1
|
Santarém VA, Panazzolo GK, Kmetiuk LB, Domingues OJ, Ferreira IB, de Souza Filho RT, Farinhas JH, Doline FR, Lescano SAZ, Biondo LM, Giuffrida R, Biondo AW, Fávero GM. One health approach to toxocariasis in quilombola communities of southern Brazil. Parasit Vectors 2023; 16:379. [PMID: 37872605 PMCID: PMC10594776 DOI: 10.1186/s13071-023-06010-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Accepted: 10/10/2023] [Indexed: 10/25/2023] Open
Abstract
BACKGROUND Toxocariasis has been listed among the most neglected parasitic diseases worldwide, with approximately one fifth of the global population exposed, particularly those living under poverty. In Brazil, communities of descendants of enslaved blacks (quilombola) have historically had some of the highest rates of vulnerability and poverty, characterized by lack of health assistance, poor quality of life, and nutritional insecurity. METHODS A cross-sectional sampling of quilombola individuals living in four communities of southern Brazil, as well as their dogs and the soil, was carried out from December 2021 to March 2022. Sociodemographic and other information such as water source, alimentary habits, and dog and cat ownership were gathered using a semi-structured questionnaire for assessing toxocariasis risk factors. Human serum samples were tested by ELISA for anti-Toxocara spp. IgG antibody detection was carried out on dog feces and hair, and soil samples were surveyed for presence of Toxocara spp. eggs. RESULTS Overall, 172/208 individuals (82.7%, 95% CI = 77.0-87.2) were seropositive, the highest seroprevalence rate to date in Brazil. Male gender (P = 0.029), educational level (P = 0.026), and drinking water source (P = 0.043) were associated with seropositivity by univariate analysis. Final logistic regression revealed increased odds (P = 0.017, OR = 7.6, 95% CI = 1.5-42.7) to have seropositivity in individuals > 50 years old (< 10 years old). As expected, individuals with soil contact were more likely seropositive (P = 0.038, OR = 4.4, 95% CI = 1.1-18.8). Although retrieved in only 5/96 (5.2%) dog feces, Toxocara spp. eggs were found in 18/60 (30.0%) soil samples. CONCLUSIONS The high vulnerability and seroprevalence observed in quilombola communities clearly demand a One Health approach for detection, monitoring, and prevention of infection by Toxocara spp. in both human and dog populations.
Collapse
Affiliation(s)
- Vamilton Alvares Santarém
- Graduate College of Animal Science, University of Western São Paulo, Presidente Prudente, São Paulo, Brazil
| | - Giovanni Kalempa Panazzolo
- Graduate College of Pharmaceutical Sciences, State University of Ponta Grossa, Ponta Grossa, Paraná, Brazil
| | - Louise Bach Kmetiuk
- Graduate College of Cellular and Molecular Biology, Federal University of Paraná, Curitiba, Paraná, Brazil
| | - Orlei José Domingues
- Graduate College of Pharmaceutical Sciences, State University of Ponta Grossa, Ponta Grossa, Paraná, Brazil
| | - Isabella Braghin Ferreira
- Graduate College of Animal Science, University of Western São Paulo, Presidente Prudente, São Paulo, Brazil
| | | | - João Henrique Farinhas
- Graduate College of Cellular and Molecular Biology, Federal University of Paraná, Curitiba, Paraná, Brazil
| | - Fernando Rodrigo Doline
- Graduate College of Cellular and Molecular Biology, Federal University of Paraná, Curitiba, Paraná, Brazil
| | | | - Leandro Meneguelli Biondo
- Brazilian Ministry of Science, Technology, and Innovation, National Institute of the Atlantic Forest (INMA), Santa Teresa, Espírito Santo, Brazil
- Interdisciplinary Graduate Studies, University of British Columbia, Kelowna, BC, Canada
| | - Rogério Giuffrida
- Graduate College of Animal Science, University of Western São Paulo, Presidente Prudente, São Paulo, Brazil
| | - Alexander Welker Biondo
- Graduate College of Cellular and Molecular Biology, Federal University of Paraná, Curitiba, Paraná, Brazil.
