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Brady MA, Toubali E, Baker M, Long E, Worrell C, Ramaiah K, Graves P, Hollingsworth TD, Kelly-Hope L, Stukel D, Tripathi B, Rubin Means A, Hadley Matendechero S, Krentel A. Persons 'never treated' in mass drug administration for lymphatic filariasis: identifying programmatic and research needs from a series of research review meetings 2020-2021. Int Health 2024; 16:479-486. [PMID: 37846645 PMCID: PMC11021373 DOI: 10.1093/inthealth/ihad091] [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: 06/08/2023] [Revised: 08/22/2023] [Accepted: 09/18/2023] [Indexed: 10/18/2023] Open
Abstract
As neglected tropical disease programs rely on participation in rounds of mass drug administration (MDA), there is concern that individuals who have never been treated could contribute to ongoing transmission, posing a barrier to elimination. Previous research has suggested that the size and characteristics of the never-treated population may be important but have not been sufficiently explored. To address this critical knowledge gap, four meetings were held from December 2020 to May 2021 to compile expert knowledge on never treatment in lymphatic filariasis (LF) MDA programs. The meetings explored four questions: the number and proportion of people never treated, their sociodemographic characteristics, their infection status and the reasons why they were not treated. Meeting discussions noted key issues requiring further exploration, including how to standardize measurement of the never treated, adapt and use existing tools to capture never-treated data and ensure representation of never-treated people in data collection. Recognizing that patterns of never treatment are situation specific, participants noted measurement should be quick, inexpensive and focused on local solutions. Furthermore, programs should use existing data to generate mathematical models to understand what levels of never treatment may compromise LF elimination goals or trigger programmatic action.
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Affiliation(s)
- Molly A. Brady
- Department of Global Health, RTI International, Washington, DC 20008, USA
| | - Emily Toubali
- Neglected Tropical Diseases Division, Office of Infectious Disease, Bureau for Global Health, United States Agency for International Development, Washington, DC 20547, USA
| | - Margaret Baker
- Department of Global Health, RTI International, Washington, DC 20008, USA
- Georgetown University, Washington, DC 20057, USA
| | - Elizabeth Long
- Neglected Tropical Diseases Support Center, Task Force for Global Health, Decatur, GA 30030, USA
| | - Caitlin Worrell
- Division of Parasitic Diseases and Malaria, U.S. Centers for Disease Control and Prevention, Atlanta, GA 30329, USA
- Department of Epidemiology, Swiss Tropical and Public Health Institute, Basel 4051, Switzerland
- Faculty of Science, University of Basel, Basel 4001, Switzerland
| | - Kapa Ramaiah
- Consultant, Lymphatic Filariasis Epidemiologist, Pondicherry, India
| | - Patricia Graves
- College of Public Health, Medical and Veterinary Sciences and WHO Collaborating Centre for Vector-Borne and Neglected Tropical Diseases, James Cook University, Nguma-bada Campus, Cairns, QLD 4870, Australia
| | - T. Deirdre Hollingsworth
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, OX3 7LF, UK
| | - Louise Kelly-Hope
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
- University of Liverpool, Institute of Infection, Veterinary and Ecological Sciences, Brownlow Hill, Liverpool, L2 5RF, UK
| | - Diana Stukel
- Act to End Neglected Tropical Diseases West, Department of Global Health and Population, FHI 360, Washington, DC 20009, USA
| | - Bhupendra Tripathi
- Bill and Melinda Gates Foundation, India Country Office, New Delhi 110067, India
| | | | | | - Alison Krentel
- School of Epidemiology and Public Health, University of Ottawa, 600 Peter Morand Drive, Ottawa, ON K1G 5Z3, Canada
- Bruyère Research Institute, Ottawa, ON K1N 5C8, Canada
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Mayfield HJ, Sartorius B, Sheridan S, Howlett M, Martin BM, Thomsen R, Tofaeono-Pifeleti R, Viali S, Graves PM, Lau CL. Ongoing transmission of lymphatic filariasis in Samoa 4.5 years after one round of triple-drug mass drug administration. PLoS Negl Trop Dis 2024; 18:e0012236. [PMID: 38935622 PMCID: PMC11210818 DOI: 10.1371/journal.pntd.0012236] [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: 01/13/2024] [Accepted: 05/22/2024] [Indexed: 06/29/2024] Open
Abstract
BACKGROUND Lymphatic filariasis (LF) remains a significant global issue. To eliminate LF as a public health problem, the World Health Organization (WHO) recommends multiple rounds of mass drug administration (MDA). In certain scenarios, including when elimination targets have not been met with two-drug MDA, triple-drug MDA (using ivermectin, diethylcarbamazine and albendazole) is recommended. In this study, we report on antigen (Ag) and microfilaria (Mf) prevalence in eight primary sampling units (PSUs) in Samoa 4.5 years after one round of triple-drug MDA. METHODOLOGY In 2023, community surveys were conducted in eight PSUs that had been surveyed previously in 2018 (between 1.5 and 3.5 months post triple-drug MDA) and 2019 (six to eight-months post triple-drug MDA). Fifteen houses were randomly selected in each PSU with household members aged ≥ 5 years invited to participate. Blood samples were tested for Ag and Mf. PRINCIPAL FINDINGS Ag-positive participants were observed in six of the eight PSUs, and Ag prevalence was significantly above the 1% threshold in four PSUs. The presence of Mf-positive participants in five PSUs confirms the presence of residual active infections. CONCLUSIONS/SIGNIFICANCE This study provides evidence of persistent LF transmission in Samoa 4.5 years after one round of triple-drug MDA, confirming that one round was insufficient for interruption of transmission in this setting. Our findings highlight the negative impact of delaying MDA rounds, for example, due to public health emergencies.
