122 research outputs found
Bathing water quality monitoring practices in europe and the United States
Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland.Many countries including EU Member States (EUMS) and the United States (U.S.) regularly monitor the microbial quality of bathing water to protect public health. This study comprehensively evaluates the EU bathing water directive (BWD) and the U.S. recreational water quality criteria (RWQC) as regulatory frameworks for monitoring microbial quality of bathing water. The major differences between these two regulatory frameworks are the provision of bathing water profiles, classification of bathing sites based on the pollution level, variations in the sampling frequency, accepted probable illness risk, epidemiological studies conducted during the development of guideline values, and monitoring methods. There are also similarities between the two approaches given that both enumerate viable fecal indicator bacteria (FIB) as an index of the potential risk to human health in bathing water and accept such risk up to a certain level. However, enumeration of FIB using methods outlined within these current regulatory frameworks does not consider the source of contamination nor variation in inactivation rates of enteric microbes in different ecological contexts, which is dependent on factors such as temperature, solar radiation, and salinity in various climatic regions within their geographical areas. A comprehensive "tool-box approach", i.e., coupling of FIB and viral pathogen indicators with microbial source tracking for regulatory purposes, offers potential for delivering improved understanding to better protect the health of bathers.Peer reviewe
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Reduction of Arcobacter at Two Conventional Wastewater Treatment Plants in Southern Arizona, USA
This study aimed to identify the bacterial community in two wastewater treatment plants (WWTPs) and to determine the occurrence and reduction of Arcobacter, along with virulence genes (ciaB and pldA). A total of 48 samples (24 influent and 24 effluent) were collected at two WWTPs in southern Arizona in the United States, monthly from August 2011 to July 2012. Bacterial DNA extract was utilized for 16S rRNA metagenomic sequencing. Quantification of Arcobacter 16S rRNA gene was conducted using a recently developed SYBR Green-based quantitative PCR assay. Among 847 genera identified, 113 (13%) were identified as potentially pathogenic bacteria. Arcobacter 16S rRNA gene was detected in all influent samples and ten (83%) and nine (75%) effluent samples at each plant, respectively. Log reduction ratios of Arcobacter 16S rRNA gene in Plant A and Plant B were 1.7 ± 0.9 (n = 10) and 2.3 ± 1.5 (n = 9), respectively. The ciaB gene was detected by quantitative PCR in eleven (92%) and twelve (100%) of 12 influent samples from Plant A and Plant B, respectively, while the pldA gene was detected in eight (67%) and six (50%) influent samples from Plant A and Plant B, respectively. The prevalence of potentially pathogenic bacteria in WWTP effluent indicated the need for disinfection before discharge into the environment.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
Pilot study on wastewater surveillance of dengue virus RNA: Lessons, challenges, and implications for future research
Dengue virus (DENV) is an enveloped, single-stranded RNA virus that causes approximately 390 million infections, leading to 40,000 deaths annually. Due to the increasing trend of urbanization, water supply scarcity, and climate change, dengue is regarded as the “disease of the future,” requiring robust surveillance for the early detection of DENV infection. Since the virus is shed in urine and saliva and persists in wastewater at different temperatures, our study conducted wastewater surveillance as a novel approach to monitor dengue outbreaks in the Kathmandu Valley, Nepal. The viral concentrates (n = 34), which were previously collected and concentrated from municipal and hospital wastewater, and river water using the electronegative membrane-vortex method, were tested for DENV using quantitative reverse transcription polymerase chain reaction (RT-qPCR) and digital PCR (RT-dPCR). Pepper mild mottle virus, a process control and endogenous biomarker, was detected in all the samples with concentrations ranging from 8.0 to 10.0 log10 copies/L, whereas DENV was not detected in any sample using RT-dPCR and RT-qPCR. The undetected DENV in this study could be attributed to the collection of grab wastewater samples during a low relative prevalence of dengue infection in the region, insufficient sample volume processed, probable viral nucleic acid degradation due to storage of viral concentrate at -25 °C for a long period of time, or inefficiency of the primary concentration method used. This study highlights critical gaps in knowledge and provides recommendations for future implementation of wastewater surveillance of dengue outbreaks, especially in regions where dengue was recently introduced, clinical surveillance is limited, and wastewater surveillance for polio has been adopted.Peer reviewe