| | - Giovani Marino Fávero
- Graduate College of Pharmaceutical Sciences, State University of Ponta Grossa, Ponta Grossa, Paraná, Brazil
| |
Collapse
|
2
|
Santarém VA, Doline FR, Ferreira IB, Farinhas JH, Biondo LM, de Souza Filho RT, Pettan-Brewer C, Giuffrida R, Lescano SAZ, dos Santos AP, Kmetiuk LB, Biondo AW. One health approach to toxocariasis in Brazilian indigenous populations, their dogs, and soil contamination. Front Public Health 2023; 11:1220001. [PMID: 37744519 PMCID: PMC10517057 DOI: 10.3389/fpubh.2023.1220001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 08/25/2023] [Indexed: 09/26/2023] Open
Abstract
Introduction Although socioeconomic vulnerability and lifestyle factors may contribute to the transmission of Toxocara spp., no study has investigated indigenous populations in Brazil using the One Health approach. Methods Accordingly, this study assessed anti-Toxocara spp. antibodies in Brazilian indigenous people and healthcare professionals by enzyme-linked immunosorbent assay. Presence of Toxocara spp. eggs (feces and hair) in dogs as definitive hosts and in soil samples of the indigenous communities were also recovered and molecularly investigated. Results Overall, 342/463 (73.9%) indigenous individuals and 46/147 (31.3%) non-indigenous healthcare professionals were seropositive for Toxocara spp. In addition, T. canis eggs were retrieved from 9/194 (4.6%) dog fecal samples and 4/204 (2.0%) dog hair samples, mainly from the Paraná State communities (3/42; 7.1%). Soil contamination was observed only in the Paraná State communities (36/90; 40.0%), with the molecular detection of T. canis. River water consumption was also associated with indigenous seropositivity (Odds ratio, 11.4). Discussion Indigenous individuals in Paraná State communities were 2.72-fold more likely to be seropositive than those in São Paulo State, likely due to a lack of sanitary infrastructure. In this scenario, a primarily soil-transmitted disease may also have become waterborne, with embryonated eggs probably spread to water supplies by rain. Full-time healthcare professionals in daily contact with indigenous communities were 9.2-fold more likely to be seropositive than professionals who visited sporadically, suggesting exposure to Toxocara spp. during their work and raising health concerns. In addition, the findings herein showed a significantly higher seroprevalence in indigenous people than in healthcare workers (χ2 = 85.5; p < 0.0001), likely due to overtime exposure to Toxocara spp. In conclusion, Brazilian indigenous communities are highly exposed to toxocariasis, with poor infrastructure and contact with contaminated river water as associated risk factors and a higher risk of infection in healthcare professionals working full-time in these communities.
Collapse
Affiliation(s)
- Vamilton Alvares Santarém
- Graduate College in Animal Sciences, University of Western São Paulo (UNOESTE), Presidente Prudente, São Paulo, Brazil
| | - Fernando Rodrigo Doline
- Graduate College of Cell and Molecular Biology, Federal University of Paraná (UFPR), Curitiba, Paraná, Brazil
| | - Isabella Braghin Ferreira
- Graduate College in Animal Sciences, University of Western São Paulo (UNOESTE), Presidente Prudente, São Paulo, Brazil
| | - João Henrique Farinhas
- Graduate College of Cell and Molecular Biology, Federal University of Paraná (UFPR), Curitiba, Paraná, Brazil
| | - Leandro Meneguelli Biondo
- National Institute of the Atlantic Forest (INMA), Brazilian Ministry of Science, Technology, and Innovation, Santa Teresa, Espirito Santo, Brazil
| | | | - Christina Pettan-Brewer
- Department of Comparative Medicine, School of Medicine, University of Washington, Seattle, WA, United States
| | - Rogério Giuffrida
- Graduate College of Cell and Molecular Biology, Federal University of Paraná (UFPR), Curitiba, Paraná, Brazil
| | | | - Andrea Pires dos Santos
- Department of Comparative Pathobiology, Purdue University, West Lafayette, IN, United States
| | - Louise Bach Kmetiuk
- Department of Comparative Pathobiology, Purdue University, West Lafayette, IN, United States
| | - Alexander Welker Biondo
