Participation of communities in onchocerciasis control in the Bandiagara area (Republic of Mali)

NOnI.D EETLTB ORCAIIIZATION ORGAIIISATION HOTTDIALE DE LA SAIITE ! oNcHocERcrAsrs coNTRoL ipnocneuuE rN wEST AFRTcA PROGRAI{!{E DE LUTTE CONTRE LTONCHOCERCOSE EN AFRIQUE DE LIOUIjST I I EXPERT ADVISORY COMHITTEE Seventh meettng Banako 15-20 June 1986 ocP lEAC7 .2 ORTGINAL : FRENCH I Descrtptton of Ehe envtronment I Health problems of t.he Dogon plateau HealEh tnfrastructures and nattonal cont,rol programmes Onchocerctasts ConErol prograrnme - acE,tvtttes - parttcularittes and results of che OCp 5. ParEtctpat.ton of Uhe vi. llage communtttes P la teau 6. Constderattons and prospects as regards communtttes tn the onchocerctasts control : IN ONCHOCERCIASIS CONTROI. (REPUBLTC OF MALr) campatgn on the Dogon plateau tn the OCP campatgn on the Dogon PARTICTPATION OF COr.MUHrtrLS IN THE BAI.IDIAGARA ARTA t 2 3 4 7 the parttctpatton of the vtllage - foreseeabre ortentatton of ocp acttvtttes on the Dogon prateau - geographtcal exEenston of thts t,ype of acttvtttes - tnEegratlon of brackfly control tnto other acttvtctes Conclus tons. 1. Descrtpt{on of the envtronnenC I'l' The Band{a8ara Plateau, or Dogon Plateau, frorn Ehe name of tEs domtnant erhntcSroupr ext,ends over some 7r5oo km2, to t,he ea6E of rtver Ntger, t,he Bandtagara Losrnttself ts located ?5 km frorn Moptt. Admtntst,rattvely, the Bandiagara prateau corresponds to the BandLagara cercle (arrondtsseoents of Bandtagara, Dourou,Goundaka,Kant-Go8ounaKendte'Es.rt@),whtchtasa1nost2oo,ooo tnhabttants, and ln part to the Douentza, Koro "r,a i"ntags cercles. 1'2' The couutry' famous for the beauty of tce altes, te conposed of a rockytableland of prtoary sandstones (ordovtctana) at a hetiht of between 3oo and almosE800 metrci' deeply sculptured by eroaton, gaehed by waierco,rreee and dootnattng rheplatns of Ehe east-by an {mpresstve cltff of alno"L zoo Eetrea, the famous Eandtagaracltff, vhtch runs fron the south-uesE to the north-eaat over "o.J"Io6-;;:- t-"" 1'3' The eltuatc saa of the northern sudan rype. Eowdyer, for nore than a decade,rhe poor ratns (a ltttle oore than 3oo mn of uater pcr year at Bandtagara stnce t9tio,t.e. half of the annual mean for Ehe 195os and l96oe) ana the ehorEen{ng of the ra{ny season froo ftve mnths (June-October) bo Ehree (July-Septeaber) have led Eo a very marked and severely felc drought and an l.ncreas(ng'eaheltzatton" of the vegetaLfon ;rnd che landacape. No. 086/VcU/ LDt4l13.2 Jt.- "" I a! r .5. p la E.eau m3 for ocP|EACT.2 Pege 2 1.4. Tlrere ts no Peroanent HaEercourse; only a few aourceE and p'ondq tI" perenntal, The tlatn'part of Ehe hydrographtc neEuork runa froo east to uestr towarde Ehe yame and other E,rtbuEartes of the Bant whtle a few Eorrents dteappear tn the "."a".n platns through spectacular falls and cascades afEer croestng the cltff' tfhtle Ehere ts no toportanl rlver, the netuork ts dense and Ehe coursea very rouSh' fhe nagural flow var{es beEseen a feu days affer Ehe heavy ratns and several monEhs(July-December). For 6ome years nou' thts pertod has been reductng dranattcally b""r,,." <lf uhe tmpover{shmenl- of the underground waters' For more t,han Een yearsr msoY dams are betng butlt (abour 50 eo far) for Lhe creaEton of sat,er tmpoudment-s of vartous stzes (maxtmum I'3 Iake Daga) for trrtgatton and 'Jater supply durtng the dry 6eason' I.6. The Dogon populattons*, alnost exclustvely aqrtcult'ural, are renowned for rhetr aEE.achmenc to the land and the tngenutty and deEerotnat,ton stth shtch they Eurn Eo besE accounE a regton and a reltef havtng a prtort fes arable lands' Mtllet and sorghum are the ma{n food crops. Hogrever, stnce the tncrease tn Ehe number of dao Iakes, markeL gardentng has been developed and expanded remarkably, Ehe growtng of ontons tn parttcular, as well 4s potato-growtng and r{.ce farrntng, tn trrtgated or waEered ftelds. 