Journal of water and health最新文献

Agriculture plays a dual role, both contributing to and being impacted by water pollution. This study evaluates the impact of tobacco and non-tobacco farming on irrigation suitability, water quality index (WQI), water health index (WHI), heavy metal (HM) pollution, and ecological risk (ER). Twenty-four water samples from six tobacco fields (TFs) and six non-tobacco fields (NTFs), collected before cropping season and after cropping season, were analyzed for major physico-chemical properties and HMs. The results suggest that TF improves sodium and alkalinity hazards but worsens nutrient and HM pollution (Pb: 0.119 mg/L, Cd: 0.021 mg/L, Ni: 0.242 mg/L), and threatens salinity, permeability, osmotic potential (OPπ), dry residue (RS), and miscellaneous hazards. Conversely, NTF has minimal impact, except for nutrient and miscellaneous hazards. WQI shifts from good to very poor, primarily driven by turbidity, PO₄-P, K⁺, and NO₃-N. Similarly, WHI declines from excellent to very poor in TF and from good to poor in NTF. HM pollution index has risen slightly above irrigation safety limits, mainly due to Cd, Ni, and Pb, resulting in a slightly elevated ER. This study demonstrates that TF, driven by excessive agrochemical use, renders water unsuitable for irrigation, underscoring the imperative for sustainable practices.

Water hygiene is a critical public health issue, particularly in developing countries like Bangladesh. Therefore, this study aimed to evaluate the bacteriological quality and antimicrobial resistance (AMR) patterns of bacterial isolates in drinking water sources commonly used by the public across Barishal district of Bangladesh. A total of 30 water samples were collected from six sources - household reserved tanks, ponds, rivers, hotels, farms, and street food vendor vans - between July 2022 and June 2023. Bacterial contamination was assessed using total viable count, most probable number (MPN), and selective culture methods, while antibiotic susceptibility testing (AST) was conducted to evaluate antimicrobial resistance (AMR) patterns. Results indicated substantial contamination, with the highest bacterial load observed in household reserved tank water (5.6 × 10⁵ CFU/mL). Predominant bacterial isolates included Escherichia coli and Staphylococcus spp., suggesting fecal contamination and potential health risks. AMR profiling revealed resistance to beta-lactam antibiotics such as amoxicillin and penicillin, with multidrug resistance observed in E. coli, Staphylococcus spp., and non-lactose fermenting bacteria. However, susceptibility to colistin and levofloxacin was noted in some isolates. These findings underscore the urgent need for routine water quality monitoring, effective disinfection strategies, and public awareness initiatives to mitigate health risks and curb the spread of AMR in environmental water sources.

Climate and socio-economic changes are expected to significantly impact waterborne pathogens and associated health risks, yet the full extent of these effects remains unclear. Accurate quantification of these risks is crucial for informing effective interventions and policy decisions. Quantitative microbial risk assessment (QMRA) serves as a valuable tool for estimating the risk of infection caused by microorganisms in drinking water. This study reviews existing QMRA studies and tools in the context of surface water and drinking water provision. Most studies have implemented various steps of the QMRA framework but often without the application of specific QMRA tools. Although several QMRA tools address climatic factors, there are currently no tools that integrate socio-economic factors into their risk assessments. This study proposes an approach for incorporating both climatic and socio-economic factors into QMRA tools. Specifically, we suggest enhancements to the Swedish QMRA tool - an open-source tool that currently does not incorporate climate and socio-economic changes. Our proposed advancements aim to systematically account for future climatic and socio-economic impacts on health risks, providing a more comprehensive microbial risk assessment tool. These recommendations are also applicable to other QMRA tools, offering a pathway for their development and improving the overall assessment of microbial health risks.

High diarrheal disease burden remains an urgent concern in low- and middle-income countries, greatly affecting children under the age of 5 years and those living with HIV and AIDS. Treatment of infectious diseases has also become increasingly difficult with the rapid rise of antimicrobial resistance (AMR). Environmental surveillance of wastewater can supplement gaps in clinical surveillance as residents on a sewage system contribute to the wastewater, providing simple, composite samples that can improve understanding about both pathogens and AMR in the community. This study evaluated the effectiveness of environmental surveillance with shotgun metagenomics as a tool to characterize a broad range of enteric pathogens, antibiotic resistance genes, and virulence factor genes (VFGs) in wastewater from six neighborhoods in Harare, Zimbabwe. Alpha and beta diversity of the microbial community were similar between high-income and low-income suburbs. Enteric pathogens of high AMR and clinical concern, including Staphylococcus aureus, Pseudomonas aeruginosa, and Salmonella enterica, were detected in all samples. The top VFGs were encoded for delivery, adherence, and motility, functions important in toxin secretion, colonization, and immune modulation. The findings provide a foundation for future studies to explore environmental surveillance and shotgun metagenomics as a public health monitoring tool for enteric diseases.

This study presents the successful optimization of enteric RT-qPCR multiplex assays for detecting Norovirus GII, Enterovirus, and Coxsackievirus A6 or Enterovirus D68 in municipal wastewater samples. Additionally, optimization of a respiratory RT-qPCR multiplex assay to detect influenza A, respiratory syncytial virus, and SARS-CoV-2 was attempted. The enteric multiplex assays successfully detected Coxsackievirus A6 in wastewater during community outbreaks of hand-foot-mouth disease. Enterovirus D68 was also successfully detected in wastewater samples (Summer/Fall, 2022), which coincided with provincial public health reports of Enterovirus D68 cases. Attempting to optimize the respiratory multiplex assay resulted in challenges due to oligonucleotide cross-reactivity and cross-talk. Specifically, when Texas Red and FAM probes detected higher abundance targets, they interfered with the Cy5 and HEX fluorophore probes that detected lower-abundance targets. In contrast, selecting probes with Cy5/HEX for high-abundance targets and Texas Red/FAM for lower-abundance targets provided more robust results.

