Results of the epidemiological evaluation of the impact of vector control in the OCP

l,lo*,r, ;i,ir' alo. r i l' i ,!, +9 OBCANIZATION ORGANIiSATION MON ONCHOCERCIASIS CONTBOL PROGRAMUE IN T{EST UUE DE TUTTE CONTRE L'ONCEOCERCOSE EN ATRI I a{r I{ORLD. EEAI.TH PROGRA &AQ Ttt-f DIALE DE tA ;. AF&ICA QUE DE LroUE i ocP lEPt /p*/ \ EPIDEMIOLOGICAL EVALUATION UNIT .q PROGRESS REPORT (May 1985-April fgA6') RESULTS OF TEE EPIDEUIOLOGICAL EVALUATION OF TEE IUPACT OT VECT N TEE OCP. EvaLuatlens done durln the reportln er Lod . 1: The Present Progress report covers the perlod of may 1985 to siprll rnfectlone 1n chlLdren born slnce the start of control. co 1986. Durlng thls perlod epidentologlcal evaluatlone were done r"-iii--indlcator villages 1n the orlglnal OCq a'tea, uslng the elnple e\ralulatlonprotocol 1n 37 vlllages and the detall:ed protocol ln L4 of then. a ltot8lof 9936 persons were examlned, whlch 1s equal to 842 of the populatltor,t-whlch was present in those vl11ages at th; tlne of the vLsit or 68Zl ofthe census Populatlon. In addltlon to these surveya, 5 detailed anal gslmple fo1lorr-uP evaluatlone"were done 1n phhse fvU, ttr"l"o-.r1led itlntermedlate zonet in the Ivory Coast. The data fromrth,ese latterivl1lages are presently belng "o.1y.ed iand the reeutts-rriii-;"-;;;;"1..a at the meetlng of Ehe EAC. I 2. .Durlng a preparatory ueetlng to determlne the sel,ectlon of ievaluation viLlages, 1t rraa declded to modtf y the routtnei 'schedule ltoenable an evaluatLon whlch lras trore responsLve to the'needs of the iprograntre. In the selectlon of the sinple eva1,.r"i1on vll1age" "p."1i"1emphasls was glven to those areas for which ,the eptdemlotogical | ,sltuatlon was not euf ficlently'.understood, or foriwhlch tfh; resultsi of ,rhe entomologlcaL-eval-uatlon have not alwayel been saErafaictory. i IEspectally lnportant 1n thls respect wae the lntenglftedferalLatlonl 1n lGhana, where the lnterpretatlon of the results hae alwaysi been arrilr""rtbecauseof1nva11dbase11nedatawh11evictorcootroI.t'lalu""" lncompLete ln 1981 and 1985 along the [Ihlre Volta/rul{ rrr,/ Slssili blasiner4 ln 1978J982 and 1985 along the stretch of rhe Black volra.t""rl-iui.The "rr"1,ratto;; i" rh" rnr".r"ir"t" ;;;; in rhe rvory coaet were I""urgently needed because no fol1o!r-up examLnartlons hai been done Iprevtouely ln thrs ares rhere resl;;.;;;r;"'i"r.rnll'n.l=rr]i"I."u isatlefactory control of S.spj!r"gg=, whlch has oit"., been preBent-rlr,htgh denslEtes but Lt's fucal--rof,e in,the transmissLon of irrrrarng i" ionchocerclasLs has remalned uncl€€lr. The detptled evaluatlone ln in[central oCP area lrere done to conflrn the p;;j""iron-at.a actlve ocirlaronchocerclasLs would become extremely rare after a perlod of 1O-11|};;;" I Ih I - i1:^-,]1,t1-t :111:u:s.1n the.o:retnar 0cp-area, the population has bpenexamlned at leaet twlce, and auitng the f ollow-up """ioii;;i;;"--;ir;i;-"L975, skln snlp examinatlone have been done trn.^1orz42 chtldren, rhol-r.reborn elnce the start of control (see table 1). Todate, 45 oi'ttro"" | ---fchlldren have been found ekln-snip posirtve t a.Ear;;a-;r qxpectea nufberrof over 8oo 1f there had been no vecror control. uoet of the lufecJE;=''chlldren eoEe fron the relnvasion areas and thes" -""""" have been I-rePorted,:,rpnevto,1r.a1y- In 47 of the 51 vlLlages eurveyed durlng the Ileport*11 perlod'1n the central area, whlch has noy undergone 1o-1llyeare of vector controlr Do skin snlp posltlve chlldren lrere detectedagalne t aa expected nuuber of over silo- rnfected chlLdren had there jbeenno control (aee alao aap 1).v s'ev rcY L' 'zo'€ F6 . ., :' e of new ive' t e rrg".] l I l srtl]v lagel ol end lb se olf thesh our t[r o s I tll Llaeletn tln I i new skln snlp po : one ln the vlL om Gbagba-Slrakor the village of P ee from'the v111a . In addtElon to conflrmed 1n a f ected skln snlp p htld from thls vi nd mLcrofllarLae tllages 8 rent year), one fr hre'e from), and thr c,ted=3.6) ctlon lras only det a ftfth c nodule a 4. IIowever, ln the remainlng f our v chlLdren were detected durlng the cur Kayoro (Sles111, Ghana ; expected=6.7(Couoe, Ivory Coast ; expected=10.2 ) , t(Dlenkoa, Burklna Faso; expected=10.4 Goreba-Souun (White VoltarGhana; expe skln snLp posltlve chll"dren, the lnf e chtld ln Pendle, lrho was hitherto the chtld 1n the central. OCP area, whl1e though skin snlp negative, had a head anterlor chamber of the eye. Trend 1n the Communlty Mlcrof lLarial Lload (CMFt). I nlp 1ne e cant are ed a s. ge lrst end, ound in P and t eed by 4 ce ve ell .ln oI 'i,s1 ai" ol- as ol,, "1. f tr I lf el dl mla I i I nl I 8l ,la I ars dl I Irl, dl rln rl I l l 1 l i cl. el ii" rlY I i Ell Results of the o ht ha 1mo 1o 1ca1 ofl1arla1 load per skin years of age at the bas decrease ln nearly all e 1). The CMFLTs have n e assocli-tgd wlth slgnl 1on. The relative Erend that the CI'IFL has decre es st111 pcllnt to a zer AGE llfespan of an 11ng off of the trends gp ls not yet very obvl lcted, acceiLerated decr y dlscernabl-e. thls general trend. The e loads have fa11en but where the overall ue to an unsatlsfactoryys. Thls exceptlon wasStsslll 1n Ghana, in th n'drru 1n Ivo ry Coa s t an ck Vol ta tri Ghana ( see v'l11aggs of, Goreba-Sonu clearly unsattsfactory 1'11ageB where 6 of the v111age of ,Pendie has h s bqt only durlng the 1 t'ly delayed and remalne t,s for Goreba-Sonun are 'data are avallable, be CMFL had only decrease 2D mf s, a level- whlch, t.a.d w{th severe ocula glcal evaluatlon tn t.!J" trol were very good. Fl icrofllarlal- load ln th a1ly reuained at zeto s of vector control. A ve Ee keratltis 1oad. The a1 load 1n the anterlor r,O Later, and SOme pOsl trol (see flgure 5). n nlcr sr 20 iinear ietgur oru 