- Graduate College of Cell and Molecular Biology, Federal University of Paraná (UFPR), Curitiba, Paraná, Brazil
- Department of Comparative Pathobiology, Purdue University, West Lafayette, IN, United States
| |
Collapse
|
3
|
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
|
4
|
Tadege B, Mekonnen Z, Dana D, Sharew B, Dereje E, Loha E, Verweij JJ, Casaert S, Vlaminck J, Ayana M, Levecke B. Assessment of environmental contamination with soil-transmitted helminths life stages at school compounds, households and open markets in Jimma Town, Ethiopia. PLoS Negl Trop Dis 2022; 16:e0010307. [PMID: 35377880 PMCID: PMC9009776 DOI: 10.1371/journal.pntd.0010307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 04/14/2022] [Accepted: 03/07/2022] [Indexed: 11/19/2022] Open
Abstract
Background It remains largely unknown where and how infections with soil-transmitted helminths (STHs; Ascaris, Trichuris, Necator and Ancylostoma) occur. We therefore aimed to identify possible sources of infection by assessing the environmental contamination in an STH-endemic area. Methods We first performed a series of laboratory experiments designed to optimize a soil straining-flotation method to detect and quantify Ascaris and Trichuris eggs in soil, and to validate the diagnostic performance of the optimized method when followed by microscopy and qPCR. In a second phase, we applied this method to assess the level of STH contamination in 399 environmental samples collected from 10 school compounds, 50 households and 9 open markets in Jimma Town (Ethiopia). Subsequently, we explored associations between the environmental contamination and both the corresponding STH epidemiology at the level of the schools and the household characteristics. Finally, we assessed the knowledge, attitude and practice (KAP) towards STHs in school children. Principal findings Our soil straining-flotation method has an analytical sensitivity of 50 eggs per 100 grams of soil and egg recovery rate of 36.0% (Ascaris) and 8.0% (Trichuris). The analysis of field samples with both microscopy and qPCR revealed the presence of 8 different helminth species of medical importance, including but not limited to the human STHs. There was a significant association between the environmental contamination and prevalence of any STH infections at the school level only. The KAP indicated a lack of knowledge and awareness of STHs. Conclusions/Significance Our optimized straining-flotation method has a moderate diagnostic performance and revealed that life stages of helminths are ubiquitous in the environment, which might be due to the poor sanitary facilities at both the schools and the households, and a poor level of KAP towards STHs. Further research is required to gain more insights into the contribution of these life stages to transmission. The recent strategies to control the morbidity caused by intestinal worms have mainly been focusing on large scale deworming programs during which drugs are administered to at-risk populations. Although these large-scale deworming programs have been successful in reducing the disease burden, re-infection in the absence of other intervention measures is unavoidable. Although there is a consensus on how infections with intestinal worms are transmitted, it remains unclear where hot spots of infectious life stages can be found in endemic communities, which in turn impedes both the design and the validation of interventions that prevent (re-)infection. We optimized a laboratory method to detect life stages in soil samples and applied this method to examine soil contamination at school compounds, households and open markets in Jimma Town (Ethiopia). Finally, we assessed the household characteristics, and the knowledge, attitude, and practice towards intestinal worms among school children. Generally, our results indicated (i) a moderate performance of our laboratory method, (ii) the ubiquitous presence of life stages in the environment, (iii) a poor level of sanitary facilities at both the schools and the households and (iv) a poor level of knowledge, attitude and practices towards intestinal worms.
