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Soultani M, Bartlett AW, Mendes EP, Hii SF, Traub R, Palmeirim MS, Lufunda LMM, Colella V, Lopes S, Vaz Nery S. Estimating Prevalence and Infection Intensity of Soil-Transmitted Helminths Using Quantitative Polymerase Chain Reaction and Kato-Katz in School-Age Children in Angola. Am J Trop Med Hyg 2024; 110:1145-1151. [PMID: 38688261 PMCID: PMC11154060 DOI: 10.4269/ajtmh.23-0821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Accepted: 01/31/2024] [Indexed: 05/02/2024] Open
Abstract
Quantitative polymerase chain reaction (qPCR) is gaining recognition in soil-transmitted helminth (STH) diagnostics, especially for Strongyloides stercoralis and differentiating hookworm species. However, sample preservation and DNA extraction may influence qPCR performance. We estimated STH prevalence and infection intensity by using qPCR in schoolchildren from Huambo, Uige, and Zaire, Angola, and compared its performance with that of the Kato-Katz technique (here termed Kato-Katz). Stool samples from 3,063 children (219 schools) were preserved in 96% ethanol and analyzed by qPCR, of which 2,974 children (215 schools) had corresponding Kato-Katz results. Cluster-adjusted prevalence and infection intensity estimates were calculated by qPCR and Kato-Katz, with cycle threshold values converted to eggs per gram for qPCR. Cohen's kappa statistic evaluated agreement between qPCR and Kato-Katz. DNA extraction and qPCR were repeated on 191 (of 278) samples that were initially qPCR negative but Kato-Katz positive, of which 112 (58.6%) became positive. Similar prevalence for Ascaris lumbricoides (37.5% versus 34.6%) and Trichuris trichiura (6.5% versus 6.1%) were found by qPCR and Kato-Katz, respectively, while qPCR detected a higher hookworm prevalence (11.9% versus 2.9%). The prevalence of moderate- or high-intensity infections was higher by Kato-Katz than by qPCR. Agreement between qPCR and Kato-Katz was very good for A. lumbricoides, moderate for T. trichiura, and fair for hookworm. Strongyloides stercoralis prevalence was 4.7% (municipality range, 0-14.3%), and no Ancylostoma ceylanicum was detected by qPCR. Despite suboptimal performance, presumably due to fixative choice, qPCR was fundamental in detecting S. stercoralis and excluding zoonotic A. ceylanicum. Further evaluations on sample fixatives and DNA extraction methods are needed to optimize and standardize the performance of qPCR.
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Affiliation(s)
- Muzhgan Soultani
- School of Population Health, University of New South Wales, Sydney, Australia
| | - Adam W. Bartlett
- Kirby Institute, University of New South Wales, Sydney, Australia
| | - Elsa P. Mendes
- National Directorate of Public Health, Ministry of Health, Luanda, Angola
| | - Sze Fui Hii
- Faculty of Science, University of Melbourne, Parkville, Australia
| | - Rebecca Traub
- Faculty of Science, University of Melbourne, Parkville, Australia
| | - Marta S. Palmeirim
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
| | | | - Vito Colella
- Faculty of Science, University of Melbourne, Parkville, Australia
| | | | - Susana Vaz Nery
- Kirby Institute, University of New South Wales, Sydney, Australia
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Mugo RM, Rausch S, Musimbi ZD, Strube C, Raulf MK, Landt O, Gichuki PM, Ebner F, Mwacharo J, Odiere MR, Ndungu FM, Njomo DW, Hartmann S. Evaluation of copromicroscopy, multiplex-qPCR and antibody serology for monitoring of human ascariasis in endemic settings. PLoS Negl Trop Dis 2024; 18:e0012279. [PMID: 38889190 PMCID: PMC11216587 DOI: 10.1371/journal.pntd.0012279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 07/01/2024] [Accepted: 05/27/2024] [Indexed: 06/20/2024] Open
Abstract
BACKGROUND The standard diagnosis of Ascaris lumbricoides and other soil-transmitted helminth (STH) infections relies on the detection of worm eggs by copromicroscopy. However, this method is dependent on worm patency and shows only limited accuracy in low-intensity infection settings. We aimed to decipher the diagnostic accuracy of different antibodies using various Ascaris antigens in reference to copromicroscopy and quantitative PCR (qPCR), four months after national STH preventative chemotherapy among school children in western Kenya. METHODOLOGY STH infection status of 390 school children was evaluated via copromicroscopy (Kato-Katz and mini-FLOTAC) and qPCR. In parallel, Ascaris-specific antibody profiles against larval and adult worm lysates, and adult worm excretory-secretory (ES) products were determined by enzyme-linked immunosorbent assay. Antibody cross-reactivity was evaluated using the closely related zoonotic roundworm species Toxocara cati and Toxocara canis. The diagnostic accuracy of each antibody was evaluated using receiver operating curve analysis and the correspondent area under the curve (AUC). PRINCIPAL FINDINGS Ascaris was the predominant helminth infection with an overall prevalence of 14.9% (58/390). The sensitivity of mini-FLOTAC and Kato-Katz for Ascaris diagnosis reached only 53.5% and 63.8%, respectively compared to qPCR. Although being more sensitive, qPCR values correlated with microscopic egg counts (R = -0.71, P<0.001), in contrast to antibody levels. Strikingly, IgG antibodies recognizing the ES products of adult Ascaris worms reliably diagnosed active Ascaris infection as determined by qPCR and microscopy, with IgG1 displaying the highest accuracy (AUC = 0.83, 95% CI: 0.75-0.91). CONCLUSION IgG1 antibody responses against adult Ascaris-ES products hold a promising potential for complementing the standard fecal and molecular techniques employed for monitoring Ascaris infections. This is of particular importance in the context of deworming programs as the antibody diagnostic accuracy was independent of egg counts.
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Affiliation(s)
- Robert M. Mugo
- Institute of Immunology, Centre for Infection Medicine, Freie Universität Berlin, Berlin, Germany
| | - Sebastian Rausch
- Institute of Immunology, Centre for Infection Medicine, Freie Universität Berlin, Berlin, Germany
| | - Zaneta D. Musimbi
- Institute of Immunology, Centre for Infection Medicine, Freie Universität Berlin, Berlin, Germany
| | - Christina Strube
- Institute for Parasitology, Centre for Infection Medicine, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Marie-Kristin Raulf
- Institute for Parasitology, Centre for Infection Medicine, University of Veterinary Medicine Hannover, Hannover, Germany
| | | | - Paul M. Gichuki
- Eastern and Southern Africa Centre of International Parasite Control, Kenya Medical Research, Nairobi, Kenya
| | - Friederike Ebner
- Institute of Immunology, Centre for Infection Medicine, Freie Universität Berlin, Berlin, Germany
- Department of Molecular Life Sciences, School of Life Sciences, Technical University of Munich, Munich, Germany
| | | | - Maurice R. Odiere
- Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Francis M. Ndungu
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Doris W. Njomo
- Eastern and Southern Africa Centre of International Parasite Control, Kenya Medical Research, Nairobi, Kenya
| | - Susanne Hartmann
- Institute of Immunology, Centre for Infection Medicine, Freie Universität Berlin, Berlin, Germany
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Maddren R, Anderson RM. Measuring heterogeneities in soil-transmitted helminth transmission and control. Trends Parasitol 2024; 40:45-59. [PMID: 38087679 DOI: 10.1016/j.pt.2023.11.003] [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] [Received: 09/18/2023] [Revised: 11/08/2023] [Accepted: 11/08/2023] [Indexed: 01/06/2024]
Abstract
The global effort over the past decade to control soil-transmitted helminths (STH) has resulted in communities with endemic infection reaching low prevalence levels suitable for the validation of elimination as a public health problem (EPHP), defined by the World Health Organisation (WHO) as <2% of infections classified as moderate or heavy intensity. The spatial scale in which this is validated is currently undefined. As the burden of STH infection decreases, the degree of aggregation of infection within individuals in a population increases. Identifying these remaining pockets of infection requires fine-scale monitoring and evaluation (M&E) programmes that are rarely implemented within current national neglected tropical disease (NTD) control. This review examines various heterogeneities that characterise the epidemiology of STH infections, and discusses their impact on control policy formulation.