1d b sltuat ishow11 ltn d AVER eld tal lave r a el pred nig ver nrd to elre th dveys r ayed d tSU rVe lpawn/ t,he Ba trle B 1a l I I ei two elma 1n s same v . The 1 year lflcan iresul sle l tne o;1 rhe ithan lassoc I1," at 1on. 5. The CI.iFL ( 1. e. the geometrl ln a cohort of adults who were a survey) has conElnued 1t I s vlrt vlllages 1n the central 0CP area fa11en far below those 1evels wh ocular pathology 1n a non-contro st111 very sinllar (see flgure 2 by more than 9O7l after 10-11 yeapolnt after 11-12 years, the est onchocercal lnfectlon, and the e result of the varlablltty around The loads are now so low that al ln the prevalence 1n adults 1s b 6. Two types of exceptlons \der type concerns a nuaber of v111ag slgnlficantly betrreen the last t though presently satlsfactory, L decrease ln the CMEL between pTe 1n a cluster of villages along',t v111age Tripoungou on an affluert the v111age of Bu1-Akanyakron a1 2). 7. The second exceptlon concer Pendi-e, where the Erend 1n the C Eoda ce ( see flgure 3 ) . These are newly lnfected chlldren lrere det five detalled surveys over the I survey was the trend of the CMFL around a value of 6 mfs per snlp definlEely worse: though no va1 the Ehlrd and the tenth year of 267. and has now still a value of non-controLled slEuatl-ons, ls us pathology. cm t1 ual(s ich 11e)a tS. lma xpe th so eco ef es I'O sd vlo he to ong ns UFL rh ect ast si .T 1d con mo ual eva ea ea 1 ee t, d nd A te cE 1s rh ml ou wh su e1 ug Ku t t rh r e ed 1 gn he ba tr re 1y 1u 8. The overall results of the ophth4lmolo central zone with 1O-11 years of vectolr con shows that the relaElve trend in the d."., m cornea (MFC) 1n cohorts of adults has vl.rtu thls 1evel was aEtalned afEer some 6 years s1m11ar trend was observed for mean pulnctua relative trend 1n the communlty mlcrodtlarl chamber of the eye (CMFL/AC) approac\es ze cases are stil1 found after 1O years of con IPage 3,l i9. The tmpllcations of this reductlon of trhe nicrof tlarlal load t]n t4" eye 1s reflected 1n the 1ow tncldence of bllndness, the arreat of tlhe developnent of eye lestons and the dlsappearance of onchocercal leslfons, 1n partlcular those 1n the early stage!s of developnent. These flnd!ngs, !-hlch heve alr-eedy-b-cc-n--Ieported for the Eurveys done aftet 7-8 yealrs qf control, cone out even more clearly after 10 yeare of control. I I 1O. Table 2 shows solne prellnlnary rQsults of the on-golng analyslls of the rate of development and dlsappLarance of onchocercal eye 1es.1 orls ' over a period of 1O-11 years of control and related factors. Thougtr] thls table glves only crude results, tt alqeady show$ lhat the 10-year {ataconflrm the previous conclusion that for the anterLor segment of the €Yer dlsappearance of lesLons 1s a more common phenomenon than the ]development of ne!, l-eslons. At the posterlor segnent the developmenJ t of new lestons ls qulte stgntflcant, though the lncldence 1s def1n1tel]y nuch lower than would be expected tf there had been no vectoi contrlol. Adetalled analysts of the 1O year data, which has only recently starited, wllL conslder such factors as observer varLatlon, whlch nay affect ithe estlmates of the above rates beeause of assoclated false posltlve qnd negative dlagnosts, and the ldentlficatlon of rlsk factors f,or thelncldence of onchocercal leslons during a perlod of vector control. l iMaln concl-uslons of the epldemlologlcal eval_uatlon. I I : y eullte1n tlhe hel 'o up ',1i a1ly, re olnly sls seems ,,ta"]1 r c h wi..r. Inololelcal ovenents tt" ]forl nplejtely 1n tlhe wlth] , l I rlv lshow ot lba-Slonurl , rlvelr. No lhild]ren t hei robllems snls]slon sls ]as a 11. The regult.a of the epldemlologlcal evaluatlon are generallgood aod conflrm once uori the effectlveness of vector controtr- central ocP area. Infectlons have renalned extrenely rare ln t chlLdren who rrere born since the atart of control whlLe thle gr cotrstltutes now close to one-thlrd of the Eotal populatlon. Thelnteualty of lnfectlon tn adulrs has conrlnued r; irri;r;..;i; mtcrofllarlae are no longer detected ln the cornea whtle they a rarely aeen Ln the anterlor chamber of the eye, and onchocercia no longer to be a probLern of publtc hdalth inportance in the ce ocP. L2, Renarkably good were even the reqults for those 4reas, whi esPeclally seLected thls year because iof less satlsfactory ento or epldemlologlcal results ln the past. Noteworthy are the lnpr along the Kulpawn ln Ghana and ln the vlllage Trlpoungou along Bandama ln rvory coast, where the cMBIle whlch had been stagnantqulte aor[e tlne, nol showed a very st!nlflcant decr€8s€o Not co satlsfactory but st111 surprietngly s,iod rras also the decreaeeCHFL ln But-Akanyakron tn Ghana, a village near catchtng sltesATP's of over L000 ln 197&-and around 5oo rn L982 and 1985. 13. Only for trro vl11ages d1d the eptde'niological results cleathat slgniflcant transnleelon had taken placle durlng the perlod vector control. The most serious exanile is the villagF of Gore along an affluent of the I{hlte Volta Jlust south of the: Kulpawnentomologlcal evaluatlon has been donq in thls area whlch lsLnacceeslble durlng the rainy season. However, al1 avalLable epldeulologlcal- data, lncludlng the results for the cohort of cborn before the start of control, indlcate a qulte hlgh 1eve1 otransolssLon durlng the past 6 years, and it is unrt['Qry that t epldeutologlcal results can be ex-plalned by the loca1 control p of 1981 a1one. More 11ke1y 1s a recurrent probleu of 1oca1 tran along thls affluent, a problem whlch has matntalned onchocercla serlous publlc health problem in this vlllage and po6stbly has contrlbuted to transmlsslon over a wlder area. 14. Quite dlfferent 1s the "Jt,r.tlon'1n the vlllage Pendle, whfch lfsone of the Bost closely folloCed-up vl11ages'1n the OCP, wlth flve detalled surveys durlng an 11 year control period. Transmission ha deflnltely taken place, and the epldeulological data suggest that has probably malnly occurred after the year L979. Ilowever, contraryl to Goreba-Somun, the eptdemLological sltuatlon ln Pendle has lnproved constderably over the last 1O years and ,the last ophthaluologlcal exanLnatto,n suggests that a signlflcant degree of dleiaee control been achleved ln thls v111age even though transmlssion has natntalnled an luportant reseirvoir of lnfection. 