1
|
Legge H, Kazungo K, Muli S, Elson L, Mwongeli J, Halliday KE, Ochwal V, Oswald W, Dreibelbis R, Njomo D, Mwandawiro C, Fillinger U, Pullan R, Kepha S. Identifying Potential Determinants of Faecal Contamination on Domestic Floors in Three Settings in Rural Kenya: A Mixed Methods Analysis. ENVIRONMENTAL HEALTH INSIGHTS 2024; 18:11786302241246454. [PMID: 38737960 PMCID: PMC11088304 DOI: 10.1177/11786302241246454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Accepted: 03/21/2024] [Indexed: 05/14/2024]
Abstract
Observational evidence suggests that household floors may be an important domain for the transmission of enteric and parasitic infections. However, little work has been done to investigate how household floors can become contaminated with human and animal faeces. This study uses a mixed methods approach to postulate the proximal and distal determinants of household floor contamination with faeces in groups of rural villages in 3 counties in Kenya (Bungoma, Kwale and Narok). Quantitative data was collected through a household census and analysed descriptively and using mixed effects logistic regression models. Qualitative data was collected through unstructured observations of daily routines and in-depth interviews. These data were analysed thematically with case memos produced for routine activities that were hypothesised to be determinants of floor contamination. Possible proximal determinants of floor contamination included; (1) animal contact with floors; (2) child faeces disposal, and; (3) floor cleaning routines. Distal determinants are suggested to be rooted in the socioeconomic, environmental, and cultural context in which households were located and included; (1) the type and number of animals owned by households; (2) presence/absence of dedicated shelters for housing animals at night, which impacted whether sleeping or cooking areas were exposed to animals; (3) Accessibility of inside spaces to poultry and other roaming animals; (4) ownership of an improved floor; (5) ability of animals to access neighbours compounds; (6) seasonal changes in weather. These results will be of use in identifying the contexts in which faecal contamination of domestic floors may be contributing towards transmission of enteric and parasitic infections and in designing effective interventions to prevent this exposure.
Collapse
Affiliation(s)
- Hugo Legge
- London School of Hygiene & Tropical Medicine, UK
| | - Karisa Kazungo
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
| | - Sharon Muli
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
| | - Lynne Elson
- KEMRI-Wellcome Trust, Nairobi, Kenya
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, UK
| | - Jacinta Mwongeli
- Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
| | | | - Victoria Ochwal
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
| | - William Oswald
- London School of Hygiene & Tropical Medicine, UK
- Global Health Division, International Development Group, RTI International, Research Triangle Park, NC, USA
| | | | - Doris Njomo
- Eastern and Southern Africa Centre of International Parasite Control, Kenya Medical Research Institute, Nairobi, Kenya
| | - Charles Mwandawiro
- Eastern and Southern Africa Centre of International Parasite Control, Kenya Medical Research Institute, Nairobi, Kenya
| | - Ulrike Fillinger
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
| | | | - Stella Kepha
- Eastern and Southern Africa Centre of International Parasite Control, Kenya Medical Research Institute, Nairobi, Kenya
| |
Collapse
|
2
|
Espira LM, Contreras JD, Felix-Arellano EE, Siebe C, Mazari-Hiriart M, Riojas-Rodríguez H, Eisenberg JNS. A comparative analysis of regional infection risk due to wastewater recontamination in the Mezquital Valley, Mexico. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 919:170615. [PMID: 38316303 DOI: 10.1016/j.scitotenv.2024.170615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2023] [Revised: 01/30/2024] [Accepted: 01/30/2024] [Indexed: 02/07/2024]
Abstract
