Predicting the environmental suitability for onchocerciasis in Africa as an aid to elimination planning.
Elizabeth A CromwellJoshua C P OsborneThomas R UnnaschMaría-Gloria BasáñezKatherine M GassKira A BarbreElex HillKimberly B JohnsonKatie M DonkersShreya ShirudeChris A SchmidtVictor T AdekanmbiOlatunji O AdetokunbohMohsen AfaridehEhsan AhmadpourMuktar Beshir AhmedTemesgen Yihunie AkaluZiyad Al-AlyFahad Mashhour AlaneziTurki M AlanziVahid AlipourCatalina Liliana AndreiFereshteh AnsariMustafa Geleto AnshaDavood AnvariSeth Christopher Yaw AppiahJalal ArablooBenjamin F ArnoldMarcel AusloosMartin Amogre AyanoreAtif Amin BaigMaciej BanachAleksandra BaracTill Winfried BärnighausenMohsen BayatiKrittika BhattacharyyaZulfiqar Ahmed BhuttaSadia BibiAli BijaniSomayeh BohlouliMahdi BohluliOliver J BradyNicola Luigi BragazziZahid Ahmad ButtFelix CarvalhoSouranshu ChatterjeeVijay Kumar ChattuSoosanna Kumary ChattuNatalie Maria CormierSaad M A DahlawiGiovanni DamianiFarah DaoudAso Mohammad DarweshAhmad DaryaniKebede DeribeSamath Dhamminda DharmaratneDaniel DiazHoa Thi DoMaysaa El Sayed ZakiMaha El TantawiDemelash Abewa EleminehAnwar FarajMajid Fassihi HarandiYousef FatahiValery L FeiginEduarda FernandesNataliya A FoigtMasoud Foroutan-RadRichard Charles FranklinMohammed Ibrahim Mohialdeen GubariDavide GuidoYuming GuoArvin Haj-MirzaianKanaan Hamagharib AbdullahSamer HamidiClaudiu HerteliuHagos Degefa de HidruTarig B HigaziNaznin HossainMehdi HosseinzadehMowafa HousehOlayinka Stephen IlesanmiMilena D IlicIrena M IlicUsman IqbalSeyed Sina Naghibi IrvaniRavi Prakash JhaFarahnaz JoukarJacek Jerzy JozwiakZubair KabirLeila R KalankeshRohollah KalhorBehzad Karami MatinSalah Eddin KarimiAmir KasaeianTaras KavetskyyGbenga Ayodele KayodeAli Kazemi KaryaniAbraham Getachew KelboreMaryam KeramatiRovshan KhalilovEjaz Ahmad KhanMd Nuruzzaman Nuruzzaman KhanKhaled KhatabMona M KhaterNeda KianipourKelemu Tilahun KibretYun Jin KimSoewarta KosenKris J KrohnDian KusumaCarlo La VecchiaVan Charles LansinghPaul Hong LeeKate E LeGrandShanshan LiJoshua LongbottomHassan Magdy Abd El RazekMuhammed Magdy Abd El RazekAfshin MalekiAbdullah A MamunAli ManafiNavid ManafiMohammad Ali MansourniaFrancisco Rogerlândio Martins MelloMohsen MazidiColm McAlindenBirhanu Geta MeharieWalter MendozaEndalkachew Worku MengeshaDesalegn Tadese MengistuSeid Tiku MeretaTomislav MeštrovićTed R MillerMohammad MiriMasoud MoghadaszadehAbdollah Mohammadian-HafshejaniReza MohammadpourhodkiShafiu MohammedMohammed F SalahuddinMasoud MoradiRahmatollah MoradzadehPaula MoragaJonathan F MosserMehdi NaderiAhamarshan Jayaraman NagarajanGurudatta NaikIonuț NegoiCuong Tat NguyenHuong Lan Thi NguyenTrang Huyen NguyenRajan NikbakhshBogdan OanceaTinuke O OlagunjuAndrew Toyin OlagunjuAhmed Omar BaliObinna Emmanuel OnwujekweAdrian PanaHadi PourjafarFakher RahimMohammad Hifz Ur RahmanPriya RathiSalman RawafDavid Laith RawafReza RawassizadehSerge ResnikoffMelese Abate RetaAziz RezapourEnrico RubagottiSalvatore RubinoEhsan SadeghiAbedin SaghafipourS Mohammad SajadiAbdallah M SamyRodrigo Sarmiento-SuárezMonika SawhneyMegan F SchippAmira A ShaheenMasood Ali ShaikhMorteza ShamsizadehKiomars SharafiAziz SheikhB Suresh Kumar ShettyYoun Ho ShinK M ShivakumarBiagio SimonettiJasvinder A SinghEirini SkiadaresiAmin SoheiliShahin SoltaniEmma Elizabeth SpurlockMu'awiyyah Babale SufiyanTakahiro TabuchiLeili TapakRobert L ThompsonAlan J ThomsonEugenio TrainiBach Xuan TranIrfan UllahSaif UllahChigozie Jesse UnekeBhaskaran UnnikrishnanOlalekan A UthmanNatalie V S Vinkeles MelchersFrancesco Saverio ViolanteHaileab Fekadu WoldeTewodros Eshete WondeTomohide YamadaOlumuyiwa OmonaiyeVahid Yazdi-FeyzabadPaul YipNaohiro YonemotoHebat-Allah Salah A YousofChuanhua YuYong YuHasan YusefzadehLeila ZakiSojib Bin ZamanMaryam ZamanianZhi-Jiang ZhangYunquan ZhangArash ZiapourSimon I HayDavid M PigottPublished in: PLoS neglected tropical diseases (2021)
Recent evidence suggests that, in some foci, elimination of onchocerciasis from Africa may be feasible with mass drug administration (MDA) of ivermectin. To achieve continental elimination of transmission, mapping surveys will need to be conducted across all implementation units (IUs) for which endemicity status is currently unknown. Using boosted regression tree models with optimised hyperparameter selection, we estimated environmental suitability for onchocerciasis at the 5 × 5-km resolution across Africa. In order to classify IUs that include locations that are environmentally suitable, we used receiver operating characteristic (ROC) analysis to identify an optimal threshold for suitability concordant with locations where onchocerciasis has been previously detected. This threshold value was then used to classify IUs (more suitable or less suitable) based on the location within the IU with the largest mean prediction. Mean estimates of environmental suitability suggest large areas across West and Central Africa, as well as focal areas of East Africa, are suitable for onchocerciasis transmission, consistent with the presence of current control and elimination of transmission efforts. The ROC analysis identified a mean environmental suitability index of 0·71 as a threshold to classify based on the location with the largest mean prediction within the IU. Of the IUs considered for mapping surveys, 50·2% exceed this threshold for suitability in at least one 5 × 5-km location. The formidable scale of data collection required to map onchocerciasis endemicity across the African continent presents an opportunity to use spatial data to identify areas likely to be suitable for onchocerciasis transmission. National onchocerciasis elimination programmes may wish to consider prioritising these IUs for mapping surveys as human resources, laboratory capacity, and programmatic schedules may constrain survey implementation, and possibly delaying MDA initiation in areas that would ultimately qualify.
Keyphrases