15. I{lth good baseline data, .the problems ln Goreba-Somun wouldprobabl-y have been detected ear1ler, but 1t ls lmportanE to note thlat i]ttook 5 detalled surveys over a perlod of 11 years to detqct the prolUteui -+-^-r+---t -- . . .-l- |uf-resl-tua1-.lrarrgru-ffinPendl'e.Theresu1tsforthls1attervr1|1a are strtklngly slmllar to the prevlously reporEed findlngs of a comlpute slmulatlon of llght transmisslon durlng a perlod of vector control study whlch lndlcated that such ltght transmLsslon nlght remaLn undetected for many years with the presently aval1able epidemiolbgllcal tooIs. The vlllage of Pendle serves therefore as another warning thlat, although the epldemlologlcal data glve sufftcient proof that the dilseasie1s under control 1n vlrtually the whole central 0CP arear oany quesltlons concernlng the extent and lmportance of the flnal reservol.r of tnfelctlon are not yet resolved and st111 requlre serlous attentlon during the comlng yeara. r{EgTEBN EXTENS ION - Tra lnL ng 77. Personnel movement wl11 be a constant worry andto affect the natlonal teams of Gulnea, three nurses, nuEBeo Replenlshment for thls four nurses have been soon start the traLnLng. Evaluatlon of phase 1 vl11ageg 16. Prlorlty has been glven to the trathing of the teams of tlncluded ln the phase 1 of the vector control programde ichedu start in 1987. The teams of the country included in phase 1,Gulnea have conpleted thelr triainlng and became operatlonal. acontrol teets for microfllarta6 countlng in the skln and Ehe c carrled out 1n Septenber 1985 for the Mallan team 1n comparleoteeE nuuber 1. The results of the quality control tedts rf,ere satlsfactory. The Senegal and Gulnea-Blssau teams have Just cothelr tralnlng. They wtLl be operatlonal by septeuber 1986. Th of the candldates for the slerra Leone tean hae not yet been c ntry I ndl Idefe ocP d1 ce ed. rted 11 he c oiu 1e d .lo Ma 11 la ua 1t tlv Yensusl n wi tih i mple te e cho]t omp r elt Idy s tia , onel and wl I 18. Up to date the national team of Guinea has surveyed 37 villagels for a total of 6976 people censused and 5537 examined and the natlorrai la""*of Ualt has evaluated 28 vl1ldges for a toEa,l of 652O people censuslea and 4454 examtned. A11 the vll1ages are accessible at i"""r durlng ltn",dry season and rrere Judged__stable. - i .l19. The geographlcal distrlbutlon of the vtllageE evaluared and thlelrentoEologlcal and epldemlolog{ca1 characterlstlcs are presented 1n lt"Ul"3. The rlver basine and catchtng polnts selected by the vector contlrol,unlt have been adequately covered by the vlllages surveyed. The stzle odthe vll'1ages ls adequate even ithough 1t w111 be preferable to lncr"ir"" 'the number of large vl11ages especlally 1n GuLnea. The dlstrlbutlonl ofhyPerendemic v111ages, evaluated tn Gulnea, by river baslns and catlchlrispoints seeus satlsfactory even though Ewo exrra hyp:jendemtc villagles I has aLrea and Ma11 selected Pag 1c ts d f i l 1 I I J ri d I I I uandr nd wl1 I the should be added 1n the Bagbe rlver baiin. Far too hypoendemtc vtllages have been evaluated 1n Mall an vtllages do not cover adequately the rlver baslns a selected by the vector control unlt. The sltuatlon durlng the next dry aeason. I I "lt .ir q rio ls dc J- "lrI I 2L. The lnportance of lnstitutlng qual-lty conLrol tests for the examlnations carrled out ln slmple and detalled surveys has been repeatedly emphaslzed. Quallty controls w111 serve not only as chethe accuracy of data for subsequent uqe by those analyslng the flgbut also to eval-uate Ehe 1evel of pro{lciency of the natlonal teamthe eventual need of retralnlng. Dur14g the past year qual_ity contEests for census, assessment of mlcrofilarlal concentratlon in the snlps, medLcal and ophthalmologlcal examinatlons rrere conducted.personnel and the Mallan natlonal team have been tested. Only Lnte observer varlatlon was studled and thd results were presented ln dlast January at the EpI I{orkshop. Pag y Eeso and he hyperende catchlng poi 1 be correct eval-uatlon20. Both natLonal teaos are .rrg.gLd at present 1nfurther 3O vl11ages in l1aL7, 24 vl1lages 1n Gulnea. sdn es r and I kln P atL l t ldn I qUALITY COITTROT rEStS 22. The results of the tests for census and mlcrofllArtal concent1n the skln snlps were conslddred satlsfactory for both OCp and thMa1lan tealns. However the perdentage dgreement at 24 houqs readlng no t lceabry lower than the percentage dg=."ement at 3o nlnqtes. The ulcrofllartae are not anymore uoblLe at the 24 hours ieadlng and c confused wlth artlfacts such 4s cottori threa,ds. 23- The results of the quallqy contrql otests for the inedical exenlnatlon were -def lnltely udsattsf aitory. lThlir type 'of lexaninatl needs careful revlew and the drlEerla for counting nodules mostly nultllobulated and for ascrlbei leslons'to onchocerclasls should beclearly descrlbed ln a tranual qf procldure. Up to date OCp has not use of the nedlcal examlnatlon data rnld the need to contl.nue this ----+€€ beet quest{+n€+- RESEARCE Imuuno 1 ogy rra a nbd oae adE fod n h n t la l" l. a1 t I gher t Een dl req e urse lng i l I alt Illr ]" I I rl, "lo "lt 1i" "1" l I ni' I ,1, tlr 24. The results of the quallty contrdl tests for the ophthalmolog examlnatlon were consldered satlsfactdry. A good percentage agreetrItas found for anterlor lesLons and mic]rofllarlae countlng ln itt"' anterlor chamber, The degree of dlsagrleement reported for the examlnatlon of the optlc disk was wtt\1n expbctatlon but EhedisagreelEent reglsEered 1n thg dlagnosis of choroldoretlnltls !rasEhan expec ted. 25. Quality control tests wiLl be conducted on a routine bagls. WProtocols and routlne conputer prograqmes w111 be developed and wilnclude thq study of lntra-observer variatlon. 