Simulating a Transmission Assessment Survey: An evaluation of current methods used in determining the elimination of the neglected tropical disease, Lymphatic Filariasis
Introduction: The World Health Organization (WHO) recommends Transmission Assessment Surveys (TAS) to determine when an evaluation unit (EU) (a designated population survey area) has achieved elimination of transmission of the vector-borne macroparasitic disease Lymphatic Filariasis (LF). These dete...
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| Format: | Article |
| Language: | English |
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Elsevier
2021-01-01
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| Series: | International Journal of Infectious Diseases |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S1201971220322803 |
| _version_ | 1819077648822829056 |
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| author | Paul S. Weiss Edwin Michael Frank O. Richards, Jr. |
| author_facet | Paul S. Weiss Edwin Michael Frank O. Richards, Jr. |
| author_sort | Paul S. Weiss |
| collection | DOAJ |
| description | Introduction: The World Health Organization (WHO) recommends Transmission Assessment Surveys (TAS) to determine when an evaluation unit (EU) (a designated population survey area) has achieved elimination of transmission of the vector-borne macroparasitic disease Lymphatic Filariasis (LF). These determinations are based on combining data from multiple survey units within an EU; it is unclear how underlying cluster-level variation influences the outcome of the TAS at EU level. We simulate LF infection distribution in an EU and compare three methods for assessing whether LF elimination has occurred based on currently recommended decision thresholds and sampling methods. Methods: We simulate an EU divided into clusters of varying size and disease prevalence. We produce 1000 samples according to LF TAS examples and WHO guidelines and compare three decision-making approaches: lot quality assurance sampling (LQAS) (recommended by WHO), one-sided interval estimate (CI), and nth order statistic (MAX). Summary statistics demonstrating the “pass” rate for the EU under different disease transmission conditions are generated using a versatile SAS® macro. Results: As the prevalence of LF decreases, the LQAS and CI approaches produce increased likelihood of a pass outcome for an EU while some cluster units may still have a high likelihood of transmission. The MAX provides an alternative that increases the likelihood of determining a pass only once the whole area has a low likelihood of transmission. LQAS and CI approaches designed to estimate the LF prevalence in the EU miss hotspots that will continue to transmit infection while the MAX approach focuses on identifying clusters with high risk of transmission. Conclusions: The current TAS methodology has a flaw that may result in false predictions of LF transmission interruption throughout an EU. Modifying the TAS methodology to address results from extreme clusters rather than being based on mean prevalence over an EU will result in greater success for global elimination of LF. |
| first_indexed | 2024-12-21T19:00:33Z |
| format | Article |
| id | doaj.art-53a3f31873d74372b2f82189bc5f7d6e |
| institution | Directory Open Access Journal |
| issn | 1201-9712 |
| language | English |
| last_indexed | 2024-12-21T19:00:33Z |
| publishDate | 2021-01-01 |
| publisher | Elsevier |
| record_format | Article |
| series | International Journal of Infectious Diseases |
| spelling | doaj.art-53a3f31873d74372b2f82189bc5f7d6e2022-12-21T18:53:30ZengElsevierInternational Journal of Infectious Diseases1201-97122021-01-01102422428Simulating a Transmission Assessment Survey: An evaluation of current methods used in determining the elimination of the neglected tropical disease, Lymphatic FilariasisPaul S. Weiss0Edwin Michael1Frank O. Richards, Jr.2Rollins School of Public Health, Emory University, Atlanta, GA, USA; Corresponding author.Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, USAThe Carter Center, Atlanta, GA, USAIntroduction: The World Health Organization (WHO) recommends Transmission Assessment Surveys (TAS) to determine when an evaluation unit (EU) (a designated population survey area) has achieved elimination of transmission of the vector-borne macroparasitic disease Lymphatic Filariasis (LF). These determinations are based on combining data from multiple survey units within an EU; it is unclear how underlying cluster-level variation influences the outcome of the TAS at EU level. We simulate LF infection distribution in an EU and compare three methods for assessing whether LF elimination has occurred based on currently recommended decision thresholds and sampling methods. Methods: We simulate an EU divided into clusters of varying size and disease prevalence. We produce 1000 samples according to LF TAS examples and WHO guidelines and compare three decision-making approaches: lot quality assurance sampling (LQAS) (recommended by WHO), one-sided interval estimate (CI), and nth order statistic (MAX). Summary statistics demonstrating the “pass” rate for the EU under different disease transmission conditions are generated using a versatile SAS® macro. Results: As the prevalence of LF decreases, the LQAS and CI approaches produce increased likelihood of a pass outcome for an EU while some cluster units may still have a high likelihood of transmission. The MAX provides an alternative that increases the likelihood of determining a pass only once the whole area has a low likelihood of transmission. LQAS and CI approaches designed to estimate the LF prevalence in the EU miss hotspots that will continue to transmit infection while the MAX approach focuses on identifying clusters with high risk of transmission. Conclusions: The current TAS methodology has a flaw that may result in false predictions of LF transmission interruption throughout an EU. Modifying the TAS methodology to address results from extreme clusters rather than being based on mean prevalence over an EU will result in greater success for global elimination of LF.http://www.sciencedirect.com/science/article/pii/S1201971220322803SimulationLymphatic FilariasisTASTransmission InterruptionElimination |
| spellingShingle | Paul S. Weiss Edwin Michael Frank O. Richards, Jr. Simulating a Transmission Assessment Survey: An evaluation of current methods used in determining the elimination of the neglected tropical disease, Lymphatic Filariasis International Journal of Infectious Diseases Simulation Lymphatic Filariasis TAS Transmission Interruption Elimination |
| title | Simulating a Transmission Assessment Survey: An evaluation of current methods used in determining the elimination of the neglected tropical disease, Lymphatic Filariasis |
| title_full | Simulating a Transmission Assessment Survey: An evaluation of current methods used in determining the elimination of the neglected tropical disease, Lymphatic Filariasis |
| title_fullStr | Simulating a Transmission Assessment Survey: An evaluation of current methods used in determining the elimination of the neglected tropical disease, Lymphatic Filariasis |
| title_full_unstemmed | Simulating a Transmission Assessment Survey: An evaluation of current methods used in determining the elimination of the neglected tropical disease, Lymphatic Filariasis |
| title_short | Simulating a Transmission Assessment Survey: An evaluation of current methods used in determining the elimination of the neglected tropical disease, Lymphatic Filariasis |
| title_sort | simulating a transmission assessment survey an evaluation of current methods used in determining the elimination of the neglected tropical disease lymphatic filariasis |
| topic | Simulation Lymphatic Filariasis TAS Transmission Interruption Elimination |
| url | http://www.sciencedirect.com/science/article/pii/S1201971220322803 |
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