Mapping geographical inequalities in access to drinking water and sanitation facilities in low-income and middle-income countries, 2000–17
Authors: Aniruddha Deshpande, Molly K Miller-Petrie, Paulina A Lindstedt, Mathew M Baumann, Kimberly B Johnson, Brigette F Blacker, Hedayat Abbastabar, Foad Abd-Allah, Ahmed Abdelalim, Ibrahim Abdollahpour, Kedir Hussein Abegaz, Ayenew Negesse Abejie, Lucas Guimarães Abreu, Michael R.M. Abrigo, Ahmed Abualhasan, Manfred Mario Kokou Accrombessi, Abdu A Adamu, Oladimeji M Adebayo, Isaac Akinkunmi Adedeji, Rufus Adesoji Adedoyin, Victor Adekanmbi, Olatunji O Adetokunboh, Tara Ballav Adhikari, Mohsen Afarideh, Marcela Agudelo-Botero, Mehdi Ahmadi, Keivan Ahmadi, Muktar Beshir Ahmed, Anwar E Ahmed, Temesgen Yihunie Akalu, Ali S Akanda, Fares Alahdab, Ziyad Al-Aly, Samiah Alam, Noore Alam, Genet Melak Alamene, Turki M Alanzi, James Albright, Ammar Albujeer, Jacqueline Elizabeth Alcalde-Rabanal, Animut Alebel, Zewdie Aderaw Alemu, Muhammad Ali, Mehran Alijanzadeh, Vahid Alipour, Syed Mohamed Aljunid, Ali Almasi, Amir Almasi-Hashiani, Hesham M Al-Mekhlafi, Khalid A Altirkawi, Nelson Alvis-Guzman, Nelson J. Alvis-Zakzuk, Saeed Amini, Arianna Maever L. Amit, Gianna Gayle Herrera Amul, Catalina Liliana Andrei, Mina Anjomshoa, Ansariadi Ansariadi, Carl Abelardo T. Antonio, Benny Antony, Ernoiz Antriyandarti, Jalal Arabloo, Hany Mohamed Amin Aref, Olatunde Aremu, Bahram Armoon, Amit Arora, Krishna K Aryal, Afsaneh Arzani, Mehran Asadi-Aliabadi, Daniel Asmelash, Hagos Tasew Atalay, Seyyede Masoume Athari, Seyyed Shamsadin Athari, Sachin R Atre, Marcel Ausloos, Shally Awasthi, Nefsu Awoke, Beatriz Paulina Ayala Quintanilla, Getinet Ayano, Martin Amogre Ayanore, Yared Asmare Aynalem, Samad Azari, Andrew S Azman, Ebrahim Babaee, Alaa Badawi, Mojtaba Bagherzadeh, Shankar M Bakkannavar, Senthilkumar Balakrishnan, Maciej Banach, Joseph Adel Mattar Banoub, Aleksandra Barac, Miguel A Barboza, Till Winfried Bärnighausen, Sanjay Basu, Vo Dinh Bay, Mohsen Bayati, Neeraj Bedi, Mahya Beheshti, Meysam Behzadifar, Masoud Behzadifar, Diana Fernanda Bejarano Ramirez, Michelle L Bell, Derrick A. Bennett, Habib Benzian, Dessalegn Ajema Berbada, Robert S Bernstein, Anusha Ganapati Bhat, Krittika Bhattacharyya, Soumyadeep Bhaumik, Zulfiqar A Bhutta, Ali Bijani, Boris Bikbov, Muhammad Shahdaat Bin Sayeed, Raaj Kishore Biswas, Somayeh Bohlouli, Soufiane Boufous, Oliver J Brady, Andrey Nikolaevich Briko, Nikolay Ivanovich Briko, Gabrielle B Britton, Alexandria Brown, Sharath Burugina Nagaraja, Zahid A Butt, Luis Alberto Cámera, Ismael R Campos-Nonato, Julio Cesar Campuzano Rincon, Jorge Cano, Josip Car, Rosario Cárdenas, Felix Carvalho, Carlos A Castañeda-Orjuela, Franz Castro, Ester Cerin, Binaya Chalise, Vijay Kumar Chattu, Ken Lee Chin, Devasahayam J Christopher, Dinh-Toi Chu, Natalie Maria Cormier, Vera Marisa Costa, Elizabeth A Cromwell, Abel Fekadu Fekadu Dadi, Tukur Dahiru, Saad M A Dahlawi, Rakhi Dandona, Lalit Dandona, Anh Kim Dang, Farah Daoud, Aso Mohammad Darwesh, Amira Hamed Darwish, Ahmad Daryani, Jai K Das, Rajat Das Gupta, Aditya Prasad Dash, Claudio Alberto Dávila-Cervantes, Nicole Davis Weaver, Fernando Pio De la Hoz, Jan-Walter De Neve, Dereje Bayissa Demissie, Gebre Teklemariam Demoz, Edgar