1
|
Waindok P, Raulf MK, Strube C. Potentials and challenges in the isolation and detection of ascarid eggs in complex environmental matrices. Food Waterborne Parasitol 2022; 28:e00174. [PMID: 36017135 PMCID: PMC9396397 DOI: 10.1016/j.fawpar.2022.e00174] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 07/05/2022] [Accepted: 08/01/2022] [Indexed: 11/22/2022] Open
Abstract
Ascarid infections constitute a major concern for both human and animal health risk assessment. Although being effectively transmitted by soil, water and contaminated food, reliable detection of ascarid eggs in environmental media often remains challenging. However, contamination of the environment with ascarid ova has gained more attention as a decisive part of proper risk assessment in recent years. Due to various factors, such as sample matrices, dissociation detergents and flotation solutions, defined and standardised protocols for the isolation of eggs from complex environmental matrices are difficult to establish and therefore limited. Thus, this study reviews common techniques used for the recovery of ascarid eggs from environmental media with special emphasis on sampling strategies, purification procedures and microscopic as well as molecular detection of egg contamination. Despite various advancements, mainly in the field of molecular methods leading to more reliable and sensitive detection, it can be concluded that there is still a need for unified guidelines for sampling and recovery of ascarid eggs derived from complex environmental matrices.
Collapse
Affiliation(s)
| | | | - Christina Strube
- Institute for Parasitology, Centre for Infection Medicine, University of Veterinary Medicine Hannover, Hanover, Germany
| |
Collapse
|
2
|
Parasitological Assessment of Sewage Sludge Samples for Potential Agricultural Reuse in Tunisia. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19031657. [PMID: 35162680 PMCID: PMC8835308 DOI: 10.3390/ijerph19031657] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 01/28/2022] [Accepted: 01/28/2022] [Indexed: 02/04/2023]
Abstract
Wastewater sludge represents an important resource for reuse in agriculture. However, potentially harmful pathogens are a main threat in this context. Thus, the aim of this study was to examine the presence of helminth ova and protozoan cysts in dried sewage sludge samples collected from ten wastewater treatment plants (WWTPs) located in eight governorates in Tunisia. Based on morphological criteria, protozoan cysts of Giardia spp., Entamoeba histolytica/dispar/moshkovskii, and Entamoeba coli, were detected in all dried sludge composite samples (N = 116) from the investigated WWTPs. The mean concentration ranged from 1.4 to 10.7 cysts per 100 g dry matter (DM). The identified helminth eggs were Ascaris spp., Strongyles, Taeniid eggs, Hymenolepis nana, Enterobius vermicularis, and hookworm species. Ascaris spp. and Taeniid eggs were detected in 56.9 and 74.1% of analyzed samples, respectively. The presence of Trichuris spp., Hymenolepis diminuta, and Toxocara spp. eggs in dried sewage sludge samples was low (0.9, 1.7, and 2.6%, respectively). The mean concentration of helminth eggs during the three-year study was less than 1 egg/100 g DM. All examined dried sewage sludge sample contents were below the WHO (2006) and US EPA (2003) recommendations, and thus, the sludge can potentially be reused in agriculture.
Collapse
|
3
|
Gyawali P. Infectious helminth ova in wastewater and sludge: A review on public health issues and current quantification practices. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2018; 77:1048-1061. [PMID: 29488968 DOI: 10.2166/wst.2017.619] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Raw and partially treated wastewater has been widely used to maintain the global water demand. Presence of viable helminth ova and larvae in the wastewater raised significant public health concern especially when used for agriculture and aquaculture. Depending on the prevalence of helminth infections in communities, up to 1.0 × 103 ova/larvae can be presented per litre of wastewater and 4 gm (dry weight) of sludge. Multi-barrier approaches including pathogen reduction, risk assessment, and exposure reduction have been suggested by health regulators to minimise the potential health risk. However, with a lack of a sensitive and specific method for the quantitative detection of viable helminth ova from wastewater, an accurate health risk assessment is difficult to achieve. As a result, helminth infections are difficult to control from the communities despite two decades of global effort (mass drug administration). Molecular methods can be more sensitive and specific than currently adapted culture-based and vital stain methods. The molecular methods, however, required more and thorough investigation for its ability with accurate quantification of viable helminth ova/larvae from wastewater and sludge samples. Understanding different cell stages and corresponding gene copy numbers is pivotal for accurate quantification of helminth ova/larvae in wastewater samples. Identifying specific genetic markers including protein, lipid, and metabolites using multiomics approach could be utilized for cheap, rapid, sensitive, specific and point of care detection tools for helminth ova and larva in the wastewater.