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Affiliation(s)
- Helen J. Mayfield
- University of Queensland Centre for Clinical Research, The University of Queensland, Brisbane, Queensland, Australia
- School of Public Health, Faculty of Medicine, The University of Queensland, Brisbane, Queensland, Australia
| | - Benn Sartorius
- University of Queensland Centre for Clinical Research, The University of Queensland, Brisbane, Queensland, Australia
- School of Public Health, Faculty of Medicine, The University of Queensland, Brisbane, Queensland, Australia
| | - Sarah Sheridan
- University of Queensland Centre for Clinical Research, The University of Queensland, Brisbane, Queensland, Australia
- School of Public Health, Faculty of Medicine, The University of Queensland, Brisbane, Queensland, Australia
| | - Maddison Howlett
- School of Public Health, Faculty of Medicine, The University of Queensland, Brisbane, Queensland, Australia
| | - Beatris Mario Martin
- University of Queensland Centre for Clinical Research, The University of Queensland, Brisbane, Queensland, Australia
- School of Public Health, Faculty of Medicine, The University of Queensland, Brisbane, Queensland, Australia
| | | | | | - Satupaitea Viali
- School of Medicine, National University of Samoa, Apia, Samoa
- Oceania University of Medicine Samoa, Apia, Samoa
| | - Patricia M. Graves
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Queensland, Australia
| | - Colleen L. Lau
- University of Queensland Centre for Clinical Research, The University of Queensland, Brisbane, Queensland, Australia
- School of Public Health, Faculty of Medicine, The University of Queensland, Brisbane, Queensland, Australia
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Antony Oliver MC, Graham M, Gass KM, Medley GF, Clark J, Davis EL, Reimer LJ, King JD, Pouwels KB, Hollingsworth TD. Reducing the Antigen Prevalence Target Threshold for Stopping and Restarting Mass Drug Administration for Lymphatic Filariasis Elimination: A Model-Based Cost-effectiveness Simulation in Tanzania, India and Haiti. Clin Infect Dis 2024; 78:S160-S168. [PMID: 38662697 PMCID: PMC11045020 DOI: 10.1093/cid/ciae108] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/28/2024] Open
Abstract
BACKGROUND The Global Programme to Eliminate Lymphatic Filariasis (GPELF) aims to reduce and maintain infection levels through mass drug administration (MDA), but there is evidence of ongoing transmission after MDA in areas where Culex mosquitoes are the main transmission vector, suggesting that a more stringent criterion is required for MDA decision making in these settings. METHODS We use a transmission model to investigate how a lower prevalence threshold (<1% antigenemia [Ag] prevalence compared with <2% Ag prevalence) for MDA decision making would affect the probability of local elimination, health outcomes, the number of MDA rounds, including restarts, and program costs associated with MDA and surveys across different scenarios. To determine the cost-effectiveness of switching to a lower threshold, we simulated 65% and 80% MDA coverage of the total population for different willingness to pay per disability-adjusted life-year averted for India ($446.07), Tanzania ($389.83), and Haiti ($219.84). RESULTS Our results suggest that with a lower Ag threshold, there is a small proportion of simulations where extra rounds are required to reach the target, but this also reduces the need to restart MDA later in the program. For 80% coverage, the lower threshold is cost-effective across all baseline prevalences for India, Tanzania, and Haiti. For 65% MDA coverage, the lower threshold is not cost-effective due to additional MDA rounds, although it increases the probability of local elimination. Valuing the benefits of elimination to align with the GPELF goals, we find that a willingness to pay per capita government expenditure of approximately $1000-$4000 for 1% increase in the probability of local elimination would be required to make a lower threshold cost-effective. CONCLUSIONS Lower Ag thresholds for stopping MDAs generally mean a higher probability of local elimination, reducing long-term costs and health impacts. However, they may also lead to an increased number of MDA rounds required to reach the lower threshold and, therefore, increased short-term costs. Collectively, our analyses highlight that lower target Ag thresholds have the potential to assist programs in achieving lymphatic filariasis goals.