1on oft a developlng lnfectlon wlthgy 1mp11es the examlnatlon of eerl ransmlsslon. For thls pupose, a th opulation llvlng 1n a hyperendemlc . The sera obtalned are tested byTroplcal Institute (STI), respolnse 1n exposed 6ut nlcofllar s who,have become posltive in the cessed for the detectlon of circul 25. Research towards the detectO. volvulus by means of Lmmunolo sera of lndtvldrials exposed to t f ollov up survey lras done in d p where transuLssl.on ie contlnu{ng several techuiques at the Swids Basel r to detect an early lmmrinefree lndlvlduals, and lndlvldual of the atudy. These sera are pro iI I I .i I i v€r tq- I ll lr the sl ed l l l SO r"g"l o parasite antlgen as well as td. serum antiboSleg. neqult,s obtalned far show thaE a seroconverslo4 occurs 1n expgsed nndivlduals withou evidence of para6lte and ln- Ehose who have r!cently turne.d mf poslt conflrmlng prevl.ous results lrtlere sero,-posltivlty and/or an lncreas the anElbody tlters were obsefved more than two yeats prior to the appearance of mlcrof tl-arl.ae ln the skln. For such tests, soue Eonoclonal antlbodies agalnst ,adult worms haye proved lntereBting a '(speclflclty 1eve1. Thelr,value wlth regard to speclflclty st111 neefurther lnvestlgatlon. In addttlon, a selection of sera w111 be tes by an lnnunoblot technlque agalnst an adult worm extract Eo ldenttf antlgeos of dlagnostlc value dor the deEectlon of early active lnfectlons. l and c.lA ne N4 !r ng n I I P.' I I rqn of I I I lrom l i 1.tg g I 1d. rdm e I Ins for I abora t lve The atm lof volvu1uls RNA was I s then i translatllon be antleelnfg for uaJor tlng rhe lg"r lray; A icDat Basell. thus avoldl I 1 lbeen broalde ology, Ira If ac 111t lle s by one grlou ave alrealdy lnfecttonl f Intcs of I nosLng a I evaluatloln nt to thel I I i -welght I wlth ".rrl fIra from t]he antlgen blut l-t, suggeist a decllniln f this. 1ol,{- I I I r severarl atory anllma f experts] t s e rved lalrg rte Iy-reared ]ze rodentls verslty olf he OCP arlea r1 I I I I I I --- dentlflcatLon and productlon of va1uab1" ..,tlge purpose 1s also being approached through a co11 lvlng Ehe STI, the Blozentrum at Basel and CiCp. ls to obtalnr ln vltro, the gene producte of 0. lr potentlal antfgenfc value. For that purposE, rom adult O. volvulus rrorns ln the field, afld wa ly translafed-ElEo at the BLozentrum. Thls n the synttresffoTl6-fypeptides which proved to ary approach conslsts 1n lsolatlng genes encodln nvolved in the course of an lnfectlon and evalua or Lmmunodlagnostlc ipurpo"."l. Thls'study 1s unde s already been constructed and ls belng.screenedgens are found Ehey could be produced 1n vltro, the paraslte. -T i cP collaboratton rr, ltn" f 1elid of lumunology has ups of the Imperlal College of Scilence end Techn ost-doctoral posltion has been granted by OCP fo Eo work fu11 tlne {n onchocerclasls qstng dn"ftg the experlence acquired 1n lymphattg fllarlae lons for the early dlagnosle of onchocerclasts ihd studles Eo dlffereirtiat.4o oldr long lasttng ectlon are env1".g"{. The r"i""""r",rrt oi the idy;ad sub classes of tndunoglobr{1l.ns could help dlag tlon, whlch could bd of great assLstance 1n the t.ro1. Ilencef orth, ceraeterlsed sera hive been ge ol1ege and the study should start rsoor. e unlversity of Hetdelberg df'nc) a Ioni-rnol-ecular s been ldenttfted "C antlgenic and non-reactlngs 1l_f3Sled__rr+h_I. Pancrofrl or q. perbtans. Sed area do noE recognlse, or blnd pioorly toThts non treated area seern to react very strongl)t to rneans of dlstlngulshing an actlve infectlon from 1s now supportlng thls group for the lso1at1on o welght antlgen. lfflculty of obtalnlng thlrd-stage larvae h4s fo a serlous handlcap to the l.mmuntsatlon of labor a1ly been posslble to """rrrJ the collabpratlon oversLty (N.Y. USA) who have obtalned anI cryopre of microf.LLarlae from the 0CP savannah area forproductlon of Ehlrd-stage larvae 1n a laborat,orb1ackf1les. These larvae wt11 be used to inmunition of monoclonal qnEl-L3 anEibodles at the Unl(USA) . Such antlbodles will then be res ted in tdlagnostlc va1ue, for the tdxonomy of L3s and fo ologlcal inves tlgat lons i c o v e f 1 i t I f a 1 0 o P r n t n f n c n c h a I e d n n I s t c 27. The dlagnostl s tudy lnv thls stud asseas th lsolated successfu resulted complemen antlgens products library h major ant resorE Eo 28. The Eo two gr London. A researche and shari Inve s t lga started a a superln classes a superlnfe vector co Inperlal 29. At tproteln h LE_{fvidua OCP treat sera fron a poslble on€ o OCP uolecular 30. The years bee IE has ft Ithaca Un quan Ei E le subsequen colony of the produ I{lsconsln for thelr lfor lmnunopa th Il Savannah and Forest Parasite dlfferentlation -4.l 31. Two laboratories are lnvolved-1n the constructtori of a DNAllbrary of O.volvulus fron the savannah and from the f,orest areaBoth laboratorles have now obtalned a probe that hybrldlzes onlythe worma of the onchocerca genus. Investlgations are contlnulngtowards determinfng-Ee specles speclflclty and forrn speclflclty. 