1.7. Ftnally, tn addtE{on ro shoutng an excepttonal farm{ng dynantsm relaEed Eo Ehe necesstEy for adapEatton Eo a very parE{-cuIar envtronmenE, Ehese populattons have been able Eo matntatn remarkably elaboraE6d soctoculEural Eradtttons and very soltd and vtvactous communtty structures as a resulE of a way of ltfe charactertzed for a long ttme by a relattve {solatton tn Ehe remarkable defenstve stEe Ehat the plateau and tEs cltffs and EorEured reltef consttcuEe' 2. Health probleos of the Dogon Plateau ,( or {ntermedtaEe-hosE on fhe mtllton 2.1. The matn vector-borne Plateau are : schtsEosontasts S. haematobium and parastttc dtseases tn the Dogon S. mansont), dracunculosts (Gutnea worm), oncltocerctasts and malarta' 2.2. Among ftrsc Ehree, collecclons. Ehese dtseases, Ehere has been a noLable and worrytng spread of fhe t n proporc'l on Eo Ehe mulCtpll.eabton or perennaE.ton of art,tf tctal water 2.3 l5 ( g.' below 2OZ) ' btlharztasts caused by of s. IOOZ tn the greaEer parL plateau. 2.4 . Gul.nea vorm Dracunculus medinens{.s vtllages up to 8OZ of the act{ve Ehts parasttosts' aE a t{me for compll caE,lons (ceEanus). 2.5. Onchocerctasts, rePorted more Lhan 30 years ago along Ehe matn eratercourses(che yame, the Dtaue, the presence of nhtch uas the Perou and Ehetr trtbutartes' et,c..)r presenced prevalences hardly exceedtng mesoendem{ctEy excepE tn some vtllages tn Che south-r.estern parE of the plateau' . The years ) nerally preva Ie nce and nearlY of Schtstosoma haemaLob{um in man was above 75 Z (60Z fron 5 Eo Ehe vtllages. Alchough less frequenE mansont ts also prevalent on the populat ton farm work, ts also htghly prevalenE and tn cerEatn was dtsabled durtng the ratny season by utEh a constderable frequency of fatal * In factr Etre 0ogon count ry exEende beyond rhe plac,eau ntze cercles and parE of thaE ftn pilETil? are stratlar s{th and Lhe Bandtagara of Tomtntan, sandy E,he exceptton of cercle, platntlre Bankass. Koro and Doue areas ( the Seno) uhoee hea onchocerctasts vrhtch ts not known Lhere' * Especl-a1lY fr{nges of th S. strbanum characterlsE. l'l .rnd domtnanL s[)ecles of Ehe souLhern rt button of Llrr' verLor comPlcx.r' flfPd O st to ocP|EACT.2 Page 3 2.6. Beeauad:of uhd rcltef, attee (raptda) naturally conduclve to pretnagtnaldevelopnent of the Staultuo daunoauo vector cooplex were'parttcularly abunJant on the8reaterPartofttrc@orkandtnlutctngfena1edenetEteg..ofthts vector conplex could locally, exceed 2oo per nan per day; these uracirri:popri.tto""preaented all the vector potenttalttles charactertettc of the aevere onchocerctaelsfoct of the eavanna tyPe. However, beeauee of the latttude the Eransataston renalnedrtutted tn ttne (re8trtcted to t,he pertod of flor of the watercoursee) and space(close to the satercoureee). 2'7 ' Theae characEertettce explatn tn part thte relattvely ntld form of chedtseaee, uhtch could have, honever, been dtsrupted ana aggravated by the consEructtonof trrtgatton daus that have created arttftcal raptds conducttve to the developnentof the aquattc forue (e8Bsr larvae, pupae) of the onchocerctasts vectora both on bhetrrtgatton canala and on the sptllways, on uhtch the pertod of flow was notablylong' etther tnrent{onally (on th" drr"-reservotrs, regulators of trrtgac,ton of thevalleys) or tnvoluntartly (leakages from Ehe soall daos nhtch are more of tmpoundmentsalls t,han real dans). 2'8' Because of the expertence of other art,tftctal foct of the sane type created tnhypo or mesoendemtc areas, eleewhere tn Malt (Kongasso) or tn netghbourtng counErtes(Lounana, Burktna Faso), together wtth the presence of blackfltes wtEh htgh veccorpotenctaltttes, tt can be afftrmed that t,he danger of an tncrease tn Ehe nuober ofsmall ctrcuoscrtbed foct w{th htgh rtsks of bltidness and severe soctoeconom{crepercusstons for the communlttes that fr6quenE the new lakes lra6 very h{gh. 3 Health tnfrasEruc t,ures and nattonal conErol proq rammes 3'1' The health tnfrastrucEures of rhe Dogon plateau depend on the GeneralDtrectorate of Haltrs ftfth Adntntstrattve [egton (Moptt) and, through t,hat, theMtntstry of Health tn Bamako. 