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Affiliation(s)
- Mary Chriselda Antony Oliver
- Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Cambridge, United Kingdom
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, United Kingdom
| | - Matthew Graham
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, United Kingdom
| | - Katherine M Gass
- Neglected Tropical Diseases Support Centre, The Task Force for Global Health, Decatur, Georgia, USA
| | - Graham F Medley
- Centre for Mathematical Modelling of Infectious Disease and Department of Global Health and Development, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Jessica Clark
- School of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, Glasgow, United Kingdom
| | - Emma L Davis
- Mathematics Institute and the Zeeman Institute for Systems Biology and Infectious Disease Epidemiological Research, University of Warwick, Coventry, United Kingdom
| | - Lisa J Reimer
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Jonathan D King
- Department of Control of Neglected Tropical Diseases, World Health Organization, Geneva, Switzerland
| | - Koen B Pouwels
- Health Economics Research Centre, Nuffield Department of Population Health, University of Oxford, Oxford, United Kingdom
| | - T Déirdre Hollingsworth
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, United Kingdom
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Dinesh RJ, Srividya A, Subramanian S, Krishnamoorthy K, Sabesan S, Raghorte MC, Kumar A, Jambulingam P. Coverage evaluation of mass drug administration with triple drug regimen in an evaluation unit in Nagpur district of Maharashtra, India. PLoS Negl Trop Dis 2023; 17:e0011588. [PMID: 37676897 PMCID: PMC10484419 DOI: 10.1371/journal.pntd.0011588] [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: 08/17/2022] [Accepted: 08/11/2023] [Indexed: 09/09/2023] Open
Abstract
BACKGROUND Triple drug regimen (IDA; Ivermectin, Diethylcarbamazine, Albendazole) recommended for accelerating elimination of lymphatic filariasis was launched in India in December 2018. Nagpur district in Maharashtra was one of the first five districts where this strategy was introduced. The National Vector Borne Disease Control Programme (NVBDCP) at the district reported ~85.0% treatment coverage in the first round of mass drug administration (MDA) with IDA implemented in EU-2 in Nagpur district in January 2019. As per the national guideline, a coverage evaluation survey was carried out and both quantitative and qualitative data were collected to assess the treatment coverage, the level of community preparation and identify the gaps, if any, for improvement. METHODOLOGY A Coverage Evaluation Survey (CES) following the WHO recommended protocol was conducted in one of the two evaluation units (EU-2) in Nagpur district in March 2019. Coverage Sample Builder (CSB) V2.9 tool was used to calculate the sample size, select sites and estimate drug coverage. The CSB tool followed a two-stage cluster sampling procedure to select 30 primary sampling units (ward/village as a cluster) and a list of random numbers for selecting households (HHs) in each cluster. The results were analyzed for operational indicators. Stata ver. 14.0 software was used to construct the 95% confidence limits accounting for clustering. RESULTS A total of 1601 individuals aged 5-85 years of both gender from 328 HHs were surveyed from the 30 randomly selected clusters in EU-2. The mean age was 33.8±17.6 years. Among the surveyed population, 78.0% received the drugs (programme reach) and 66.1% consumed the drugs (survey coverage). Survey coverage was significantly higher in rural (82.6%) than in urban (59.4%) and peri-urban (58.6%) areas (P<0.001). Directly observed treatment (DOT) among the surveyed population was 51.6%. Adverse events were reported among 6.9% respondents who reported to have consumed the drugs. CONCLUSION The IDA based MDA strategy could achieve just the required level of treatment coverage (~65%) in EU-2, Nagpur district, which had previously undergone several rounds of DA-MDAs (Diethylcarbamazine, Albendazole). Having achieved an effective treatment coverage of >80% in rural areas, the coverage in urban and peri-urban areas need to be improved in order to attain the impact of IDA-MDA. It is imperative to strengthen drug delivery and community preparation activities along with improved DOT especially in urban and peri-urban areas to achieve the required level of treatment coverage. Addition of ivermectin did not have any additional perceived adverse events.