Free-living amoebae (FLA) are ubiquitous protozoa capable of enduring harsh environmental conditions. These microorganisms are commonly found in water, soil, and air and can be transmitted to humans in areas with high human activity. This study aimed to investigate the prevalence of FLA and their associated genotypes/species in five rivers in Tehran province, Iran. A total of 60 water samples were collected from the Jajrud, Kan, Farhzad, Darakeh, and Shadchay rivers. Samples were subjected to filtration and cultivation onto non-nutrient agar. The genera/species of FLA were characterized based on the amplification and sequencing of the specific genetic fragments. Microscopic analysis suggested the presence of trophozoites and cysts of FLA in 18/60 (30%) of samples, of which Acanthamoeba spp., Vermamoeba sp., and Vahlkampfiidae were identified. Sequence analysis showed the presence of the genotypes T11, T4, T3, and T5 in five, five, four, and one isolates, respectively. The molecular analysis of the T4 genotype showed gene flow between the current isolates with previously described sequences. The findings suggest a clear association between environmental and clinical isolates of Acanthamoeba spp. Therefore, scheduled monitoring of environmental waters, particularly in regions with high human activities, is highly recommended.

This study analyzes the trend and forecasts the future proportion of the people in Bangladesh using safely managed drinking water and sanitation services, aiming for progress toward SDGs. The annual datasets cover the years 2000-2022 and are sourced from the World Bank Databank, focusing on 'Proportion of people using safely managed drinking water services' and 'Proportion of people using safely managed sanitation services.' Initially, the Mann-Kendall test is applied to detect seasonal trends in the time series data. The ARIMA (0,1,0) model is identified as the optimal fit for forecasting drinking water services, while Holt's method is preferred for sanitation services. Results show an upward trend in both areas; however, the rates remain inadequate to meet SDG 6 targets. Projections indicate that by 2025, 60.6% of the population will have access to safely managed drinking water and 33.5% will have access to sanitation services, whereas the Bangladeshi government aims for 75 and 80%, respectively. Furthermore, by 2030, these proportions are expected to increase to 63.7% for drinking water and 37.2% for sanitation. This analysis suggests that, if current trends continue, the national targets and the SDG targets 6.1 and 6.2 will not be achievable by 2030.

Escherichia coli and Klebsiella pneumoniae isolates with multiple antibiotic-resistance genes in wastewater pose serious public health risks, as they can potentially contaminate the food and water supply. The main aim of this study was to isolate and identify E. coli and K. pneumoniae from community wastewater samples, and determine their antibiotic-resistance profiles and their antibiotic-resistant genes. From the northern part of Dhaka, Bangladesh, 36 wastewater samples were collected across 11 different areas, which were then serially diluted, and cultured using selective media. Isolates were identified via polymerase chain reaction. Out of the 197 isolates identified, E. coli and K. pneumoniae accounted for 55.8% (n = 110) and 44.2% (n = 87), respectively. Antibiotic susceptibility tests revealed multidrug resistance (MDR) in 30% of E. coli and 35.56% of K. pneumoniae isolates. Among E. coli, the prevalence of antibiotic-resistance genes included bla_NDM-1 (8.9%), bla_SHV (13.9%), and bla_CTX-M (7.6%). In K. pneumoniae, the percentages were bla_NDM-1 (12.8%), bla_SHV (4.3%), and bla_CTX-M (5.0%). Co-existence of multiple antibiotic-resistance genes was observed in 4.54% of E. coli isolates (n = 5) and 5.74% of K. pneumoniae isolates (n = 5). This suggests the escalating issue of infectious species becoming increasingly resistant to antibiotics in wastewater systems.

Enterococci, flagged by the WHO as a rising cause of antibiotic-resistant infections, make surveillance crucial to control resistant strains. We investigated the resistance to linezolid, quinupristin/dalfopristin (Q/D), and erythromycin in Enterococcus faecalis (n = 251) and Enterococcus faecium (n = 434) isolates collected from patients, healthy carriers, hospitals, poultry, livestock, and municipal wastewater in Ardabil, Iran. The isolates were tested for resistance using phenotypic and genotypic methods. Although none of the isolates were resistant to linezolid, 24.9% of E. faecium isolates were resistant to Q/D, particularly those from patients and poultry slaughterhouse wastewater effluent (P < 0.05). The Q/D resistance genes msrC and ermB were detected in 76.85 and 20.37% of E. faecium isolates, respectively. Erythromycin resistance was common in E. faecalis (51.8%) and E. faecium (37.5%), with no significant difference between sources. However, isolates from patients and livestock wastewater had higher erythromycin MICs. Erythromycin resistance genes, such as ermB, ermC, ermTR, and ermA, were found in 80.7, 41.2, 26.5, and 19% of E. faecium and 80.3, 51.6, 22.4, and 25.8% of E. faecalis isolates, respectively. In conclusion, linezolid is a viable treatment for enterococcal infections in Ardabil, but widespread erythromycin- and Q/D-resistant enterococci pose a public health risk.