32- Another attempt to dlfferentlate the two forue of the parasltebelng made through enzyme eleotrophoresls studies. For th.is purposeO.volvulus adult worms rrere collected from patlents livlng 1; vart<ffirII."t,savannahanq1nterned1ate.ZoIl€8cThe1qveetrg.trj] under way. Apart frou the dlfferentlatlon of the two forus of l"rr"l1t is exPected, from the sEud)1, to obtaln lnformatlon on whether o.l ag 8e o w "l I "1"fl llt mlc ocP. h 1s , us n ls 1te, notthere 1s a gene flow between ghe two populatlons of p4raelte. Fertlllty and Fecundlty of the paraslte r e I I I I33. The invesElgatlons prevldusly carrl*ed ol,rt to eetlmate the tonglevttvof the parastte have streesed the need do. the aspeasment of th; -o1---'rJfert11lty of _o.yolvu1us adultJ. A technlque for the quantltati;; Iassessment of the sPerm 1n the testls and the fernele reproduct'tve tlract1s now avallable. Recent studl,es carrled out in the sl,acld vorta ,r"1.---have conflrmed that the reproductlve turnover of the denale worrns ti""become 1ow. The examlnatlon of the uale wortri popu[atlon of thls ;r;l; hasshown thac only LOZ of then have been sexually acpfve'and ::":"tfy idellvered their mature sperm dompared to 502 1n npn-contqolled areals.These results and future ones iwl11 be usbd for fupthet delvelopment iofthe nathematlcal -uodel of on"docerclasis. - ,'---r---" l"' }IIGRATION STUDIES I I 34. wlth the approach of nevJlurlon in the central zone of the I -----?rograul[e, uouc,-urrrffiere-n e:{nresaed over the posslbl.e qole of Ilnnlgrants on the transmLsslon:of the dlsease. ee vector control Iaetlvitles wlLl decrease and dtttrnately stop, the fltes qre "*p""t.la torePopulate the river valleys cnd 1f a suffi;ienrty high reser"oi;;lf;h"parastte will st111 be presen{ ln the controlled aread the dlseabe lwf fi-relapse at an httherto unknowri velocity. seasonall anat"iJil;-i;;i;rl;;;;fron non conErolled areas may ]very weli playi an luportant rof"-i.r' l-'--bulldlng uP the reservolr of !he parastte rr,a conErtur-,t" ao itr"--- IaPPearauce of relapses of theldlsease and the velbclty' of its "or.rlar.,*.Because of thls concern migr.{ton studles have become routlne;;;;;i;t:;of the EPI unit and conducted iin srrlcr collaboratlon wtrh-iio-;;; i;;;:- General objecttve I I35. To aEaeas the lmportance lof seaaonal and stable lmnlgrant" "" laource of resldual infectlon dnd transmlsslon. r 1 - ' -- I I36. Speclflc obJectlvee i1.To-cotrPa!e prevalence and lntenslty of lnfectlon of new and loldeertlement vlllages l -- 11. to coruPare prevalenc. i..ra lntenslty of inf ectlon of ,r"rf o Ireglstered people and the total populatlon of exlstlng indl""alotvtllageo ---l-- Ili1. to corDpare prevalence and intenslty, of inf ec11o4 of vl11rgl"."that have nlgrated 1n areas where onchLcerclasle lras ii.n;;i;;l;;'dgIl"s thelr perlod of restdence wlrh rhe roEar pop,rra;i;;-;;-l;;"vlllage l- - P.e.l e i ll I lll,- from preas w111 lbe I I1i ) "1",1 I I Ma1 thn rllagls ntol I P simlple s. Th[s I coverl ttrqlllihel ,ut bepausle 'the I rreva llenc e de r,rlrttreirer I I .97 5 tF," l ,nEro 1l o f , a"golodrl r fI r Thle rrd oclr See Alnne:l I oCP f]orn numbpr of ,l L ,.'.or[ rJr zear wias rrako iareai . , 1e781). r of t]he ,ne orl nore(Pecteld Ehe pleriod the pierlod i l. i iv. to assess the potenttal threatl of seasonaL lnutgrants where onchocerciasts has jnot beenl controlled; when f1les allowed to repopulate Ehe rlver blasins. ' I 37. During Ehe last worklng season onily speclftc obJectlves (1 ( ili ) were addressed. i !ii Methods ; 'i38. Couparlson of newly regldtered anld total Popu18ttron. In 5(Farako rlver) and 3 Ghanatar! (B1ack iVolta rlver) lndlcator vL the surveys rilere exEended beydnd the o]riglnal- cohort populatlon lnclude all lmnlgrants and other new alrrivals. The standard 0C evaluation methodology was used 1n thel survey of the I "l1Lagestype of study w111 be routtnell:I conducced every yPar and wt11 lnltlal zone of the Prograrume ion a sardple basl,s. 39. Comparison of villagers Ehat have nlgrated 1n areas where onchocerclasls is-transmitted land of tlhe total populatlonr of t vi1lage. A formal calcuLatlon'iof samplle sLze was not carrled ou of t.he lack of an estlmatlon of the pr:oportlon of lmmlgrants. I declded to conduct thls surve! 1n the 11O v11-lagea selqcted for Farako study in Southern Mall rl estirnatied populatlon 20OO and pq-f-qnchgcercL4sls 102, and to use the jexperLence !atned to guid lnvestlgatlons. Thls area wae ]selected] becau'se 1E has lbeern undlarvlcide treatment for nore than 18 years etven thougti untlL Lg control uas unsatlsfactory and only sLrnce the starE of OCPr co transmlsslon has been achleved. The vlillages of thts area have record of collaboratlon yteldtng a higih percentagP of exalmlned populatlon and present an honggeneous'epldemil.ologlcal sit,uatlon total popul-atlon of the v111a!es was s,urveyed uslpS the s:tqndar slnple evaluatlon neLhodology and a mllgratlon f orp was adlded ( 1). ' i i 40. Inf oroatlon f or each perdon was ,]""orded on the s tan,dara and on the ulgratlon f orn and 'ldentif lied by number of vi1l1a8€ rfaully and lndlvldual number. lThe namei of v111age, sub-dlstrlct dlstrict, reglon and country qr the naire of village aha nearest place of blrth and place of resldence abroad for more than l ye recorded as well as the numbeE of yearls of resldence 1n the Fa The exact date of resLdence welre specf,ffea (e.g. frod 1975 to The surn of the years of reeldence has lto correspond to the agepersoD. A nlgrant ldas deflned;as a person that has 1lved for oyears outslde the Farako area 1n the l,ast 15 years (maxinurn exp 11fe of an Lnfectlon) ln an area of kn,own trgnsmisslon durlng t of hie/her restdence. The 1r3""-:,1, knlown transmlsslon durlng of reeldence