Collapse
Affiliation(s)
- Bamlaku Tadege
- School of Medicine, Hawassa University, Hawassa, Ethiopia
- School of Medical Laboratory Sciences, Jimma University, Jimma, Ethiopia
- Department of Translational Physiology, Infectiology and Public Health, Ghent University, Merelbeke, Belgium
- * E-mail: (BT); (BL)
| | - Zeleke Mekonnen
- School of Medical Laboratory Sciences, Jimma University, Jimma, Ethiopia
- Molecular Biology and NTDs Research Center, Jimma University, Jimma, Ethiopia
| | - Daniel Dana
- School of Medical Laboratory Sciences, Jimma University, Jimma, Ethiopia
- Molecular Biology and NTDs Research Center, Jimma University, Jimma, Ethiopia
| | - Bizuwarek Sharew
- School of Medical Laboratory Sciences, Jimma University, Jimma, Ethiopia
| | - Eden Dereje
- Molecular Biology and NTDs Research Center, Jimma University, Jimma, Ethiopia
| | - Eskindir Loha
- Chr. Michelsen Institute, Bergen, Norway
- Centre for International Health, University of Bergen, Bergen, Norway
| | - Jaco J. Verweij
- Microvida, Laboratory for Medical Microbiology and Immunology, Elisabeth-TweeSteden Hospital, Tilburg, The Netherlands
| | - Stijn Casaert
- Department of Translational Physiology, Infectiology and Public Health, Ghent University, Merelbeke, Belgium
| | - Johnny Vlaminck
- Department of Translational Physiology, Infectiology and Public Health, Ghent University, Merelbeke, Belgium
| | - Mio Ayana
- School of Medical Laboratory Sciences, Jimma University, Jimma, Ethiopia
- Department of Translational Physiology, Infectiology and Public Health, Ghent University, Merelbeke, Belgium
- Molecular Biology and NTDs Research Center, Jimma University, Jimma, Ethiopia
| | - Bruno Levecke
- Department of Translational Physiology, Infectiology and Public Health, Ghent University, Merelbeke, Belgium
- * E-mail: (BT); (BL)
| |
Collapse
|
5
|
Luca I, Ilie MS, Florea T, Olariu-Jurca A, Stancu A, Dărăbuş G. The Use of Pythium oligandrum in the Biological Control of Roundworm Infection in Dogs and Cats. Pathogens 2022; 11:pathogens11030367. [PMID: 35335690 PMCID: PMC8950547 DOI: 10.3390/pathogens11030367] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 03/15/2022] [Accepted: 03/16/2022] [Indexed: 12/04/2022] Open
Abstract
Pythium oligandrum is an oomycete used in veterinary medicine to treat dermatophytosis in animals. The ovicidal potential against various types of parasite eggs has not been investigated. Ascarids are very common in young animals and the resistance of eggs in the external environment is very high. A commercial product containing P. oligandrum was used in the present study. Its ovicidal action against Toxocara spp. eggs was investigated. Thus, two categories of media (soil and sandstone) were used, on which the ascarid eggs were dispersed. The commercial product was prepared as a solution and was applied according to the manufacturer. The treatment scheme indicated in case of animals with dermatophytosis was used. Thus, the external natural conditions were recreated in the laboratory, in order to establish whether there is any applicability for this oomycete in the biological control of some parasitic diseases. The results indicated an ovicidal action of Pythium oligandrum, supporting the prospects of its use in the decontamination methods of various surfaces or environments where ascarid eggs from carnivores are found.
Collapse
Affiliation(s)
- Iasmina Luca
- Department of Parasitology and Dermatology, Banat’s University of Agricultural Sciences and Veterinary Medicine “King Michael I of Romania” from Timisoara, Calea Aradului 119, 300645 Timisoara, Romania; (M.S.I.); (T.F.); (G.D.)
- Correspondence: ; Tel.: +40-728416063
| | - Marius Stelian Ilie
- Department of Parasitology and Dermatology, Banat’s University of Agricultural Sciences and Veterinary Medicine “King Michael I of Romania” from Timisoara, Calea Aradului 119, 300645 Timisoara, Romania; (M.S.I.); (T.F.); (G.D.)
| | - Tiana Florea
- Department of Parasitology and Dermatology, Banat’s University of Agricultural Sciences and Veterinary Medicine “King Michael I of Romania” from Timisoara, Calea Aradului 119, 300645 Timisoara, Romania; (M.S.I.); (T.F.); (G.D.)
| | - Adrian Olariu-Jurca
- Department of Pathological Anatomy and Forensic Medicine, Banat’s University of Agricultural Sciences and Veterinary Medicine “King Michael I of Romania” from Timisoara, Calea Aradului 119, 300645 Timisoara, Romania; (A.O.-J.); (A.S.)
| | - Adrian Stancu
- Department of Pathological Anatomy and Forensic Medicine, Banat’s University of Agricultural Sciences and Veterinary Medicine “King Michael I of Romania” from Timisoara, Calea Aradului 119, 300645 Timisoara, Romania; (A.O.-J.); (A.S.)