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Affiliation(s)
- Rosie Maddren
- Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, Imperial College London, London, UK.
| | - Roy M Anderson
- Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, Imperial College London, London, UK
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Gaidhane S, Gaidhane A, Khatib MN, Telrandhe S, Patil M, Saxena D, Bhardwaj P, Choudhari S, Zahiruddin QS. Estimation of the Parasitic Burden of Soil-Transmitted Helminths Among Pregnant Women in the Maharashtra State of India Using qPCR: A Community-Based Study. Indian J Community Med 2024; 49:157-164. [PMID: 38425985 PMCID: PMC10900441 DOI: 10.4103/ijcm.ijcm_249_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 11/01/2023] [Indexed: 03/02/2024] Open
Abstract
Background Soil-transmitted helminth (STH) infections are widespread in developing countries with inadequate sanitation facilities. These infections can lead to malnutrition, anemia, and other complications that can negatively impact both the mother's and fetus's health during pregnancy. This study aimed to estimate the burden of STH by Kato-Katz microscopy and quantitative polymerase chain reaction (qPCR) in pregnant women from rural India. The diagnostic accuracy of these two methods was also compared. Material and Methods A community-based cross-sectional study was conducted in rural areas of Wardha district of Maharashtra state. We randomly selected and interviewed 688 pregnant women. A total of 534 (77.61%) participants gave stool samples. Two containers (60 mL) labeled with a unique identification number were given to pregnant women to collect stool samples for Kato-Katz microscopy and qPCR. Stool specimens were transported to an accredited lab and examined within 24 hours. Suitable examinations were conducted to compare sensitivity between two tests. Results The results are presented for 534 participants who gave stool samples. The prevalence of any STH by Kato-Katz stool microscopy was 6.55% (95%CI 4.46-12.19), and that by qPCR was 20.41 (95%CI 17.53-29.40). The sensitivity of Kato-Katz microscopy was 29.17% compared to sensitivity of 90.83% by qPCR (P = 0.001). Pregnant women with STH infection have a significantly lower weight gain during pregnancy, and the majority were either mild or moderate anemic compared to those without STH. Conclusion The study highlighted significant differences in prevalence of STH among pregnant women by Kato-Katz microscopy and qPCR. The sensitivity of qPCR for detecting STH was higher than that of Kato-Katz microscopy.
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Affiliation(s)
- Shilpa Gaidhane
- Jawaharlal Nehru Medical College, Datta Meghe Institute of Higher Education and Research, Wardha, Maharashtra, India
| | - Abhay Gaidhane
- Centre of One Health, School of Epidemiology and Public Health, Jawaharlal Nehru Medical College, Datta Meghe Institute of Higher Education and Research, Wardha, Maharashtra, India
| | - Mahalaqua Nazli Khatib
- Global Evidence Synthesis Initiative, Division of Evidence Synthesis, Jawaharlal Nehru Medical College, Datta Meghe Institute of Higher Education and Research, Wardha, Maharashtra, India
| | - Shital Telrandhe
- Global Health Academy, Centre of Early Childhood Development - Stepping Stones Project, Wardha, Maharashtra, India
| | - Manoj Patil
- Global Health Consortium Public Health and Research, School of Epidemiology and Public Health, Jawaharlal Nehru Medical College, Datta Meghe Institute of Higher Education and Research, Wardha, Maharashtra, India
| | - Deepak Saxena
- i Health Consortium, Department of Epidemiology, Indian Institute of Public Health, Gandhinagar, Gujarat, India
| | - Pankaj Bhardwaj
- School of Public Health (SPH), Department of Community Medicine and Family Medicine, AIIMS, Jodhpur, Rajasthan, India
| | - Sonali Choudhari
- School of Epidemiology and Public Health, Jawaharlal Nehru Medical College, Datta Meghe Institute of Higher Education and Research, Wardha, Maharashtra, India
| | - Quazi S. Zahiruddin
- South Asia Infant Feeding Research Network (SAIFRN), School of Epidemiology and Public Health, Jawaharlal Nehru Medical College, Datta Meghe Institute of Higher Education and Research, Wardha, Maharashtra, India
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Ng'etich AI, Amoah ID, Bux F, Kumari S. Anthelmintic resistance in soil-transmitted helminths: One-Health considerations. Parasitol Res 2023; 123:62. [PMID: 38114766 PMCID: PMC10730643 DOI: 10.1007/s00436-023-08088-8] [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] [Received: 07/03/2023] [Accepted: 12/05/2023] [Indexed: 12/21/2023]
Abstract
The One-Health approach recognizes the intricate connection between human, animal, and environmental health, and that cooperative effort from various professionals provides comprehensive awareness and potential solutions for issues relating to the health of people, animals, and the environment. This approach has increasingly gained appeal as the standard strategy for tackling emerging infectious diseases, most of which are zoonoses. Treatment with anthelmintics (AHs) without a doubt minimizes the severe consequences of soil-transmitted helminths (STHs); however, evidence of anthelmintic resistance (AR) development to different helminths of practically every animal species and the distinct groups of AHs is overwhelming globally. In this regard, the correlation between the application of anthelmintic drugs in both human and animal populations and the consequent development of anthelmintic resistance in STHs within the context of a One-Health framework is explored. This review provides an overview of the major human and animal STHs, treatment of the STHs, AR development and drug-related factors contributing towards AR, One-Health and STHs, and an outline of some One-Health strategies that may be used in combating AR.
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Affiliation(s)
- Annette Imali Ng'etich
- Institute for Water and Wastewater Technology, Durban University of Technology (DUT), Durban, South Africa
| | - Isaac Dennis Amoah
- Institute for Water and Wastewater Technology, Durban University of Technology (DUT), Durban, South Africa
- Department of Environmental Science, University of Arizona, Tucson, AZ, USA
| | - Faizal Bux
- Institute for Water and Wastewater Technology, Durban University of Technology (DUT), Durban, South Africa
| | - Sheena Kumari
- Institute for Water and Wastewater Technology, Durban University of Technology (DUT), Durban, South Africa.
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Rotejanaprasert C, Chuaicharoen P, Prada JM, Thantithaveewat T, Adisakwattana P, Pan-ngum W. Evaluation of Kato-Katz and multiplex quantitative polymerase chain reaction performance for clinical helminth infections in Thailand using a latent class analysis. Philos Trans R Soc Lond B Biol Sci 2023; 378:20220281. [PMID: 37598708 PMCID: PMC10440171 DOI: 10.1098/rstb.2022.0281] [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] [Received: 10/29/2022] [Accepted: 05/27/2023] [Indexed: 08/22/2023] Open
Abstract
Using an appropriate diagnostic tool is essential to soil-transmitted helminth control and elimination efforts. Kato-Katz (KK) is the most commonly used diagnostic, but recently other tools, such as real-time quantitative polymerase chain reaction (multiplex qPCR), are starting to be employed more. Here, we evaluated the performance of these two diagnostic tools for five helminth species in Thailand. In the absence of a gold standard, diagnostic performance can be evaluated using latent class analysis. Our results suggest that in moderate to high prevalence settings above 2% multiplex qPCR could be more sensitive than KK, this was particularly apparent for Opisthorchis viverrini in the northeastern provinces. However, for low prevalence, both diagnostics suffered from low sensitivity. Specificity of both diagnostics was estimated to be high (above 70%) across all settings. For some specific helminth infection such as O. viverrini, multiplex qPCR is still a preferable choice of diagnostic test. KK performed equally well in detecting Ascaris lumbricoides and Taenia solium when the prevalence is moderate to high (above 2%). Neither test performed well when the prevalence of infection is low (below 2%), and certainly in the case for hookworm and Trichuris trichiura. Combination of two or more diagnostic tests can improve the performance although the cost would be high. Development of new methods for helminth surveillance at the pre-elimination phase is therefore very important. This article is part of the theme issue 'Challenges and opportunities in the fight against neglected tropical diseases: a decade from the London Declaration on NTDs'.
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Affiliation(s)
- Chawarat Rotejanaprasert
- Department of Tropical Hygiene, Mahidol University, Bangkok, Thailand
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Mahidol University, Bangkok, Thailand
| | | | - Joaquin M. Prada
- Faculty of Health and Medical Sciences, School of Veterinary Medicine, University of Surrey, Guildford, UK
| | | | - Poom Adisakwattana
- Department of Helminthology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Wirichada Pan-ngum
- Department of Tropical Hygiene, Mahidol University, Bangkok, Thailand
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Mahidol University, Bangkok, Thailand
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Chandrasena NTGA, Gunaratna IE, Ediriweera D, de Silva NR. Lymphatic filariases and soil-transmitted helminthiases in Sri Lanka: the challenge of eliminating residual pockets of transmission. Philos Trans R Soc Lond B Biol Sci 2023; 378:20220280. [PMID: 37598710 PMCID: PMC10440162 DOI: 10.1098/rstb.2022.0280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 04/06/2023] [Indexed: 08/22/2023] Open
Abstract
Sri Lanka has successfully met the challenge of controlling both lymphatic filariasis (LF) and soil-transmitted helminthiases (STH) as public health problems. The primary public health strategy for combatting both conditions has been preventive chemotherapy. The national programme for the elimination of LF implemented five annual rounds of mass chemotherapy in the endemic districts from 2002 to 2006 using a combination of diethylcarbamazine and albendazole. The overall microfilaria rate declined from 0.21% in 2001 before the mass chemotherapy, to 0.06% in 2016, at declaration of elimination of LF as a public health problem by the World Health Organization. Currently Sri Lanka is in the phase of post-validation surveillance. Achieving control of STH has been more difficult. Mass deworming programmes have been implemented for nearly a century, and national-level surveys reported prevalence rates declining from 6.9% in 2003 to 1% in 2017. However, neither of these infections has been completely eliminated. A situation analysis indicates continued transmission of both among high-risk communities. This paper explores the reasons for persistence of transmission of both LF and STH in residual pockets and the measures that are required to achieve long-term control, or perhaps even interrupt transmission in Sri Lanka. This article is part of the theme issue 'Challenges and opportunities in the fight against neglected tropical diseases: a decade from the London Declaration on NTDs'.
