IDEAS home Printed from https://ideas.repec.org/a/plo/pntd00/0007514.html
   My bibliography  Save this article

Sampling strategies for monitoring and evaluation of morbidity targets for soil-transmitted helminths

Author

Listed:
  • Federica Giardina
  • Luc E Coffeng
  • Sam H Farrell
  • Carolin Vegvari
  • Marleen Werkman
  • James E Truscott
  • Roy M Anderson
  • Sake J de Vlas

Abstract

Background: The current World Health Organization (WHO) target for the three major soil-transmitted helminth (STH) infections is to reduce prevalence of moderate-to-heavy infections to below 1% by 2020. In terms of monitoring and evaluation (M&E), the current WHO guidelines for control of STHs recommend evaluation of infection levels in school-age children (SAC) after five to six years of preventive chemotherapy (PC), using the standard Kato-Katz faecal smear. Here, we assess the predictive performance of various sampling designs for the evaluation of the morbidity target. Methodology/Principal findings: Using two mathematical models for STH transmission and control, we simulate how the number of villages and SAC sampled affect the ability of survey results in sentinel villages to predict the achievement of the morbidity target in PC implementation units (e.g. districts). As PC is stopped when the prevalence of infection in SAC in sentinel villages is less than 1%, we estimate the positive predictive value (PPV) of this indicator for meeting the morbidity target in the whole district. The PPV varies by species and PC strategy, and it is generally higher in areas with lower pre-control prevalence. Sampling a fixed number of SAC spread out over 10 instead of 5 sentinel villages may increase the PPV by up to 20 percentage points. If every SAC in a village is tested, a higher number of villages may increase the PPV by up to 80 percentage points. Increasing the proportion of SAC tested per village does not result in a relevant increase of PPV. Conclusions/Significance: Although the WHO guidelines provide a combined strategy to control the three STH species, the efficacy of PC strategies clearly differs by species. There is added value in considering more villages within implementation units for M&E of morbidity targets, the extent varying by STH species. A better understanding of pre- and post-control local STH prevalence levels is essential for an adequate M&E strategy including the definition of morbidity targets at the appropriate geographical scale. Author summary: Soil-transmitted helminths (STHs) affect approximately 1.5 billion people worldwide. The World Health Organization target for STHs is to achieve 1% in the entire PC implementation unit. Evaluating the prevalence of any infection over a higher number of sentinel villages improves the accuracy in assessing the morbidity target at the implementation unit level, even when a lower proportion of SAC per village is tested. A better understanding of pre- and post-control local STH prevalence levels through large scale data collection is essential for the definition of an adequate M&E strategy for STH control.

Suggested Citation

  • Federica Giardina & Luc E Coffeng & Sam H Farrell & Carolin Vegvari & Marleen Werkman & James E Truscott & Roy M Anderson & Sake J de Vlas, 2019. "Sampling strategies for monitoring and evaluation of morbidity targets for soil-transmitted helminths," PLOS Neglected Tropical Diseases, Public Library of Science, vol. 13(6), pages 1-17, June.
    • Handle: RePEc:plo:pntd00:0007514
    DOI: 10.1371/journal.pntd.0007514
    as

    Download full text from publisher

    File URL: https://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0007514
    Download Restriction: no
    File URL: https://journals.plos.org/plosntds/article/file?id=10.1371/journal.pntd.0007514&type=printable
    Download Restriction: no
    File URL: https://libkey.io/10.1371/journal.pntd.0007514?utm_source=ideas
    LibKey link: if access is restricted and if your library uses this service, LibKey will redirect you to where you can use your library subscription to access this item
    ---><---

    References listed on IDEAS

    as
    1. Catherine Linard & Marius Gilbert & Robert W Snow & Abdisalan M Noor & Andrew J Tatem, 2012. "Population Distribution, Settlement Patterns and Accessibility across Africa in 2010," PLOS ONE, Public Library of Science, vol. 7(2), pages 1-8, February.
    Full references (including those not matched with items on IDEAS)

