The global distribution of lymphatic filariasis, 2000–18: a geospatial analysis
Authors: Elizabeth A Cromwell, Chris A Schmidt, Kevin T Kwong, David M Pigott, Denise Mupfasoni, Gautam Biswas, Shreya Shirude, Elex Hill, Katie M Donkers, Amir Abdoli, Michael R M Abrigo, Victor Adekanmbi, Olatunji O Adetokunboh Sr., Srividya Adinarayanan, Ehsan Ahmadpour, Muktar Beshir Ahmed, Temesgen Yihunie Akalu, Fahad Mashhour Alanezi, Turki M Alanzi, Cyrus Alinia, Vahid Alipour, Arianna Maever L Amit Sr., Nahla Hamed Anber, Robert Ancuceanu, Zewudu Andualem, Mina Anjomshoa, Fereshteh Ansari, Carl Abelardo T Antonio, Davood Anvari, Seth Christopher Yaw Appiah, Jalal Arabloo, Benjamin F Arnold, Marcel Ausloos, Martin Amogre Ayanore Sr., Alireza Badirzadeh, Atif Amin Baig Jr., Maciej Banach Sr., Adhanom Gebreegziabher Baraki Sr., Till Winfried Bärnighausen, Mohsen Bayati, Krittika Bhattacharyya Sr., Zulfiqar A Bhutta, Ali Bijani, Donal Bisanzio, Moses John Bockarie, Somayeh Bohlouli, Mehdi Bohluli, Zahid A Butt, Jorge Cano, Felix Carvalho, Vijay Kumar Chattu, Ali Reza Chavshin, Natalie Maria Cormier, Giovanni Damiani, Lalit Dandona, Rakhi Dandona, Aso Mohammad Darwesh, Ahmad Daryani, Aditya Prasad Dash, Kebede Deribe, Aniruddha Deshpande, Blen Kassahun Dessu, Meghnath Dhimal, Mostafa Dianatinasab, Daniel Diaz, Hoa Thi Do, Lucas Earl, Maha El Tantawi, Anwar Faraj, Nazir Fattahi, Eduarda Fernandes, Florian Fischer, Nataliya A Foigt, Masoud Foroutan, Yuming Guo, Gessessew Bugssa Hailu, Ahmed I Hasaballah, Hadi Hassankhani, Claudiu Herteliu, Hagos Degefa de Hidru, Michael K Hole, Julia Hon, Naznin Hossain, Mehdi Hosseinzadeh, Mowafa Househ, Ayesha Humayun, Olayinka Stephen Ilesanmi, Irena M Ilic, Milena D Ilic, Usman Iqbal, Seyed Sina Naghibi Irvani, M Mofizul Islam, Ravi Prakash Jha, John S Ji, Kimberly B Johnson, Jacek Jerzy Jozwiak, Ali Kabir, Leila R Kalankesh, Rohollah Kalhor, Behzad Karami Matin, André Karch, Salah Eddin Karimi, Amir Kasaeian, Gbenga A Kayode, Ali Kazemi Karyani, Abraham Getachew Kelbore, Morteza Abdullatif Khafaie, Rovshan Khalilov, Junaid Khan, Khaled Khatab, Mona M Khater, Mohammad Taghi Khodayari, Neda Kianipour, Yun Jin Kim, Damaris K Kinyoki, G Anil Kumar, Dian Kusuma, Carlo La Vecchia, Van Charles Lansingh, Paul H Lee, Kate E LeGrand, Aubrey J Levine, Shanshan Li, Shokofeh Maleki, Mohammad Ali Mansournia, Francisco Rogerlândio Martins-Melo, Benjamin Ballard Massenburg, Benjamin K Mayala, Wahengbam Bigyananda Meitei, Walter Mendoza, Desalegn Tadese Mengistu, Seid Tiku Mereta, Tomislav Mestrovic, Kebadnew Mulatu Mihretie, Molly K Miller-Petrie, Abdollah Mohammadian-Hafshejani, Shafiu Mohammed, Ali H Mokdad, Masoud Moradi, Rahmatollah Moradzadeh, Paula Moraga, Shane Douglas Morrison, Jonathan F Mosser, Seyyed Meysam Mousavi, Sandra B Munro, Saravanan Muthupandian, Upendo J mwingira, Mehdi Naderi, Ahamarshan Jayaraman Nagarajan, Gurudatta Naik, Ionut Negoi, Trang Huyen Nguyen, Huong Lan Thi Nguyen, Andrew T Olagunju, Ahmed Omar Bali, Osayomwanbo Osarenotor, Frank B Osei, Deepak Kumar Pasupula, Meghdad