Denova-Gutiérrez, Kebede Deribe, Assefa Desalew, Samath Dhamminda Dharmaratne, Preeti Dhillon, Meghnath Dhimal, Govinda Prasad Dhungana, Daniel Diaz, Isaac Oluwafemi Dipeolu, Hoa Thi Do, Christiane Dolecek, Kerrie E Doyle, Eleonora Dubljanin, Andre Rodrigues Duraes, Hisham Atan Edinur, Andem Effiong, Aziz Eftekhari, Nevine El Nahas, Maysaa El Sayed Zaki, Maha El Tantawi, Hala Rashad Elhabashy, Shaimaa I. El-Jaafary, Ziad El-Khatib, Hajer Elkout, Aisha Elsharkawy, Shymaa Enany, Daniel Adane Endalew, Babak Eshrati, Sharareh Eskandarieh, Arash Etemadi, Oluchi Ezekannagha, Emerito Jose A. Faraon, Mohammad Fareed, Andre Faro, Farshad Farzadfar, Alebachew Fasil Fasil, Mehdi Fazlzadeh, Valery L. Feigin, Wubalem Fekadu, Netsanet Fentahun, Seyed-Mohammad Fereshtehnejad, Eduarda Fernandes, Irina Filip, Florian Fischer, Carsten Flohr, Nataliya A. Foigt, Morenike Oluwatoyin Folayan, Masoud Foroutan, Richard Charles Franklin, Joseph Jon Frostad, Takeshi Fukumoto, Mohamed M Gad, Gregory M Garcia, Augustine Mwangi Gatotoh, Reta Tsegaye Gayesa, Ketema Bizuwork Gebremedhin, Yilma Chisha Dea Geramo, Hailay Abrha Gesesew, Kebede Embaye Gezae, Ahmad Ghashghaee, Farzaneh Ghazi Sherbaf, Tiffany K Gill, Paramjit Singh Gill, Themba G Ginindza, Alem Girmay, Zemichael Gizaw, Amador Goodridge, Sameer Vali Gopalani, Bárbara Niegia Garcia Goulart, Alessandra C Goulart, Ayman Grada, Manfred S Green, Mohammed Ibrahim Mohialdeen Gubari, Harish Chander Gugnani, Davide Guido, Rafael Alves Guimarães, Yuming Guo, Rajeev Gupta, Rahul Gupta, Giang Hai Ha, Juanita A. Haagsma, Nima Hafezi-Nejad, Dessalegn H Haile, Michael Tamene Haile, Brian J. Hall, Samer Hamidi, Demelash Woldeyohannes Handiso, Hamidreza Haririan, Ninuk Hariyani, Ahmed I. Hasaballah, Md. Mehedi Hasan, Amir Hasanzadeh, Hamid Yimam Hassen, Desta Haftu Hayelom, Mohamed I Hegazy, Behzad Heibati, Behnam Heidari, Delia Hendrie, Andualem Henok, Claudiu Herteliu, Fatemeh Heydarpour, Hagos Degefa de Hidru, Thomas R Hird, Chi Linh Hoang, Gillian I Hollerich, Praveen Hoogar, Naznin Hossain, Mehdi Hosseinzadeh, Mowafa Househ, Guoqing Hu, Ayesha Humayun, Syed Ather Hussain, Mamusha Aman A Hussen, Segun Emmanuel Ibitoye, Olayinka Stephen Ilesanmi, Milena D. Ilic, Mohammad Hasan Imani-Nasab, Usman Iqbal, Seyed Sina Naghibi Irvani, Sheikh Mohammed Shariful Islam, Rebecca Q Ivers, Chinwe Juliana Iwu, Nader Jahanmehr, Mihajlo Jakovljevic, Amir Jalali, Achala Upendra Jayatilleke, Ensiyeh Jenabi, Ravi Prakash Jha, Vivekanand Jha, John S Ji, Jost B. Jonas, Jacek Jerzy Jozwiak, Ali Kabir, Zubair Kabir, Tanuj Kanchan, André Karch, Surendra Karki, Amir Kasaeian, Gebremicheal Gebreslassie Kasahun, Habtamu Kebebe Kasaye, Gebrehiwot G Kassa, Getachew Mullu Kassa, Gbenga A. Kayode, Mihiretu M Kebede, Peter Njenga Keiyoro, Daniel Bekele Ketema, Yousef Saleh Khader, Morteza Abdullatif Khafaie, Nauman Khalid, Rovshan Khalilov, Ejaz Ahmad Khan, Junaid Khan, Md Nuruzzaman Khan, Khaled Khatab, Mona M Khater, Amir M Khater, Maryam Khayamzadeh, Mohammad Khazaei, Mohammad Hossein Khosravi, Jagdish Khubchandani, Ali Kiadaliri, Yun Jin Kim, Ruth W Kimokoti, Sezer Kisa, Adnan Kisa, Sonali Kochhar, Tufa Kolola, Hamidreza Komaki, Soewarta Kosen, Parvaiz A Koul, Ai Koyanagi, Kewal Krishan, Barthelemy Kuate Defo, Nuworza Kugbey, Pushpendra Kumar, G