Urban wastewater reuse for agriculture provides reliable nutrient-rich water, reduces water stress, and strengthens food systems. However, wastewater reuse also presents health risks and characterizing the spatial dynamics of wastewater can help optimize risk mitigation. We conducted comparative risk analysis of exposure to wastewater in irrigation canals, where we compared those exposed to a) treated vs. untreated wastewater, and b) wastewater upstream vs. downstream from communities in the Mezquital Valley. The canal system with treated wastewater was sampled prior to being treated, directly after treatment, as well as before and after it flowed through a community. Along the canal system that carried untreated wastewater, we sampled before and after a community. We quantified the concentrations of bacterial, protozoal, and viral pathogens in the wastewater. Pathogen concentration data were used to calculate measures of relative risk between sampling points. Wastewater treatment reduced predicted bacterial pathogen infection risk in post-treatment locations (RR = 0.73, 95 % CI 0.61, 0.87), with no evidence of similar reductions in Giardia or viral pathogens (RR = 1.02, 95 % CI 0.56, 1.86 and RR = 1.18, 95 % CI 0.70, 2.02 respectively). Although infection risk decreased further down the canals, infection risk increased for bacterial pathogens after our sentinel community (RR = 1.94, 95 % 1.34, 2.86). For Giardia and viral pathogens infection risk was elevated but not significantly. We found similar evidence for increases in risk when comparing the treated section of the canal system with a canal section whose wastewater was not treated, i.e., the risk benefits of wastewater treatment were lost after our sentinel community for bacteria (RR = 5.27 vs. 2.08 for sampling points before and after our sentinel community respectively) and for Giardia (RR = 6.98 vs. 3.35 respectively). The increase in risk after transit through communities could have resulted from local community recontamination of the treated wastewater stream.
Collapse
Affiliation(s)
- Leon M Espira
- Department of Epidemiology, University of Michigan, Ann Arbor, MI 48109, United States of America
| | - Jesse D Contreras
- Department of Epidemiology, University of Michigan, Ann Arbor, MI 48109, United States of America
| | - Eunice E Felix-Arellano
- Dirección de Salud Ambiental, Instituto Nacional de Salud Pública, Universidad No. 655 Colonia Santa María Ahuacatitlán, Cerrada Los Pinos y Caminera, 62100 Cuernavaca, Morelos, Mexico
| | - Christina Siebe
- Instituto de Geología, Universidad Nacional Autonóma de México, Circuito de la Investigación Científica s/n, Ciudad Universitaria, 04510 Ciudad de México, Mexico
| | - Marisa Mazari-Hiriart
- Laboratorio Nacional de Ciencias de la Sostenibilidad, Instituto de Ecología, Universidad Nacional Autónoma de Mexico, Circuito Exterior s/n. Anexo Jardín Botanico Exterior, Ciudad Universitaria, 04510 Ciudad de México, Mexico
| | - Horacio Riojas-Rodríguez
- Dirección de Salud Ambiental, Instituto Nacional de Salud Pública, Universidad No. 655 Colonia Santa María Ahuacatitlán, Cerrada Los Pinos y Caminera, 62100 Cuernavaca, Morelos, Mexico
| | - Joseph N S Eisenberg
- Department of Epidemiology, University of Michigan, Ann Arbor, MI 48109, United States of America.
| |
Collapse
|
3
|
Rao G, Capone D, Zhu K, Knoble A, Linden Y, Clark R, Lai A, Kim J, Huang CH, Bivins A, Brown J. Simultaneous detection and quantification of multiple pathogen targets in wastewater. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.06.23.23291792. [PMID: 37425908 PMCID: PMC10327253 DOI: 10.1101/2023.06.23.23291792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
Wastewater-based epidemiology has emerged as a critical tool for public health surveillance, building on decades of environmental surveillance work for pathogens such as poliovirus. Work to date has been limited to monitoring a single pathogen or small numbers of pathogens in targeted studies; however, few studies consider simultaneous quantitative analysis of a wide variety of pathogens, which could greatly increase the utility of wastewater surveillance. We developed a novel quantitative multi-pathogen surveillance approach (35 pathogen targets including bacteria, viruses, protozoa, and helminths) using TaqMan Array Cards (TAC) and applied the method on concentrated wastewater samples collected at four wastewater treatment plants in Atlanta, GA from February to October of 2020. From sewersheds serving approximately 2 million people, we detected a wide range of targets including many we expected to find in wastewater (e.g., enterotoxigenic E. coli and Giardia in 97% of 29 samples at stable concentrations) as well as unexpected targets including Strongyloides stercoralis (a human threadworm rarely observed in the USA). Other notable detections included SARS-CoV-2, but also several pathogen targets that are not commonly included in wastewater surveillance like Acanthamoeba spp., Balantidium coli, Entamoeba histolytica, astrovirus, norovirus, and sapovirus. Our data suggest broad utility in expanding the scope of enteric pathogen surveillance in wastewaters, with potential for application in a variety of settings where pathogen quantification in fecal waste streams can inform public health surveillance and selection of control measures to limit infections.