| | - Gheorghe Dărăbuş
- Department of Parasitology and Dermatology, Banat’s University of Agricultural Sciences and Veterinary Medicine “King Michael I of Romania” from Timisoara, Calea Aradului 119, 300645 Timisoara, Romania; (M.S.I.); (T.F.); (G.D.)
| |
Collapse
|
6
|
Papavasilopoulos V, Pitiriga V, Birbas K, Elefsiniotis J, Bonatsos G, Tsakris A. Soil contamination by Toxocara canis and human seroprevalence in the Attica region, Greece. Germs 2018; 8:155-161. [PMID: 30250835 DOI: 10.18683/germs.2018.1143] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 09/02/2018] [Accepted: 09/02/2018] [Indexed: 11/08/2022]
Abstract
Background Toxocara canis is one of the most widespread public health and economically important zoonotic parasitic infections humans share with canids, mainly dogs. Human infection occurs by the accidental ingestion of embryonated eggs or larvae from a range of wild and domestic paratenic hosts. The aim of the present study was to examine the soil contamination of public places by the parasitic ova and to estimate serologically the prevalence of T. canis human infection in the Attica region, Greece. Methods In this region, public areas are permanently inhabited by dogs, mostly stray dog population that is hardly kept down to a manageable level. A total of 1,510 soil samples were collected from 33 public places of six regional units of Attica from March 2014 to April 2014 and ova were detected using a microscopic assay. In addition, sera were collected from 250 residents, routinely active in the sampled areas, and tested for T. canis IgG antibodies using an enzyme immunoassay. Results T. canis eggs were isolated from 31 (94%) of the examined public areas. Of the total samples, T. canis ova were recovered from 258 samples, suggesting an overall T. canis ova contamination of 17.2%. The areas of higher socioeconomic status presented lower percentages of soil contamination in a statistically significant level, compared to the areas of lower socioeconomic status. T. canis IgG seropositivity was detected in 40 (16%) serum samples. Similar rates were established among T. canis seropositivity and soil contamination within the same geographical areas. The proportion of seropositive samples in the group of children was significantly higher compared to the proportion of adults (48% versus 8%, p<0.001). Conclusion The level of environmental T. canis contamination as well as human infection found in the Attica region calls for a greater awareness towards this public issue. Preventing measures should be implemented to control the spread of this parasitic infection.
Collapse
Affiliation(s)
| | - Vassiliki Pitiriga
- Assist Prof, Department of Microbiology, Medical School, National and Kapodistrian University of Athens, 75 Mikras Asias Street, 11527 Athens, Greece
| | - Konstantinos Birbas
- Assoc Prof, Faculty of Nursing, School of Public Health, National and Kapodistrian University of Athens, 123 Papadiamantopoulou Street, 11526 Athens, Greece
| | - John Elefsiniotis
- Assoc Prof, Faculty of Nursing, School of Public Health, National and Kapodistrian University of Athens, 123 Papadiamantopoulou Street, 11526 Athens, Greece
| | - Gerasimos Bonatsos
- Prof, Faculty of Nursing, School of Public Health, National and Kapodistrian University of Athens, 123 Papadiamantopoulou Street, 11526 Athens, Greece
| | - Athanasios Tsakris
- Prof, Department of Microbiology, Medical School, National and Kapodistrian University of Athens, 75 Mikras Asias Street, 11527 Athens, Greece
| |
Collapse
|
7
|
Amoah ID, Reddy P, Stenström TA. Effect of reagents used during detection and quantification of Ascaris suum in environmental samples on egg viability. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2017; 76:2389-2400. [PMID: 29144297 PMCID: PMC7797636 DOI: 10.2166/wst.2017.324] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Accepted: 05/15/2017] [Indexed: 06/07/2023]
Abstract
Soil-transmitted helminths (STHs) are a major health concern globally. Infection is mostly through contact with contaminated water, food or soil. Therefore to break the cycle of viable transmission STH eggs must be quantitatively detected in the environment. The effect of different reagents on the viability of Ascaris suum eggs during laboratory detection and quantification was assessed and different incubation solutions compared. Sulphuric acid gave a slightly higher recovery percentage of viable eggs (91.2%) than distilled water (90.0%) and 0.5% formalin (87.6%), although the difference was not statistically significant (p > 0.05). Acetoacetic acid, ethyl acetate, ammonium bicarbonate, zinc sulphate, magnesium sulphate and Tween 80, are reagents widely used in test protocols for the detection and quantification of STH eggs. Eggs were exposed to these reagents for different time durations. Acetoacetic acid resulted in the highest loss of viability (3.4 ± 0.7% viable), while magnesium sulphate resulted in the least effect (88.5 ± 1.2% viable). In conclusion the use of the selected reagents in the detection of these eggs was found to affect the viability of exposed eggs, especially during prolonged exposures. Therefore we recommended that eggs be exposed for ≤5 minutes, to reduce the risk of viability loss.
