scholarly journals Disposable swim diaper retention of Cryptosporidium-sized particles on human subjects in a recreational water setting

2011 ◽  
Vol 9 (4) ◽  
pp. 653-658 ◽  
Author(s):  
James E. Amburgey ◽  
J. Brian Anderson
Keyword(s):  
Human Subject ◽  
Human Subjects ◽  
Disease Outbreaks ◽  
Protozoan Parasite ◽  
Bulk Water ◽  
Recreational Water ◽  
Swimming Pools ◽  
Polystyrene Microspheres ◽  
Cryptosporidium Oocysts ◽  
The Usa

Cryptosporidium is a chlorine-resistant protozoan parasite responsible for the majority of waterborne disease outbreaks in recreational water venues in the USA. Swim diapers are commonly used by diaper-aged children participating in aquatic activities. This research was intended to evaluate disposable swim diapers for retaining 5-μm diameter polystyrene microspheres, which were used as non-infectious surrogates for Cryptosporidium oocysts. A hot tub recirculating water without a filter was used for this research. The microsphere concentration in the water was monitored at regular intervals following introduction of microspheres inside of a swim diaper while a human subject undertook normal swim/play activities. Microsphere concentrations in the bulk water showed that the majority (50–97%) of Cryptosporidium-sized particles were released from the swim diaper within 1 to 5 min regardless of the swim diaper type or configuration. After only 10 min of play, 77–100% of the microspheres had been released from all swim diapers tested. This research suggests that the swim diapers commonly used by diaper-aged children in swimming pools and other aquatic activities are of limited value in retaining Cryptosporidium-sized particles. Improved swim diaper solutions are necessary to efficiently retain pathogens and effectively safeguard public health in recreational water venues.

scholarly journals Removal of Cryptosporidium and polystyrene microspheres from swimming pool water with sand, cartridge, and precoat filters

2011 ◽  
Vol 10 (1) ◽  
pp. 31-42 ◽  
Author(s):  
James E. Amburgey ◽  
Kimberly J. Walsh ◽  
Roy R. Fielding ◽  
Michael J. Arrowood
Keyword(s):  
Tap Water ◽  
Disease Outbreaks ◽  
Field Trials ◽  
Swimming Pool ◽  
Future Research ◽  
Recreational Water ◽  
Polystyrene Microspheres ◽  
Pool Water ◽  
Cryptosporidium Oocysts ◽  
Removal Efficiencies

Cryptosporidium has caused the majority of waterborne disease outbreaks in treated recreational water venues in the USA for many years running. This research project evaluated some common US swimming pool filters for removing Cryptosporidium oocysts, 5-µm diameter polystyrene microspheres, and 1-µm diameter polystyrene microspheres. A 946 L hot tub with interchangeable sand, cartridge, and precoat filters was used at room temperature for this research. Simulated pool water for each experiment was created from Charlotte, NC (USA) tap water supplemented with alkalinity, hardness, chlorine, and a mixture of artificial sweat and urine. Precoat (i.e., diatomaceous earth and perlite) filters demonstrated pathogen removal efficiencies of 2.3 to 4.4 log (or 99.4–99.996%). However, sand and cartridge filters had average Cryptosporidium removals of 0.19 log (36%) or less. The combined low filter removal efficiencies of sand and cartridge filters along with the chlorine-resistant properties of Cryptosporidium oocysts could indicate a regulatory gap warranting further attention and having significant implications on the protection of public health in recreational water facilities. The 5-µm microspheres were a good surrogate for Cryptosporidium oocysts in this study and hold promise for use in future research projects, field trials, and/or product testing on swimming pool filters.

scholarly journals Cryptosporidium and Giardia in recreational water in Belgium

2015 ◽  
Vol 13 (3) ◽  
pp. 870-878 ◽  
Author(s):  
Amimul Ehsan ◽  
Stijn Casaert ◽  
Bruno Levecke ◽  
Liesbet Van Rooy ◽  
Joachim Pelicaen ◽  
...  
Keyword(s):  
Infection Risk ◽  
Human Infection ◽  
Water Bodies ◽  
Recreational Water ◽  
Swimming Pools ◽  
Giardia Infection ◽  
Recreational Activities ◽  
Cryptosporidium Oocysts ◽  
Water Recreation ◽  
Giardia Cysts