Collapse
Affiliation(s)
- Gouthami Rao
- Department of Environmental Sciences and Engineering, Gillings School of Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Drew Capone
- Department of Environmental and Occupational Health, School of Public Health, Indiana University, Bloomington, IN, USA
| | - Kevin Zhu
- Department of Environmental Sciences and Engineering, Gillings School of Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Abigail Knoble
- Department of Environmental Sciences and Engineering, Gillings School of Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Yarrow Linden
- Department of Environmental Sciences and Engineering, Gillings School of Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Ryan Clark
- Department of Environmental Sciences and Engineering, Gillings School of Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Amanda Lai
- Department of Environmental Sciences and Engineering, Gillings School of Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Juhee Kim
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Ching-Hua Huang
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Aaron Bivins
- Department of Civil & Environmental Engineering, Louisiana State University, Baton Rouge, LA, USA
| | - Joe Brown
- Department of Environmental Sciences and Engineering, Gillings School of Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| |
Collapse
|
4
|
Capone D, Bakare T, Barker T, Chatham AH, Clark R, Copperthwaite L, Flemister A, Geason R, Hoos E, Kim E, Manoj A, Pomper S, Samodal C, Smith S, Poole C, Brown J. Risk Factors for Enteric Pathogen Exposure among Children in Black Belt Region of Alabama, USA. Emerg Infect Dis 2023; 29. [PMID: 37987604 PMCID: PMC10683812 DOI: 10.3201/eid2912.230780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2023] Open
Abstract
We collected stool from school-age children from 352 households living in the Black Belt region of Alabama, USA, where sanitation infrastructure is lacking. We used quantitative reverse transcription PCR to measure key pathogens in stool that may be associated with water and sanitation, as an indicator of exposure. We detected genes associated with > 1 targets in 26% of specimens, most frequently Clostridioides difficile (6.6%), atypical enteropathogenic Escherichia coli (6.1%), and enteroaggregative E. coli (3.9%). We used generalized estimating equations to assess reported risk factors for detecting > 1 pathogen in stool. We found no association between lack of sanitation and pathogen detection (adjusted risk ratio 0.95 [95% CI 0.55–1.7]) compared with specimens from children served by sewerage. However, we did observe an increased risk for pathogen detection among children living in homes with well water (adjusted risk ratio 1.7 [95% CI 1.1–2.5]) over those reporting water utility service.
Collapse
|
5
|
Capone D, Bivins A, Brown J. Producing ratio measures of effect with quantitative microbial risk assessment. RISK ANALYSIS : AN OFFICIAL PUBLICATION OF THE SOCIETY FOR RISK ANALYSIS 2023. [PMID: 35689350 DOI: 10.17605/osf.io/jwzy9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Estimating the risk of infections or other outcomes incident to pathogen exposure is a primary goal of quantitative microbial risk assessment (QMRA). Such estimates are useful to predict population-level risks, to evaluate exposures based on normative or tolerable risk guidelines, and to interpret the likely public health relevance of microbial measurements in environmental media. To evaluate alternative control measures (interventions), ratio estimates of effect (e.g., odds and risk ratios) are needed that are more broadly interpretable in the health sciences and consistent with convention in epidemiology. In this paper, we propose a general method for estimating widely used ratio measures of effect derived from stochastic QMRA approaches, including the generation of appropriate confidence intervals. Such QMRA-derived ratios can be used as a basis for evaluating interventions via hypothesis testing and for inclusion in systematic reviews and meta-analyses in a form consistent with risk estimation approaches commonly used in epidemiology.