3'2' In Bandtagara' Just as tn each cerclers chtef tosn, these structures areheaded by a chtef Medtcal offtcer srhosfGiTncrudes : - a medtcal offtcer (asststant) t - a mtdutfe - several health t,echntctans - a communtt,y developmenE Eechntctan - several male and female nurses. 3'3' outstde Bandtagara, there ts a health poet tn each arrbndtssement,rs chteftoBn'headedbyachtefhea1thpostnurae,andanauxt1t..ffit;;-;",. of each baatc aector; each of tireo te assisted, at the vtllage level, by ruralEatrona and hygteatete/ftrst-atd rorkere. 3'4' The latter' at least one per conurbatton (141 f.or 4o7 vtllages), are vtlragersserect'ed by the connuntty on the baata of thetr abtltttee and qualtttee and tratnedtn the cerclers chtef town. They are tn charge of ftrst atd and have a small vtltagepharoaclEFEEit; they aleo deal wtth envlroioental aanttat(on, vtlrage cleanltness,houstng toproveuent, drtnktng water aupply and treaEoent of rater for doaesEtc use.They are voluntary uorkera conpenaated {n- ktnd by the coomuntty for the ttme theydevote to thetr healEh dut,tes to the deErtment of thetr agrtcuitrral acLtvtt,tes. 3'5' An tategrated developnent proJect, rhtch tncludes, tn parttcular, a ..HealthActton" coEPonenE' te betng carrted out, for several years norr, on t,he DogonPIa toau. I ocPlg,Ac7.2 Page 4 3.6. The..above-nenE,toned componenE, whtch gtves Sreater lnportanCc to preventlon and 6he,managemenE by Ehe comraurrtttes of Ehetr orn probleoa, coverS healch educatton' tratntng and retrarntng of auxtltary healEh peraonnel and tnprpvenenE and eanttatton of Ehe uaEer eupply polncs be chey -"o.r."." and nodes of drtnk{I}8 uaEer aupply or dam reservotrs - 3.7. The concrol of vect,or-borne dtseases and tnE,ernedtate-hoata ta, Eherefore, based, for a large Part, on Ehe local sl-rucEures' espectally vtllage iygt.nt"as/ftrsclatd workers tratned and supervtsed by the santtary rechntctans of Bandtagara - 3.g. The ftghE agatnst, malarta constsEs oatnly (n the mass admtntstratton of ntvaqutne, envtronmental santtatton and health education' 3.g. For Ehe conErol of Gutnea worm, che hygtentsus/ftrsE-atd workArs chlortnate, pertodtcally, tradtttonal or recently sunk or re-dug eells; furthermore' they promoge the construcEton of dooesttc ftlters' encourage part'tctPatton tn Ehe constructton of well coptngs and, above aIl, arouse the awareness of the populaEtons' through thetr example.nd rdrt"., to Ehe causes,and consequencea of the dtsease' the means to eradtcate tt and Ehe reasons for Ehe oithods advocated' 3.10. The publtc asareness poltcy ts acEtvely pursued by the hygtentets/ftrst-atd porkers agatnst btlharztasts Eoo, buE Ehe conErol of the dtsease ts also betng carrted ouE through a projecE tnplemenEed'Lrith tnEernaEtonal atd and comprlstnS three comPonents : a) pertodtc Parasttologl cal screentng of populatton samples tn the oonttored vtllagee and thetr nedtcal treaEmenE lrtEh praztquantel (general treatment srhen the prevalence exceeds 752, treaEment of only lnfested aubjects shen tE ts 2Ol and 757 for btlarztasts caused Dv S. haemaEontum no chemotheraPYbet[,een ts appl by che Eeams; ted when the prevalence ts below 202 thts betng t obJecttve atmed at proJect); these acEtvtEtes are carrt ed ouE by spectaltzed cenEral b) control of the tngermedtate snatl hosEs (bultnus and planorbtdae) and Ehetr tnfestatton of erater collect{-ons frequent'ed by the vtllagers and the pertodtc EreaEmen6 of those uater colle.cttons utrh Baylusctd 1n the man-mollusc conEacE zones; c) health educaEton: promotton of rhe awareness of E.he vt11a8e masses, starEtng wtEh schools, tf Ehey extst, and consEructton of laErtnes. 