The objective of this study was to investigate the presence of Cryptosporidium and Giardia in different recreational water bodies in Belgium and to estimate the infection risk associated with swimming and other recreational activities. Cryptosporidium oocysts and/or Giardia cysts were detected in three out of 37 swimming pools, seven out of 10 recreational lakes, two out of seven splash parks and four out of 16 water fountains. In the swimming pools no infection risk for Cryptosporidium could be calculated, since oocysts were only detected in filter backwash water. The risk of Giardia infection in the swimming pools varied from 1.13 × 10−6 to 2.49 × 10−6 per swim per person. In recreational lakes, the infection risk varied from 2.79 × 10−5 to 5.74 × 10−5 per swim per person for Cryptosporidium and from 7.04 × 10−5 to 1.46 × 10−4 for Giardia. For other outdoor water recreation activities the estimated infection risk was 5.71 × 10−6 for Cryptosporidium and 1.47 × 10−5 for Giardia. However, most positive samples in the recreational lakes belonged to species/genotypes that are either animal-specific or predominantly found in animals. No Cryptosporidium was found in splash parks and water fountains, but the presence of Giardia cysts suggests a risk for human infection. The infection risk of Giardia infection during a 3.5-minute visit to a splash park for children equalled 1.68 × 10−4.

scholarly journals Inactivation of Cryptosporidium parvum under chlorinated recreational water conditions

2008 ◽  
Vol 6 (4) ◽  
pp. 513-520 ◽  
Author(s):  
Joan M. Shields ◽  
Vincent R. Hill ◽  
Michael J. Arrowood ◽  
Michael J. Beach
Keyword(s):  
Public Health ◽  
Tissue Culture ◽  
Sodium Hypochlorite ◽  
Cryptosporidium Parvum ◽  
Protozoan Parasite ◽  
Recreational Water ◽  
Log Reduction ◽  
Cryptosporidium Oocysts ◽  
Water Conditions ◽  
Control And Prevention

Cryptosporidium is a chlorine-resistant protozoan parasite and the etiological agent in many disinfected recreational water outbreaks. While previous studies have reported disinfection Ct values for Cryptosporidium parvum using sodium hypochlorite, these studies have employed conditions and procedures which are not ideal for establishing public health remediation recommendations for chlorinated recreational water venues. In the present study, free chlorine Ct values were measured at pH 7.5 using young oocysts (<1 month old) and tissue culture to determine oocyst viability. Two different oocyst isolates were used: one originating from Iowa and one from Maine (USA). This study determined that the Ct values for a 3-log reduction in oocyst viability were 10,400 (Iowa) and 15,300 (Maine) at pH 7.5. These Ct values are higher than the Centers for Disease Control and Prevention (USA) currently recommends (Ct=9,600) for achieving a 3.0-log inactivation of Cryptosporidium oocysts during remediation of recreational water venues following fecal diarrhea accidents.

scholarly journals A rapid phenotype change in the pathogen Perkinsus marinus was associated with a historically significant marine disease emergence in the eastern oyster

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ryan B. Carnegie ◽  
Susan E. Ford ◽  
Rita K. Crockett ◽  
Peter R. Kingsley-Smith ◽  
Lydia M. Bienlien ◽  
...  
Keyword(s):  
South Carolina ◽  
Climatic Factors ◽  
Disease Outbreaks ◽  
Protozoan Parasite ◽  
Eastern Oyster ◽  
Perkinsus Marinus ◽  
Novel Ecosystem ◽  
The Usa ◽  
Exotic Pathogen ◽  
Dermo Disease

AbstractThe protozoan parasite Perkinsus marinus, which causes dermo disease in Crassostrea virginica, is one of the most ecologically important and economically destructive marine pathogens. The rapid and persistent intensification of dermo in the USA in the 1980s has long been enigmatic. Attributed originally to the effects of multi-year drought, climatic factors fail to fully explain the geographic extent of dermo’s intensification or the persistence of its intensified activity. Here we show that emergence of a unique, hypervirulent P. marinus phenotype was associated with the increase in prevalence and intensity of this disease and associated mortality. Retrospective histopathology of 8355 archival oysters from 1960 to 2018 spanning Chesapeake Bay, South Carolina, and New Jersey revealed that a new parasite phenotype emerged between 1983 and 1990, concurrent with major historical dermo disease outbreaks. Phenotypic changes included a shortening of the parasite’s life cycle and a tropism shift from deeper connective tissues to digestive epithelia. The changes are likely adaptive with regard to the reduced oyster abundance and longevity faced by P. marinus after rapid establishment of exotic pathogen Haplosporidium nelsoni in 1959. Our findings, we hypothesize, illustrate a novel ecosystem response to a marine parasite invasion: an increase in virulence in a native parasite.