rrere ldentlfled by VCU. Results and dlscusslon he f; an4 s ade ly lty ibld Eudy 8r€ deptcEed ln Tables 4 and 5 opulatllon newly reglstered presents f lnfecltlon as the total populaElongistereld present a hlgher prevalenc v111age]s and lower in dthers and th Only 1r] the age grpup of 1o to 19 n lstently lower prevalence'and lnten re suall and ascrtbable Eo chance ( semi-colhort (Tab1e 5) shows that th ldentologlcal sltuatlon of the v111 s rJere also part of, the second stud mlgrarlt was used to loclude only p e first s hat the p tenslty o Newly de 1n somq nd sex. have cons erences a hort ".dts the 6p n v111age nlElon of 4L. The results of th Over all, 1t appears E sane prevalence and 1n the vlllage surveyed. lntenslty of lnfectlon mlxed pattern by age a reglstered appears to of lnfectlon. The dlff 4). Cornparlson with co anaLysls well represen surveyed. The 5 Ma1la where a dlfferent deft es p1e E lia l" 1t l" e e e s T I a v e II l I v r 0 1 t I e 'i , i L 1.. P'e"l e Ithat have been exposed to lnfectlon dqrl.ng thelr reeldence abroaa. !otthe 103 newly reglstered people only I satlsfled the d"iini;i;;-;; l--nigrants aa used 1u the second study (r6.BZ) versus z4),oui oi-;h"-arh(3.02) f or total popularlon e*anlnei. -ithi" type of Btudy has the l-advantage of belng of easy executlon and anaiysrs h,o_lrdver the ilnformatlon acgulred 1s unsat+sfactory becausL tne t-i'q populatlon" 1.r",and prevlously reglstered do not.bppelr to dlf fer sub"t.rrirrrry i" l;;;past and present rlsk of acqutrlng onchocerciasrs, tnfecttons. i - I42' The results of the second survey are depicted ln Table 6. rn ain"vl11ages surveyed 22oB people,wer. examined (ag.rl of the popuratroln-Present and 77.52 of. the populatlon ""lrr"used) and thelr ulgratlon -1" hlstory collected- only 56 v1l1agers Here cLasslfled as migrants onl thbasis of the above stated deflnlito.r. The average tlne of resla"rr"J urrabroad for people classlf ied as- nlgrants lras 5,2 yeate, ,4.6 for at1"lnfected ulgrants and 5.4 for the "on,infected. Beta,ree of marked ;];"difference betrreen ulgrants .rrg non ,!g.rnt" only, the peopre aged ,13-years and above lfere consldered 1l th!-analysts. fhe prevalence andllntenslty of lnfectlon 1s hlgher in n!grants but this rdlfferencea alrenot statisrlcally slgnlficant.' only nr,grants from rhe r;;;t a;;;; -i'-present a statlsrtcalry srgni{icant hljgher prevalence (p t='o.o4r. Iconsidering the length of iarytctdar clJntrol in rhe "d.i, ,or.'ii"ni rayears, these f lndlngs may appdar Burp"lrsrr,g. However l1t should b; i -"consldered thatr "li I 1 durlng rhe years 19ZO-rifgZS thet f"r.rf"ldlnl g treatnent w a8unsatlsfacrorv aa the L7.62 prlevar""";-i;f";;i;;-;;;icated ti thar tt ,1" ofren lrdosslbt" j.o locafe the v{tta located lln aa breedlng slte. control. I e I d sample reqdlred to ftnd la lstatlstlcally signlflcant hlgtler prev t L I 1 I TARAKO STUDY ON TEE BTBECT OF IiNTEBRUPTING VECiOR CONTROL I I sulds d o el Is proml"]1nS an'd wllX. yfdld rclearer r a d c 43. Thls rype of srudy .pp"ri as the perlod of veetorr'rtnrr^ t t e a I I t f m n e t t n e f e o ht e vt s t s ri d P 1 I z r n a e e e t v n]. 51 p dn h 'a a co e c t h n p t e a e I a1 fl "l o 11 e 1t h I' Ia t T no grants w111 also decreasINlll c no t I c efnna o f I o c e na o tP e sef II1 1 nof vectorpproach 15 Ieardas lre al I 44' rn vlew of the upconing devolutton ln the centraL r",*" "* an" lProgramme the vcu and EPr,rrrtts have dert.;J-";;[-iI aerermine tnel rareat whlch Eransmlsslon and nerd,lnfecttolns build up, 1i rrt"" are "rroir"l'=Eo repopulate an area where rtie parastite hae ueeii ii*g". elimtnat"dl";;prolonged vecror conrrol. the Farako "i."" i; s""Ir,-;;il has bee n ll,rvrvuts'Es Y sE'or Er r. r'he alrea 1n Soutfr Hall en iselected for thte proJect stnde 1t has'been under larvLcldal controil formore than 18 years and the pr(valence of lnfecrloh h"q dropped froml 6oIto Less than 2oz wlth ,""orp".{Itrg steep falt in the durl.'i;-.i""iprakoaleo lnterruPtlon of 1arvl"ia"i "I"troii'wri1-b;--rbiior"d by repopullatlonof the area by the f11es. tI" llarvrcraial conrrol has Ieen unaarl"fj|]:;:;untl1 1975 and only ernce rhe lstart ori ocr, conrrol "i-;;r;;;i;;i;n, nr"beenachleved.'irLro"Ylt""t'ti General ob-JectLve I I45' To deteruLne ln a selected area, where parastte has been "tro"lacoopletely eLlu-lnated by proLQngea vecjtor controrn the rates atn,nij"nthe f1y populatlon, trans*tsstloi and r];; infectlone begln ro brrld [;,tf larvlctdlng ie inrerrupred., I I l I I I i e"s"]. ro ]iliii 1.To assess the reaervolrl of,the Id1".""" by surveyLng the tota[ .populatlon of selected v111age' Phase ili-il. Li.To uonLtor the raEe at whlch S;.damnosum poPulatlon butlds uP the changes ln ATP as larvicldlng oPeraElq;ffi; l"terrupted 1n caEchlnp potnls closely related to th; ".1u"tedi v11lages. Phase 2 | I i11.To monltor the appearance of i.r"t caBes of onchocerclasl" '1" the populatlon of the selected vlllages' Plhase 3' I I 47 . The lntroducElon of lverruectln, t,n Ehe near f uture, w111 ethrcpl-1v JusEify the last phase of thd study' i I ' I ,ll IPhasel i i t / r , I 4g. Thts is the only phase aicompliehled up to date. After ProBPectltng the area and uP datlng- the nap 1O vllliages were sglecEed lusing the I l'following pre-establlshed crllerla. i II - rr-- 1i. rhe raa jorlEy of the vl1lagee shlould be f lrst llne I ,'l ii.rhe vtllages shoul-d tei relatedl to weLl knbwn !reedlng slte i I iri. rhe villages shouta lu. of arlrr"rent srzi: rncirudilng at r"rl"t one blg vlllage i li,l iv.rhe vll1ages should hi,ve d1ffepent pfdvalbnced and lntensttI ofl lnfectLons. I I ilil49. The roral pdpularlon of Ehe selecltea vl11agep wad sulrveyed uslinB the standard OCP slmple