3.1f. As regard6 conErol, the hygtentsts/ftrsl--atd workers stttl parEtctpate only as asststants tn the mollusctctdtng alone, r,rlt.h the exceptton of a vtllage havtng a vtllage health worker wtth a htgher level' 3.12. Onchocerctasts, whose cltntcal and soctoeconom.tc rnantfestattons were felt only excepttonally on the plateau before the OCP operaEtons, does noE dtrectly foro part of the objecc{ves of the Health Actton project' 3.13. In a country uhere sater eupply was from ttne tmnemortal a naJor concern, the iro"gtlt of the.:pa"t f"r, decadea rould have t,aken on catastrophtc proporttone had tt not f,een for thi tntenstfted etnktng of uells (uore than 30 nelle sunk or,re-sunk, oore than 40 boga-holea) and the tncrease (n Ehe number of arttftctal reaervotrs, ,i,"t,-tt"re noE bnly toproved ltvtng condttlons but have, tn several casee, enaured the survtval of vtllages; but tE ts cerla{n also EhaE Lhe beneftE,s of'Lhese savtng act.tons uould have been Jeopardtzed wtEhouI the acttvtEtes for the countroL of dracunculosts, schtatoeontasts and onchocerctasts. 3.14. The result,s are very obvtous as rt'Bards Gulrrea worm' the prevalence havtng dplrp'ed by some 9OZ {n Ehe besr, edrrc;rLed vt llages; alEhotrgh cangtble, che resulEs of ocP|B.AC7.2 Page 5 Ehe btlharztaata eoncrol are leea apecEacular and bear sttnee I to the aeeil toconttnue the health educatton and aorluactctde and therapeutte trcataeat .canpatgns lnorder to prol0ng the regreeaton of the prevalence of s. haeoatoblua rhfch tn 1983fell beloy 757 (lO vtllagee) and even 2OI (2 vtllage8 tn vt lagea vtetted. 3'r5. Just as for the control, Ehese acttvtttea are percetved favourabli by thepopulatton whose awareneaa has been aroused to onchocirctaete (see aectrln a), bothby the health norkersr educattonal eanpatgn and by the reeulte. 4. Onchocerctasta Control p roEranme Acttvlttes 4'l' The Bandtagara Plateau was tncorporat,ed tnto the onchocerctasts ControlProgramme tn the Volta Rtver Bastln Area (oCP) tn 1977 and occuptes tts Eoat northerly "appendtx" (see @p). 4'2. rt should be recalled Ehat the obJecttve of the progranme ts to reduce thetransmtsston of the dteease Eo and matntatn tt at a tolerable levell L.€. whtch nolonger reprdsents a 6evere eye tnfectton rtsk for Ehe populattons ltvtng along chewatercourses. The proSraatrers stgntftcance can be fully realtzed tn the eontext ofthe tragtc drought shtch ts strtktng south-Saharan efrtta, rhere the development, andtherefore the health proEectton, of Ehe rtveratde landa aipe'ara to be-a palitattveboth for the settlenent of che populatton6 forced uy aeseiitftcatton to Eove towardsthe souEh and for the food self-sufftcteney of the nattves and otgrante. 4'3' The conErol strategy conststs tn the dest,ructton of the vector blackfly larvaetn thetr breedtng ettes (faet-flostng'areae of watercoursee) by neekly atrboinespraytng (by ftxed-wtng atrcraft and, eepectally, heltcopteis) lf ,""y- low doeages(o'g?-ol.m8/1/lo nn.) of non-renanent tnsecttctdee; the operalton ts nog atoed at theeradtcatton but the Eatntenance of the vectors at qutte low btttng denettte6 toprevent a stgntftcant transmtssLon. 4'4' The effecttveness of the control ts evaluated Ehrought regurar sEandardtzedblackfly catches and dtssecttons at enEooologtcal evaluacton checkpotnte to asseisEhe nuober of btEes and the tnEenetty of Eransratsston. Furthermore, manual checks onbreedtng sttes, carrted out after the weekly larvtctdtng, make tt poaetble to assessthe lebhal effect of the larvtctdes and adjust the spraying tacttc accordlngly. 