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Affiliation(s)
| | - I. E. Gunaratna
- Anti-Filariasis Campaign, Ministry of Health, Elvitigala Mawatha, Colombo 00500, Sri Lanka
| | - Dileepa Ediriweera
- Health Data Science Unit, University of Kelaniya, Talagolla Road, Ragama 11010, Sri Lanka
| | - N. R. de Silva
- Department of Parasitology, Faculty of Medicine, University of Kelaniya, Talagolla Road, Ragama 11010, Sri Lanka
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Phillips AE, Ower AK, Mekete K, Liyew EF, Maddren R, Mengistu B, Anjulo U, Chernet M, Dunn JC, Mohammed H, Belay H, Gidey B, Tasew G, Tadesse G, Salasibew M, Tollera G, Anderson R. Baseline soil-transmitted helminth and schistosome infection in the Geshiyaro project, Ethiopia: A unique transmission interruption project using biometric fingerprinting for longitudinal individual analysis. PLoS Negl Trop Dis 2023; 17:e0011589. [PMID: 37851666 PMCID: PMC10615263 DOI: 10.1371/journal.pntd.0011589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 10/30/2023] [Accepted: 09/07/2023] [Indexed: 10/20/2023] Open
Abstract
BACKGROUND The Geshiyaro project aims to assess the feasibility of interrupting transmission of soil-transmitted helminths (STH) and schistosome (SCH) infection in the Wolaita zone of southern Ethiopia through high coverage community-wide mass drug administration (MDA), in combination with improved water, sanitation, and hygiene services and behaviour change communication delivered through the existing health care infrastructure. To accurately measure treatment coverage a population census was conducted enrolling individuals with biometric fingerprinting and barcoded ID cards. This paper details the baseline census and parasitology surveys conducted before the start of any interventions. METHODS The census was conducted in five of the 15 Wolaita districts between October 2018 and December 2019, enrolling all consenting participants from every household. Simultaneously, a cross-sectional parasitology survey was conducted in 130 out of 361 randomly selected communities from all 15 districts, with 100 individuals across all age groups (infant to adult) per community providing stool and urine for analysis by duplicate Kato-Katz and a point-of-care circulating cathodic antigen (POC-CCA) to test for Schistosoma mansoni and STH, and microhaematuria and urine filtration for Schistosoma haematobium. Of the 130 communities, 30 were randomly selected for annual, longitudinal parasitological monitoring, with 150 randomly selected individuals from infant to adult providing two days of stool and urine samples for analysis by the same diagnostic tests per community. RESULTS In total 97,919 households participated in the baseline census enrolling 466,071 individuals, with parasitological data obtained from 10,785 people. At baseline, 15.5% were infected with at least one STH species, with Ascaris lumbricoides (9.5%), followed by hookworm (7.2%) and Trichuris trichiura (1.8%). Substantial heterogeneity in STH prevalence was observed between communities ranging from 0% to 61% where most infections were low intensity. Schistosoma mansoni infection was the dominant schistosome infection (0.85% by Kato-Katz and 13.3% by POC-CCA trace negative and 21.5% trace positive), with few Schistosoma haematobium infections identified (2.77% haematuria positive and 0.13% positive by urine filtration). CONCLUSIONS While the national control program in Ethiopia has made good progress in reducing prevalence of STH and SCH in Wolaita since it was launched in 2015, there remain areas of persistent infection suggesting the existence of environmental or behavioural risk factors that contribute to ongoing transmission. This project aims to identify the most efficient intervention strategies to reduce community burden and reach interruption of transmission.
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Affiliation(s)
- Anna E. Phillips
- MRC Centre for Global Infectious Disease Analysis, Imperial College London, St Mary’s Campus, London, United Kingdom
- London Centre for Neglected Tropical Disease Research, London, United Kingdom
| | - Alison K. Ower
- MRC Centre for Global Infectious Disease Analysis, Imperial College London, St Mary’s Campus, London, United Kingdom
- London Centre for Neglected Tropical Disease Research, London, United Kingdom
| | | | | | - Rosie Maddren
- MRC Centre for Global Infectious Disease Analysis, Imperial College London, St Mary’s Campus, London, United Kingdom
| | - Birhan Mengistu
- MRC Centre for Global Infectious Disease Analysis, Imperial College London, St Mary’s Campus, London, United Kingdom
- London Centre for Neglected Tropical Disease Research, London, United Kingdom
| | - Ufaysa Anjulo
- Children’s Investment Fund Foundation, London, United Kingdom
| | - Melkie Chernet
- Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | - Julia C. Dunn
- MRC Centre for Global Infectious Disease Analysis, Imperial College London, St Mary’s Campus, London, United Kingdom
- London Centre for Neglected Tropical Disease Research, London, United Kingdom
| | | | - Habtamu Belay
- Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | | | - Geremew Tasew
- Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | | | | | | | - Roy Anderson
- MRC Centre for Global Infectious Disease Analysis, Imperial College London, St Mary’s Campus, London, United Kingdom
- London Centre for Neglected Tropical Disease Research, London, United Kingdom
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Nguemnang Kamdem C, Soubgwi Fogue P, Zebaze Tiofack AA, Mezajou Mewamba E, Tekeu Mengoue LE, Womeni MH, Simo G. Assessment of the capacity of Whatman filter papers as support to store stools for the molecular diagnostic testing of soil-transmitted helminthiasis. J Microbiol Methods 2023; 213:106824. [PMID: 37717625 DOI: 10.1016/j.mimet.2023.106824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 09/12/2023] [Accepted: 09/14/2023] [Indexed: 09/19/2023]
Abstract
Storage of stools for the detection of soil-transmitted helminths (STH) remains challenging for the molecular diagnostic testing of STH infections. This study aimed to overcome this challenge by assessing the capacity of Whatman filter papers to store stools for the molecular detection of STHs. Stool samples were collected from school-aged children of soil-transmitted helminthiasis endemic areas of Cameroon and then, analysed using Kato Katz technique. For this study, 128 and 40 stool samples respectively with and without STH eggs were analysed. From each sample, 10, 20, 40 and 80 mg of stool were weighted and spread on 6 grades of Whatman filter papers that were stored at room temperature from one to ten weeks. DNA was extracted from spread stool using CTAB based-method. The amount of stool to spread on filter papers and the grade of filter paper offering good storage were determined by amplifying specific DNA fragments of Ascaris lumbricoides. The capacity of filter papers to store stool samples for several weeks before the molecular detection of STH species was assessed by amplifying specific DNA fragments of different STHs. The amplification rates of A. lumbricoides were significantly higher (P < 0.0001) for 10 and 20 mg of stored stools. Stools spread on Whatman paper grade 2 yielded the highest amplification rate of 100% for A. lumbricoides, T. trichiura and hookworm. PCR revealed STH infections in all the 128 spread stools carrying STH eggs. It also revealed Necator americanus and Ancylostoma duodenale respectively in 10 and 13 of 15 spread stools contained hookworm eggs. PCR confirmed the co-infections of these hookworm species as well as that of A. lumbricoides and Trichuris trichiura in 7 spread stools. Out of 40 stools without STH eggs, PCR revealed that 5 (12.5%) and 9 (22.5%) had respectively A. lumbricoides and T. trichiura infections. The amplification rate of each STH species was 100% from one to 8 weeks and decreased to 86.7% after 10 weeks of storage. This study highlighted the capacity of filter papers to store stools for the molecular detection of STHs. Storing stools on these papers will enable to monitor and evaluate control programs and ensure post-elimination surveillance.
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Affiliation(s)
- Cyrille Nguemnang Kamdem
- Molecular Parasitology and Entomology Unit, Department of Biochemistry, Faculty of Science, University of Dschang, Dschang, Cameroon
| | - Pythagore Soubgwi Fogue
- Molecular Parasitology and Entomology Unit, Department of Biochemistry, Faculty of Science, University of Dschang, Dschang, Cameroon
| | - Auvaker Arnol Zebaze Tiofack
- Molecular Parasitology and Entomology Unit, Department of Biochemistry, Faculty of Science, University of Dschang, Dschang, Cameroon
| | - Estelle Mezajou Mewamba
- Molecular Parasitology and Entomology Unit, Department of Biochemistry, Faculty of Science, University of Dschang, Dschang, Cameroon
| | - Loic Edmond Tekeu Mengoue
- Molecular Parasitology and Entomology Unit, Department of Biochemistry, Faculty of Science, University of Dschang, Dschang, Cameroon
| | - Macaire Hilaire Womeni
- Unité de Recherche de Biochimie, des plantes Médicinales, des Sciences alimentaires et Nutrition, University of Dschang, Dschang, Cameroon
| | - Gustave Simo
- Molecular Parasitology and Entomology Unit, Department of Biochemistry, Faculty of Science, University of Dschang, Dschang, Cameroon.