evaluatlon metihodology' i i ,'l50. The geographtcal charaet!rlstics of the villages selected are Ideplcted 1n Table 7,,hereas !t"f, pt"]r"lence andiintqnElty of^11felctlon .fs-depl-cEed_-tn-ffi$csllzeofthl"v11.1agestar1edfrom].8.ol315.. tnhabtranrs. Of rhe 1O v111ag{s, 7 arei flrst 11ne; 2 second and 1 tlhlrd line. Slx are located ar 1 kn jor less if rorn the rebpective breedlng lsite and the others between 1 and 5 kus. Wllth the exceirtlon of the vl11alge of Mah located on the Tlntienko qlver all, the other vlllages are lobat;ed oa the Farako rLver. The prevaleri"e of fnlfectlon varLed fron 13.07. to lO.8Z nlth Ehe exceptlon of ttr" one faml1y v111age'of Bababougou 38.52. T,1"georgetrtc mean varled from 0.3 to O.O iwlth the exiept4on of the vlL11age of Bababougou 1.8. I I I ,1..:l Conc lus lons I 51. The vl,11ages surveyed do'"aElsfy itn" pre-establlshed crlt".f, iof selectlon and should be retairied for t]t" foll-owlng phases of the sEludy. Because of the rapldly f a11tng prevaleinces and lnten"lty of lnf ectllons, 1r is urgenr to pio"".a to th4 iecond inhase to avoLd teducirtg the i varLabtltty of thle rwo lndlc{tors f n ]it " 1O vllLages ,to a l-evef atl which the Farako area wl11 not anymorQ be sultable for the studY. I il,ir Al'1INAIIONS IN [Hi 1bonru siucE THE sTABT oF coNTHoL ) rr\ -$, No-chlldrEh infEeEel__-Q: os/exr-an Q : oBs/EXP - 75I .jrt, !: oBs>aP 6 ItbEH >5 N c.o o\tH !iP; EX ! ,/ \-i _r-vw\ Ihe clrcles shor per vlllage the raHo Detreen ll the nuser of lnfected chtldren actually observeO (tESl the nurter expected tEXP) had thsre been n, .rnt"oi--l a./ i tr JX acplfipr/TR/96.7 0 s t lrL-0 L' ,td t 'Jl ,l J-i.,lL tL !'X-r .J LJ tr s. t; i;-cc.,iE tDbi9f,(!o.: CL-;ii (-r oor t, -J tnc:co *'-t i4{-{E=r.,; --o,3tiI # 5--9 @i :\ v t_ ) tJ- - 5tri IEi .<,- 6H- aA z.lr, d t-o 6LrJ E J lt z6x o_ PHEt-u rt -ft-t. o a=aEu z JNCJU F cl 5 < LrJ U1 Y! tl-l --LD i- lo G -)[H trr g* = +o E u- a. \a9 Lr-, ?FFcnz =)Eu =-' ELL !2oH ,v f ->rz- z<J*-t .!/ .jj clEH, o <OL) 'oo? JO E Ircug O o- - \ --- t\ B '3', s( \ i ,1l\t\w .z\ )L -.,- I -*', acPf_,pr/pt1/96.t Figure 1: '\-- - \ ---- \_\ RELATIVE TRENiD IN CMFL VII..IAGES CLUSTERS WrrH >1O YRS CON.IROL Figure Z-: ---l o .5 70 c o ol60 oL o. ': 50o t( E40 c)!J0 i) /.o l l l l Ir ,1 -r-.--:]-*.]---_ t, TREND IN CMFL IN THE CENTRAL OCP VIIIAGES CLUS]ERS WrrH >IO YRS CONTROL - -r - ''---r':---r---'.- ---r_--, TtARs OF \ECTOR CON]ROL s 68 _ETu oF vEcroR CoNTROL i I I I I I I --t I 10 l2 I r0 100 I 90 80 70 60 50 .1{) JO 20 lo 0 :-. PREDICIEP IRj1{D acPNVPR/P5.1 Figure 3: RELATIVE TRENb IN CMFL RESULTS FOR pEJDtE ANq GORE&A-SOUUN 6E YEARS OF VECTOR CONTROL I I d o oL c o o I a o o x a o JL o f PFligtE v Go!E3^-SOMUN I t0 100 -ic I ocP/E|tftR/?.6.L Figure 4: Relattve trend ln MFC LOAD vlLl^GErltr* l0-1r YTARS oF coNrRoL 't Figure '5 : -\ \\ .\ n:AR:, 0r ',/E(,TOF COli-rh-OL. V i.:rrdis t- (_ 1 t, 70 €0 50 4€ -1 L', 2a i0 4- 6 I YEARS OF YECTOR CONTROL v - Pen<ilo Relatlve trend tn CMFL/AC I VILTAGES IVITI.I 1O-I1 YEARS OF CONTROL - =:{--\-'l l0 100 s0 8C 70 60 50 10 2A 10 0 t-- l,-ft\- ti \,'I,- i -l II _l I -l I I -1 I _.j I I -l li i I -l- -, a I l( l!: J otr F- c I trl 0- L! o N { o{ -}h: "r It$I \\\, -.1 ' '..t.i\ -l I 1 II I I -1 I I .1 l I ro IocP/EFrfi'T:/PGL Table I : :ff:l:i of skln-enip examrnarlon6 1n childrenbor'. slnce the sEarr of Zone Nuuber ofNuuber of Villages wlth vlllages Infected Chlldren Nuqber of Chlldren 4L63 1446 L7 64 570 243.6 L32.9 161.4 Ratlo Obs/Exp(ta Z) 1.6 o.o 2.5 ooz 1 ooz 2 ooz 8 ooz 5 63 25 24 L2 1 0 2 1 o 4 r tw r 3g.O 2.6 Subtotal t24 4 7943 9 575.9 1.6 REINVADED OOZ'S IN THE WEST o0 3 13 3 lzl 4 23.1 L7 .3 ____::_1______:: 3 otz 7 110.5 6.3 SubrotaL 2; ---------_-;-------;;;;-----;----;;;:, ----;;--- REINVADED OOZIS IN THE EAST00z6 9 3 47L 5 2o.5 24.3ooz 7 13 g 629 20 7g.2 25.6Subtoral 22 tt tlOO 25 9g.g 25.3 8. o table 2 cEAI.tcES oCCURRING IN THE DEVELOP}IEM OF NEW LESIONS ofr /n,14.i1/?,(,.1 PART OF TIIF COHORT I.IITH ALREADY EXISTING LESION AS WELL AS IN TtrE pARt oF THE CoHoRT INITIALLY wITHoUT LESIONS FoLLowING 10-11 YEARS OF VECTOR CONTOL ANTERToR h ----L rrldocyclrtr"*i EGMENT Scleroslng Keratltls* POSTERIOR SEGMENT Choroido Retlnl tl s* Opt 1c Atrophy* CHANGES OCCURING 1985 EYE STATUS 1975 Part of cohort free of leslon Part of cohort with leslon Number wlth lesion dl sappea rl ng I Number wlth develop- ment of new lesion LL22 (9L.4) LL22 (9L.4) 106 (8.6) 106 (A.O) 6,t LL22 (9L.4) 1124 (91.5. 81 (6.6) 104 (8. s l4 86 L2 56 46 18 31 *Perr:entage in parenEhesis and related to the cohorE. i Table 3 River Basin _-----_ Sanka ran r Bagbe ila f ing Bakoye I rnkisso Bani6 Fi6 Total Bakoye Baoul-6 Dlemba Dla ni n I INo. ofl No. of Vi 1lagre s ca Echlng II PojnL s =--=.-r: = Level of Endeni.city Hyper- Meso- Hypo size of thevillag(100 100-3oo >300 -tu=i l+ 10 ac?/wvPR/g(,,.1 ENTOMOLOGICAL AND EPIDEMIOLOGICAL CHARACTERISTICS /0F TI1{E VILLAGES SURVEYED IN IGUINEA AND MALI uoun t rt' Villages i cat.ching Ipoints i :: gt, 3 I 1 a) 1 l1l t2 8 1 1 Cuinea I ,,1 I I I I I Mal :l I L2 3 2 1 9 3 1 9 3 1 I 5 1 1 10 i 1 I 5 2 1 3 3 2 3 1 I 1 T2 -2 -7 -o U -3 15 11 1 1 72 oo 1 1 5 ) 9 6 1 11 3 13 I 83 ),161n') .) I 2BTotal -t I i ri l Ilr I I I I I I rl;I'Jr ocP/!pVPR/86.L Table 4 IqIl , 5 vr11a86 ln ttE Parsko rlEE basin PFI: vALENCE (tnl) Total FotrrL8tlo Net lY Rcdrtsed GEOHETRIC !IEAN Tot l Pc,trd.etlcn lhdY Reglst€r€d I \(' t.,ral hllrlalim ].(} YALE FE},I. TCNAL ()-{ q4 91 16' .- -i t'{ 143 IO-tr 1l t: i6 I 1-lq 19 "y rn8/J;.,q ll hl r4 10- Il|, 115 :t i irrtAt -lr i j" 8ll l.xAMrNlil) NqlY ReSlsterad AM !{ATE FEII. IUIAI. 11 16 l1 27 5-q 19 12 li lo-I4 3 6 9 r5-t9 0 lo i0 1/r-?Q I 7 t] 1)+ lo I 18 nrul las y Io3 MALE tE{. I('IIL .E:E#. 