Collapse
Affiliation(s)
- Drew Capone
- Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Aaron Bivins
- Department of Civil & Environmental Engineering, Louisiana State University, Baton Rouge, Louisiana, USA
| | - Joe Brown
- Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| |
Collapse
|
6
|
Capone D, Bivins A, Brown J. Producing ratio measures of effect with quantitative microbial risk assessment. RISK ANALYSIS : AN OFFICIAL PUBLICATION OF THE SOCIETY FOR RISK ANALYSIS 2023; 43:917-927. [PMID: 35689350 PMCID: PMC9734285 DOI: 10.1111/risa.13972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 05/12/2022] [Accepted: 05/12/2022] [Indexed: 05/06/2023]
Abstract
Estimating the risk of infections or other outcomes incident to pathogen exposure is a primary goal of quantitative microbial risk assessment (QMRA). Such estimates are useful to predict population-level risks, to evaluate exposures based on normative or tolerable risk guidelines, and to interpret the likely public health relevance of microbial measurements in environmental media. To evaluate alternative control measures (interventions), ratio estimates of effect (e.g., odds and risk ratios) are needed that are more broadly interpretable in the health sciences and consistent with convention in epidemiology. In this paper, we propose a general method for estimating widely used ratio measures of effect derived from stochastic QMRA approaches, including the generation of appropriate confidence intervals. Such QMRA-derived ratios can be used as a basis for evaluating interventions via hypothesis testing and for inclusion in systematic reviews and meta-analyses in a form consistent with risk estimation approaches commonly used in epidemiology.
Collapse
Affiliation(s)
- Drew Capone
- University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Aaron Bivins
- Louisiana State University, Baton Rouge, Louisiana, USA
| | - Joe Brown
- University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| |
Collapse
|
7
|
Capone D, Adriano Z, Cumming O, Irish SR, Knee J, Nala R, Brown J. Urban Onsite Sanitation Upgrades and Synanthropic Flies in Maputo, Mozambique: Effects on Enteric Pathogen Infection Risks. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:549-560. [PMID: 36516327 PMCID: PMC9835884 DOI: 10.1021/acs.est.2c06864] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 11/30/2022] [Accepted: 11/30/2022] [Indexed: 06/17/2023]
Abstract
Synanthropic filth flies transport enteric pathogens from feces to food, which upon consumption poses an infection risk. We evaluated the effect of an onsite sanitation intervention─including fly control measures─in Maputo, Mozambique, on the risk of infection from consuming fly-contaminated food. After enumerating flies at intervention and control sites, we cultured fecal indicator bacteria, quantified gene copies for 22 enteric pathogens via reverse transcription quantitative polymerase chain reaction (RT-qPCR), and developed quantitative microbial risk assessment (QMRA) models to estimate annual risks of infection attributable to fly-contaminated foods. We found that the intervention reduced fly counts at latrine entrances by 69% (aRR = 0.31, [0.13, 0.75]) but not at food preparation areas (aRR = 0.92, [0.33, 2.6]). Half of (23/46) of individual flies were positive for culturable Escherichia coli, and we detected ≥1 pathogen gene from 45% (79/176) of flies, including enteropathogenic E. coli (37/176), adenovirus (25/176), Giardia spp. (13/176), and Trichuris trichiura (12/176). We detected ≥1 pathogen gene from half the flies caught in control (54%, 30/56) and intervention compounds (50%, 17/34) at baseline, which decreased 12 months post-intervention to 43% (23/53) at control compounds and 27% (9/33) for intervention compounds. These data indicate flies as a potentially important mechanical vector for enteric pathogen transmission in this setting. The intervention may have reduced the risk of fly-mediated enteric infection for some pathogens, but infrequent detection resulted in wide confidence intervals; we observed no apparent difference in infection risk between groups in a pooled estimate of all pathogens assessed (aRR = 0.84, [0.61, 1.2]). The infection risks posed by flies suggest that the design of sanitation systems and service delivery should include fly control measures to prevent enteric pathogen transmission.
