诊治

20 0 2年 1 1月至 2 0 0 3年 2月我国广东省暴发非典型肺炎 ,该病很快在中国香港地区以及世界上2 0多个国家地区流行。今年 3月初 ,世界卫生组织将此病命名为严重急性呼吸道综合征 ( severe acuterespiratory syndrome,SARS) [1]。该病由于是人类历史上新发现的传染病 ,且其传染性强 ,病死率高 ,引起了世界各国政府、科研工作者及普通群众的高度关注。现将该病的病原、流行病学、临床诊断及治疗措施综述如下。1　SARS的病原学自 SARS流行后的 2个月 ,全世界 1 3个实验室的科研工作者和医务人员通力合作 ,在短短的 2个月内 ,经过经典的…     

The adult respiratory distress syndrome

The adult respiratory distress syndrome (ARDS) is a common form of acute respiratory failure that has been increasingly reported as associated with a wide variety of medical conditions. Unlike other identifiable pathological events causing severe lung injury, it is now recognized that ARDS is not a single disease, but a complex interaction of pathophysiological events that result in diffuse injury to lung parenchyma. Only through a thorough understanding of ARDS pathophysiology, pathogenesis, and clinical course can medical intervention be instituted in a judicious and timely manner. This review article is intended to provide an overview of the suspected precipitating causes, discrete pathophysiologic changes, and monitorable clinical events associated with ARDS. With mortality from ARDS high, significant attention is being given to improving therapeutic intervention with such conventional measures as mechanical ventilation, positive end-expiratory pressure, and fluid management, along with corticosteroids and several new experimental pharmacologic approaches.     

Epidemics of acute respiratory infections in Madagascar in 2002: from alert to confirmation

An epidemiological investigation (Ministry of Health/Institut Pasteur de Madagascar (IPM)) was conducted in July 2002, in two districts of a same province (Fianarantsoa: Fianarantsoa II and Ikongo) considering the high frequency of deaths linked with acute respiratory infection (ARI). Morbidity and mortality data was collected in the Centre de Santé de Base (CSB) which gave the alert (village of Sahafata, district Fianarantsoa II). Analysis of monthly activity reports (MAR) allowed calculation of incidence rates of ARI/pneumonia in Fianarantsoa province. Virological data was based on the analysis of nasopharyngeal samples collected during the investigations. Clinical symptoms and homogeneity of laboratory results are consistent with an origin of these epidemics being related to the circulation of an influenza virus A subtype H3N2. Attack rates were very high. CFR was significantly higher in individuals of less than 1 year and more than 65 years. This data was confirmed by posterior investigations of teams from MoH/WHO. Surprisingly, this large epidemic was due to a known influenza virus that previously circulated in countries of northern hemisphere (the year before) and even in Antananarivo weeks before. Different hypothesis could be proposed to explain such phenomenon: great restriction of exchanges between different geographical zones, nutritional status.... Conclusion: The epidemic episodes of acute respiratory infections in Madagascar in July 2002 were due to an influenza virus A subtype H3N2 without any genotypic or phenotypic features. Various factors, could explain the importance of the epidemic and particular high lethality found in some age groups. This epidemic illustrates the relative incapacity for a developing country, to face and manage a flu epidemic caused by a classical influenza virus.