Tag: Lymphatic Filariasis

A key component to achieving the global goal of elimination of lymphatic filariasis (LF) is the availability of appropriate tools for disease mapping, monitoring, and surveillance. However, the development of these tools for a neglected disease such as LF can be a challenge. The lack of a commercial market and low familiarity with these diseases leave little incentive for diagnostic manufacturers to invest in this space. The Filarial Test Strip (FTS) development story provides a case study on how a multi-stakeholder, public-private partnership model facilitated the development, evaluation, and introduction of a new monitoring and surveillance tool for LF. This paper will reflect on the experience with the FTS and document the process from development of the target product profile to adoption and scale-up in country programs. Lessons learned from both the successes and challenges experienced during this process may help inform future efforts to develop and introduce new diagnostic or surveillance tools for neglected diseases.

Anastasia Pantelias, Jonathan D King, Patrick Lammie, Gary J Weil. Am J Trop Med Hyg. 2022 Mar 15;tpmd210990. doi: 10.4269/ajtmh.21-0990.

As lymphatic filariasis (LF) programs move closer to established targets for validation elimination of LF as a public health problem, diagnostic tools capable of supporting the needs of the programs are critical for success. Known limitations of existing diagnostic tools make it challenging to have confidence that program endpoints have been achieved. In 2019, the World Health Organization (WHO) established a Diagnostic Technical Advisory Group (DTAG) for Neglected Tropical Diseases tasked with prioritizing diagnostic needs including defining use-cases and target product profiles (TPPs) for needed tools. Subsequently, disease-specific DTAG subgroups, including one focused on LF, were established to develop TPPs and use-case analyses to be used by product developers. Here, we describe the development of two priority TPPs for LF diagnostics needed for making decisions for stopping mass drug administration (MDA) of a triple drug regimen and surveillance. Utilizing the WHO core TPP development process as the framework, the LF subgroup convened to discuss and determine attributes required for each use case. TPPs considered the following parameters: product use, design, performance, product configuration and cost, and access and equity. Version 1.0 TPPs for two use cases were published by WHO on 12 March 2021 within the WHO Global Observatory on Health Research and Development. A common TPP characteristic that emerged in both use cases was the need to identify new biomarkers that would allow for greater precision in program delivery. As LF diagnostic tests are rarely used for individual clinical diagnosis, it became apparent that reliance on population-based surveys for decision making requires consideration of test performance in the context of such surveys. In low prevalence settings, the number of false positive test results may lead to unnecessary continuation or resumption of MDA, thus wasting valuable resources and time. Therefore, highly specific diagnostic tools are paramount when used to measure low thresholds. The TPP process brought to the forefront the importance of linking use case, program platform and diagnostic performance characteristics when defining required criteria for diagnostic tools.

Kimberly Y Won, Katherine Gass, Marco Biamonte, Daniel Argaw Dagne, Camilla Ducker, Christopher Hanna, Achim Hoerauf, Patrick J Lammie, Sammy M Njenga, Rahmah Noordin, Kapa D Ramaiah, Reda Ramzy, Ronaldo G Carvalho Scholte, Anthony W Solomon, Ashley A Souza, Jordan Tappero, Emily Toubali, Gary J Weil, Steven A Williams, Jonathan D King. PLoS Negl Trop Dis 15(11): e0009968. https://doi.org/10.1371/journal.pntd.0009968

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.

Patricia M Graves, Hayley Joseph, Shaun P Coutts, Helen J Mayfield, Fuatai Maiava, Tile Ann Ah Leong-Lui, Palanitina Tupuimatagi Toelupe, Vailolo Toeaso Iosia, Siatua Loau, Paulo Pemita, Take Naseri, Robert Thomsen, Alvaro Berg Soto, Thomas R Burkot, Peter Wood, Wayne Melrose, Padmasiri Aratchige, Corinne Capuano, Sung Hye Kim, Masayo Ozaki, Aya Yajima, Patrick J Lammie, Eric Ottesen, Lepaitai Hansell, Rasul Baghirov, Colleen L Lau, Kazuyo Ichimori. Adv Parasitol. 2021;114:27-73. doi: 10.1016/bs.apar.2021.03.002

The Global Programme to Eliminate Lymphatic Filariasis (GPELF) was established with the ambitious goal of eliminating LF as a public health problem. The remarkable success of the GPELF over the past 2 decades in carrying out its principal strategy of scaling up and scaling down mass drug administration has relied first on the development of a rigorous monitoring and evaluation (M&E) framework and then the willingness of the World Health Organization and its community of partners to modify this framework in response to the practical experiences of national programmes. This flexibility was facilitated by the strong partnership that developed among researchers, LF programme managers and donors willing to support the necessary research agenda. This brief review summarizes the historical evolution of the GPELF M&E strategies and highlights current research needed to achieve the elimination goal.

Patrick J Lammie, Katherine M Gass, Jonathan King, Michael S Deming, David G Addiss, Gautam Biswas, Eric A Ottesen, Ralph Henderson. Int Health. 2020 Dec 22;13(Supplement_1):S65-S70. doi: 10.1093/inthealth/ihaa084.