Anil Kumar, Manasi Kumar, Dian Kusuma, Carlo La Vecchia, Ben Lacey, Aparna Lal, Dharmesh Kumar Lal, Hilton Lam, Faris Hasan Lami, Van Charles Lansingh, Savita Lasrado, Georgy Lebedev, Paul H Lee, Kate E LeGrand, Mostafa Leili, Tsegaye Lolaso Lenjebo, Cheru Tesema Leshargie, Aubrey J Levine, Sonia Lewycka, Shanshan Li, Shai Linn, Shiwei Liu, Jaifred Christian F Lopez, Platon D Lopukhov, Muhammed Magdy Abd El Razek, D.R. Mahadeshwara Prasad, Phetole Walter Mahasha, Narayan B. Mahotra, Azeem Majeed, Reza Malekzadeh, Deborah Carvalho Malta, Abdullah A Mamun, Navid Manafi, Mohammad Ali Mansournia, Chabila Christopher Mapoma, Gabriel Martinez, Santi Martini, Francisco Rogerlândio Martins-Melo, Manu Raj Mathur, Benjamin K Mayala, Mohsen Mazidi, Colm McAlinden, Birhanu Geta Meharie, Man Mohan Mehndiratta, Entezar Mehrabi Nasab, Kala M Mehta, Teferi Mekonnen, Tefera Chane Mekonnen, Gebrekiros Gebremichael Meles, Hagazi Gebre Meles, Peter T N Memiah, Ziad A Memish, Walter Mendoza, Ritesh G Menezes, Seid Tiku Mereta, Tuomo J Meretoja, Tomislav Mestrovic, Workua Mekonnen Metekiya, Workua Mekonnen Metekiya, Bartosz Miazgowski, Ted R Miller, GK Mini, Erkin M Mirrakhimov, Babak Moazen, Bahram Mohajer, Yousef Mohammad, Dara K. Mohammad, Naser Mohammad Gholi Mezerji, Roghayeh Mohammadibakhsh, Shafiu Mohammed, Jemal Abdu Mohammed, Hassen Mohammed, Farnam Mohebi, Ali H Mokdad, Yoshan Moodley, Masoud Moradi, Ghobad Moradi, Mohammad Moradi-Joo, Paula Moraga, Linda Morales, Abbas Mosapour, Jonathan F. Mosser, Simin Mouodi, Seyyed Meysam Mousavi, Miliva Mozaffor, Sandra B Munro, Moses K. Muriithi, Christopher J L Murray, Kamarul Imran Musa, Ghulam Mustafa, Saravanan Muthupandian, Mehdi Naderi, Ahamarshan Jayaraman Nagarajan, Mohsen Naghavi, Gurudatta Naik, Vinay Nangia, Bruno Ramos Nascimento, Javad Nazari, Duduzile Edith Ndwandwe, Ionut Negoi, Henok Biresaw Netsere, Josephine W. Ngunjiri, Cuong Tat Nguyen, Huong Lan Thi Nguyen, QuynhAnh P Nguyen, Solomon Gedlu Nigatu, Dina Nur Anggraini Ningrum, Chukwudi A Nnaji, Marzieh Nojomi, Ole F Norheim, Jean Jacques Noubiap, Bogdan Oancea, Felix Akpojene Ogbo, In-Hwan Oh, Andrew T Olagunju, Jacob Olusegun Olusanya, Bolajoko Olubukunola Olusanya, Obinna E Onwujekwe, Doris V. Ortega-Altamirano, Osayomwanbo Osarenotor, Frank B Osei, Mayowa O Owolabi, Mahesh P A, Jagadish Rao. Padubidri, Smita Pakhale, Adrian Pana, Eun-Kee Park, Sangram Kishor Patel, Ashish Pathak, Ajay Patle, Kebreab Paulos, Veincent Christian Filipino Pepito, Norberto Perico, Aslam Pervaiz, Julia Moreira Pescarini, Konrad Pesudovs, Hai Quang Pham, David M Pigott, Thomas Pilgrim, Meghdad Pirsaheb, Mario Poljak, Ian Pollock, Maarten J Postma, Farshad Pourmalek, Akram Pourshams, Sergio I Prada, Liliana Preotescu, Hedley Quintana, Navid Rabiee, Mohammad Rabiee, Amir Radfar, Alireza Rafiei, Fakher Rahim, Siavash Rahimi, Vafa Rahimi-Movaghar, Muhammad Aziz Rahman, Mohammad Hifz Ur Rahman, Fatemeh Rajati, Chhabi Lal Ranabhat, Puja C Rao, Davide Rasella, Goura Kishor Rath, Salman Rawaf, Lal Rawal, Wasiq Faraz Rawasia, Giuseppe Remuzzi, Vishnu Renjith, Andre M.N. Renzaho, Serge Resnikoff, Seyed Mohammad Riahi, Ana Isabel Ribeiro, Jennifer Rickard, Leonardo Roever, Luca Ronfani, Enrico Rubagotti, Salvatore Rubino, Anas M Saad, Siamak Sabour, Ehsan