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Affiliation(s)
| | | | | | | | | | | | - Ashwani Kumar
- ICMR-Vector Control Research Centre, Puducherry, India
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Willis GA, Kearns T, Mayfield HJ, Sheridan S, Thomsen R, Naseri T, David MC, Engelman D, Steer AC, Graves PM, Lau CL. Scabies prevalence after ivermectin-based mass drug administration for lymphatic filariasis, Samoa 2018-2019. PLoS Negl Trop Dis 2023; 17:e0011549. [PMID: 37607196 PMCID: PMC10497159 DOI: 10.1371/journal.pntd.0011549] [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: 12/22/2022] [Revised: 09/12/2023] [Accepted: 07/24/2023] [Indexed: 08/24/2023] Open
Abstract
BACKGROUND Scabies is a common skin infestation caused by the Sarcoptes scabei mite. Ivermectin, one of three drugs used in mass drug administration (MDA) for lymphatic filariasis, is also effective for treating scabies. Ivermectin-based MDA was first conducted in Samoa in August 2018, with ivermectin being offered to those aged ≥5 years. Here, we report scabies prevalence in Samoa after MDA. METHODS We conducted household surveys 1.5-3.5 months (Survey 1) and 6-8 months (Survey 2) after the 2018 MDA in 35 primary sampling units. We conducted clinical examination for scabies-like rash and used International Alliance for the Control of Scabies classification criteria. We estimated scabies prevalence by age, gender and region. Multivariable logistic regression was used to assess factors associated with prevalence. RESULTS We surveyed 2868 people (499 households) and 2796 people (544 households) aged 0-75 years in Surveys 1 and 2, respectively. Scabies prevalence increased from 2.4% (95% CI 2.1-2.7%) to 4.4% (95% CI 4.0-4.9%) between surveys. Scabies was associated with younger age (0-4 years: aOR 3.5 [2.9-4.2]; 5-15 years: aOR 1.6 [1.4-1.8] compared to ≥16 years), female gender (aOR 1.2 [95% CI 1.1-1.4]; region (aOR range from 1.4 [1.1-1.7] to 2.5 [2.1-3.1] between regions), large households (aOR 2.6 [2.0-3.4] households ≥13), and not taking MDA in 2018 (aOR 1.3 [95% CI 1.1-1.6]). CONCLUSIONS We found moderate prevalence of scabies in two population-representative surveys conducted within 8 months of the 2018 MDA for lymphatic filariasis. Prevalence appeared to increase between the surveys, and ongoing surveillance is recommended, particularly in young children.
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Affiliation(s)
- Gabriela A. Willis
- Research School of Population Health, Australian National University, Canberra, Australia
| | - Therese Kearns
- Menzies School of Health Research, Charles Darwin University, Darwin, Australia
| | - Helen J. Mayfield
- Research School of Population Health, Australian National University, Canberra, Australia
- School of Public Health, Faculty of Medicine, University of Queensland, Brisbane, Australia
| | - Sarah Sheridan
- National Centre for Immunisation Research and Surveillance, Sydney, Australia
| | | | | | - Michael C. David
- School of Medicine and Dentistry, Griffith University, Gold Coast, Australia
- The Daffodil Centre, The University of Sydney, a joint venture with Cancer Council NSW, Sydney, Australia
| | - Daniel Engelman
- Tropical Diseases, Murdoch Children’s Research Institute, Melbourne, Australia
| | - Andrew C. Steer
- Tropical Diseases, Murdoch Children’s Research Institute, Melbourne, Australia
| | - Patricia M. Graves
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Cairns, Australia
| | - Colleen L. Lau
- Research School of Population Health, Australian National University, Canberra, Australia
- School of Public Health, Faculty of Medicine, University of Queensland, Brisbane, Australia
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Maddren R, Phillips A, Rayment Gomez S, Forbes K, Collyer BS, Kura K, Anderson R. Individual longitudinal compliance to neglected tropical disease mass drug administration programmes, a systematic review. PLoS Negl Trop Dis 2023; 17:e0010853. [PMID: 37459369 PMCID: PMC10374057 DOI: 10.1371/journal.pntd.0010853] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 07/27/2023] [Accepted: 06/05/2023] [Indexed: 07/28/2023] Open
Abstract
Repeated distribution of preventative chemotherapy (PC) by mass drug administration forms the mainstay of transmission control for five of the 20 recognised neglected tropical diseases (NTDs); soil-transmitted helminths, schistosomiasis, lymphatic filariasis, onchocerciasis and trachoma. The efficiency of such programmes is reliant upon participants swallowing the offered treatment consistently at each round. This is measured by compliance, defined as the proportion of eligible participants swallowing treatment. Individually linked longitudinal compliance data is important for assessing the potential impact of MDA-based control programmes, yet this accurate monitoring is rarely implemented in those for NTDs. Longitudinal compliance data reported by control programmes globally for the five (PC)-NTDs since 2016 is examined, focusing on key associations of compliance with age and gender. PubMed and Web of Science was searched in January 2022 for articles written in English and Spanish, and the subsequent extraction adhered to PRISMA guidelines. Study title screening was aided by Rayyan, a machine learning software package. Studies were considered for inclusion if primary compliance data was recorded for more than one time point, in a population larger than 100 participants. All data analysis was conducted in R. A total of 89 studies were identified containing compliance data, 57 were longitudinal studies, of which 25 reported individually linked data reported by varying methods. The association of increasing age with the degree of systematic treatment was commonly reported. The review is limited by the paucity of data published on this topic. The varying and overlapping terminologies used to describe coverage (receiving treatment) and compliance (swallowing treatment) is reviewed. Consequently, it is recommended that WHO considers clearly defining the terms for coverage, compliance, and longitudinal compliance which are currently contradictory across their NTD treatment guidelines. This review is registered with PROSPERO (number: CRD42022301991).