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Lima RRM, Lima JVA, Ribeiro JFF, Nascimento JB, Oliveira WF, Cabral Filho PE, Fontes A. Emerging biomedical tools for biomarkers detection and diagnostics in schistosomiasis. Talanta 2023; 265:124900. [PMID: 37423177 DOI: 10.1016/j.talanta.2023.124900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 06/21/2023] [Accepted: 07/01/2023] [Indexed: 07/11/2023]
Abstract
Schistosomiasis is a neglected disease that strikes many people from tropical and subtropical countries where there are not satisfactory sanitation and wide access to clean water. Schistosoma spp., the causative agents of schistosomiasis, exhibit a quite complex life cycle that involves two hosts (humans and snails, respectively, the definitive and the intermediate), and five evolutive forms: cercariae (human infective form), schistosomula, adult worms, eggs, and miracidia. The techniques to diagnose schistosomiasis still have various limitations, mainly regarding low-intensity infections. Although various mechanisms associated with schistosomiasis have already been evidenced, there is still a need to fulfill the comprehension of this disease, especially to prospect for novel biomarkers to improve its diagnosis. Developing methods with more sensitivity and portability to detect the infection is valuable to reach schistosomiasis control. In this context, this review has gathered information not only on schistosomiasis biomarkers but also on emerging optical and electrochemical tools proposed in selected studies from about the last ten years. Aspects of the assays regarding the sensibility, specificity, and time needed for detecting diverse biomarkers are described. We hope this review can guide future developments in the field of schistosomiasis, contributing to improving its diagnosis and eradication.
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Affiliation(s)
- Rennan R M Lima
- Departamento de Biofísica e Radiobiologia, Centro de Biociências, Universidade Federal de Pernambuco, Recife, PE, 50670-901, Brazil
| | - João V A Lima
- Departamento de Biofísica e Radiobiologia, Centro de Biociências, Universidade Federal de Pernambuco, Recife, PE, 50670-901, Brazil
| | - Jéssika F F Ribeiro
- Departamento de Biofísica e Radiobiologia, Centro de Biociências, Universidade Federal de Pernambuco, Recife, PE, 50670-901, Brazil
| | - Júlio B Nascimento
- Departamento de Biofísica e Radiobiologia, Centro de Biociências, Universidade Federal de Pernambuco, Recife, PE, 50670-901, Brazil
| | - Weslley F Oliveira
- Departamento de Bioquímica, Centro de Biociências, Universidade Federal de Pernambuco, Recife, PE, 50670-901, Brazil
| | - Paulo E Cabral Filho
- Departamento de Biofísica e Radiobiologia, Centro de Biociências, Universidade Federal de Pernambuco, Recife, PE, 50670-901, Brazil.
| | - Adriana Fontes
- Departamento de Biofísica e Radiobiologia, Centro de Biociências, Universidade Federal de Pernambuco, Recife, PE, 50670-901, Brazil.
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Hughes A, Ng-Nguyen D, Clarke NE, Dyer CEF, Hii SF, Clements ACA, Anderson RM, Gray DJ, Coffeng LE, Kaldor JM, Traub RJ, Vaz Nery S. Epidemiology of soil-transmitted helminths using quantitative PCR and risk factors for hookworm and Necator americanus infection in school children in Dak Lak province, Vietnam. Parasit Vectors 2023; 16:213. [PMID: 37370075 DOI: 10.1186/s13071-023-05809-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2022] [Accepted: 05/14/2023] [Indexed: 06/29/2023] Open
Abstract
BACKGROUND Soil-transmitted helminth (STH) infection is driven by a complex interaction of demographic, socioeconomic and behavioural factors, including those related to water, sanitation and hygiene (WASH). Epidemiological studies that measure both infection and potential risk factors associated with infection help to understand the drivers of transmission in a population and therefore can provide information to optimise STH control programmes. METHODS During October and November 2019, we conducted a cross-sectional survey of the prevalence and intensity of STH infection and associated risk factors among 7710 primary-school-age children from 64 primary schools across 13 districts in Dak Lak province, Vietnam. Quantitative PCR (qPCR) was used to detect and quantify STH infections. RESULTS The predominant STH species was the hookworm Necator americanus (overall cluster-adjusted prevalence of 13.7%), and its prevalence was heterogeneously distributed across surveyed schools (0% to 56.3%). All other STH species had a prevalence of less than 1%. Using mixed-effects logistic regression, we found that the adjusted odds ratio (aOR) was significantly higher for both infection and moderate-to-heavy-intensity infection with N. americanus among children from multiple ethnic minority groups, compared to children from the majority group (Kinh). Adjusted odds of infection with N. americanus were also higher in children who reported practising open defecation at school (aOR 1.42, 95% CI 1.05, 1.93, P = 0.02) and in those who had an unimproved household water supply (aOR 1.28, 95% CI 1.04, 1.57, P = 0.02). Conversely, children with a flushing household toilet had a reduced risk of infection (aOR 0.58, 95% CI 0.47, 0.70, P < 0.01), as did those whose primary female carer attended secondary (aOR 0.65, 95% CI 0.51, 0.84, P < 0.01) or tertiary education (aOR 0.39, 95% CI 0.24, 0.63, P < 0.01). CONCLUSIONS This study is the largest reported prevalence survey of STH infections conducted using qPCR as a diagnostic technique. The findings of higher adjusted odds of infection amongst ethnic minority children highlight that STH control programmes may not be reaching certain population groups and that additional culturally appropriate approaches may be required. Additionally, the associations between specific WASH factors and infection indicate potential programmatic targets to complement preventive chemotherapy programmes.
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Affiliation(s)
- Angus Hughes
- School of Population Health, University of New South Wales, Sydney, Australia.
| | - Dinh Ng-Nguyen
- Faculty of Animal Sciences and Veterinary Medicine, Tay Nguyen University, Buon Ma Thuot, Dak Lak, Vietnam
| | - Naomi E Clarke
- The Kirby Institute for Infection and Immunity in Society, University of New South Wales, Sydney, Australia
| | - Clare E F Dyer
- The Kirby Institute for Infection and Immunity in Society, University of New South Wales, Sydney, Australia
| | - Sze Fui Hii
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, Australia
| | - Archie C A Clements
- Faculty of Health Sciences, Curtin University, Perth, Australia
- Telethon Kids Institute, Perth, Australia
| | - Roy M Anderson
- Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, Imperial College London, London, UK
| | - Darren J Gray
- Research School of Population Health, Australian National University, Canberra, Australia
| | - Luc E Coffeng
- Department of Public Health, Erasmus MC, University Medical Centre Rotterdam, Rotterdam, The Netherlands
| | - John M Kaldor
- The Kirby Institute for Infection and Immunity in Society, University of New South Wales, Sydney, Australia
| | - Rebecca J Traub
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, Australia
| | - Susana Vaz Nery
- Faculty of Animal Sciences and Veterinary Medicine, Tay Nguyen University, Buon Ma Thuot, Dak Lak, Vietnam
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12
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Papaiakovou M, Fraija-Fernández N, James K, Briscoe AG, Hall A, Jenkins TP, Dunn J, Levecke B, Mekonnen Z, Cools P, Doyle SR, Cantacessi C, Littlewood DTJ. Evaluation of genome skimming to detect and characterise human and livestock helminths. Int J Parasitol 2023; 53:69-79. [PMID: 36641060 DOI: 10.1016/j.ijpara.2022.12.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Revised: 12/08/2022] [Accepted: 12/08/2022] [Indexed: 01/13/2023]
Abstract
The identification of gastrointestinal helminth infections of humans and livestock almost exclusively relies on the detection of eggs or larvae in faeces, followed by manual counting and morphological characterisation to differentiate species using microscopy-based techniques. However, molecular approaches based on the detection and quantification of parasite DNA are becoming more prevalent, increasing the sensitivity, specificity and throughput of diagnostic assays. High-throughput sequencing, from single PCR targets through to the analysis of whole genomes, offers significant promise towards providing information-rich data that may add value beyond traditional and conventional molecular approaches; however, thus far, its utility has not been fully explored to detect helminths in faecal samples. In this study, low-depth whole genome sequencing, i.e. genome skimming, has been applied to detect and characterise helminth diversity in a set of helminth-infected human and livestock faecal material. The strengths and limitations of this approach are evaluated using three methods to characterise and differentiate metagenomic sequencing data based on (i) mapping to whole mitochondrial genomes, (ii) whole genome assemblies, and (iii) a comprehensive internal transcribed spacer 2 (ITS2) database, together with validation using quantitative PCR (qPCR). Our analyses suggest that genome skimming can successfully identify most single and multi-species infections reported by qPCR and can provide sufficient coverage within some samples to resolve consensus mitochondrial genomes, thus facilitating phylogenetic analyses of selected genera, e.g. Ascaris spp. Key to this approach is both the availability and integrity of helminth reference genomes, some of which are currently contaminated with bacterial and host sequences. The success of genome skimming of faecal DNA is dependent on the availability of vouchered sequences of helminths spanning both taxonomic and geographic diversity, together with methods to detect or amplify minute quantities of parasite nucleic acids in mixed samples.
