scholarly journals Does each bead count? A reduced-cost approach for recovering waterborne protozoa from challenge water using immunomagnetic separation

2021 ◽  
Author(s):  
Natália de Melo Nasser Fava ◽  
Kamila Jessie Sammarro Silva ◽  
William John Snelling ◽  
Nigel George Ternan ◽  
James Stephen Gerard Dooley ◽  
...  
Keyword(s):  
Immunofluorescence Microscopy ◽  
Giardia Duodenalis ◽  
Immunomagnetic Separation ◽  
World Health ◽  
Waterborne Diseases ◽  
Recovery Efficiency ◽  
Analytical Quality ◽  
Experimental Conditions ◽  
Concentration Step ◽  
Health Organization

Abstract Giardia duodenalis and Cryptosporidium spp. are two of the most prominent aetiological agents of waterborne diseases. Therefore, efficient and affordable methodologies for identifying and quantifying these parasites in water are increasingly necessary. USEPA Method 1623.1 is a widely used and validated protocol for detecting these parasites in water samples. It consists of a concentration step, followed by parasite purification and visualization by immunofluorescence microscopy. Although efficient, this method has a high cost particularly due to the immunomagnetic separation (IMS) step, which is most needed with complex and highly contaminated samples. Based on this, the present study aimed to determine whether it is possible to maintain the efficiency of Method 1623.1 while reducing the amount of beads per reaction, using as a matrix the challenge water recommended by the World Health Organization. As for Giardia cysts, a satisfactory recovery efficiency (RE) was obtained using 50% less IMS beads. This was evaluated both with a commercial cyst suspension (56.1% recovery) and an analytical quality assessment (47.5% recovery). Although RE rates obtained for Cryptosporidium parvum did not meet Method 1623.1 criteria in any of the experimental conditions tested, results presented in this paper indicated the relevance of the described adaptations, even in challenge water.

scholarly journals A Facile Colorimetric Method For Ultra-Rapid And Sensitive Detection of Copper Ions In Water

2021 ◽  
Author(s):  
Lei Chen ◽  
Yan Li ◽  
Ping Sun ◽  
Hualin Chen ◽  
He Li ◽  
...  
Keyword(s):  
Color Change ◽  
Copper Ions ◽  
Colorimetric Method ◽  
Ethanol Solution ◽  
Sensitive Detection ◽  
World Health ◽  
Great Promise ◽  
Experimental Conditions ◽  
Interesting Phenomenon ◽  
Health Organization

Abstract It is of great meaning to develop a facile, reliable and sensitive method to detect copper ions in water. In the study, a facile method has been developed for rapid and sensitive detection of Cu2+. An interesting phenomenon has been observed that 3,3',5,5'-tetramethylbenzidine (TMB) ethanol solution can be extremely fast passed from colorless to yellow once Cu2+ ions are added. It easily occurs to us that Cu2+ can be quantitatively determined via the absorbance at 904 nm of the color changed TMB solution. More importantly, some specific anions (Cl- , Br- ) can significantly enhance the absorption intensity. Under the optimized experimental conditions, this method exhibits a good linear response range for Cu2+ from 0.5 to 100 μM, with the detection limit of 93 nM. Moreover, the possible detection principle has been explored. It is worth mentioning that the color change can be clearly observed by naked eyes for the detection of 1 μM Cu2+, which is far below the threshold limit of Cu2+ in drinking water suggested by World Health Organization. It means that this method possess great promise for on-site Cu2+ detection.

scholarly journals Microbial indicators, pathogens and methods for their monitoring in water environment

2014 ◽  
Vol 13 (2) ◽  
pp. 319-339 ◽  
Author(s):  
Gaurav Saxena ◽  
Ram Naresh Bharagava ◽  
Gaurav Kaithwas ◽  
Abhay Raj
Keyword(s):  
Drinking Water ◽  
Water Environment ◽  
Microbiological Quality ◽  
World Health ◽  
Waterborne Diseases ◽  
Safe Drinking Water ◽  
Water Safety ◽  
Indicator Microorganisms ◽  
Water Safety Plan ◽  
Health Organization

Water is critical for life, but many people do not have access to clean and safe drinking water and die because of waterborne diseases. The analysis of drinking water for the presence of indicator microorganisms is key to determining microbiological quality and public health safety. However, drinking water-related illness outbreaks are still occurring worldwide. Moreover, different indicator microorganisms are being used in different countries as a tool for the microbiological examination of drinking water. Therefore, it becomes very important to understand the potentials and limitations of indicator microorganisms before implementing the guidelines and regulations designed by various regulatory agencies. This review provides updated information on traditional and alternative indicator microorganisms with merits and demerits in view of their role in managing the waterborne health risks as well as conventional and molecular methods proposed for monitoring of indicator and pathogenic microorganisms in the water environment. Further, the World Health Organization (WHO) water safety plan is emphasized in order to develop the better approaches designed to meet the requirements of safe drinking water supply for all mankind, which is one of the major challenges of the 21st century.

scholarly journals Assessing viability and infectivity of foodborne and waterborne stages (cysts/oocysts) of Giardia duodenalis, Cryptosporidium spp., and Toxoplasma gondii: a review of methods