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Affiliation(s)
- Rosie Maddren
- Department of Infectious Disease Epidemiology, Imperial College London, Saint Mary's Campus, Norfolk Place, London, United Kingdom
| | - Anna Phillips
- Department of Infectious Disease Epidemiology, Imperial College London, Saint Mary's Campus, Norfolk Place, London, United Kingdom
- FHI 360, Durham, North Carolina, United States of America
| | - Santiago Rayment Gomez
- Department of Infectious Disease Epidemiology, Imperial College London, Saint Mary's Campus, Norfolk Place, London, United Kingdom
| | - Kathryn Forbes
- Department of Infectious Disease Epidemiology, Imperial College London, Saint Mary's Campus, Norfolk Place, London, United Kingdom
- London Centre for Neglected Tropical Disease Research (LCNTDR), Imperial College London, Saint Mary's Campus, Norfolk Place, London, United Kingdom
| | - Benjamin S Collyer
- Department of Infectious Disease Epidemiology, Imperial College London, Saint Mary's Campus, Norfolk Place, London, United Kingdom
| | - Klodeta Kura
- Department of Infectious Disease Epidemiology, Imperial College London, Saint Mary's Campus, Norfolk Place, London, United Kingdom
| | - Roy Anderson
- Department of Infectious Disease Epidemiology, Imperial College London, Saint Mary's Campus, Norfolk Place, London, United Kingdom
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Shaw C, McLure A, Graves PM, Lau CL, Glass K. Lymphatic filariasis endgame strategies: Using GEOFIL to model mass drug administration and targeted surveillance and treatment strategies in American Samoa. PLoS Negl Trop Dis 2023; 17:e0011347. [PMID: 37200375 DOI: 10.1371/journal.pntd.0011347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 05/31/2023] [Accepted: 04/29/2023] [Indexed: 05/20/2023] Open
Abstract
American Samoa underwent seven rounds of mass drug administration (MDA) for lymphatic filariasis (LF) from 2000-2006, but subsequent surveys found evidence of ongoing transmission. American Samoa has since undergone further rounds of MDA in 2018, 2019, and 2021; however, recent surveys indicate that transmission is still ongoing. GEOFIL, a spatially-explicit agent-based LF model, was used to compare the effectiveness of territory-wide triple-drug MDA (3D-MDA) with targeted surveillance and treatment strategies. Both approaches relied on treatment with ivermectin, diethylcarbamazine, and albendazole. We simulated three levels of whole population coverage for 3D-MDA: 65%, 73%, and 85%, while the targeted strategies relied on surveillance in schools, workplaces, and households, followed by targeted treatment. In the household-based strategies, we simulated 1-5 teams travelling village-to-village and offering antigen (Ag) testing to randomly selected households in each village. If an Ag-positive person was identified, treatment was offered to members of all households within 100m-1km of the positive case. All simulated interventions were finished by 2027 and their effectiveness was judged by their 'control probability'-the proportion of simulations in which microfilariae prevalence decreased between 2030 and 2035. Without future intervention, we predict Ag prevalence will rebound. With 3D-MDA, a 90% control probability required an estimated ≥ 4 further rounds with 65% coverage, ≥ 3 rounds with 73% coverage, or ≥ 2 rounds with 85% coverage. While household-based strategies were substantially more testing-intensive than 3D-MDA, they could offer comparable control probabilities with substantially fewer treatments; e.g. three teams aiming to test 50% of households and offering treatment to a 500m radius had approximately the same control probability as three rounds of 73% 3D-MDA, but used < 40% the number of treatments. School- and workplace-based interventions proved ineffective. Regardless of strategy, reducing Ag prevalence below the 1% target threshold recommended by the World Health Organization was a poor indicator of the interruption of LF transmission, highlighting the need to review blanket elimination targets.
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Affiliation(s)
- Callum Shaw
- National Centre for Epidemiology and Population Health, Australian National University, Canberra, ACT, Australia
| | - Angus McLure
- National Centre for Epidemiology and Population Health, Australian National University, Canberra, ACT, Australia
| | - Patricia M Graves
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Cairns, Queensland, Australia
| | - Colleen L Lau
- School of Public Health, Faculty of Medicine, The University of Queensland, Brisbane, Queensland, Australia
| | - Kathryn Glass
- National Centre for Epidemiology and Population Health, Australian National University, Canberra, ACT, Australia
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Evaluating Molecular Xenomonitoring as a Tool for Lymphatic Filariasis Surveillance in Samoa, 2018-2019. Trop Med Infect Dis 2022; 7:tropicalmed7080203. [PMID: 36006295 PMCID: PMC9414188 DOI: 10.3390/tropicalmed7080203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 08/09/2022] [Accepted: 08/12/2022] [Indexed: 11/17/2022] Open
Abstract
Molecular xenomonitoring (MX), the detection of filarial DNA in mosquitoes using molecular methods (PCR), is a potentially useful surveillance strategy for lymphatic filariasis (LF) elimination programs. Delay in filarial antigen (Ag) clearance post-treatment is a limitation of using human surveys to provide an early indicator of the impact of mass drug administration (MDA), and MX may be more useful in this setting. We compared prevalence of infected mosquitoes pre- and post-MDA (2018 and 2019) in 35 primary sampling units (PSUs) in Samoa, and investigated associations between the presence of PCR-positive mosquitoes and Ag-positive humans. We observed a statistically significant decline in estimated mosquito infection prevalence post-MDA at the national level (from 0.9% to 0.3%, OR 0.4) but no change in human Ag prevalence during this time. Ag prevalence in 2019 was higher in randomly selected PSUs where PCR-positive pools were detected (1.4% in ages 5–9; 4.8% in ages ≥10), compared to those where PCR-positive pools were not detected (0.2% in ages 5–9; 3.2% in ages ≥10). Our study provides promising evidence for MX as a complement to human surveys in post-MDA surveillance.