4'5' Up to 1981' the larvtctdtng on the Dogon Plateau was carrted out once a weekevery season' fron July to Novenber, by a heltcopEer from Ehe Bobo-Dloulasso aertaloperattons base (OCP has two bases, each wtth four heltcopters and a ftxed-wtngatrcrafc) durtag one of tts seekly ctrcutts. More than looo lttres of AbaEe, the onlylarvtctde enployed tn the savanna areas of oCP, rrere applted every week. Theevaluatton uas carrted out by e tean of vector collectois and a laboratory asststantfrom one of the ocP operattonal bases tn Malt (stkasso, and then Baaako) headed byone of Ehe authors of thts docuo€DE. 4'6. ocPre obJecttve raa attatged on the Dogon prateau tntts caup.algn- fn order sordar..the annual btttig ratea (ABR.)t ranente Bton potenttal -(ATp) *wpre.r,'eve rywhere, brought dornvaluee conetdered by EEo as tdierable, i.". compattble wtthocular rtek, pf the rtvera.tde ,laade .(iOOo bttee per oan andper uan), and have atnce qfin Feeo contalned far be.10r thoee the very ftrst year of and the annual belos the theorettcal a aettlenent, wtthout lOO O. volnrlue larvae 1tn(te. ParEtcularlttes and reaults of the OCp canpatgn on the Dogon Plateau 4'7' Becluee of thi.htgtr eob4'et'!ha apptlcaEton ro rhe Dogon ptaEeau of thlacontror cacttct:":|tbl o.cl 1f itri 764,000 km2 of tts rrear.J,..r, tr sae dectded tn1981 to cartr @t.tha !.qrvtctdtng locaily and "ot"ry-ri;;-il; [iouna, accordtng ro etacEtc largely based on t,he EDF/occGE caopatgn undertaken nor iong ago tn the rvoryCrr.r.:, M.rl I rnf ll,rrlrf 6. E...... ocPl 2 Page 6 4.8. Every rachl.durtag the pertod of blackfly aettvtty (June-Decduber ), " twolary(ctdtng teaDa.. frol the OCp Vecior Conrrol Untc (VCU), baaed tn BandtaBara, one conpoaed of an ,argtstant entonologte t, tn charge 0f the canpatgn a he lp{r and adrtvar; pnd the.oEhcqia,.la boratory aaetatant, a heLper and a drlverl go all over theplateau on noped and tn all-roada vehtcle, ltet the poatttve breedtng a(collecttoo and tdeotlflcatton of pretoagtnal forus of S. daunoeun 6.1. natural raptde and dau aplllraya) and carry out , upe t reii-iFTflf6ieedt {g atte,larvteLdtng by nanual appltcattop (etnple graduat,ed contatner and a )ofaquanttty of Abate proporttonal to Ehe measured flow rate (O.3 lttres c.). Up to40 potnts can thus be vtstEed and treated weekly, tf nece 88ary. I4.9. In addttton to the checks on the breedtng sttes one ueek after tde larvtctdtng(aad not the follortng day or the day after thai as ts the case durt.," Jt.bo"rr"larvtctdtng), the reeulte are evaluated by standardtzed btctng feoale "{t"tr""(dtaeecced by the asatetant entoaoloStst tn a aummary laboratory tn Bandtagara) madeat sone Een potnta montEored three sreeks per mont,h fron July to Novenber. The three catchtng teaEs (each havtng crro vecEor collectors and a drtver) are on eeconduenEfrom the VCU bases tn Bamako and Bobo-Dtoulasso. Furtheroore, thts year sEtcky craps(Bellec plates : adheetve-coated aluntntum sheets equtpped with floats and placed tnthe satercoursee) have been tnetalled at certatn checkpotnts to etgnal the earlyarrtval or local productton of S. dannosuo s.l. adults.- 4.1O. The reeults are spectaeular. Fron O.6 btte per qan per day tn 1981, the meanbtttng denslttes fell to O.2o and o.23 ln'1982 and 1983 (253 and 188 catchtng days respecttvely). Trangmteaton sas n{l everynhere tn 1982. In 1983, an ApT of 4 and ABRof 115 were recorded at one and t,he saoe potnt (ntI values reeorded for the others).In 1984, only oge blackfly was caught Ehroughout the plateau tn l9O catchtng days covertng ftve monthe at ntne nonttortng potnts. t{trtle the 1984 rea-u.lqs were iuprovedby the poor ralna, tt ta obvtouri that che resuite obtatned stnce fS'Af, l.e. stnce thetnterruptton of atrborne larvtctdtng, have been as good as and even better than thoseof the 1977-1980 perlod, neanlng that Ehe blackfly nutaanee has been eltutnated andthe transmteslon vtrtually tnterrupted. The dtsappearance of btttng blaekfltes has, moreover' been noted stth eattsfactton by the tnhabttants of the plateau llvtng alongthe watercourses t4.11. The appltcaEton of thts tacttc, based on larvtctdtng exclustvely from theground' has led to annual savtngs of $ 4o,ooo on lnsecttctdes (223 ltties on averagefrom 1982 to 1984 lnclustve) and, parttcurarly, flytng hours. 