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Affiliation(s)
- Marina Papaiakovou
- Natural History Museum, Cromwell Road, London, UK; Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
| | - Natalia Fraija-Fernández
- Natural History Museum, Cromwell Road, London, UK; Marine Zoology Unit, Cavanilles Institute of Biodiversity and Evolutionary Biology, University of Valencia, Spain
| | - Katherine James
- Natural History Museum, Cromwell Road, London, UK; Interdisciplinary Computing and Complex BioSystems, School of Computing, Newcastle University, Newcastle upon Tyne, UK
| | - Andrew G Briscoe
- Natural History Museum, Cromwell Road, London, UK; NatureMetrics, Surrey Research Park, Guildford, UK
| | - Andie Hall
- Natural History Museum, Cromwell Road, London, UK
| | - Timothy P Jenkins
- Department of Veterinary Medicine, University of Cambridge, Cambridge, UK; Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Julia Dunn
- Department of Infectious Disease Epidemiology, Imperial College, London W2 1PG, UK
| | - Bruno Levecke
- Department of Translational Physiology, Infectiology and Public Health, Ghent University, Merelbeke, Belgium
| | - Zeleke Mekonnen
- Jimma University Institute of Health (JUIH), Jimma, Ethiopia
| | - Piet Cools
- Department of Translational Physiology, Infectiology and Public Health, Ghent University, Merelbeke, Belgium
| | | | - Cinzia Cantacessi
- Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
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Walker M, Lambert S, Neves MI, Worsley AD, Traub R, Colella V. Modeling the effectiveness of One Health interventions against the zoonotic hookworm Ancylostoma ceylanicum. Front Med (Lausanne) 2023; 10:1092030. [PMID: 36960338 PMCID: PMC10028197 DOI: 10.3389/fmed.2023.1092030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 02/14/2023] [Indexed: 03/09/2023] Open
Abstract
Hookworm disease is a major global public health concern, annually affecting 500-700 million of the world's poorest people. The World Health Organization is targeting the elimination of hookworm as a public health problem by 2030 using a strategy of mass drug administration (MDA) to at-risk human populations. However, in Southeast Asia and the Pacific the zoonotic hookworm species, Ancylostoma ceylanicum, is endemic in dogs and commonly infects people. This presents a potential impediment to the effectiveness of MDA that targets only humans. Here, we develop a novel multi-host (dog and human) transmission model of A. ceylanicum and compare the effectiveness of human-only and "One Health" (human plus dog) MDA strategies under a range of eco-epidemiological assumptions. We show that One Health interventions-targeting both dogs and humans-could suppress prevalence in humans to ≤ 1% by the end of 2030, even with only modest coverage (25-50%) of the animal reservoir. With increasing coverage, One Health interventions may even interrupt transmission. We discuss key unresolved questions on the eco-epidemiology of A. ceylanicum, the challenges of delivering MDA to animal reservoirs, and the growing importance of One Health interventions to human public health.
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Affiliation(s)
- Martin Walker
- Department of Pathobiology and Populations Sciences, Royal Veterinary College, Hatfield, United Kingdom
- Department of Infectious Disease Epidemiology, London Centre for Neglected Tropical Disease Research, Imperial College London, London, United Kingdom
- *Correspondence: Martin Walker
| | - Sébastien Lambert
- Department of Pathobiology and Populations Sciences, Royal Veterinary College, Hatfield, United Kingdom
- Department of Infectious Disease Epidemiology, London Centre for Neglected Tropical Disease Research, Imperial College London, London, United Kingdom
- IHAP, INRAE, ENVT, Université de Toulouse, Toulouse, France
| | - M. Inês Neves
- Department of Pathobiology and Populations Sciences, Royal Veterinary College, Hatfield, United Kingdom
- Department of Infectious Disease Epidemiology, London Centre for Neglected Tropical Disease Research, Imperial College London, London, United Kingdom
| | - Andrew D. Worsley
- Department of Veterinary Biosciences, The University of Melbourne, Melbourne, VIC, Australia
| | - Rebecca Traub
- Department of Veterinary Biosciences, The University of Melbourne, Melbourne, VIC, Australia
| | - Vito Colella
- Department of Veterinary Biosciences, The University of Melbourne, Melbourne, VIC, Australia
- Vito Colella
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Dyer CEF, Clarke NE, Nguyen DN, Herath HMPD, Hii SF, Pickford R, Traub RJ, Vaz Nery S. Assessing the efficacy of albendazole against hookworm in Vietnam using quantitative PCR and sodium nitrate flotation. PLoS Negl Trop Dis 2022; 16:e0010767. [PMID: 36315591 PMCID: PMC9668116 DOI: 10.1371/journal.pntd.0010767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 11/16/2022] [Accepted: 08/23/2022] [Indexed: 11/17/2022] Open
Abstract
Preventive chemotherapy (PC), consisting of the regular distribution of anthelmintics to populations or groups of populations at risk, is the primary tool used to control soil-transmitted helminth (STH) infections. This strategy, whilst cost-effective, raises the concern of potential emergence of drug resistance. The efficacy of anthelmintics against STH infections is measured using cure rate (CR) and egg reduction rate (ERR), using microscopy-based techniques such as the Kato-Katz thick smear. However, Kato-Katz has low sensitivity, especially for low-intensity infections, and requires fresh samples that need to be processed quickly. Realtime quantitative PCR (qPCR), which is more sensitive, is emerging as a "gold standard" for STH diagnostics given its higher sensitivity (important in low prevalence settings) and ability to differentiate hookworm species, while sodium nitrate flotation (SNF) may provide a low-cost more sensitive and practical alternative to Kato-Katz in the field. In this study, we examined the efficacy of a locally manufactured brand of albendazole 400 mg ("Alzental") against hookworm in Đắk Lắk province, Vietnam, using both qPCR and SNF. For qPCR, formulae to convert qPCR cycle threshold (Ct) values into eggs per gram of faeces (EPG) were utilised to determine efficacy calculations, and these values directly compared with efficacy values generated using SNF. Factors associated with CR and ERR were examined, and Alzental tablet quality was assessed by comparing with an Australian TGA-approved equivalent "Eskazole" tablet. We observed a CR and ERR of 64.9% and 87.5% respectively using qPCR, and 68.4% and 67.6% respectively using SNF. The tablet composition of Alzental was comparable to Eskazole in terms of active albendazole drug concentration with no evidence of impurities. This study demonstrates that the efficacy of Alzental against hookworm is within the range of previously reported studies for albendazole 400 mg. The study also demonstrates the value of qPCR and SNF as alternatives to standard Kato-Katz methodology for assessment of anthelmintic efficacy.
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Affiliation(s)
- Clare E. F. Dyer
- Kirby Institute, University of New South Wales, Sydney, Australia
- * E-mail:
| | - Naomi E. Clarke
- Kirby Institute, University of New South Wales, Sydney, Australia
| | - Dinh Ng Nguyen
- Faculty of Animal Sciences and Veterinary Medicine, Tay Nguyen University, Đắk Lắk, Vietnam
| | | | - Sze Fui Hii
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Victoria, Australia
| | - Russell Pickford
- Bioanalytical Mass Spectrometry Facility, University of New South Wales Analytical Centre, Sydney, Australia
| | - Rebecca J. Traub
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Victoria, Australia
| | - Susana Vaz Nery
- Kirby Institute, University of New South Wales, Sydney, Australia
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15
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Machrumnizar M, Devita A, Yuliana Y, Tan S. Application of Ziehl Neelsen Staining Method for Taenia spp. Eggs Differentiation. IRANIAN JOURNAL OF PARASITOLOGY 2022; 17:332-338. [PMID: 36466028 PMCID: PMC9682374 DOI: 10.18502/ijpa.v17i3.10623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 04/11/2022] [Indexed: 06/17/2023]
Abstract
BACKGROUND Three of Taenia species, named Taenia saginata, T. solium and T. asiatica can be found in Indonesia, but only T. solium can lead to neurocysticercosis. The morphology of those 3 Taenia spp. egg is indistinguishable by standard parasitology procedure. We aimed to use Ziehl Neelsen staining for differentiation of eggs of T. saginata and T. solium. METHODS As many as 40 containers of stool samples from the positive helminthiasis patients in Jakarta, Indonesia were collected during the year 2018. From each container, 10 slides prepared for staining with Kato-Katz technique as the preliminary examination. From those stool samples with positive taeniasis, we then once again made 10 slides/container for Ziehl Neelsen staining. RESULTS The first 400 slides stained with Kato-Katz technique as preliminary test were all positive for Taenia spp. The second 400 slides, we got 244 slides that gave good results as we could distinguished between the eggs of T. saginata and T. solium, meanwhile the remainder 156 slides gave unconfirmed results. From those 244 slides, 154 slides showed T. saginata eggs with magenta colored and 90 slides showed T. solium eggs with blue/purple colored. The eggs of T. solium slightly smaller if compared to Taenia saginata and had round shape, meanwhile T. saginata eggs were oval in shape. CONCLUSION Ziehl Neelsen staining method can be used as an alternative parasitological method to differentiate the eggs of T. saginata and T. solium.