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Bhoj P, Togre N, Khatri V, Goswami K. Harnessing Immune Evasion Strategy of Lymphatic Filariae: A Therapeutic Approach against Inflammatory and Infective Pathology. Vaccines (Basel) 2022; 10:vaccines10081235. [PMID: 36016123 PMCID: PMC9415972 DOI: 10.3390/vaccines10081235] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 07/27/2022] [Accepted: 07/29/2022] [Indexed: 02/04/2023] Open
Abstract
Human lymphatic filariae have evolved numerous immune evasion strategies to secure their long-term survival in a host. These strategies include regulation of pattern recognition receptors, mimicry with host glycans and immune molecules, manipulation of innate and adaptive immune cells, induction of apoptosis in effector immune cells, and neutralization of free radicals. This creates an anti-inflammatory and immunoregulatory milieu in the host: a modified Th2 immune response. Therefore, targeting filarial immunomodulators and manipulating the filariae-driven immune system against the filariae can be a potential therapeutic and prophylactic strategy. Filariae-derived immunosuppression can also be exploited to treat other inflammatory diseases and immunopathologic states of parasitic diseases, such as cerebral malaria, and to prevent leishmaniasis. This paper reviews immunomodulatory mechanisms acquired by these filariae for their own survival and their potential application in the development of novel therapeutic approaches against parasitic and inflammatory diseases. Insight into the intricate network of host immune-parasite interactions would aid in the development of effective immune-therapeutic options for both infectious and immune-pathological diseases.
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Affiliation(s)
| | - Namdev Togre
- Department of Biological Sciences, University of Texas, El Paso, TX 79968, USA
- Correspondence: (N.T.); (K.G.)
| | | | - Kalyan Goswami
- All India Institute of Medical Sciences, Saguna, Kalyani 741245, India
- Correspondence: (N.T.); (K.G.)
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Abuelazm MT, Abdelazeem B, Badr H, Gamal M, Ashraf M, Abd‐elsalam S. Efficacy and Safety of Triple Therapy Versus Dual Therapy for Lymphatic Filariasis: A Systematic Review and Meta‐Analysis. Trop Med Int Health 2022; 27:226-235. [PMID: 35080325 DOI: 10.1111/tmi.13727] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | - Basel Abdelazeem
- McLaren Health Care, Flint/ Michigan State University Michigan USA
| | - Helmy Badr
- Faculty of Medicine Tanta University Tanta Egypt
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Graves PM, Joseph H, Coutts SP, Mayfield HJ, Maiava F, Ah Leong-Lui TA, Tupuimatagi Toelupe P, Toeaso Iosia V, Loau S, Pemita P, Naseri T, Thomsen R, Berg Soto A, Burkot TR, Wood P, Melrose W, Aratchige P, Capuano C, Kim SH, Ozaki M, Yajima A, Lammie PJ, Ottesen E, Hansell L, Baghirov R, Lau CL, Ichimori K. Control and elimination of lymphatic filariasis in Oceania: Prevalence, geographical distribution, mass drug administration, and surveillance in Samoa, 1998-2017. ADVANCES IN PARASITOLOGY 2021; 114:27-73. [PMID: 34696844 DOI: 10.1016/bs.apar.2021.03.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Lymphatic filariasis (LF) is a major public health problem globally and in the Pacific Region. The Global Programme to Eliminate LF has made great progress but LF is persistent and resurgent in some Pacific countries and territories. Samoa remains endemic for LF despite elimination efforts through multiple two-drug mass drug administrations (MDA) since 1965, including renewed elimination efforts started in 1999 under the Pacific Programme for Elimination of LF (PacELF). Despite eight rounds of national and two rounds of subnational MDA under PacELF, Samoa failed transmission assessment surveys (TAS) in all three evaluation units in 2017. In 2018, Samoa was the first to distribute countrywide triple-drug MDA using ivermectin, diethylcarbamazine (DEC), and albendazole. This paper provides a review of MDAs and historical survey results from 1998 to 2017 in Samoa and highlights lessons learnt from LF elimination efforts, including challenges and potential ways to overcome them to successfully achieve elimination.