Collapse
Affiliation(s)
- Drew Capone
- Department
of Environmental and Occupational Health, School of Public Health, Indiana University, 2719 E 10th St, Bloomington, Indiana47401, United States
| | - Zaida Adriano
- WE
Consult ltd, 177 Rua
Tomas Ribeiro, Maputo1102, Mozambique
| | - Oliver Cumming
- Department
of Disease Control, London School of Hygiene
and Tropical Medicine, LondonWC1E 7HT, United
Kingdom
| | - Seth R. Irish
- Epidemiology
and Public Health Department, Swiss Tropical
and Public Health Institute, Kreuzstrasse 2, Allschwil4123, Switzerland
| | - Jackie Knee
- Department
of Disease Control, London School of Hygiene
and Tropical Medicine, LondonWC1E 7HT, United
Kingdom
| | - Rassul Nala
- Ministério
da Saúde, Instituto Nacional de Saúde
Maputo, Maputo1102, Mozambique
| | - Joe Brown
- Department
of Environmental Sciences and Engineering, Gillings School of Public
Health, University of North Carolina at
Chapel Hill, Chapel
Hill, North Carolina27599, United States
| |
Collapse
|
8
|
Capone D, Barker T, Cumming O, Flemister A, Geason R, Kim E, Knee J, Linden Y, Manga M, Meldrum M, Nala R, Smith S, Brown J. Persistent Ascaris Transmission Is Possible in Urban Areas Even Where Sanitation Coverage Is High. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:15969-15980. [PMID: 36288473 PMCID: PMC9671051 DOI: 10.1021/acs.est.2c04667] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 10/13/2022] [Accepted: 10/14/2022] [Indexed: 06/16/2023]
Abstract
In low-income, urban, informal communities lacking sewerage and solid waste services, onsite sanitation (sludges, aqueous effluent) and child feces are potential sources of human fecal contamination in living environments. Working in informal communities of urban Maputo, Mozambique, we developed a quantitative, stochastic, mass-balance approach to evaluate plausible scenarios of localized contamination that could explain why the soil-transmitted helminth Ascaris remains endemic despite nearly universal coverage of latrines that sequester most fecal wastes. We used microscopy to enumerate presumptively viable Ascaris ova in feces, fecal sludges, and soils from compounds (i.e., household clusters) and then constructed a steady-state mass-balance model to evaluate possible contamination scenarios capable of explaining observed ova counts in soils. Observed Ascaris counts (mean = -0.01 log10 ova per wet gram of soil, sd = 0.71 log10) could be explained by deposits of 1.9 grams per day (10th percentile 0.04 grams, 90th percentile 84 grams) of child feces on average, rare fecal sludge contamination events that transport 17 kg every three years (10th percentile 1.0 kg, 90th percentile 260 kg), or a daily discharge of 2.7 kg aqueous effluent from an onsite system (10th percentile 0.09 kg, 90th percentile 82 kg). Results suggest that even limited intermittent flows of fecal wastes in this setting can result in a steady-state density of Ascaris ova in soils capable of sustaining transmission, given the high prevalence of Ascaris shedding by children (prevalence = 25%; mean = 3.7 log10 per wet gram, sd = 1.1 log10), the high Ascaris ova counts in fecal sludges (prevalence = 88%; mean = 1.8 log10 per wet gram, sd = 0.95 log10), and the extended persistence and viability of Ascaris ova in soils. Even near-universal coverage of onsite sanitation may allow for sustained transmission of Ascaris under these conditions.