    Most related items

    These are the items that most often cite the same works as this one and are cited by the same works as this one.
    1. Forrest R Stevens & Andrea E Gaughan & Catherine Linard & Andrew J Tatem, 2015. "Disaggregating Census Data for Population Mapping Using Random Forests with Remotely-Sensed and Ancillary Data," PLOS ONE, Public Library of Science, vol. 10(2), pages 1-22, February.
    2. Gollin, Douglas & Lagakos, David & Kirchberger, Martina, 2017. "In Search of a Spatial Equilibrium in the Developing World," CEPR Discussion Papers 12114, C.E.P.R. Discussion Papers.
    3. Elizabeth C Lee & Andrew S Azman & Joshua Kaminsky & Sean M Moore & Heather S McKay & Justin Lessler, 2019. "The projected impact of geographic targeting of oral cholera vaccination in sub-Saharan Africa: A modeling study," PLOS Medicine, Public Library of Science, vol. 16(12), pages 1-17, December.
    4. Jennifer L Smith & Rebecca M Flueckiger & Pamela J Hooper & Sarah Polack & Elizabeth A Cromwell & Stephanie L Palmer & Paul M Emerson & David C W Mabey & Anthony W Solomon & Danny Haddad & Simon J Bro, 2013. "The Geographical Distribution and Burden of Trachoma in Africa," PLOS Neglected Tropical Diseases, Public Library of Science, vol. 7(8), pages 1-13, August.
    5. Beatrice Asenso Barnieh & Li Jia & Massimo Menenti & Min Jiang & Jie Zhou & Yelong Zeng & Ali Bennour, 2021. "Modeling the Underlying Drivers of Natural Vegetation Occurrence in West Africa with Binary Logistic Regression Method," Sustainability, MDPI, vol. 13(9), pages 1-37, April.
    6. D. Woods & A. Cunningham & C. E. Utazi & M. Bondarenko & L. Shengjie & G. E. Rogers & P. Koper & C. W. Ruktanonchai & E. zu Erbach-Schoenberg & A. J. Tatem & J. Steele & A. Sorichetta, 2022. "Exploring methods for mapping seasonal population changes using mobile phone data," Palgrave Communications, Palgrave Macmillan, vol. 9(1), pages 1-17, December.
    7. Alexandros Korkovelos & Babak Khavari & Andreas Sahlberg & Mark Howells & Christopher Arderne, 2019. "The Role of Open Access Data in Geospatial Electrification Planning and the Achievement of SDG7. An OnSSET-Based Case Study for Malawi," Energies, MDPI, vol. 12(7), pages 1-36, April.
    8. Joël Masimo Kabuanga & Onésime Mubenga Kankonda & Mehdi Saqalli & Nicolas Maestripieri & Thomas Mumuni Bilintoh & Jean-Pierre Mate Mweru & Aimé Balimbaki Liama & Radar Nishuli & Landing Mané, 2021. "Historical Changes and Future Trajectories of Deforestation in the Ituri-Epulu-Aru Landscape (Democratic Republic of the Congo)," Land, MDPI, vol. 10(10), pages 1-24, October.
    9. T Alex Perkins & Thomas W Scott & Arnaud Le Menach & David L Smith, 2013. "Heterogeneity, Mixing, and the Spatial Scales of Mosquito-Borne Pathogen Transmission," PLOS Computational Biology, Public Library of Science, vol. 9(12), pages 1-16, December.
    10. Kara G Marson & Kenneth Tapia & Pamela Kohler & Christine J McGrath & Grace C John-Stewart & Barbra A Richardson & Julia W Njoroge & James N Kiarie & Samah R Sakr & Michael H Chung, 2013. "Male, Mobile, and Moneyed: Loss to Follow-Up vs. Transfer of Care in an Urban African Antiretroviral Treatment Clinic," PLOS ONE, Public Library of Science, vol. 8(10), pages 1-1, October.
    11. Kanta Kumari Rigaud & Alex de Sherbinin & Bryan Jones & Susana Adamo & David Maleki & Nathalie E. Abu-Ata & Anna Taeko Casals Fernandez & Anmol Arora & Tricia Chai-Onn & Briar Mills, 2021. "Groundswell Africa [Groundswell Afrique]," World Bank Publications - Reports 36404, The World Bank Group.
    12. Carl Müller-Crepon & Yannick Pengl & Nils-Christian Bormann, 2022. "Linking Ethnic Data from Africa (LEDA)," Journal of Peace Research, Peace Research Institute Oslo, vol. 59(3), pages 425-435, May.