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Affiliation(s)
- Patricia M Graves
- College of Public Health, Medical and Veterinary Sciences, Australian Institute of Tropical Health and Medicine, and JCU WHO Collaborating Centre for Vector-Borne and Neglected Tropical Diseases, James Cook University, Cairns and Townsville, QLD, Australia.
| | - Hayley Joseph
- Division of Population Health and Immunity, Walter and Eliza Hall Institute of Medical Research and Department of Medical Biology, The University of Melbourne, Melbourne, VIC, Australia
| | - Shaun P Coutts
- Research School of Population Health, ANU College of Health and Medicine, The Australian National University, Canberra, ACT, Australia
| | - Helen J Mayfield
- School of Public Health, University of Queensland, Brisbane, QLD, Australia
| | | | | | | | | | - Siatua Loau
- Ministry of Health and Health Services, Apia, Samoa
| | - Paulo Pemita
- Ministry of Health and Health Services, Apia, Samoa
| | - Take Naseri
- Ministry of Health and Health Services, Apia, Samoa
| | | | - Alvaro Berg Soto
- College of Public Health, Medical and Veterinary Sciences, Australian Institute of Tropical Health and Medicine, and JCU WHO Collaborating Centre for Vector-Borne and Neglected Tropical Diseases, James Cook University, Cairns and Townsville, QLD, Australia
| | - Thomas R Burkot
- College of Public Health, Medical and Veterinary Sciences, Australian Institute of Tropical Health and Medicine, and JCU WHO Collaborating Centre for Vector-Borne and Neglected Tropical Diseases, James Cook University, Cairns and Townsville, QLD, Australia
| | - Peter Wood
- College of Public Health, Medical and Veterinary Sciences, Australian Institute of Tropical Health and Medicine, and JCU WHO Collaborating Centre for Vector-Borne and Neglected Tropical Diseases, James Cook University, Cairns and Townsville, QLD, Australia
| | - Wayne Melrose
- College of Public Health, Medical and Veterinary Sciences, Australian Institute of Tropical Health and Medicine, and JCU WHO Collaborating Centre for Vector-Borne and Neglected Tropical Diseases, James Cook University, Cairns and Townsville, QLD, Australia
| | | | | | - Sung Hye Kim
- WHO Division of Pacific Technical Support, Suva, Fiji
| | - Masayo Ozaki
- WHO Division of Pacific Technical Support, Suva, Fiji
| | - Aya Yajima
- WHO Regional Office for the Western Pacific, Manila, Philippines
| | | | - Eric Ottesen
- Task Force for Global Health, Atlanta, GA, United States
| | | | | | - Colleen L Lau
- Research School of Population Health, ANU College of Health and Medicine, The Australian National University, Canberra, ACT, Australia; School of Public Health, University of Queensland, Brisbane, QLD, Australia
| | - Kazuyo Ichimori
- College of Public Health, Medical and Veterinary Sciences, Australian Institute of Tropical Health and Medicine, and JCU WHO Collaborating Centre for Vector-Borne and Neglected Tropical Diseases, James Cook University, Cairns and Townsville, QLD, Australia
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Graves PM, Sheridan S, Scott J, Amosa-Lei Sam F, Naseri T, Thomsen R, King CL, Lau CL. Triple-Drug Treatment Is Effective for Lymphatic Filariasis Microfilaria Clearance in Samoa. Trop Med Infect Dis 2021; 6:tropicalmed6020044. [PMID: 33916264 PMCID: PMC8167748 DOI: 10.3390/tropicalmed6020044] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 03/26/2021] [Accepted: 03/31/2021] [Indexed: 11/16/2022] Open
Abstract
Following the first triple-drug mass drug administration (MDA) for lymphatic filariasis in Samoa in 2018, unexpected persistence of microfilaria (Mf) positivity in 18 (15%) of 121 antigen-positive persons was observed in a nationwide household survey 1–2 months later. Of the 18 Mf positive persons, 14 reported taking the MDA, raising concerns about MDA efficacy. In 2019, 5–6 months after the 2018 survey, a monitored treatment study was done to evaluate directly observed weight-based treatment in these Mf positive individuals. Mf presence and density were assessed before and 7 days after treatment, using 1 mL membrane filtered venous blood, and 60 uL thick blood films on slides prepared from venous or fingerprick blood. All 14 participants were still Mf positive on filters from venous blood pre-treatment samples, but two were negative by slide made from the same samples. Mf were cleared completely by day 7 in 12 of 13 participants followed up, and by day 30 in the remaining participant. Filtered blood using EDTA samples (to reduce clumping of Mf) is preferred over slides alone for improving the likelihood of detecting Mf and estimating their density. The triple-drug MDA strategy was effective at clearing Mf when given and taken at the correct dose.