Collapse
Affiliation(s)
- Drew Capone
- Department
of Environmental and Occupational Health, School of Public Health, Indiana University, Bloomington, Indiana47401, United States
| | - Troy Barker
- Department
of Environmental Sciences and Engineering, Gillings School of Public
Health, University of North Carolina at
Chapel Hill, Chapel
Hill, North Carolina27599, United States
| | - Oliver Cumming
- Department
of Disease Control, London School of Hygiene
and Tropical Medicine, LondonWC1E 7HT, U.K.
| | - Abeoseh Flemister
- Department
of Biology, University of North Carolina
at Chapel Hill, Chapel
Hill, North Carolina27599, United States
| | - Riley Geason
- Department
of Biology, University of North Carolina
at Chapel Hill, Chapel
Hill, North Carolina27599, United States
| | - Elizabeth Kim
- Department
of Biology, University of North Carolina
at Chapel Hill, Chapel
Hill, North Carolina27599, United States
| | - Jackie Knee
- Department
of Disease Control, London School of Hygiene
and Tropical Medicine, LondonWC1E 7HT, U.K.
| | - Yarrow Linden
- Department
of Environmental Sciences and Engineering, Gillings School of Public
Health, University of North Carolina at
Chapel Hill, Chapel
Hill, North Carolina27599, United States
| | - Musa Manga
- Department
of Environmental Sciences and Engineering, Gillings School of Public
Health, University of North Carolina at
Chapel Hill, Chapel
Hill, North Carolina27599, United States
| | - Mackenzie Meldrum
- Department
of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia30332, United States
| | - Rassul Nala
- Ministério
da Saúde, Instituto Nacional de Saúde
Maputo, Maputo1102, Mozambique
| | - Simrill Smith
- Department
of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia30332, United States
| | - Joe Brown
- Department
of Environmental Sciences and Engineering, Gillings School of Public
Health, University of North Carolina at
Chapel Hill, Chapel
Hill, North Carolina27599, United States
| |
Collapse
|
9
|
Geophagic Materials Characterization and Potential Impact on Human Health: The Case Study of Maputo City (Mozambique). APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12104832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
This study aims to characterize and estimate risk assessment associated with geophagic materials consumption in Maputo city (Mozambique). Samples were collected in extraction mines, unprepared and prepared ones, and in Maputo markets. Fractions < 2 mm (total consumed material) and <63 μm were analyzed to determine pH, EC, OM, chemical composition (XRF), and mineral phases present (XRD). The results revealed pH from slightly acidic to slightly alkaline, and electrical conductivity ranging from 13 to 47 μS/cm in mine unprepared and prepared samples, while 264–465 μS/cm in sampled sold in markets. Organic matter content was <2.76%, except in one sample (8.14%), suggesting a potential risk of containing bacteria. Textural analysis revealed that sand-size particles were more representative in all samples (57.2–93.02%). Mineralogical phases identified in the consumed sample were ranked quartz (>60%) > Fe oxides/hidroxides > phyllosilicates (micas and kaolinite) > feldspars, suggesting a risk of dental enamel damage and perforation of the sigmoid colon. The chemical concentration of some elements was higher than recommended daily dose, suggesting a potential risk. However, geophagic materials’ chemical composition does not pose a carcinogenic risk.