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Affiliation(s)
| | - Arleen Devita
- Department of Microbiology, Faculty of Medicine, Trisakti University, Jakarta, Indonesia
| | - Yuliana Yuliana
- Department of Parasitology, Faculty of Medicine, Trisakti University, Jakarta, Indonesia
| | - Suriyani Tan
- Department of Parasitology, Faculty of Medicine, Trisakti University, Jakarta, Indonesia
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16
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Eneanya OA, Gankpala L, Goss CW, Momolu AT, Nyan ES, Gray EB, Fischer K, Curtis K, Bolay FK, Weil GJ, Fischer PU. Community-based trial assessing the impact of annual versus semiannual mass drug administration with ivermectin plus albendazole and praziquantel on helminth infections in northwestern Liberia. Acta Trop 2022; 231:106437. [PMID: 35405102 PMCID: PMC9168441 DOI: 10.1016/j.actatropica.2022.106437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 03/10/2022] [Accepted: 03/28/2022] [Indexed: 11/30/2022]
Abstract
Mass drug administration (MDA) with ivermectin plus albendazole was more effective for clearing bancroftian filariasis than it was for onchocerciasis or hookworm. Semiannual MDA was no more effective than annual MDA for reducing prevalences of W. bancrofti, O. volvulus, or hookworm infections. Decreases in bancroftian filariasis prevalence were achieved despite unavoidable interruptions in our study related to the 2014 West Africa Ebola epidemic and the 2020 SARS-CoV-2 pandemic. Neglected Tropical Disease elimination programs in areas coendemic for lymphatic filariasis and onchocerciasis should focus on delivering high quality annual MDA with high coverage and compliance and not try to stretch limited resources to deliver semiannual MDA. MDA with praziquantel had little impact on Schistosoma mansoni infection in the heavily infected area.
We assessed the impact of three annual vs five semiannual rounds of mass drug administration (MDA) with ivermectin plus albendazole followed by praziquantel for the control or elimination of lymphatic filariasis (LF), onchocerciasis, soil-transmitted helminth (STH) infections and schistosomiasis in Lofa County, Liberia. The study started in 2012 and was interrupted in 2014 during the Ebola virus outbreak. Repeated cross-sectional surveys were conducted in individuals 5 years and older to measure infection markers. Wuchereria bancrofti antigenemia prevalences decreased from 12.5 to 1.2% (90% reduction) and from 13.6 to 4.2% (69% reduction) one year after three rounds of annual or five rounds of semiannual MDA, respectively. Mixed effects logistic regression models showed decreases in odds of antigenemia positivity were 91 and 74% at that time in the annual and semiannual treatment zones, respectively (p < 0.001). Semiannual MDA was slightly more effective for reducing Onchocerca volvulus microfiladermia prevalence and at follow-up 3 were 74% (from 14.4 to 3.7%) and 83% (from 23.6 to 4.5%) in the annual and semiannual treatment zones, respectively. Both treatment schedules had similar beneficial effects on hookworm prevalence. Thus, annual and semiannual MDA with ivermectin and albendazole had similar beneficial impacts on LF, onchocerciasis, and STH in this setting. In contrast, MDA with praziquantel had little impact on hyperendemic Schistosoma mansoni in the study area. Results from a long-term follow-up survey showed that improvements in infection parameters were sustained by routine annual MDA provided by the Liberian Ministry of Health after our study endpoint.
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Affiliation(s)
- Obiora A Eneanya
- Department of Medicine, Infectious Diseases Division, Washington University School of Medicine, St. Louis, MO, United States
| | - Lincoln Gankpala
- Division of Public Health and Medical Research, National Public Health Institute of Liberia, Charlesville, Liberia
| | - Charles W Goss
- Division of Biostatistics, Washington University School of Medicine, St. Louis, MO, United States
| | - Aaron T Momolu
- Division of Public Health and Medical Research, National Public Health Institute of Liberia, Charlesville, Liberia
| | - Enoch S Nyan
- Division of Public Health and Medical Research, National Public Health Institute of Liberia, Charlesville, Liberia
| | - Emmanuel B Gray
- Ministry of Health of Liberia, C.B. Dunbar Hospital, Gbarnga, Liberia
| | - Kerstin Fischer
- Department of Medicine, Infectious Diseases Division, Washington University School of Medicine, St. Louis, MO, United States
| | - Kurt Curtis
- Department of Medicine, Infectious Diseases Division, Washington University School of Medicine, St. Louis, MO, United States
| | - Fatorma K Bolay
- Division of Public Health and Medical Research, National Public Health Institute of Liberia, Charlesville, Liberia
| | - Gary J Weil
- Department of Medicine, Infectious Diseases Division, Washington University School of Medicine, St. Louis, MO, United States
| | - Peter U Fischer
- Department of Medicine, Infectious Diseases Division, Washington University School of Medicine, St. Louis, MO, United States.
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Papaiakovou M, Littlewood DTJ, Doyle SR, Gasser RB, Cantacessi C. Worms and bugs of the gut: the search for diagnostic signatures using barcoding, and metagenomics-metabolomics. Parasit Vectors 2022; 15:118. [PMID: 35365192 PMCID: PMC8973539 DOI: 10.1186/s13071-022-05225-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Accepted: 02/25/2022] [Indexed: 02/07/2023] Open
Abstract
Gastrointestinal (GI) helminth infections cause significant morbidity in both humans and animals worldwide. Specific and sensitive diagnosis is central to the surveillance of such infections and to determine the effectiveness of treatment strategies used to control them. In this article, we: (i) assess the strengths and limitations of existing methods applied to the diagnosis of GI helminth infections of humans and livestock; (ii) examine high-throughput sequencing approaches, such as targeted molecular barcoding and shotgun sequencing, as tools to define the taxonomic composition of helminth infections; and (iii) discuss the current understanding of the interactions between helminths and microbiota in the host gut. Stool-based diagnostics are likely to serve as an important tool well into the future; improved diagnostics of helminths and their environment in the gut may assist the identification of biomarkers with the potential to define the health/disease status of individuals and populations, and to identify existing or emerging anthelmintic resistance.
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Affiliation(s)
- Marina Papaiakovou
- Department of Veterinary Medicine, University of Cambridge, Cambridge, CB3 0ES UK
- Department of Life Sciences, Natural History Museum, Cromwell Road, London, SW7 5BD UK
| | | | | | - Robin B. Gasser
- Melbourne Veterinary School, The University of Melbourne, Parkville, VIC 3010 Australia
| | - Cinzia Cantacessi
- Department of Veterinary Medicine, University of Cambridge, Cambridge, CB3 0ES UK
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Mationg MLS, Williams GM, Tallo VL, Olveda RM, Aung E, Alday P, Reñosa MD, Daga CM, Landicho J, Demonteverde MP, Santos ED, Bravo TA, Bieri FA, Bedford A, Li Y, Clements ACA, Steinmann P, Halton K, Stewart DE, McManus DP, Gray DJ. "The Magic Glasses Philippines": a cluster randomised controlled trial of a health education package for the prevention of intestinal worm infections in schoolchildren. THE LANCET REGIONAL HEALTH. WESTERN PACIFIC 2022; 18:100312. [PMID: 35024651 PMCID: PMC8671727 DOI: 10.1016/j.lanwpc.2021.100312] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 09/01/2021] [Accepted: 09/01/2021] [Indexed: 11/01/2022]
Abstract
Background Soil-transmitted helminths (STH) cause substantial disease and disability globally. Health education has proven complementary to school-based drug administration programs for STH control. We determined the generalizability of the impact of "The Magic Glasses" health education package for STH prevention in schoolchildren in Laguna province, the Philippines, having previously shown its positive impact in China. Methods We conducted a cluster-randomised controlled trial, in schoolchildren, aged 9-10 years, across 40 schools over one year. Schools were randomly assigned either to the "Magic Glasses Philippines" health education intervention package (consisting of a cartoon video, classroom discussions, drawing and essay competition) complementing the standard health education activities of the Philippines Departments of Health and Education, or to a control group, which involved only the standard health education activities. The primary trial outcomes were the proportion of STH infected schoolchildren and their knowledge, attitude and behaviour of STH assessed in both groups at baseline and through two follow-up surveys undertaken immediately prior to the semi-annual national mass administration of albendazole. The outcomes between the study arms were compared using generalized estimating equation models, accounting for clustering at the school level. The trial is registered with Australian New Zealand Clinical Trials Registry number: ACTRN12616000508471. Findings At follow-up assessments, the mean knowledge and behaviour scores in the intervention group were, respectively, 5·3 (95% confidence interval [CI]:4·2-6·5; p=<0.001) and 1·1 (95% CI: 0·4-1·7; p=0.002) percentage points higher than the control group. There was no overall effect on helminth infections (any STH; adjusted odds ratio [aOR]:1·0; 95% CI: 0·8-1·3; p=0·856), Ascaris lumbricoides; aOR:1·0; 95% CI: 0·7-1·6; p=0·894, or Trichuris trichiura; aOR:1·7; 95% CI: 0·9-1·6; p=0·315) but sub-group analysis showed a 60% reduction in the odds of any STH infection resulting from the "Magic Glasses" intervention in schools with a baseline prevalence ≤15% (aOR: 0·4; 95% CI: 0·2-0·7; p=0·001). Interpretation The health-education package demonstrated a modest but statistically significant impact on the students' overall STH knowledge and changes in their behaviour but was only effective in preventing STH infections in intervention schools where the baseline prevalence was ≤15%. Funding National Health and Medical Research Council, Australia, and the UBS-Optimus Foundation, Switzerland.