Sadeghi, Sahar Saeedi Moghaddam, Yahya Safari, Rajesh Sagar, Mohammad Ali Sahraian, S. Mohammad Sajadi, Mohammad Reza Salahshoor, Nasir Salam, Ahsan Saleem, Hosni Salem, Marwa Rashad Salem, Yahya Salimi, Hamideh Salimzadeh, Abdallah M Samy, Juan Sanabria, Itamar S Santos, Milena M. Santric-Milicevic, Bruno Piassi Sao Jose, Sivan Yegnanarayana Iyer Saraswathy, Nizal Sarrafzadegan, Benn Sartorius, Brijesh Sathian, Thirunavukkarasu Sathish, Maheswar Satpathy, Monika Sawhney, Mehdi Sayyah, Alyssa N Sbarra, Lauren E Schaeffer, David C Schwebel, Anbissa Muleta Senbeta, Subramanian Senthilkumaran, Sadaf G Sepanlou, Edson Serván-Mori, Azadeh Shafieesabet, Amira A Shaheen, Izza Shahid, Masood Ali Shaikh, Ali S Shalash, Mehran Shams-Beyranvand, MohammadBagher Shamsi, Morteza Shamsizadeh, Mohammed Shannawaz, Kiomars Sharafi, Rajesh Sharma, Aziz Sheikh, B Suresh Kumar Shetty, Wondimeneh Shibabaw Shiferaw, Mika Shigematsu, Jae Il Shin, Rahman Shiri, Reza Shirkoohi, K M Shivakumar, Si Si, Soraya Siabani, Tariq Jamal Siddiqi, Diego Augusto Santos Silva, Virendra Singh, Narinder Pal Singh, Balbir Bagicha Singh Singh, Jasvinder A. Singh, Ambrish Singh, Dhirendra Narain Sinha, Malede Mequanent Sisay, Eirini Skiadaresi, David L Smith, Adauto Martins Soares Filho, Mohammad Reza Sobhiyeh, Anton Sokhan, Joan B Soriano, Muluken Bekele Sorrie, Ireneous N Soyiri, Emma Elizabeth Spurlock, Chandrashekhar T Sreeramareddy, Agus Sudaryanto, Mu'awiyyah Babale Sufiyan, Hafiz Ansar Rasul Suleria, Bryan L. Sykes, Rafael Tabarés-Seisdedos, Takahiro Tabuchi, Degena Bahrey Tadesse, Ingan Ukur Tarigan, Bineyam Taye, Yonatal Mesfin Tefera, Arash Tehrani-Banihashemi, Shishay Wahdey Tekelemedhin, Merhawi Gebremedhin Tekle, Mohamad-Hani Temsah, Berhe Etsay Tesfay, Fisaha Haile Tesfay, Zemenu Tadesse Tessema, Kavumpurathu Raman Thankappan, Akhil Soman ThekkePurakkal, Nihal Thomas, Robert L Thompson, Alan J Thomson, Roman Topor-Madry, Marcos Roberto Tovani-Palone, Eugenio Traini, Bach Xuan Tran, Khanh Bao Tran, Irfan Ullah, Bhaskaran Unnikrishnan, Muhammad Shariq Usman, Olalekan A Uthman, Benjamin S. Chudi Uzochukwu, Pascual R Valdez, Santosh Varughese, Yousef Veisani, Francesco S Violante, Sebastian Vollmer, Feleke Gebremeskel W/hawariat, Yasir Waheed, Mitchell Taylor Wallin, Yuan-Pang Wang, Yafeng Wang, Kinley Wangdi, Daniel J Weiss, Girmay Teklay Weldesamuel, Adhena Ayaliew Werkneh, Ronny Westerman, Taweewat Wiangkham, Kirsten E Wiens, Tissa Wijeratne, Charles Shey Wiysonge, Haileab Fekadu Wolde, Dawit Zewdu Wondafrash, Tewodros Eshete Wonde, Getasew Taddesse Worku, Ali Yadollahpour, Seyed Hossein Yahyazadeh Jabbari, Tomohide Yamada, Mehdi Yaseri, Hiroshi Yatsuya, Alex Yeshaneh, Mekdes Tigistu Yilma, Paul Yip, Engida Yisma, Naohiro Yonemoto, Mustafa Z Younis, Hebat-Allah Salah A Yousof, Chuanhua Yu, Hasan Yusefzadeh, Siddhesh Zadey, Telma Zahirian Moghadam, Zoubida Zaidi, Sojib Bin Zaman, Mohammad Zamani, Hamed Zandian, Heather J Zar, Taddese Alemu Zerfu, Yunquan Zhang, Arash Ziapour, Sanjay Zodpey, Yves Miel H Zuniga, Simon I Hay, Robert C Reiner
Journal: The Lancet Global Health (2020)