Collapse
Affiliation(s)
- Isaac Dennis Amoah
- Institute for Water and Wastewater Technology, Durban University of Technology, P.O. Box 1334, Durban 4000, South Africa E-mail: ; Department of Community Health Studies, Faculty of Health Sciences, Durban University of Technology, P.O. Box 1334, Durban 4000, South Africa
| | - Poovendhree Reddy
- Department of Community Health Studies, Faculty of Health Sciences, Durban University of Technology, P.O. Box 1334, Durban 4000, South Africa
| | - Thor Axel Stenström
- Institute for Water and Wastewater Technology, Durban University of Technology, P.O. Box 1334, Durban 4000, South Africa E-mail:
| |
Collapse
|
8
|
Detection and quantification of soil-transmitted helminths in environmental samples: A review of current state-of-the-art and future perspectives. Acta Trop 2017; 169:187-201. [PMID: 28214519 DOI: 10.1016/j.actatropica.2017.02.014] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Revised: 02/06/2017] [Accepted: 02/10/2017] [Indexed: 12/20/2022]
Abstract
It is estimated that over a billion people are infected with soil-transmitted helminths (STHs) globally with majority occurring in tropical and subtropical regions of the world. The roundworm (Ascaris lumbricoides), whipworm (Trichuris trichiura), and hookworms (Ancylostoma duodenale and Necator americanus) are the main species infecting people. These infections are mostly gained through exposure to faecally contaminated water, soil or contaminated food and with an increase in the risk of infections due to wastewater and sludge reuse in agriculture. Different methods have been developed for the detection and quantification of STHs eggs in environmental samples. However, there is a lack of a universally accepted technique which creates a challenge for comparative assessments of helminths egg concentrations both in different samples matrices as well as between locations. This review presents a comparison of reported methodologies for the detection of STHs eggs, an assessment of the relative performance of available detection methods and a discussion of new emerging techniques that could be applied for detection and quantification. It is based on a literature search using PubMed and Science Direct considering all geographical locations. Original research articles were selected based on their methodology and results sections. Methods reported in these articles were grouped into conventional, molecular and emerging techniques, the main steps in each method were then compared and discussed. The inclusion of a dissociation step aimed at detaching helminth eggs from particulate matter was found to improve the recovery of eggs. Additionally the selection and application of flotation solutions that take into account the relative densities of the eggs of different species of STHs also results in higher egg recovery. Generally the use of conventional methods was shown to be laborious and time consuming and prone to human error. The alternate use of nucleic acid-based techniques has improved the sensitivity of detection and made species specific identification possible. However, these nucleic acid based methods are expensive and less suitable in regions with limited resources and skill. The loop mediated isothermal amplification method shows promise for application in these settings due to its simplicity and use of basic equipment. In addition, the development of imaging soft-ware for the detection and quantification of STHs shows promise to further reduce human error associated with the analysis of environmental samples. It may be concluded that there is a need to comparatively assess the performance of different methods to determine their applicability in different settings as well as for use with different sample matrices (wastewater, sludge, compost, soil, vegetables etc.).
Collapse
|
9
|
Collender PA, Kirby AE, Addiss DG, Freeman MC, Remais JV. Methods for Quantification of Soil-Transmitted Helminths in Environmental Media: Current Techniques and Recent Advances. Trends Parasitol 2015; 31:625-639. [PMID: 26440788 DOI: 10.1016/j.pt.2015.08.007] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Revised: 08/12/2015] [Accepted: 08/14/2015] [Indexed: 12/24/2022]
Abstract
Limiting the environmental transmission of soil-transmitted helminths (STHs), which infect 1.5 billion people worldwide, will require sensitive, reliable, and cost-effective methods to detect and quantify STHs in the environment. We review the state-of-the-art of STH quantification in soil, biosolids, water, produce, and vegetation with regard to four major methodological issues: environmental sampling; recovery of STHs from environmental matrices; quantification of recovered STHs; and viability assessment of STH ova. We conclude that methods for sampling and recovering STHs require substantial advances to provide reliable measurements for STH control. Recent innovations in the use of automated image identification and developments in molecular genetic assays offer considerable promise for improving quantification and viability assessment.