Collapse
Affiliation(s)
- P Gyawali
- Institute of Environmental Science and Research Ltd (ESR), Kenepuru Science Centre, Porirua 5240, New Zealand E-mail:
| |
Collapse
|
4
|
Cranston I, Teoh PJ, Baker SM, Sengupta ME, Ensink JHJ. Evaluating the efficacy of a centrifugation-flotation method for extracting Ascaris ova from soil. Trans R Soc Trop Med Hyg 2017; 110:400-7. [PMID: 27496514 DOI: 10.1093/trstmh/trw044] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2016] [Accepted: 06/23/2016] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Soil transmitted helminths (STH) continue to be associated with high burdens of disease, with an estimated 1.45 billion people infected with STH globally. The promotion and construction of latrines is considered the first barrier to prevent transmission of STH. The absence of a reliable method to extract STH ova from soil makes it challenging to examine whether the use of latrines may or may not have an effect on environmental contamination with ova. The present study evaluated the recovery rate of a method developed to extract STH ova from soil. METHODS The adapted centrifugation and flotation technique was applied to 15 soil types, which were seeded with Ascaris suum ova. Soil type, soil moisture content, soil texture and organic matter content were assessed for each soil sample. RESULTS The average ova recovery rate was 28.2%, with the recovery rate of the method decreasing with increasing soil moisture content, particle size and organic matter content. The association between recovery rate and organic matter content was statistically significant. CONCLUSIONS The present study identified a low recovery rate for an adapted centrifugation-flotation method, although this was similar to the recovery rate demonstrated by other methods developed for soil. Soil organic matter content was significantly associated with ova recovery rates.
Collapse
Affiliation(s)
- Imogen Cranston
- Environmental Health Group, Department of Disease Control, Faculty of Infectious Disease, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Penelope J Teoh
- Environmental Health Group, Department of Disease Control, Faculty of Infectious Disease, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Sarah M Baker
- School of Medicine, Tulane University, 1430 Tulane Ave, New Orleans, LA 70112, USA
| | - Mita E Sengupta
- Section for Parasitology and Aquatic Diseases, Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Dyrlaegevej 100, 1870 Frederiksberg C, Denmark
| | - Jeroen H J Ensink
- Environmental Health Group, Department of Disease Control, Faculty of Infectious Disease, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| |
Collapse
|
5
|
Stevens DP, Surapaneni A, Thodupunuri R, O'Connor NA, Smith D. Helminth log reduction values for recycling water from sewage for the protection of human and stock health. WATER RESEARCH 2017; 125:501-511. [PMID: 28942117 DOI: 10.1016/j.watres.2017.08.069] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Revised: 07/15/2017] [Accepted: 08/24/2017] [Indexed: 06/07/2023]
Abstract
The LRVs required to decrease HE concentrations in raw sewage to an acceptable level to manage the risk to human and livestock health were determined. An LRV of 3.0 was required to meet the HBT of 1 μDALY pppy in SE Australia where human helminth infections are not endemic. In comparison, a similar exposure volume and LRV in endemic regions would result in a HBT of 100 μDALY pppy. The risks posed by cattle- and pig-related helminths were also managed acceptably with the treatment of sewage providing an LRV of 3.0. New design equations were derived to determine LRVs based on hydraulic residence times (HRTs) in an activated sludge plant (ASP) and lagoons. The new equation for lagoons indicated that an LRV of 3.0 could be achieved with a HRT of 18 days or less.
Collapse
Affiliation(s)
- Daryl P Stevens
- Atura Pty Ltd, PO Box 434, Preston, Victoria 3072, Australia.
| | | | | | - Nicholas A O'Connor
- Ecos Environmental Consulting Pty Ltd, PO Box 1064G, North Balwyn, Victoria 3104, Australia
| | - David Smith
- South East Water, 101 Wells Street, Frankston, Victoria 3199, Australia
| |
Collapse
|
6
|
Abia ALK, James C, Ubomba-Jaswa E, Benteke Momba MN. Microbial Remobilisation on Riverbed Sediment Disturbance in Experimental Flumes and a Human-Impacted River: Implication for Water Resource Management and Public Health in Developing Sub-Saharan African Countries. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2017; 14:E306. [PMID: 28295001 PMCID: PMC5369142 DOI: 10.3390/ijerph14030306] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Revised: 03/09/2017] [Accepted: 03/10/2017] [Indexed: 11/29/2022]
Abstract
Resuspension of sediment-borne microorganisms (including pathogens) into the water column could increase the health risk for those using river water for different purposes. In the present work, we (1) investigated the effect of sediment disturbance on microbial resuspension from riverbed sediments in laboratory flow-chambers and in the Apies River, Gauteng, South Africa; and (2) estimated flow conditions for sediment-borne microorganism entrainment/resuspension in the river. For mechanical disturbance, the top 2 cm of the sediment in flow-chambers was manually stirred. Simulating sudden discharge into the river, water (3 L) was poured within 30 s into the chambers at a 45° angle to the chamber width. In the field, sediment was disturbed by raking the riverbed and by cows crossing in the river. Water samples before and after sediment disturbance were analysed for Escherichia coli. Sediment disturbance caused an increase in water E. coli counts by up to 7.9-35.8 times original values. Using Shields criterion, river-flow of 0.15-0.69 m³/s could cause bed particle entrainment; while ~1.57-7.23 m³/s would cause resuspension. Thus, sediment disturbance in the Apies River would resuspend E. coli (and pathogens), with possible negative health implications for communities using such water. Therefore, monitoring surface water bodies should include microbial sediment quality.