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Affiliation(s)
- Patricia M. Graves
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Cairns, QLD 4870 and Townsville, QLD 4811, Australia;
- Correspondence: ; Tel.: +61-(0)-424-096571
| | - Sarah Sheridan
- School of Public Health and Community Medicine, University of New South Wales, Sydney NSW 2033, Australia;
| | - Jessica Scott
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Cairns, QLD 4870 and Townsville, QLD 4811, Australia;
| | | | - Take Naseri
- Ministry of Health, Apia, Samoa; (T.N.); (R.T.)
| | | | - Christopher L. King
- Center for Global Health, School of Medicine and Veterans Affairs Administration, Case Western Reserve University, Cleveland, OH 44106, USA;
| | - Colleen L. Lau
- School of Public Health, The University of Queensland, Brisbane, QLD 4006, Australia;
- Research School of Population Health, The Australian National University, Canberra, ACT 2601, Australia
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Lau CL, Meder K, Mayfield HJ, Kearns T, McPherson B, Naseri T, Thomsen R, Hedtke SM, Sheridan S, Gass K, Graves PM. Lymphatic filariasis epidemiology in Samoa in 2018: Geographic clustering and higher antigen prevalence in older age groups. PLoS Negl Trop Dis 2020; 14:e0008927. [PMID: 33347456 PMCID: PMC7785238 DOI: 10.1371/journal.pntd.0008927] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 01/05/2021] [Accepted: 10/28/2020] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Samoa conducted eight nationwide rounds of mass drug administration (MDA) for lymphatic filariasis (LF) between 1999 and 2011, and two targeted rounds in 2015 and 2017 in North West Upolu (NWU), one of three evaluation units (EUs). Transmission Assessment Surveys (TAS) were conducted in 2013 (failed in NWU) and 2017 (all three EUs failed). In 2018, Samoa was the first in the world to distribute nationwide triple-drug MDA using ivermectin, diethylcarbamazine, and albendazole. Surveillance and Monitoring to Eliminate LF and Scabies from Samoa (SaMELFS Samoa) is an operational research program designed to evaluate the effectiveness of triple-drug MDA on LF transmission and scabies prevalence in Samoa, and to compare the usefulness of different indicators of LF transmission. This paper reports results from the 2018 baseline survey and aims to i) investigate antigen (Ag) prevalence and spatial epidemiology, including geographic clustering; ii) compare Ag prevalence between two different age groups (5-9 years versus ≥10 years) as indicators of areas of ongoing transmission; and iii) assess the prevalence of limb lymphedema in those aged ≥15 years. METHODS A community-based cluster survey was conducted in 30 randomly selected and five purposively selected clusters (primary sampling units, PSUs), each comprising one or two villages. Participants were recruited through household surveys (age ≥5 years) and convenience surveys (age 5-9 years). Alere Filariasis Test Strips (FTS) were used to detect Ag, and prevalence was adjusted for survey design and standardized for age and gender. Adjusted Ag prevalence was estimated for each age group (5-9, ≥10, and all ages ≥5 years) for random and purposive PSUs, and by region. Intraclass correlation (ICC) was used to quantify clustering at regions, PSUs, and households. RESULTS A total of 3940 persons were included (1942 children aged 5-9 years, 1998 persons aged ≥10 years). Adjusted Ag prevalence in all ages ≥5 years in randomly and purposively selected PSUs were 4.0% (95% CI 2.8-5.6%) and 10.0% (95% CI 7.4-13.4%), respectively. In random PSUs, Ag prevalence was lower in those aged 5-9 years (1.3%, 95% CI 0.8-2.1%) than ≥10 years (4.7%, 95% CI 3.1-7.0%), and poorly correlated at the PSU level (R-square = 0.1459). Adjusted Ag prevalence in PSUs ranged from 0% to 10.3% (95% CI 5.9-17.6%) in randomly selected and 3.8% (95% CI 1.3-10.8%) to 20.0% (95% CI 15.3-25.8%) in purposively selected PSUs. ICC for Ag-positive individuals was higher at households (0.46) compared to PSUs (0.18) and regions (0.01). CONCLUSIONS Our study confirmed ongoing transmission of LF in Samoa, in accordance with the 2017 TAS results. Ag prevalence varied significantly between PSUs, and there was poor correlation between prevalence in 5-9 year-olds and older ages, who had threefold higher prevalence. Sampling older age groups would provide more accurate estimates of overall prevalence, and be more sensitive for identifying residual hotspots. Higher prevalence in purposively selected PSUs shows local knowledge can help identify at least some hotspots.
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Affiliation(s)
- Colleen L. Lau
- Research School of Population Health, Australian National University, Canberra, Australia
- * E-mail:
| | - Kelley Meder
- Research School of Population Health, Australian National University, Canberra, Australia
| | - Helen J. Mayfield
- Research School of Population Health, Australian National University, Canberra, Australia
| | - Therese Kearns
- Menzies School of Health Research, Charles Darwin University, Brisbane, Australia
| | - Brady McPherson
- Research School of Population Health, Australian National University, Canberra, Australia
| | | | | | - Shannon M. Hedtke
- Department of Physiology, Anatomy and Microbiology, La Trobe University, Bundoora, Victoria, Australia
| | - Sarah Sheridan
- School of Public Health and Community Medicine, University of New South Wales, Sydney, Australia
| | - Katherine Gass
- Neglected Tropical Diseases Support Center, The Task Force for Global Heath, Decatur, Georgia, United States of America
| | - Patricia M. Graves
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Cairns, Queensland, Australia
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