<h2>Summary</h2><h3>Background</h3> Universal access to safe drinking water and sanitation facilities is an essential human right, recognised in the Sustainable Development Goals as crucial for preventing disease and improving human wellbeing. Comprehensive, high-resolution estimates are important to inform progress towards achieving this goal. We aimed to produce high-resolution geospatial estimates of access to drinking water and sanitation facilities. <h3>Methods</h3> We used a Bayesian geostatistical model and data from 600 sources across more than 88 low-income and middle-income countries (LMICs) to estimate access to drinking water and sanitation facilities on continuous continent-wide surfaces from 2000 to 2017, and aggregated results to policy-relevant administrative units. We estimated mutually exclusive and collectively exhaustive subcategories of facilities for drinking water (piped water on or off premises, other improved facilities, unimproved, and surface water) and sanitation facilities (septic or sewer sanitation, other improved, unimproved, and open defecation) with use of ordinal regression. We also estimated the number of diarrhoeal deaths in children younger than 5 years attributed to unsafe facilities and estimated deaths that were averted by increased access to safe facilities in 2017, and analysed geographical inequality in access within LMICs. <h3>Findings</h3> Across LMICs, access to both piped water and improved water overall increased between 2000 and 2017, with progress varying spatially. For piped water, the safest water facility type, access increased from 40·0% (95% uncertainty interval [UI] 39·4–40·7) to 50·3% (50·0–50·5), but was lowest in sub-Saharan Africa, where access to piped water was mostly concentrated in urban centres. Access to both sewer or septic sanitation and improved sanitation overall also increased across all LMICs during the study period. For sewer or septic sanitation, access was 46·3% (95% UI 46·1–46·5) in 2017, compared with 28·7% (28·5–29·0) in 2000. Although some units improved access to the safest drinking water or sanitation facilities since 2000, a large absolute number of people continued to not have access in several units with high access to such facilities (>80%) in 2017. More than 253 000 people did not have access to sewer or septic sanitation facilities in the city of Harare, Zimbabwe, despite 88·6% (95% UI 87·2–89·7) access overall. Many units were able to transition from the least safe facilities in 2000 to safe facilities by 2017; for units in which populations primarily practised open defecation in 2000, 686 (95% UI 664–711) of the 1830 (1797–1863) units transitioned to the use of improved sanitation. Geographical disparities in access to improved water across units decreased in 76·1% (95% UI 71·6–80·7) of countries from 2000 to 2017, and in 53·9% (50·6–59·6) of countries for access to improved sanitation, but remained evident subnationally in most countries in 2017. <h3>Interpretation</h3> Our estimates, combined with geospatial trends in diarrhoeal burden, identify where efforts to increase access to safe drinking water and sanitation facilities are most needed. By highlighting areas with successful approaches or in need of targeted interventions, our estimates can enable precision public health to effectively progress towards universal access to safe water and sanitation. <h3>Funding</h3> Bill & Melinda Gates Foundation.