Two decades of lymphatic filariasis elimination efforts in Nigeria: History, progress, challenges, and prospects for achieving the 2030 targets

Introduction Lymphatic filariasis (LF) is one of the priority neglected tropical diseases targeted for elimination by 2030 in 58 endemic countries, including Nigeria, through a dual strategy of interrupting transmission and providing morbidity management and disability prevention (MMDP) services. Only two African countries (Togo and Malawi) have eliminated the disease. The extent to which other African countries have progressed towards elimination is uncertain. It will be helpful to understand the progress endemic countries are making towards elimination. Here, a comprehensive review of the history, progress and prospects for achieving 2030 elimination targets in Nigeria, the most endemic country for LF in Africa was provided. This review will be useful in evaluating the extent of investment that is required before elimination can be achieved in Nigeria. Methods Programmatic data was extracted from the National Lymphatic Filariasis Elimination Programme (NLFEP) database for endemicity, treatment history, mass administration of medicines (MAM) coverage, epidemiological assessments, and morbidity management across 774 Local Government Areas (LGAs) in Nigeria. Status of endemic LGAs were identified, and those that had completed a minimum of five effective MAM rounds were assessed on their progress of elimination using the recommended Transmission Assessment Survey (TAS) and Morbidity Management and Disability Prevention (MMDP) guidelines. The number of LGAs expected to achieve LF elimination by 2030 was forecasted. All statistical analyses and visualizations were descriptive and performed in R software (v4.5.2). Findings Nigeria completed LF mapping in all 774 LGAs between 2000 and 2011, revealing 583 endemic LGAs. All the endemic LGAs (herein referred to as implementation units (IUs)) received 3–15 rounds of MAM between 2000 and 2015, and 529 (90.7%) completed the required five effective MAM rounds. As of 2024, 445 (76.3%) passed Epidemiological Monitoring Survey (EMS), 346 (59.3%) passed TAS-1 and stopped MAM, while 40 (6.9%) passed TAS-2 and 30 (5.1%) passed TAS-3 (achieve elimination). By 2030, we project that MAM would have stopped in 497 Evaluation Units (EUs) i.e., 85.2% of all IUs, and 309 (62.2%) of those would have passed TAS-3 (achieve elimination). However, under a conservative assumption that 3–5% of planned surveys can fail, these figures could decline to 454 (77.9%) EUs stopping MAM and 284 achieving elimination. For MMDP, Lymphoedema was reported in 450 IUs, totaling 7,824 cases, with 5,828 (74.5%) actively managed. Hydrocele was reported across 503 IUs, with 22,195 documented cases, 72.4% of which received management. Conclusion Nigeria has made substantial progress toward the elimination of lymphatic filariasis. The overall trajectory suggests that Nigeria remains on course to stop MAM and achieve elimination in 85% and 53% of all IUs, respectively.