Parasite ◽  
2018 ◽  
Vol 25 ◽  
pp. 14 ◽  
Author(s):  
Angélique Rousseau ◽  
Stéphanie La Carbona ◽  
Aurélien Dumètre ◽  
Lucy J. Robertson ◽  
Gilles Gargala ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Exposure Assessment ◽  
Foodborne Pathogens ◽  
Giardia Duodenalis ◽  
Human Infection ◽  
Control Measures ◽  
World Health ◽  
Protozoan Parasites ◽  
Analytical Strategy ◽  
Health Organization

Giardia duodenalis, Cryptosporidium spp. and Toxoplasma gondii are protozoan parasites that have been highlighted as emerging foodborne pathogens by the Food and Agriculture Organization of the United Nations and the World Health Organization. According to the European Food Safety Authority, 4786 foodborne and waterborne outbreaks were reported in Europe in 2016, of which 0.4% were attributed to parasites including Cryptosporidium, Giardia and Trichinella. Until 2016, no standardized methods were available to detect Giardia, Cryptosporidium and Toxoplasma (oo)cysts in food. Therefore, no regulation exists regarding these biohazards. Nevertheless, considering their low infective dose, ingestion of foodstuffs contaminated by low quantities of these three parasites can lead to human infection. To evaluate the risk of protozoan parasites in food, efforts must be made towards exposure assessment to estimate the contamination along the food chain, from raw products to consumers. This requires determining: (i) the occurrence of infective protozoan (oo)cysts in foods, and (ii) the efficacy of control measures to eliminate this contamination. In order to conduct such assessments, methods for identification of viable (i.e. live) and infective parasites are required. This review describes the methods currently available to evaluate infectivity and viability of G. duodenalis cysts, Cryptosporidium spp. and T. gondii oocysts, and their potential for application in exposure assessment to determine the presence of the infective protozoa and/or to characterize the efficacy of control measures. Advantages and limits of each method are highlighted and an analytical strategy is proposed to assess exposure to these protozoa.

Health Impact of Community Based Water Treatment Systems in Honduras

2012 ◽  
Vol 34 (2) ◽  
pp. 24-29
Author(s):  
Jeffery Deal
Keyword(s):  
Drinking Water ◽  
United Nations ◽  
Health Impact ◽  
World Health ◽  
Waterborne Diseases ◽  
Safe Drinking Water ◽  
Community Based ◽  
Development Goal ◽  
Basic Sanitation ◽  
Health Organization

The United Nations Millennium Development Goal Number 7 states that it wants to "Halve, by 2015 the proportion of the population (global) without sustainable access to safe drinking water and basic sanitation" (United Nations 2010). Most waterborne diseases result in diarrhea, which continues to be a leading cause of morbidity and mortality worldwide. According to World Health Organization data, if existing technologies were widely used, ten percent of the worldwide burden of disease would be removed by the water supply, sanitation, hygiene, and management of water resources. This estimate makes water related diseases arguably the most manageable set of health problems affecting humans (Prüss-Üstün et al. 2008).

A study on contamination risks of wells from Kollam district, southern India

2014 ◽  
Vol 4 (4) ◽  
pp. 727-732 ◽  
Author(s):  
S. Usha ◽  
P. S. Rakesh ◽  
S. Subhagan ◽  
M. Shaji ◽  
K. Salila
Keyword(s):  
High Risk ◽  
Hepatitis A ◽  
Southern India ◽  
World Health ◽  
Waterborne Diseases ◽  
Quality Of Water ◽  
Dug Wells ◽  
Kerala State ◽  
Health Organization

The key to provide microbiologically safe drinking-water lies in understanding the various mechanisms by which water gets contaminated. This study assessed the risk of contamination and microbiological and chemical quality of water from protected dug wells in five selected Panchayats in Kollam district, Kerala state, southern India. Sanitary inspection was conducted for 70 protected dug wells using World Health Organization established procedures for risk of contamination scoring. Microbiological and chemical analysis of water samples was done. The areas with higher incidence of hepatitis A had a higher proportion of wells with high risk of contamination scores (p = 0.006). High risk of contamination scores for wells were associated with higher incidence of fecal pollution (odds ratio 11.80; 95% confidence interval 1.87–74.86). The study highlighted the need to make the wells safe in this area, for control of waterborne diseases.