scholarly journals Human response to the thermal indoor environment created by a radiant, and a combined radiant and convective cooling system

2019 ◽  
Vol 111 ◽  
pp. 02060
Author(s):  
Ongun B. Kazanci ◽  
Dolaana Khovalyg ◽  
Takayoshi Iida ◽  
Yoshitaka Uno ◽  
Tomo-oki Ukiana ◽  
...  
Keyword(s):  
Human Subject ◽  
Indoor Environment ◽  
Cooling System ◽  
Human Subjects ◽  
Whole Body ◽  
Indoor Environments ◽  
Climate Chamber ◽  
Convective Cooling ◽  
Physical Measurements ◽  
Two Systems

This study reports the main findings from a series of human subject experiments, where the subjects were exposed to the different indoor environments created by different cooling systems. The studied systems were a radiant cooling system (chilled ceiling and mixing ventilation, CCMV), and a combined radiant and convective cooling system (radiant diffuse ceiling ventilation, RDCV). The experiments were conducted in a climate chamber under controlled conditions. The climate chamber was configured as a two-person office room. 24 human subjects (12 female and 12 male) were chosen. The exposure lasted three hours and the participants were allowed to work on their own tasks (normal office work) during the exposure. The cooling load was 54 W/m2 and the room temperature at a reference location was kept constant at 26°C (summer conditions). The results show that under both systems, whole body thermal sensation was between slightly warm and neutral (closer to neutral with the RDCV system), and the overall thermal acceptability was almost the same for both systems (close to clearly acceptable). The satisfaction of the human subjects with the thermal environment was very close under the two systems; between satisfactory and slightly satisfactory (closer to satisfactory). Air movement acceptability (slightly higher and closer to clearly acceptable with the RDCV system) was also very close with the two systems. The results of the human subject experiments agree well with the physical measurements of the thermal indoor environment and confirm that the studied systems created very similar thermal indoor environments.

scholarly journals Cryptosporidium spp. Infections in Livestock and Wild Animals in Azerbaijan Territory

2020 ◽  
Vol 2 (1) ◽  
pp. 44
Author(s):  
Simuzer Mamedova ◽  
Panagiotis Karanis
Keyword(s):  
Staining Method ◽  
Current Knowledge ◽  
Protozoan Parasite ◽  
Structural Features ◽  
Cryptosporidium Spp ◽  
Faecal Samples ◽  
Cryptosporidium Oocysts ◽  
Stool Specimens ◽  
Intracellular Protozoan Parasite ◽  
Acid Fast Staining

Cryptosporidium is an intracellular protozoan parasite and is increasingly gaining attention as a human and an animal pathogen, mainly due to its predominant involvement in worldwide waterborne outbreaks. This paper reviews the current knowledge and understanding of Cryptosporidium spp. in terrestrial and aquatic animals in Azerbaijan. The diagnosis of cryptosporidiosis relies on the identification of oocysts in faecal samples released by the infected host. Stool specimens were processed using the modified acid-fast staining method (Ziehl-Neelsen) and microscopically examined for Cryptosporidium oocysts. Thirteen species of Cryptosporidium (C. fragile, C. ducismarci, C. serpentis, C. varani, C. baileyi, C. meleagridis, C. muris, C. parvum, C. ubiquitum, C. andersoni, C. bovis, C. hominis, C. suis) from amphibians, reptiles, birds and mammals have been identified as a result of studies conducted between 1987 and 2019 on the structural features of Cryptosporidium oocysts in Azerbaijan territory.

scholarly journals Characterizing Current Attitudes and Practices for Human Subject Safety in Studies Involving Pupil Dilation

2020 ◽  
pp. 155626462096898
Author(s):  
Jacob Szpernal ◽  
Joseph Carroll ◽  
Ryan Spellecy ◽  
Jane A. Bachman Groth
Keyword(s):  
Informed Consent ◽  
Adverse Effects ◽  
Vision Research ◽  
Human Subject ◽  
Human Subjects ◽  
Pupil Dilation ◽  
Institutional Review Boards ◽  
Human Subjects Research ◽  
Attitudes And Practices ◽  
Institutional Review

Standards in pupil dilation practices regarding the safety of human subjects are not present in vision research despite the potential for significant adverse effects. We developed two surveys to examine current practices around pupil dilation among vision researchers and individuals associated with oversight of human subjects research. While both groups note an absence of adverse events associated with pupil dilation, vision researcher practices differed with informed consent use and measures taken to minimize complications. For Institutional Review Boards, general risk assumption associated with dilation was not unanimous and there was a lack of specific guidance available to researchers for minimizing risk. These results uncover the need for standardized practices regarding pupil dilation in human subjects research.