Collapse
|
10
|
Espira L, Aung T, Han K, Jagger P, Eisenberg JNS. Determinants of Pathogen Contamination of the Environment in the Greater Yangon Area, Myanmar. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:16465-16476. [PMID: 34792323 DOI: 10.1021/acs.est.1c02887] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Recent results from water, sanitation, and hygiene interventions highlight the need to better understand environmental influences on enteropathogen transmission. We quantified a range of viral, bacterial, and protozoal pathogens and one indicator, Enterococcus faecalis in soil and water from urban and rural sites in and around Yangon, Myanmar. We found that environmental characteristics associated with contamination differed by pathogens and substrates. In soil, bacterial pathogen gene counts were associated with elevation and drainage ditches (compared to stagnant water) (RR = 0.96, 95% CI 0.93, 0.99 and RR = 1.70, 95% CI 1.18, 2.45, respectively), while viral gene counts were associated with the presence of sanitation facilities within 50 m of the collection point (RR = 3.99, 95% CI 1.12, 14.24). In water, E. faecalis, total pathogen, and bacterial pathogen gene counts were associated with drainage ditches (RR = 1.86, 95% CI 1.27, 2.72, RR = 1.38 95% CI 1.09, 1.74, and RR = 1.38 95% CI 1.07, 1.77, respectively). E. faecalis, total pathogen, bacterial pathogen, and viral gene counts were associated with the presence of uncollected garbage within 50 m of the collection point (RR = 1.57, 95% CI 1.00, 2.47, RR = 1.52, 95% CI 1.16, 2.00, RR = 1.52, 95% CI 1.13, 2.06, and RR = 1.75, 95% CI 1.17, 2.61 respectively). Measuring the environment provides added specificity toward identifying important environmental pathways that require mitigation.
Collapse
Affiliation(s)
- Leon Espira
- Department of Epidemiology, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Ther Aung
- Carolina Population Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27516, United States
| | - Khin Han
- Department of Geography, West Yangon University, Yangon 13393, Myanmar
| | - Pamela Jagger
- School for Environment and Sustainability, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Joseph N S Eisenberg
- Department of Epidemiology, University of Michigan, Ann Arbor, Michigan 48109, United States
| |
Collapse
|
11
|
Platts-Mills JA, Rogawski McQuade ET. Shigellosis in young children in low-income and middle-income countries: insights from molecular diagnostics. Curr Opin Infect Dis 2021; 34:463-470. [PMID: 34261903 DOI: 10.1097/qco.0000000000000758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE OF REVIEW To describe the impact of molecular diagnostics on our understanding of the burden and epidemiology of shigellosis in children in low-income and middle-income countries. RECENT FINDINGS The incorporation of molecular diagnostics has led to a substantial increase in estimates of the burden of shigellosis and have allowed for further resolution of other aspects of Shigella epidemiology, including the clinical characteristics of shigellosis, the association between clinical and subclinical Shigella infection and linear growth shortfalls, protection after natural infection, duration of convalescent shedding, and host determinants of susceptibility. SUMMARY The increased sensitivity and precision afforded by molecular approaches has represented a major advance in our understanding of the epidemiology and burden of shigellosis in the settings of highest importance.
Collapse
Affiliation(s)
- James A Platts-Mills
- Division of Infectious Diseases and International Health, University of Virginia Health System, Charlottesville, Virginia, USA
| | | |
Collapse
|
12
|
Capone D, Berendes D, Cumming O, Holcomb D, Knee J, Konstantinidis KT, Levy K, Nalá R, Risk BB, Stewart J, Brown J. Impact of an Urban Sanitation Intervention on Enteric Pathogen Detection in Soils. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:9989-10000. [PMID: 34236178 PMCID: PMC8327413 DOI: 10.1021/acs.est.1c02168] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Environmental fecal contamination is common in many low-income cities, contributing to a high burden of enteric infections and associated negative sequelae. To evaluate the impact of a shared onsite sanitation intervention in Maputo, Mozambique on enteric pathogens in the domestic environment, we collected 179 soil samples at shared latrine entrances from intervention (n = 49) and control (n = 51) compounds during baseline (preintervention) and after 24 months (postintervention) as part of the Maputo Sanitation Trial. We tested soils for the presence of nucleic acids associated with 18 enteric pathogens using a multiplex reverse transcription qPCR platform. We detected at least one pathogen-associated gene target in 91% (163/179) of soils and a median of 3 (IQR = 1, 5) pathogens. Using a difference-in-difference analysis and adjusting for compound population, visibly wet soil, sun exposure, wealth, temperature, animal presence, and visible feces, we estimate the intervention reduced the probability of detecting ≥1 pathogen gene by 15% (adjusted prevalence ratio, aPR = 0.85; 95% CI: 0.70, 1.0) and the total number of pathogens by 35% (aPR = 0.65; 0.44, 0.95) in soil 24 months following the intervention. These results suggest that the intervention reduced the presence of some fecal contamination in the domestic environment, but pathogen detection remained prevalent 24 months following the introduction of new latrines.