Application of digital PCR for public health-related water quality monitoring
Digital polymerase chain reaction (dPCR) is emerging as a reliable platform for quantifying microorganisms in the field of water microbiology. This paper reviews the fundamental principles of dPCR and its application for health-related water microbiology. The relevant literature indicates increasing adoption of dPCR for measuring fecal indicator bacteria, microbial source tracking marker genes, and pathogens in various aquatic environments. The adoption of dPCR has accelerated recently due to increasing use for wastewater surveillance of Severe Acute Respiratory Coronavirus 2 (SARS-CoV-2) -the virus that causes Coronavirus Disease 2019 (COVID-19). The collective experience in the scientific literature indicates that well-optimized dPCR assays can quantify genetic material from microorganisms without the need for a calibration curve and often with superior analytical performance (i.e., greater sensitivity, precision, and reproducibility) than quantitative polymerase chain reaction (qPCR). Nonetheless, dPCR should not be viewed as a panacea for the fundamental uncertainties and limitations associated with measuring microorganisms in water microbiology. With dPCR platforms, the sample analysis cost and processing time are typically greater than qPCR. However, if improved analytical performance (i.e., sensitivity and accuracy) is critical, dPCR can be an alternative option for quantifying microorganisms, including pathogens, in aquatic environments.Peer reviewe
Association between Global Monkeypox Cases and Meteorological Factors
The emergence of an outbreak of Monkeypox disease (MPXD) is caused by a contagious zoonotic Monkeypox virus (MPXV) that has spread globally. Yet, there is no study investigating the effect of climatic changes on MPXV transmission. Thus, studies on the changing epidemiology, evolving nature of the virus, and ecological niche are highly paramount. Determination of the role of potential meteorological drivers including temperature, precipitation, relative humidity, dew point, wind speed, and surface pressure is beneficial to understand the MPXD outbreak. This study examines the changes in MPXV cases over time while assessing the meteorological characteristics that could impact these disparities from the onset of the global outbreak. To conduct this data-based research, several well-accepted statistical techniques including Simple Exponential Smoothing (SES), Auto-Regressive Integrated Moving Average (ARIMA), Automatic forecasting time-series model (Prophet), and Autoregressive Integrated Moving Average with Explanatory Variables (ARIMAX) were applied to delineate the correlation of the meteorological factors on global daily Monkeypox cases. Data on MPXV cases including affected countries spanning from 6 May 2022, to 9 November 2022, from global databases and meteorological data were used to evaluate the developed models. According to the ARIMAX model, the results showed that temperature, relative humidity, and surface pressure have a positive impact [(51.56, 95% confidence interval (CI): -274.55 to 377.68), (17.32, 95% CI: -83.71 to 118.35) and (23.42, 95% CI: -9.90 to 56.75), respectively] on MPXV cases. In addition, dew/frost point, precipitation, and wind speed show a significant negative impact on MPXD cases. The Prophet model showed a significant correlation with rising MPXD cases, although the trend predicts peak values while the overall trend increases. This underscores the importance of immediate and appropriate preventive measures (timely preparedness and proactive control strategies) with utmost priority against MPXD including awareness-raising programs, the discovery, and formulation of effective vaccine candidate(s), prophylaxis and therapeutic regimes, and management strategies.Peer reviewe
Mental health issues in pregnant women in Nepal
Mental health of pregnant women and new mothers is a growing area of concern in both low- and high-income countries. This editorial highlights some of the key mental issues faced by women in rural Nepal and outlines an intervention based on training community health care workers by experienced UK volunteers