Contamination of swimming pools and hot tubs biofilms with Acanthamoeba

2018 ◽  
Vol 63 (1) ◽  
pp. 147-153 ◽  
Author(s):  
Behroz Mahdavi Poor ◽  
Abdolhossein Dalimi ◽  
Fatemeh Ghafarifar ◽  
Fariba Khoshzaban ◽  
Jalal Abdolalizadeh
Keyword(s):  
Pcr Amplification ◽  
Cross Sectional Study ◽  
Recreational Water ◽  
Swimming Pools ◽  
Cross Sectional ◽  
Swimming Pool Water ◽  
Specific Fragment ◽  
Hot Tubs ◽  
High Degree ◽  
Tabriz City

Abstract The members of Acanthamoeba genus are ubiquitous amoeba which could be a pathogenic parasite. The amoeba is resistant to the common chlorine concentration that used for disinfecting the swimming pool water. Therefore, the pools can be suitable environments for the survival and multiplication of the amoeba. In this cross sectional study, 10 indoor recreational water centers from different regions of Tabriz city were selected and sampling was done from fixed and floating biofilms of the swimming pools and hot tubs. The samples were cultured and monitored for the presence of amoeba cyst or trophozoite. For molecular identification of Acanthamoeba, PCR (polymerase chain reaction) and sequencing were conducted based on genus specific fragment of 18S ribosomal DNA (Rns). Acanthamoeba contamination was observed in 6 centers of 10 recreational centers. Based on the amoeba isolation from fixed and floating biofilms, 2 (20%) swimming pools, and 5 (50%) hot tubs were contaminated. Based on the type of the sample, the highest contamination was found in the hot tub water (40%) and the least was found in the swimming pools water (10%) and fixed biofilms of the swimming pools (10%). Out of 8 isolates, 5 (62.5%) were shown expected product in PCR amplification. Sequence analysis showed that Acanthamoeba isolates belonged to the T3 and T4 genotypes. The study revealed a high degree of contamination in the indoor recreational water centers in Tabriz city. So, it is essential to pay closer attention to the hygiene of swimming pools and hot tubs.

Progressive Increase in Platelet Activation With Smoke Exposure: Human Subject and In-Vitro Studies

2007 ◽  
Author(s):  
Gaurav Girdhar ◽  
Sulan Xu ◽  
Jolyon Jesty ◽  
Danny Bluestein
Keyword(s):  
Cigarette Smoke ◽  
Platelet Activation ◽  
Human Subject ◽  
Prolonged Exposure ◽  
Human Subjects ◽  
Progressive Increase ◽  
In Vitro Studies ◽  
Protective Effects ◽  
Shs Exposure

Second hand cigarette smoke (SHS) is one of the major risk factors for cardiovascular disease (CVD) and has been shown to substantiate platelet activation and aggregation in several studies [1, 2]. Most of these studies, under chronic or acute exposure conditions or over prolonged exposure, do not represent the initiation of a disease state or hematological damage under normal levels of cigarette smoke. These above studies of platelet activation with SHS together with our previous in-vitro studies demonstrating cardio-protective effects of nicotine [3], have motivated the present investigation of physiological levels of SHS exposure on human subjects and within an in-vitro endothelial cell-platelet system, with cigarettes (or smoke extracts) of varying nicotine content to confirm analogous cardio-protective effects of nicotine.

Privacy, Privilege, and Transportation Research

1976 ◽  
Vol 18 (5) ◽  
pp. 507-516 ◽  
Author(s):  
Kent B. Joscelyn
Keyword(s):  
Human Subject ◽  
Human Subjects ◽  
Broad Definition ◽  
Privacy Act ◽  
Right Of Privacy ◽  
Definition Of ◽  
Transportation Research

The increasing danger of legal entanglement for researchers who disregard the rights of human subjects used in research, in particular their right of privacy, is examined. The broad definition of a human subject and the equally broad definition of injury are discussed. The implications of the Privacy Act of 1974 are noted, and the critical need for a researcher-privilege statute set forth.

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