Collapse
Affiliation(s)
- Drew Capone
- Department of Environmental Sciences and Engineering, Gillings School of Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - David Berendes
- Waterborne Disease Prevention Branch, Division of Foodborne, Waterborne, and Environmental Diseases, National Center for Emerging Zoonotic and Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Oliver Cumming
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - David Holcomb
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Jackie Knee
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Konstantinos T. Konstantinidis
- Civil and Environmental Engineering, Georgia Institute of Technology, 311 Ferst Drive, Atlanta, Georgia, United States of America
| | - Karen Levy
- Environmental and Occupational Health Sciences, University of Washington, 2980 15th Ave NE, Seattle, Washington, United States of America
| | - Rassul Nalá
- Ministério da Saúde, Instituto Nacional de Saúde Maputo, Maputo, Mozambique
| | - Benjamin B. Risk
- Department of Biostatistics and Bioinformatics, Emory University, Atlanta, Georgia, United States of America
| | - Jill Stewart
- Department of Environmental Sciences and Engineering, Gillings School of Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Joe Brown
- Department of Environmental Sciences and Engineering, Gillings School of Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| |
Collapse
|
13
|
Lei S, Chen S, Zhong Q. Digital PCR for accurate quantification of pathogens: Principles, applications, challenges and future prospects. Int J Biol Macromol 2021; 184:750-759. [PMID: 34171259 DOI: 10.1016/j.ijbiomac.2021.06.132] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 06/16/2021] [Accepted: 06/18/2021] [Indexed: 12/25/2022]
Abstract
Pathogens pose a severe threat to food safety and human health. The traditional methods for pathogen detection can't meet the growing diagnosis and control need. Digital PCR (dPCR) attracts a considerable attention for its ability to absolutely quantify pathogens with features of high selectivity, simplicity, accuracy and rapidity. The dPCR technique that achieves absolute quantification based on end-point measurement without standard curve offers a guideline for further genetic analysis and molecular diagnosis. It could contribute to the quantification of low level of nucleic acid, early detection and timely prevention of pathogenic diseases. In this review, 1442 publications about dPCR were selected and the detections of various pathogens by dPCR were reviewed comprehensively, including viruses, bacteria, parasites and fungi. A number of examples are cited to illustrate that dPCR is a new powerful tool with desired accuracy, sensitivity, and reproducibility for quantification of different types of pathogens. Moreover, the benefits, challenges and future prospects of the dPCR were also highlighted in this review.
Collapse
Affiliation(s)
- Shuwen Lei
- Guangdong Provincial Key Laboratory of Food Quality and Safety, College of Food Science, South China Agricultural University, Guangzhou 510642, China; Guangdong Laboratory of Lingnan Modern Agriculture, South China Agricultural University, Guangzhou 510642, China
| | - Song Chen
- Guangdong Provincial Key Laboratory of Food Quality and Safety, College of Food Science, South China Agricultural University, Guangzhou 510642, China; Guangdong Laboratory of Lingnan Modern Agriculture, South China Agricultural University, Guangzhou 510642, China
| | - Qingping Zhong
- Guangdong Provincial Key Laboratory of Food Quality and Safety, College of Food Science, South China Agricultural University, Guangzhou 510642, China; Guangdong Laboratory of Lingnan Modern Agriculture, South China Agricultural University, Guangzhou 510642, China.
| |
Collapse
|