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Affiliation(s)
- Mary Lorraine S Mationg
- Research School of Population Heath, The Australian National University, Canberra, Australia.,Department of Epidemiology and Biostatistics, Research Institute for Tropical Medicine, Manila, Philippines
| | - Gail M Williams
- School of Public Health, University of Queensland, Brisbane, Australia
| | - Veronica L Tallo
- Department of Epidemiology and Biostatistics, Research Institute for Tropical Medicine, Manila, Philippines
| | - Remigio M Olveda
- Department of Epidemiology and Biostatistics, Research Institute for Tropical Medicine, Manila, Philippines
| | - Eindra Aung
- Research School of Population Heath, The Australian National University, Canberra, Australia.,St Vincent's Clinical School, University of New South Wales, Sydney, Australia
| | - Portia Alday
- Department of Epidemiology and Biostatistics, Research Institute for Tropical Medicine, Manila, Philippines
| | - Mark Donald Reñosa
- Department of Epidemiology and Biostatistics, Research Institute for Tropical Medicine, Manila, Philippines
| | - Chona Mae Daga
- Department of Epidemiology and Biostatistics, Research Institute for Tropical Medicine, Manila, Philippines
| | - Jhoys Landicho
- Department of Epidemiology and Biostatistics, Research Institute for Tropical Medicine, Manila, Philippines
| | - Maria Paz Demonteverde
- Department of Epidemiology and Biostatistics, Research Institute for Tropical Medicine, Manila, Philippines
| | - Eunice Diane Santos
- Department of Epidemiology and Biostatistics, Research Institute for Tropical Medicine, Manila, Philippines
| | - Thea Andrea Bravo
- Department of Epidemiology and Biostatistics, Research Institute for Tropical Medicine, Manila, Philippines
| | - Franziska Angly Bieri
- Research School of Population Heath, The Australian National University, Canberra, Australia
| | - Andrew Bedford
- Research School of Population Heath, The Australian National University, Canberra, Australia
| | - Yuesheng Li
- Molecular Parasitology Laboratory, Infectious Diseases Division, QIMR Berghofer Medical Research Institute, Brisbane, Australia.,Hunan Institute of Parasitic Diseases, World Health Organization Collaborating Centre for Research and Control on Schistosomiasis in Lake Region, Yueyang, China
| | | | - Peter Steinmann
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Kate Halton
- School of Public Health and Social Work, Queensland University of Technology, Brisbane, Australia
| | - Donald E Stewart
- Research School of Population Heath, The Australian National University, Canberra, Australia.,School of Medicine, Griffith University, Brisbane, Australia
| | - Donald P McManus
- Molecular Parasitology Laboratory, Infectious Diseases Division, QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Darren J Gray
- Research School of Population Heath, The Australian National University, Canberra, Australia
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19
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Colella V, Khieu V, Worsley A, Senevirathna D, Muth S, Huy R, Odermatt P, Traub RJ. Risk profiling and efficacy of albendazole against the hookworms Necator americanus and Ancylostoma ceylanicum in Cambodia to support control programs in Southeast Asia and the Western Pacific. THE LANCET REGIONAL HEALTH. WESTERN PACIFIC 2021; 16:100258. [PMID: 34590062 PMCID: PMC8403762 DOI: 10.1016/j.lanwpc.2021.100258] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 07/17/2021] [Accepted: 07/26/2021] [Indexed: 11/18/2022]
Abstract
Background: Hookworm disease is endemic throughout many parts of the Asia Pacific, despite targeted control programs of at-risk populations. The success of these programs has been hindered by the limited efficacy of widely-used mebendazole, rapid re-infection rates linked to persistent reservoirs of untreated people and dogs, and the low sensitivity of conventional coprodiagnostic techniques employed. Methods: Here, we used standard faecal flotation (SFF) and a multiplex qPCR (mqPCR) assay to calculate and compare species-specific cure and egg reduction rates of single dose albendazole (400 mg) against hookworm infections at community level. Data from a cross-sectional survey in 1,232 people from Cambodia were used to inform a generalised linear mixed model to identify risk factors linked to hookworm infection(s) at baseline. Furthermore, we calculated risk factors associated to the probability of being cured after albendazole administration. Findings: Overall, 13·5% of all 1,232 people tested by SFF were positive for hookworm infection(s). Most (80·1%) infected people were >12 years of age, hence above the age targeted by the WHO control program. We estimate that as age increases, the odds of being infected increases at a faster rate for females than for males. We revealed a substantial difference in cure rate of hookworm infection(s) following albendazole treatment using the SFF (81·5%) and mqPCR (46·4%) assays, and provide the first data on the efficacy of this drug against the zoonotic hookworm Ancylostoma ceylanicum. We estimated that as age increases by one year, the odds of being cured decreases by 0·4%-3·7%. Similarly, the odds of being cured for people who boiled drinking water was estimated to be between 1·02 and 6·82. Interpretation: These findings show that the adoption of refined diagnostic techniques is central to monitoring hookworm infection(s) and the success of control strategies, which can ultimately aid in reducing associated morbidity in human populations. The approach taken is likely to be directly applicable to other parts of Southeast Asia and the Western Pacific, where specific epidemiological conditions might hamper the success of targeted treatment programs. Funding: Faculty of Veterinary and Agricultural Sciences Strategic Research Funds, The University of Melbourne.
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Affiliation(s)
- Vito Colella
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Australia
| | - Virak Khieu
- National Centre for Parasitology, Entomology and Malaria Control, Ministry of Health, Phnom Penh, Cambodia
| | | | - Dammika Senevirathna
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Australia
| | - Sinuon Muth
- National Centre for Parasitology, Entomology and Malaria Control, Ministry of Health, Phnom Penh, Cambodia
| | - Rekol Huy
- National Centre for Parasitology, Entomology and Malaria Control, Ministry of Health, Phnom Penh, Cambodia
| | - Peter Odermatt
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Rebecca J. Traub
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Australia
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20
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Detection of six soil-transmitted helminths in human stool by qPCR- a systematic workflow. PLoS One 2021; 16:e0258039. [PMID: 34591904 PMCID: PMC8483301 DOI: 10.1371/journal.pone.0258039] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 09/16/2021] [Indexed: 11/19/2022] Open
Abstract
Soil-transmitted helminths (STH) infect up to one-quarter of the global population, with a significant associated disease burden. The main human STH are: Ancylostoma spp. and Necator americanus (hookworms); Ascaris lumbricoides, Trichuris trichiura, and Strongyloides stercoralis. The aim of this study was to establish a scalable system for stool STH multiplex quantitative real-time polymerase chain reactions (qPCR). Stool samples collected in Fiji and preserved in potassium dichromate were transferred to Melbourne at ambient temperature. Samples were washed to remove potassium dichromate and DNA was extracted with the Mini-Beadbeater-24 and a column-based kit. A SYBR green qPCR to detect the vertebrate mitochondrial gene was used as a DNA extraction control. Samples were tested using a probe-based multiplex qPCR targeting A. lumbricoides, T. trichiura and S. stercoralis, and in a second multiplex reaction to detect hookworms to the species level (A. duodenale, A. ceylanicum, N. americanus). An internal amplification control in both multiplex assays was included to prevent false-negative results due to PCR inhibitors. Samples were homogenised for a single cycle of 40 seconds to release STH DNA and washed stool was stored for up to 15 weeks at -30°C without compromising DNA. Our multiplex qPCR detected multiple species of STH without reduced sensitivity compared to singleplex. qPCR data from 40 stools was validated against STH-positive stools determined by microscopy. We have developed and validated an efficient and staged system for detecting six clinically important STH affecting humans that could be easily implemented without advanced automation in any qPCR-capable laboratory.