0.0 0.0 0.0 u.o c.o 0.0 0.o o.0 0.o 0.0 ?.o 1.5 16.1 4.8 8.t 28.2 lr.9 19.z 9.1 4.6 6.9 I{ALE FEI. ISIAL 0.0 0.0 0.0 0.0 0.o 0.0 o.0 0.o 0.o 0.0 0.o 0.0 0.0 0.0 tr.o 12.5 A.2 6.1 r.9 3.9 HAIX IE{. TEAL* o.m 0.m 0.@ 0.@ 0.@ 0.@ o.m o.m 0.m o.@ 0.6 0.04 0.4E O.07 0.I9 o.9z o.26. 0.53 0.25 0.09 0.16 T{AIE Fnl. IUTAL 0,m 0.m 0.m 0.m 0.@ 0.m 0.@ o.@ 0.@ o.@ 0.@ 0.m 0.m 0.m L.U 0.26 0.73 0.18 0.04 0.10 'oral IbFrIatld, t?m Bole, vlllage ln itE BI&I volta rlwr b651n t€uly ReS,rstered Toul Potr]lat16 NilIy ReSlsteJed Total Pogrlatlm lbrIy ReSlster€d lArl lE{. ISIAL o.m 0.@ 0.m 0.@ 0.m 0.@ 0.m 0.@ 0.@ 0.m o.@ o.@ z.fi o.49 1.34 0.78 0.47 0.58 0.43 0.19 0.79 MALE FE,I. ISUIL 0.@ 0.m 0.m 0.m 0.m 0.m 0.m 0.@ 0.@ 1.88 0.m 0.89 6.52 r.99 3.14 2.13 1.01 1.79 r.15 0.41 0.82 l.u\Lr !-D{. :toTAI ALE r',!Ar-E Ff,}l. ISIAL MAIE [!I. -I(,IAL'i5===i-#-+--= Gw- LEfo, vlllage -u- tlE BlKl( VoIt!-ElveJ Basil HAII Ff!t. ]SIAL o.m r.* o:m r.* 0.m 0.@ t.t t.r *.t t.r o.@ 0.@ 13.75 0.78 2.@ 2.3? O.@ L.22 2.6 0.26 0.u lEufy Per.t {€d }t{tE Fo{. ETf,AL 0.m r,r o:m 0.m 0.@ 0.m 0.@ 0.m 0.@L.r o.m o.@ / 2.76 Z.% 2.5r 1.lt r.r 1,15 0.54 0.66 0.t9 Nfrtf+el" _.".d- I{AIE FE{. lg[At r.* 0.m 0,@ 0.m o.@ 0.@ 'i.. 0.@ o.@ 13.50 r.r 13.50 12.41 2.50 4.& \5.32 1.18 lz.9?. 6.fl t.gz ?.t5 0.0 0.0 0.0 0.c 0.0 0.0 0.0 0.0 0.0 0.0 0.o 0.0 57.3 21.4 31 ,9 35.3 ?5.O u.6 17.5 10.8 13.7 HAI,,E FIX. IUIAL 0.0 0.0' 0.0 0.0 0-0 0.0 0.0 0.o 0.0 13.3 0.0 n.o 15.0 62.5 68.8 53.8 33.3 48.6 12.r. t8.2 26,8 HALE FTH. TUTAL# 0.0 r.t 0.0 0.0 0.0 1., *.* 0.0 0.0 1@.0 25.0 50.0 to.o 0.0 13.3 50.0 10.0 25.0 UALE FE!I. I TIL 0.0 r.* 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.o 0.0 33.1 @.0 50.0 60.0 r,t 60.0 '@ ?2.2 25.O 27.3 O* ]t- ti rl 54Jlt Tl ta!-t.. il 14 ll 15-19 ro l/. l-i n-29 15 14 29 .lO* 17 32 \e 'rgIAL 8n t02 182 AG IALE FEI. I,L\L 0-r. U l0 2i t-!r e 1 l<, 10-14 1 6 I5_lc/ 6 !. )0 T-1s 8 g i(, D4?02 5-4033 iri-14 C O O 15-lo o 2 2 TJ-zq 2 t 6 30+2ll TmAL 6 l0 i6 AGE I.IALE FEII. ISTAL 0-rrzo25-4rt9 10-14 3 1 4 15-19 0 2 2 ?D-?9 I 5 8 lO+505 TnrAL 18 12 lo Iotci Pofu]atrm lbly Registered Total Pc'tr[atia Nrly ReSlstered Total Potrl]8tlm 'Y)- 2f, 9 15 h{ia{ ftw --- h:r , vrllage in tlE- B1&.1 "'olt ii"t Uut- ')-4 q ; lh tH O I I o.o o.o o'o oo o'o 0'@ 0'm 0'm s-(, iL L \4 I 4 7 o.o o'o o'o o'o o'o o'o 0'@ 0'@ 0'@5-(,iLL\1Jctv-v r,-*r* : 12 Io-I4 o I 1 lloo o'o 8'3 o? .^9'9 :T ::: :Tl!F1q15-rq . i { r5-1s I o I 75.0 75'o 75'o I@'o :'l' '3': .?i: :T 2';t5-lq 1 9 0 t. /)'U t>'u rw'v -'-' rw'vlo-:cL-li2Flo-2c35888'281'885'71@'060'075'Ol4'rt4'929't,5 ,AQil"' , i: ;., rL,+ 2 ? -.---! 82.6 eo'o 84'8 Im'o lm'o Im'o rr'u 3'26 7'88ii===-========:==--=.== :--:===5 # I)L\l .' r(r 'lq IOTAI- q 1l ?? sB 5 42'9 51 8 €6 7 lS'5 5O'O t''57 l'35 Z'& Table 5 Cohort Semi cohort +30 in r.oral +30 in newly Prevalence and intensity of of the central zone of OCp ocP/*rftR/e,6.1 infection in B villages by 4 rypes of analysis A LI population regis Eered Prevalence 14.7 t6.2 L9.2 ),) , (in Z) SE 2.7 2.5 Intensity of 0.38 (0.21 o.42 (0.22 0.53 0.73 iofection c.T.95Z - 0.s9) - 0.66 Cohort Semi cohort +30 in Eotal +30 in newly Population regis tered 33. 3 zcj. s 28 .6 33. 3 GHANA-BOLE 7.9 6.9 0.64 (0.22 - i.19) 0.57 (0.14 - 1.1s) 0. 58 | .22 3.09 (0.54 - 9.84) 3.1s (0.69 - 9.18) L,79 1 -15 ,l GHANA BUANFO Cohor t Seui cohort +30 in total +30 iu newl-y popul ation registered 54 .5 60.0 48.6 60. 0 1s.0 11.0 GHANA Cohor L Semi coirort +30 in roral +30 in newr \ [)L,r)LlIation reri stered 90. 5 92.9 84.8 I00. 0 6.4 5.8 9.67 (4.39 - 20.i3) 8.73 (3.81 - r8.68) 7 .88 L2.92 IwP/EPWR/86.L TabLe 6 € :''l'.': [rtrr"r,." lfrorn Malt .Ulgrants from ' Burklna Faso 20 15.0 NS 0.39NS 5 20.0 NS o.62NS Position resPect Distance to VtllageNaneSlzeBreedlngsltebreedlngbreedlngRlver ' , site site --------- Samorosonl Finkolo llne 1 kn L.lne. - -2-Lm---I lne 5 km. 1km rt Farako Samorosoni I'-ete Djassa Nt.enebougou Flnkolo 733 260 4L2 915 1st 2qd 3rd 1st I lne AdJueted prevalence ,and geonetrlc mean ln Eotal and nlgrant populatloo uy .ouiaty-i"-ro vl1lages of tfe Farako rlver basln Total Populatlon No exanioed 85O Prevalence (ln Z) L7 '6 Geouetric mean o'44 Mlgrants 44 25.O NS 0.59NS Migrants from Ivory CoasE 19 36.8 P*O.O4 0.79 NS SI ne sounfaToUougou Badarakorobougou Bababougou Ngolokounadougou Sanankoro Mah Badarako robougou , Bababougou ' Cascade Mah 89 18 L23 90 160 lst lst lst 2nd lst line line 11ne 11ne 11ne 1 1 4 5 1 km km km kn km Tlentlenko TABLE= 7-i -- vEl-ages-thtracl-erisrlc s Table B Villages Samorosoni Fete Djassa Nt.enebougou Finko 1o Soungalobougou Bad arakorobougou Bababougou Ngo lokounadougou Sanankoro Mah ON IN 10 VILI,AGTS Distribution number of mf/snip 64+ 4 0 0 2 0 0 0 0 0 0 o C) H F{b oo o\ a H Pop. pfesent Prevalence .5 - 3 16 3 5 37 2 1 0 5 2 0 14 3 3 23 2 3 3 6 2 0 623 222 381 793 s9 62 L4 LL2 74 139 +,6P' lt p, Is ,b, {,, ,,PO I 10.7 5.2 4.4 13.2 L6.7 9.7 50.0 16. 0 t2..8 0.0 7.s [, I r.3 t2.4 Ip: p.s 3P.s ,b. o b.s I P.8 I 4.8 1.8 0.5 tL.7 4.0 3.2 28.6 10. 3 0.3 0.1 0.1 0.3 0.3 0.2 2.7 0.4 0.3 0.0 0.1 r 0.0 i , 0.0 0.2 0.0 0.1 . L.2 0.2 0.3 0.0 I o.2 ri l0.1 0.0 0.3 0.1 0.1 ;1.8 I 0,tr o. rl I o.q I 8 1 0 19 0 0 2 3 1 1 Geometric mean'" I 4-15 :: 'i i 3enent/cercle/Reglon fvaYs ,Lieu cle naissance annde d'e r6sidence i. ':.i --r- *+ It-- ArrE( 1 t:l--lg Fanjll-: ,." i_[:i I PROFESSTOI,I DU | ()i[.iF lE i'1[M.L LIE I I l .... J r... i I I Au.tres lodarlit6s de r6sidence i i I he plus d.tur Jl et p6riocle d'e r5siQence .l Ie plus proche (Oate) I ito ,rr-,ee r6sidence I oo*urraricnsI rtoto I "i.,AiffArent que I'iali (date) ou villalgp/ --;-,-- i I I ._L_--_ I I I I -i- I I Lg TH,'5-8 Date deIienql€te : l.? -I4 Yillage lio rovi- oire .L --i__ I I