4.L2. Thts Eacttc uttltses a favourable sptn-off of che small dams whtch, whtlehavtng conslderably tnproved resources and saved certatns vtllages on the plateau, are ever)rrrhere else a publtc health scourge, espectally tn regard Eo onchocerctasts; rhey have, tn fact, neceasttated Ehe constructton of roads reiattvely suttable for ootor vehtcles, naktng tt poeetble nos to geE Eo the eatercourses along the damdtrhereae Ehe accesa roada trear the raptds were naturally alnost non-extstent. Parttc(patlon of the vtl lage connunttte6 tn the OCP eanpatgn on the Dogon Plateau ttee lon ttre buc[.et /mrr.[ se 5.1. StarEtng..froa 1982, a epectal effort has been nade by the OCp offtce tn Malt and che adototatratl,ve, healch,'nactonal poltttcal (Baaako), regtonal (Hopct) andlocal (Baqddagar-8iglglg) author{ttee to mobtltze the. populattons. ;' Ehetr 5.2. More loca}y 1ltlrLr.every yeat stnce chen, the techntctan tn charge.of the OCp campatgn on the Bandtagatl: Dlateau undertakes, every ralny 6eason, alraye ntth thehealth' poltttcal and adqtntstrattve auchor{Etes, publtc awareneas and tnforraatton rounds {n the vtllagear. ftrat Eo conaulE the vtllage chtefe and the(r advteere, cradlElonal authorlttes, leadere of youth and nonen aeeoctattone and the vttlaiehealth workers.'Subaequantly, publtc eonferences are organtzed to present onchocerclasta, the foroa of the dtsease, Ehe vectora, ihetr developaent eondtttons and pathogentb role, the necesatty and the forms of control of chese vectors and the meLhods of the OCP campatgn. The llsteners nre then lnv{ted to fac{lltate lt as for a lr ocP|BACT.2 Page 7 5 a 3 a F{nellyr af Eer 1982, rhe hygtentsts/ftrst-atd corkera froo r,trIr:g6. 'ra llagea concerned have recetved every year, tn one or several tralntng perf,odi.;18 ohort retratntng covertng the aaoe subJecte, but uore pracEtcal and nore.detatlca,tlluatrated and connented on, enabling then, tn parttcular, to recognt-zc the S. daonosun breed tng attear the aquattc forua of the blackfly and the btttag feEa-leg. Th.te Eratntng haa been tnereaetngly auccesaful, fron year to year, (63 laboratory aoatsEants retratned eo far) and has raptdly gone beyond the frauerork of the rtverslde vtI lages thaE are concerned ntuh the dtaease. rt haa nor becone a compulaory coEponent of t,he bastc tratntng for all the hygtentete/ftr8t-atd workera of the Dogon Plateau. 5.4. At present,, the hyglentsts/ftrst-etd srorkere of the rtyerstde and netghbourtng vtllages parEtctpate tn all the weekly acttvlttee of the OCP teana yhen carrted outtn thetr respecttve vtllagea : uater-gauge readtnge, checka on breedlng ettee, seParatton of presumed S. damnosum s.l. larvae fron thoee of other epectea,tnstallatton, reooval an-aTffire fance of plate-t,raps, preparatton and appltcat,ton ofAbaEe doses, prtnctples and nodes of btutng female catehes on man, scrubling of dansptllways tnvaded by blackfly larvae. They do not carry out spraytnge alone and arenot requtred for the standardtzed datly caEches. llorever, there le a ueegenger-relay systen for the cooountcatt6n of thetr eesent,tal neteorologtcal, hydrologtcal and entomologtcal'observattona to the OCP statton tn Bandtagarso On the rhole, theaesldutty of Ehe hygtentsts/ftscs-atd workers Ls renarkable and thetr reltabtlttyqutte sattsfactory. . 6. Constderattons and roa cEs as rds the rttct tton of the vl collllnun Etes tn o ocerctasts contro Foreseeable ortentatton of OCp acttvlttes on the Dogon plateau 6.1. In the uell-protected ?ones of tts treated area, oCp le at preeenE engaged tnthe preparatton of an undertalctng for the reductton of infrastructurea, logt-tics andoperattonal costs whtch ts atned aE maktng tt posstble to tranefer OCp actlvtttes tothe Parttctpattng Countrtes. 