Assessing placement of nasoduodenal tube and its usefulness in maintaining nutrition in critically ill patients
ABSTRACT Nutritional supplements to the critically ill patients are one of the major issues to be discussed. Enteric feeding is advantageous over parentral feeding because it maintains gut integrity and prevents bacterial translocation. Small intestinal feeding shows significant beneficial results. Nasoduodenal tube placement and its confirmation by serial pH monitoring and by radiological examination was done; and time taken to reach duodenum was assessed. This study was done in 40 critically ill patients, who were divided into two groups (group 1 and Group2). Early enteric feeding via a nasoduodenal tube was found to be preferable with parentral therapy when there are no contraindications. Advantages of nasoduodenal tube feeding in critical ill patients were that feeding can be continued even in the absence of bowel sounds and passage of flatus. Insignificant complications were noted
Monkeypox Outbreak: Wastewater and Environmental Surveillance Perspective
Monkeypox disease (MPXD), a viral disease caused by monkeypox virus (MPXV), is an emerging zoonotic disease endemic in some countries of Central and Western Africa but seldom reported outside the affected region. Since May 2022, MPXD has been reported at least in 74 countries globally, prompting the World Health Organization to declare the MPXD outbreak a Public Health Emergency of International Concern. As of July 24, 2022, 92% (68/74) of the countries with reported MPXD cases had no historical MPXD case reports. From the One Health perspective, the spread of MPXV in the environment poses a risk not only to humans but also to small mammals and may, ultimately, spread to potent novel host populations. Wastewater-based surveillance (WBS), has been extensively utilized for monitoring communicable diseases, particularly during the ongoing coronavirus disease, the COVID-19 pandemic It helped to monitor infectious disease caseloads as well as specific viral variants circulating in communities. The detection of MPXV DNA in various body fluids, including respiratory and nasal secretions, saliva, urine, feces, and semen of infected individuals, supports the possibility of using WBS as an early proxy for the detection of MPXV infections. WBS of MPXV DNA can be used to monitor MPXV activity/trends in sewerage network areas even before detecting laboratory-confirmed clinical cases within a community. However, several factors affect the detection of MPXV in wastewater including, but not limited to, routes and duration time of virus shedding by infected individuals, infection rates in the relevant affected population, environmental persistence, the processes and analytical sensitivity of the used methods. Further research is needed to identify the key factors that impact the detection of MPXV biomarkers in wastewater and improve the utility of WBS of MPXV as an early warning and monitoring tool for safeguarding human health. In this review, we shortly summarize aspects of MPXV outbreak relevant to wastewater monitoring and discuss the challenges associated with WBS.Peer reviewe
The Importance of Research on the Origin of SARS-CoV-2
The origin of the severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) virus causing the COVID-19 pandemic has not yet been fully determined. Despite the consensus about the SARS-CoV-2 origin from bat CoV RaTG13, discrepancy to host tropism to other human Coronaviruses exist. SARS-CoV-2 also possesses some differences in its S protein receptor-binding domain, glycan-binding N-terminal domain and the surface of the sialic acid-binding domain. Despite similarities based on cryo-EM and biochemical studies, the SARS-CoV-2 shows higher stability and binding affinity to the ACE2 receptor. The SARS-CoV-2 does not appear to present a mutational “hot spot” as only the D614G mutation has been identified from clinical isolates. As laboratory manipulation is highly unlikely for the origin of SARS-CoV-2, the current possibilities comprise either natural selection in animal host before zoonotic transfer or natural selection in humans following zoonotic transfer. In the former case, despite SARS-CoV-2 and bat RaTG13 showing 96% identity some pangolin Coronaviruses exhibit very high similarity to particularly the receptor-binding domain of SARS-CoV-2. In the latter case, it can be hypothesized that the SARS-CoV-2 genome has adapted during human-to-human transmission and based on available data, the isolated SARS-CoV-2 genomes derive from a common origin. Before the origin of SARS-CoV-2 can be confirmed additional research is required
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