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21
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Khurana S, Singh S, Mewara A. Diagnostic Techniques for Soil-Transmitted Helminths - Recent Advances. Res Rep Trop Med 2021; 12:181-196. [PMID: 34377048 PMCID: PMC8349539 DOI: 10.2147/rrtm.s278140] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 07/01/2021] [Indexed: 12/26/2022] Open
Abstract
Soil-transmitted helminth (STH) infections (hookworms, Trichuris, Ascaris) and Strongyloides spp. are associated with a substantial global burden and high morbidity. Sensitive and specific methods for diagnosis of these infections are essential for mapping the burden in communities, accurate assessment of infection levels, to guide interventions and monitoring the success of STH control programs. Despite considerable progress to control STH over several decades, we are still far from identifying a fully adequate diagnostic test. Conventional microscopy-based methods such as direct Kato–Katz smear or mounts after stool centrifugation/flotation-based concentration techniques have been the mainstay of diagnosis, especially in resource-poor countries where these infections abound. However, recently, these are being adapted to closed, easy to perform, digital formats, thereby improving the sensitivity as well as applicability in a remote, resource-limited setting. The use of image analysis systems to identify and quantify helminth eggs, with potential adaptation to smartphones, is also promising. Antibody detection tests have a limited role mostly in the case of Strongyloides hyperinfection. Coproantigen detection tests have been developed and used in veterinary practice for detection of STH, but these have not been evaluated for use in humans. More sensitive molecular diagnostics, including assays developed with new bioinformatic tools and techniques such as polymerase chain reaction (PCR), quantitative PCR (qPCR) and loop-mediated amplification assay, can help in the clear and precise assessment of STH burden during elimination phase and are of immense value for diagnosis in areas with low endemicity and in travelers to endemic regions. Moreover, the molecular techniques will help detect new species that may emerge. Sample preservation and efficient DNA extraction are critical and significantly affect the efficiency of molecular diagnostic tests. In addition to the diagnosis of clinical or asymptomatic infection in humans, detection of STH eggs in environmental samples is imperative to boost STH control efforts. Overall the diagnostic performance, cost-effectiveness, ease of performance, rapidity and in-field applicability of any test should be considered when choosing from the various diagnostic assays in areas with different endemicity, in addition to striving towards the development of novel technologies and optimization of existing methods.
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Affiliation(s)
- Sumeeta Khurana
- Department of Medical Parasitology, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Shreya Singh
- Department of Medical Microbiology, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Abhishek Mewara
- Department of Medical Parasitology, Post Graduate Institute of Medical Education and Research, Chandigarh, India
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22
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Papaiakovou M, Littlewood DTJ, Gasser RB, Anderson RM. How qPCR complements the WHO roadmap (2021-2030) for soil-transmitted helminths. Trends Parasitol 2021; 37:698-708. [PMID: 33931342 DOI: 10.1016/j.pt.2021.04.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 04/02/2021] [Accepted: 04/08/2021] [Indexed: 12/19/2022]
Abstract
Complementing the launch of the World Health Organization (WHO) roadmap (2021-2030) we explore key elements needing attention before recruitment of qPCR as the main diagnostics tool to confirm reduction or elimination of soil-transmitted helminth (STH) transmission in both control and elimination programmes. Given the performance limitations of conventional methods, a proposed harmonised qPCR will provide a diagnostic tool, with the sensitivity and specificity required to monitor low-intensity infections, following mass drug administration (MDA). Technical and logistical challenges associated with introducing qPCR as a stand-alone tool are highlighted, and a decision-making scheme on how qPCR can support surveillance, resistance detection, and elimination is presented. An accurate point-of-care (POC) diagnostic test needs to be developed to support STH control in the field, and STH biorepositories need to be established and maintained to ensure that reference materials are available for research and validation.
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Affiliation(s)
- Marina Papaiakovou
- Department of Infectious Disease Epidemiology, St Mary's Campus, Imperial College London, London, UK; London Centre for Neglected Tropical Disease Research (LCNTDR), Imperial College London, London, UK.
| | - D Timothy J Littlewood
- Science Directorate, Natural History Museum, London, UK; London Centre for Neglected Tropical Disease Research (LCNTDR), Imperial College London, London, UK
| | - Robin B Gasser
- Department of Veterinary Biosciences, Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Roy M Anderson
- Department of Infectious Disease Epidemiology, St Mary's Campus, Imperial College London, London, UK; London Centre for Neglected Tropical Disease Research (LCNTDR), Imperial College London, London, UK
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23
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Prevalence, Intensity, and Correlates of Soil-Transmitted Helminth Infections among School Children after a Decade of Preventive Chemotherapy in Western Rwanda. Pathogens 2020; 9:pathogens9121076. [PMID: 33371488 PMCID: PMC7767502 DOI: 10.3390/pathogens9121076] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 12/16/2020] [Accepted: 12/17/2020] [Indexed: 02/06/2023] Open
Abstract
Preventive chemotherapy (PC) is a WHO-recommended core intervention measures to eliminate Soil-Transmitted Helminths (STH) as a public health problem by 2020, defined as a reduction in prevalence to <1% of moderate or high-intensity infection. We conducted a cross-sectional study to investigate the prevalence, intensity, and correlates of STH after a decade of PC in Rwanda. A total of 4998 school children (5–15 years old) from four districts along Lake Kivu in the western province were screened for STH using Kato-Katz. The overall prevalence of Soil-transmitted helminths among school children was 77.7% (range between districts = 54% to 92%). Trichirus trichiura was the most common STH (66.8%, range between districts = 23% to 88.2%), followed by Ascaris lumbricoides (49.9%, range between district = 28.5% to 63.3%) and hookworms (1.9%, range between districts = 0.6% to 2.9%). The prevalence of single, double and of triple parasite coinfection were 48.6%, 50.3%, and 1.1%, respectively. The overall prevalence of moderate or high-intensity infection for Trichirus trichiura and Ascaris lumbricoides was 7.1% and 13.9, respectively. Multivariate logistic regression model revealed that male sex, district, stunting, and schistosomiasis coinfection as significant predictors of STH infection. Despite a decade of PC implementation, STH remain a significant public health problem in Rwanda.
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24
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Keller L, Patel C, Welsche S, Schindler T, Hürlimann E, Keiser J. Performance of the Kato-Katz method and real time polymerase chain reaction for the diagnosis of soil-transmitted helminthiasis in the framework of a randomised controlled trial: treatment efficacy and day-to-day variation. Parasit Vectors 2020; 13:517. [PMID: 33059756 PMCID: PMC7558729 DOI: 10.1186/s13071-020-04401-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 10/09/2020] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Accurate, scalable and sensitive diagnostic tools are crucial in determining prevalence of soil-transmitted helminths (STH), assessing infection intensities and monitoring treatment efficacy. However, assessments on treatment efficacy comparing traditional microscopic to newly emerging molecular approaches such as quantitative Polymerase Chain Reaction (qPCR) are scarce and hampered partly by lack of an established diagnostic gold standard. METHODS We compared the performance of the copromicroscopic Kato-Katz method to qPCR in the framework of a randomized controlled trial on Pemba Island, Tanzania, evaluating treatment efficacy based on cure rates of albendazole monotherapy versus ivermectin-albendazole against Trichuris trichiura and concomitant STH infections. Day-to-day variability of both diagnostic methods was assessed to elucidate reproducibility of test results by analysing two stool samples before and two stool samples after treatment of 160 T. trichiura Kato-Katz positive participants, partially co-infected with Ascaris lumbricoides and hookworm, per treatment arm (n = 320). As negative controls, two faecal samples of 180 Kato-Katz helminth negative participants were analysed. RESULTS Fair to moderate correlation between microscopic egg count and DNA copy number for the different STH species was observed at baseline and follow-up. Results indicated higher sensitivity of qPCR for all three STH species across all time points; however, we found lower test result reproducibility compared to Kato-Katz. When assessed with two samples from consecutive days by qPCR, cure rates were significantly lower for T. trichiura (23.2 vs 46.8%), A. lumbricoides (75.3 vs 100%) and hookworm (52.4 vs 78.3%) in the ivermectin-albendazole treatment arm, when compared to Kato-Katz. CONCLUSIONS qPCR diagnosis showed lower reproducibility of test results compared to Kato-Katz, hence multiple samples per participant should be analysed to achieve a reliable diagnosis of STH infection. Our study confirms that cure rates are overestimated using Kato-Katz alone. Our findings emphasize that standardized and accurate molecular diagnostic tools are urgently needed for future monitoring within STH control and/or elimination programmes.
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Affiliation(s)
- Ladina Keller
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4051 Basel, Switzerland
- University of Basel, Petersplatz 1, 4051 Basel, Switzerland
| | - Chandni Patel
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4051 Basel, Switzerland
- University of Basel, Petersplatz 1, 4051 Basel, Switzerland
| | - Sophie Welsche
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4051 Basel, Switzerland
- University of Basel, Petersplatz 1, 4051 Basel, Switzerland
| | - Tobias Schindler
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4051 Basel, Switzerland
- University of Basel, Petersplatz 1, 4051 Basel, Switzerland
| | - Eveline Hürlimann
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4051 Basel, Switzerland
- University of Basel, Petersplatz 1, 4051 Basel, Switzerland
| | - Jennifer Keiser
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4051 Basel, Switzerland
- University of Basel, Petersplatz 1, 4051 Basel, Switzerland
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