6.2. The Dogon Plateau forms part of thts zone where, from an operattonal vtewpotnt, ocP acctvtttes have entered Ehe oatnt,enance phase. 6'3. In the years to come, Eherefore, OCP wtll conttnue tts sork of tnvolvtng EheIocal communtttes tn che blackfly cont,ro1. 6.4. The conttnuous developoent of thts parEtctpatton wtll sttll be centred on Ehehygtentsts/ftrst-atd wookers and wtll be organtzed aecordtng to Beveral gutde-ltnes: a) ltncreastng reducEton tn oCP parttctpatton tn the acttvttte6 of entomologtcal ,monttortng through catche.s; b) conttnuatton of the promoEton of the asareneaa and the nobtliratton of thepopulattons, the tratntng of nes hygtentata/ftrst-atd rorkere and the c) progresstve replacenent of huoan-batt catchea by blackfffct"'p1piog, " noo-quantttaEtve ueens of evaluatton but whoae uee te auch llaa cuirU.iiore thanthe catcheg on Een, eopectally tn a rell-protected regton rherc,the.vectoraare no longer abundant enough to Justtfy a full-ttue udirttortng byprofesstonal personnel ; d) tncreased take-over of the montEortng of chb blackfly breedtag attce and, consequently, the carrytng outr progreaelvcly tn apace, rften'.tnttlal supervtston' of larvtctdtng of poetttve breedtng attee or thoae bordertng on zones t,lhere blackf1y nutsance has been esuabltehed. ,ocPlEACT.2 Page 8 6.5. fhte declatve etage of devolutton ta feaatble tnaenueh aa eooe of thehygtentets/flrat-atd sorkers anong the ooat reaponstble wtll have already had expertence- tn the handltng of nolluactctdee uhtch are generally much nore toxtc thanthe antt-blackfly larvtctde". Thi tnportant questton oi doeage, uhtch ta the eubJect of great Precautton tn OCP' could be aolved by the placlng, at each larvtctdtngpotnt, of knorn doaes of Abate tn contatnere coloured dtfiirently accordtng Eo thetr capactEy, the colours corre6pondtng to that of a prevtoua narktng-out of ttre level of Ehe catercourse to be treated, or by platea ranged tn tters or qultt-coloured uater- Bau8e sEaffs. The greateet posstble use would be oade of mechantcal control on Ehedao sptllrayar e-tther by serubbtng then or letttng theu dry out alternately wtth sudden releases (tn consultatton otth the rtveratde market:gardeners and agrtcultural extenston workers). 6.6. Intttally, at least, these acttvtttes wtll rematn under the supervtslon and Eratntng of the OCP servtbee tn llalt, natertaltzed by the tenporary presence of an asstsEanE entomologtst and/or a laboratory asststant on the spot. GeoAraphtcal exEenston of thts Eype of acttvtttes 6.7.' To envtsaSe an extenston of thts type of vector controlrtE ts necessary toltst carefully the facEors for the success of the expertoenE and those whtch makett posstble to hope for tts perfectton, t.€. a) sruall-stzed uatercourses, manual lArvtctdtng utthtn the reach of the vtllage communtttes; b) high populatton denstty and tntense trrtgated agrtculture acEtvtttes, leadtng t,o frequent concacts betlreen the vtllagers and the watercourses andfactlttattng ar the same ttoe access Eo the latter; c) the foct Eo be nonttored and treated well ctrcuuscrtbe.d tn ttme and space, r,rtEh vector populattons tn a precartous natural or tnduced balance a prtoit easter Eo destabtltze raptdly and durably; .d) consequenEly, a cltntcal form noE, presenttng a htgh degree of enderatclty Ehatwtll make sertous rtsks of sudden recrudescence of transmtsston Eo be d:traded; t') human communtttes EhaE are concerned, respecEtve, senstEtzed and motlvated andprovtded stEh soctal structures trhtch make tE posstble to appotnt execu6ors '*ho are effecLtve, consctenttous and concerned stth the "o.ron good; fi dyrtamtc, expertenced and excepttonally moctvated tratners and organtzers, recogntzed and respected by the populattons among whom they work aqd operattng wl rhln Ehe framework of 6truetures and/or proJects of proven vtabtltty: I"t "r:Jl fon of blackf eontrol tnto other act tvtttes 1.9- .nr)Lher characcertst,tc of the onchocerctasts vect,or control on Ehe Dogon Pr.r:-r'i,rr !s that tt' ts carrted out tn parrallel utth another progranme nhtch, for t.si)ari, {:r tnteSrated tnEo the nattonal health atruetureo and dtrecEed agatnsi che 'i nLt.cter.