    13. Rachel L Pullan & Matthew C Freeman & Peter W Gething & Simon J Brooker, 2014. "Geographical Inequalities in Use of Improved Drinking Water Supply and Sanitation across Sub-Saharan Africa: Mapping and Spatial Analysis of Cross-sectional Survey Data," PLOS Medicine, Public Library of Science, vol. 11(4), pages 1-17, April.
    14. Amjath-Babu, T.S. & Krupnik, Timothy J. & Kaechele, Harald & Aravindakshan, Sreejith & Sietz, Diana, 2016. "Transitioning to groundwater irrigated intensified agriculture in Sub-Saharan Africa: An indicator based assessment," Agricultural Water Management, Elsevier, vol. 168(C), pages 125-135.
    15. Siyu Ma & Lin Yang & Mei-Po Kwan & Zejun Zuo & Haoyue Qian & Minghao Li, 2021. "Do Individuals’ Activity Structures Influence Their PM 2 . 5 Exposure Levels? Evidence from Human Trajectory Data in Wuhan City," IJERPH, MDPI, vol. 18(9), pages 1-27, April.
    16. Liu, Weiping & Yang, Chaoxian & Liu, Yong & Wei, Chaofu & Yang, Xinyue, 2018. "Impacts of concentrated rural resettlement policy on rural restructuring in upland areas: A case study of Qiantang Town in Chongqing, China," Land Use Policy, Elsevier, vol. 77(C), pages 732-744.
    17. Jayne, T.S. & Chamberlin, Jordan & Headey, Derek D., 2014. "Land pressures, the evolution of farming systems, and development strategies in Africa: A synthesis," Food Policy, Elsevier, vol. 48(C), pages 1-17.
    18. David Kraybill, 2013. "Rural development in sub-Saharan Africa," Chapters, in: Gary Paul Green (ed.), Handbook of Rural Development, chapter 14, pages i-ii, Edward Elgar Publishing.
    19. Miguel A Campo-Bescós & Rafael Muñoz-Carpena & David A Kaplan & Jane Southworth & Likai Zhu & Peter R Waylen, 2013. "Beyond Precipitation: Physiographic Gradients Dictate the Relative Importance of Environmental Drivers on Savanna Vegetation," PLOS ONE, Public Library of Science, vol. 8(8), pages 1-14, August.
    20. Daniela Palacios-Lopez & Felix Bachofer & Thomas Esch & Wieke Heldens & Andreas Hirner & Mattia Marconcini & Alessandro Sorichetta & Julian Zeidler & Claudia Kuenzer & Stefan Dech & Andrew J. Tatem & , 2019. "New Perspectives for Mapping Global Population Distribution Using World Settlement Footprint Products," Sustainability, MDPI, vol. 11(21), pages 1-24, October.

    More about this item

    Statistics

    Access and download statistics

    Corrections

    All material on this site has been provided by the respective publishers and authors. You can help correct errors and omissions. When requesting a correction, please mention this item's handle: RePEc:plo:pntd00:0007514. See general information about how to correct material in RePEc.

    If you have authored this item and are not yet registered with RePEc, we encourage you to do it here. This allows to link your profile to this item. It also allows you to accept potential citations to this item that we are uncertain about.

    If CitEc recognized a bibliographic reference but did not link an item in RePEc to it, you can help with this form .

    If you know of missing items citing this one, you can help us creating those links by adding the relevant references in the same way as above, for each refering item. If you are a registered author of this item, you may also want to check the "citations" tab in your RePEc Author Service profile, as there may be some citations waiting for confirmation.

    For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: plosntds (email available below). General contact details of provider: https://journals.plos.org/plosntds/ .

    Please note that corrections may take a couple of weeks to filter through the various RePEc services.

    IDEAS is a RePEc service. RePEc uses bibliographic data supplied by the respective publishers.