Pathogenic parasites and enteroviruses in wastewater: support for a regulation on water reuse

2013 ◽  
Vol 67 (7) ◽  
pp. 1512-1518 ◽  
Author(s):  
Elayse M. Hachich ◽  
Ana T. Galvani ◽  
Jose A. Padula ◽  
Nancy C. Stoppe ◽  
Suzi C. Garcia ◽  
...  
Keyword(s):  
Environmental Protection Agency ◽  
Water Reuse ◽  
Wastewater Treatment Plants ◽  
Immunomagnetic Separation ◽  
World Health ◽  
Treated Wastewater ◽  
Quantitative Microbial Risk Assessment ◽  
Microbial Risk Assessment ◽  
Wastewater Samples ◽  
Health Organization

Brazilian regulations for nonpotable reuse are being established using World Health Organization guidelines, however, they should be developed based on local monitoring studies. This study intended to analyze enteroviruses, protozoa and viable Ascaris sp. eggs in raw (24) and treated (24) effluents from four Wastewater Treatment Plants of São Paulo State, Brazil. The protozoa were detected with the US Environmental Protection Agency (USEPA) Method 1623 in the treated effluents and by centrifugation/Immunomagnetic Separation in the raw influent samples. Viable Ascaris sp. eggs were analyzed according to a modified USEPA method. Enteroviruses were quantified by using human rhabdomyosarcoma cells after adequate concentration procedures. All wastewater influents were positive for Giardia sp. whereas Cryptosporidium sp. was detected in 58.3% of the samples. Giardia sp. and Cryptosporidium sp. were present in 79.2 and 25.0% respectively, of the treated wastewater samples. Viable Ascaris sp. eggs were detected in 50.0 and 12.5% of influent and treated wastewater samples. Enteroviruses were isolated in the 24 raw influent samples and in 46% of the treated samples. Taking into account the densities of Giardia sp. in some treated wastewaters intended to be used as reclaimed water, Quantitative Microbial Risk Assessment studies should be conducted to establish pathogen quantitative criteria for a future Brazilian regulation for water reuse.

scholarly journals Hydrogeochemistry of Surface and Ground Water in Alatening Village, Northwest Region, Cameroon

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Kahnji Iren Njoyim ◽  
Lucas Kengni ◽  
Margaret Awah Tita ◽  
Estella Njoyim Buleng Tamungang ◽  
Vitalis Fonfo Fonzenyuy ◽  
...  
Keyword(s):  
Water Samples ◽  
Rural Areas ◽  
Local Population ◽  
World Health ◽  
Waterborne Diseases ◽  
Rock Interaction ◽  
Quality Of Water ◽  
Guideline Values ◽  
Health Organization ◽  
Northwest Region

The purpose of this study was to evaluate petrography and the quality of water for drinking purposes in Alatening, Northwest Cameroon, with respect to the World Health Organization (WHO) standards. The indigenes of the study area, as well as other dwellers in rural areas, consume water from these sources whose quality is unknown; thus, it can lead to contamination and waterborne diseases. Three springs and two streams of Alatening village were investigated in early December 2017 and late July 2018 for organoleptic, physicochemical, and bacteriological parameters using standard methods. The petrographic studies revealed trachyte and benmoreite, and weathering of minerals from these rocks into the soil leads to the water-rock interaction, thus water hydrogeochemistry. All the water samples were clean except that of Alabong which had slight odour due to leaf fall. pH showed acidic water with the springs of Ngog and Alabong falling below the WHO limit in the dry season. Electrical conductivity and total dissolved solids (TDS) were low implying low mineralised water which can also lead to shortage of important minerals in humans. All the essential ions were found within the WHO guideline values without any significant change in concentrations between seasons ( p > 0.05 ). The water facies were such as Mg-Ca, Cl-Ca, and HCO3-CO3, suggesting an influence of rock silicate weathering and anthropogenic influence. Aluminium and iron contents were above the WHO limit in both seasons due to their abundance in the soils which could be a risk factor for the local population. Faecal coliforms as well as specific bacteria such as Enterobacter, Escherichia coli, Streptococcus, Salmonella, and Shigella were found in all the water samples, attributable to poor hygiene. Health data in the locality indicated the prevalence of typhoid, dysentery, and amoebiasis with a total of 2702 cases recorded between 2016 and 2017, therefore requiring treatment before consumption.

Obstacles to Claiming Permanence and Injury-Relatedness for “Posttraumatic” Headache

2009 ◽  
Vol 14 (3) ◽  
pp. 3-6
Author(s):  
Robert J. Barth
Keyword(s):  
Complete Recovery ◽  
World Health ◽  
Related Factors ◽  
Posttraumatic Headache ◽  
Sixth Edition ◽  
Causative Relationship ◽  
Short Period ◽  
The One ◽  
Health Organization ◽  
Subjective Reports

Abstract “Posttraumatic” headaches claims are controversial because they are subjective reports often provided in the complex of litigation, and the underlying pathogenesis is not defined. This article reviews principles and scientific considerations in the AMAGuides to the Evaluation of Permanent Impairment (AMA Guides) that should be noted by evaluators who examine such cases. Some examples in the AMA Guides, Sixth Edition, may seem to imply that mild head trauma can cause permanent impairment due to headache. The author examines scientific findings that present obstacles to claiming that concussion or mild traumatic brain injury is a cause of permanent headache. The World Health Organization, for example, found a favorable prognosis for posttraumatic headache, and complete recovery over a short period of time was the norm. Other studies have highlighted the lack of a dose-response correlation between trauma and prolonged headache complaints, both in terms of the frequency and the severity of trauma. On the one hand, scientific studies have failed to support the hypothesis of a causative relationship between trauma and permanent or prolonged headaches; on the other hand, non–trauma-related factors are strongly associated with complaints of prolonged headache.

Sign in / Sign up

Export Citation Format

Share Document