Collapse
Affiliation(s)
- Philip A Collender
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, USA
| | - Amy E Kirby
- Center for Global Safe Water, Hubert Department of Global Health, Rollins School of Public Health, Emory University, Atlanta, GA, USA
| | | | - Matthew C Freeman
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, USA.
| | - Justin V Remais
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, USA
| |
Collapse
|
10
|
Etewa SE, Abdel-Rahman SA, Abd El-Aal NF, Fathy GM, El-Shafey MA, Ewis AMG. Geohelminths distribution as affected by soil properties, physicochemical factors and climate in Sharkyia governorate Egypt. J Parasit Dis 2014; 40:496-504. [PMID: 27413327 DOI: 10.1007/s12639-014-0532-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2014] [Accepted: 08/12/2014] [Indexed: 10/24/2022] Open
Abstract
Soil-transmitted helminths are mainly a group of parasitic nematodes causing human infection through contact with parasite eggs or larvae; they survive in the warm and moist soil of the tropical and subtropical countries. This study was carried out in Sharkyia governorate from October, 2011 to October, 2013, to correlate between the prevalence and distribution of these parasites in the soil and the physicochemical factors affecting the examined samples of the soil. One hundred and twenty samples of different types of soil (clay, silt, sand) from different localities were collected and examined. Diagnosis of geohelminths was confirmed by the recovery of their eggs and larvae with other protozoa by different parasitological methods. The modified baermann method was found to be more efficient in detection of geohelminths larvae than charcoal culture method. Among the examined sites geohelminths were much more numerous in the soil of rural areas especially in the spring and summer seasons, while the contamination of canal banks by geohelminths was the worst (80 %). An insignificant correlation was reported between the soil texture and the number of positive samples in the examined areas while the relationship was directly proportional among (moisture, PH, organic). It appeared that the most common geohelminthic stage was Toxocara spp. eggs besides other types of protozoa especially Balantidium coli cysts. This suggests that factors other than soil texture are important in the prevalence of geohelminths in the soil e.g. temperature, moisture, PH and organic matter. So, to change some of these factors in a trial to control geoparasites transmission but with keeping the environment should be tried. These results also open the way to further studies to highlight the mutual affection between inhabitants of these sites and the prevalence of these geoparasites.
Collapse
Affiliation(s)
- Samia E Etewa
- Medical Parasitological Department, Faculty of Medicine, Zagazig University, Sharkyia, Egypt
| | - Sara A Abdel-Rahman
- Medical Parasitological Department, Faculty of Medicine, Zagazig University, Sharkyia, Egypt
| | - Naglaa F Abd El-Aal
- Medical Parasitological Department, Faculty of Medicine, Zagazig University, Sharkyia, Egypt
| | - Ghada M Fathy
- Medical Parasitological Department, Faculty of Medicine, Zagazig University, Sharkyia, Egypt
| | - Mahmoud A El-Shafey
- Clinical Pathology Department, Faculty of Medicine, Zagazig University, Sharkyia, Egypt
| | - A M G Ewis
- Soil and Water Department, Faculty of Technology, Development, Zagazig University, Sharkyia, Egypt
| |
Collapse
|
11
|
Geohelminth egg contamination of children's play areas in the city of Lodz (Poland). Vet Parasitol 2013; 192:228-33. [DOI: 10.1016/j.vetpar.2012.09.033] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2012] [Revised: 09/19/2012] [Accepted: 09/21/2012] [Indexed: 11/23/2022]
|
12
|
Recovery of Toxocara canis eggs from soil. Vet Parasitol 2010; 168:175. [DOI: 10.1016/j.vetpar.2009.11.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2009] [Accepted: 11/24/2009] [Indexed: 11/20/2022]
|