+laEe hosts of schtatosontaste, using the eane urorkere (hygtentsts/f trst-atdj(,!'ti..,.i'., i.nd of ten operaElng tn the sarne stEes. 5.8- It should be adntEEed thaE tn the present OCP area, very few foct offer atpresctt and s{nultaneously all these eseenttal charactertsttcs, etEher naturally or afLer ttrr! /€8rs of control of the dt.sease; conaequently the p.o"p""t" of extenston of rhe Dogtrn Plateau expertence to other foct are very ltttle tnaeea, although not excloieqi cons{dertng the changes tn eptdotolog{cal contexte that can result frora OCP*s acgtvtttes. ocPlEACT.2 Page 9 6'lo. Thts sttuatlon (s paradoxtcal because the ecologlcal eondtEtone neceasarythe Gastropoda' tntermedtaEe hoeta of echtstoeootaete, exclude blackfltes, vecEorsonchocerctasts. However, tn the preaent caoe, nany blackfly larvtctdtng potrrt" ...sptllnays of arrtftctal rakes, hosts of tnfeeted bultnultdae. for of 6'11' In the tmpendtng cont,exE of greatly-reduced onchocerctaete survetllance, ttcould be of tnteresE Eo study Ehe posetbtltttes of and the condtc,tons for , gi."t.. coordtnaEton between the two pro8ranaee, and even an tntegratton of chetr suplrvtstonaod tnplementaEton, because, tn addttton to the worke.".nd operattng sttis,'Ehetrparasttologtcal tdent,tftcaEtons and peettctde appltcattone tn aquaEtc envtronmentsare stmtlar. 7 Conclustons 7'I' Under che ausptces of oCP, th the Dogon Plateau, tn Malt, an onchocerctastsvector control programme, uttltztng ground-based means and Eechnologtes eastlyasstmtlat,ed by che local rural communtttes, has successfully replaced, for foursucesstve years now, the atrborne larvtctdtng carrted out there earlter. 7 '2' Thts contror EacEtc tncludes the promotton of the tnterest and the tncreastngparttctpatton of Ehe rtverstde vtllage comnuntttes and has been growtngry successfullocally' rt ts posstble to envtsage tn the relattvely near future the almosE completetake-over of the entomologtcal evaluatton and blackfly control operattons by these communt E tes . 7'3' The Dogon Plateau expertment ts an excepttonar case resulttng fromcombtnatton of a Sreat number of favourable factors, whtch are so far meEvery few foc{ tn the OCP area' even aft,er ten years of largely successfulcontrol. 7'4' Because o{ rn. constratnEs tmposed by the bto-ecology of the vectors,espectally thetr extreme mobtltty and relattve ubtqutty, ali the soctoeconomtcconsequences of Ehe dtsease, whtch make man go atray from the btg watercourses,onchocerctasts conErol rematns, at least dur.ing tEs atEack and consortdatton phases,tf noE chac of ma{'ntenancer a very large-scale affatr, that necessartry calls forSreaE logtst{c means shtch are beyond the tndtvtdual fosetbtltttes of the states anda forLlort those of the rural communtttes. 7'5' There is very ltEEle chance of nuch exEenston of the Dogon prateau exampre lnEhe near fuLure' Hosrever, tE shows that, provtded certatn condittons are furfti-1"a,and ac the expense of a long-term work, devolutton of blackfly conErol acttvtEtes lsfeastble, jusE as thetr tntegratton tnto the nattonal mulEtdtsctprtnary programmesfor uhe control of ot,her dtseases whose vecEors or tntermedtaEe hosEs are alsorelat.ed t.o wal_er {.s concetvable. 7.6. On these vartous accounts, and although tt.stmttatton, the Dogon plaEeau expertment deseivee tothrough. Ehe tn only a b lackf ly very untque naEure resLrtcts tEs be known and, above all, carrted