Pirsaheb, Hadi Pourjafar, Priya Rathi, David Laith Rawaf, Salman Rawaf, Reza Rawassizadeh, Robert C Reiner Jr, Melese Abate Reta, Aziz Rezapour, Ana Isabel Ribeiro, Ali Rostami, Shanmugavelu Sabesan, Ehsan Sadeghi, S Mohammad Sajadi, Abdallah M Samy, Benn Sartorius, Lauren E Schaeffer, Masood Ali Shaikh, Kiomars Sharafi, Zeinab Sharafi, Hamid Sharifi, Kenji Shibuya, Jae Il Shin, Amin Soheili, Shahin Soltani, Adel Spotin, Wilma A Stolk, Berhe Etsay Tesfay, Akhil Soman ThekkePurakkal, Roman Topor-Madry, Khanh Bao Tran, Bach Xuan Tran, Irfan Ullah, Bhaskaran Unnikrishnan, Yasser Vasseghian, Natalie V S Vinkeles Melchers, Francesco S Violante, Tomohide Yamada, Sanni Yaya, Vahid Yazdi-Feyzabadi, Paul Yip, Naohiro Yonemoto, Leila Zaki, Sojib Bin Zaman, Maryam Zamanian, Alireza Zangeneh, Zhi-Jiang Zhang, Yunquan Zhang, Arash Ziapour, Jonathan D King, Simon I Hay
Journal: The Lancet Global Health (2020)

Lymphatic filariasis is a neglected tropical disease that can cause permanent disability through disruption of the lymphatic system. This disease is caused by parasitic filarial worms that are transmitted by mosquitos. Mass drug administration (MDA) of antihelmintics is recommended by WHO to eliminate lymphatic filariasis as a public health problem. This study aims to produce the first geospatial estimates of the global prevalence of lymphatic filariasis infection over time, to quantify progress towards elimination, and to identify geographical variation in distribution of infection.A global dataset of georeferenced surveyed locations was used to model annual 2000-18 lymphatic filariasis prevalence for 73 current or previously endemic countries. We applied Bayesian model-based geostatistics and time series methods to generate spatially continuous estimates of global all-age 2000-18 prevalence of lymphatic filariasis infection mapped at a resolution of 5 km2 and aggregated to estimate total number of individuals infected.We used 14 927 datapoints to fit the geospatial models. An estimated 199 million total individuals (95% uncertainty interval 174-234 million) worldwide were infected with lymphatic filariasis in 2000, with totals for WHO regions ranging from 3·1 million (1·6-5·7 million) in the region of the Americas to 107 million (91-134 million) in the South-East Asia region. By 2018, an estimated 51 million individuals (43-63 million) were infected. Broad declines in prevalence are observed globally, but focal areas in Africa and southeast Asia remain less likely to have attained infection prevalence thresholds proposed to achieve local elimination.Although the prevalence of lymphatic filariasis infection has declined since 2000, MDA is still necessary across large populations in Africa and Asia. Our mapped estimates can be used to identify areas where the probability of meeting infection thresholds is low, and when coupled with large uncertainty in the predictions, indicate additional data collection or intervention might be warranted before MDA programmes cease.Bill & Melinda Gates Foundation.