Collapse
Affiliation(s)
- Akebe Luther King Abia
- Departments of Biotechnology, Vaal university of Technology, Private Bag X021, Andries Potgieter Blvd, Vanderbijlpark 1911, South Africa.
| | - Chris James
- School of Civil & Environmental Engineering, University of the Witwatersrand, Johannesburg 2050, South Africa.
| | - Eunice Ubomba-Jaswa
- Natural Resources and the Environment, CSIR, P.O. Box 395, Pretoria 0001, South Africa.
| | - Maggy Ndombo Benteke Momba
- Department of Environmental, Water and Earth Science, Tshwane University of Technology, Arcadia Campus, 175 Nelson Mandela Drive, Pretoria 0001, South Africa.
| |
Collapse
|
7
|
Abia ALK, Ubomba-Jaswa E, Genthe B, Momba MNB. Quantitative microbial risk assessment (QMRA) shows increased public health risk associated with exposure to river water under conditions of riverbed sediment resuspension. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 566-567:1143-1151. [PMID: 27297265 DOI: 10.1016/j.scitotenv.2016.05.155] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2016] [Revised: 05/20/2016] [Accepted: 05/21/2016] [Indexed: 06/06/2023]
Abstract
Although higher microbial concentrations have been reported in sediments than in the overlying water column, most quantitative microbial risk assessment (QMRA) studies have not clearly indicated the contribution of sediment-borne pathogens to estimated risks. Thus, the present study aimed at determining the public health risk associated with exposure to pathogenic bacteria in polluted river water under undisturbed conditions and conditions of sediment resuspension in the Apies River, Gauteng, South Africa. Microbial pathogens were isolated and identified using culture and molecular methods. The beta-Poisson dose-response model was used to estimate the probability of infection (Pi) with the various pathogens, following accidental/intentional ingestion of 1mL or 100mL (or 50mL) of untreated river water. Mean wet season Escherichia coli counts ranged between 5.8E+01 and 8.8E+04MPN/100mL (water column) and between 2.40E+03 and 1.28E+05MPN/100mL (sediments). Mean dry season E. coli counts ranged between 5.11E+00 and 3.40E+03MPN/100mL (water column) and between 5.09E+00 and 6.30E+03MPN/100mL (sediments). Overall (water and sediments) Vibrio cholerae was the most detected pathogen (58.8%) followed by Salmonella spp. (23.9%) and Shigella (10.1%). Ingestion of 1mL of river water could lead to 0%-4% and 1%-74% Pi with E. coli during the dry and wet season, respectively. During the dry season, the Pi with V. cholerae, Salmonella spp. and Shigella spp. were 0%-1.39%, 0%-4.11% and 0%-0.16% respectively, depending on volume of water ingested. The risks of infections with all microorganisms increased during the wet season. A 2-log increase in water E. coli count following sediments disturbance led to approximately 10 times higher Pi with E. coli than when sediments were undisturbed. Therefore, the use of the untreated water from the Apies River for drinking, household purposes or recreational activities poses a potential health risk to the users of the river.
Collapse
Affiliation(s)
- Akebe Luther King Abia
- Department of Environmental, Water and Earth Science, Tshwane University of Technology, Arcadia Campus, 175 Nelson Mandela Drive, Pretoria 0001, South Africa.
| | - Eunice Ubomba-Jaswa
- Natural Resources and the Environment, CSIR, PO Box 395, Pretoria 0001, South Africa.
| | - Bettina Genthe
- Natural Resources and the Environment, CSIR, Stellenbosch, South Africa.
| | - Maggy Ndombo Benteke Momba
- Department of Environmental, Water and Earth Science, Tshwane University of Technology, Arcadia Campus, 175 Nelson Mandela Drive, Pretoria 0001, South Africa.
| |
Collapse
|
8
|
Removal of Cryptosporidium parvum oocysts in low quality water using Moringa oleifera seed extract as coagulant. Food Waterborne Parasitol 2016. [DOI: 10.1016/j.fawpar.2016.03.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
|