Basic epidemiological evaluation for the onchocerciasis control programme in Ghana: parasitology

t,' X' WORIlt IIEALUII CRG.i,ITIZ.{r,_L,f O}I Cnchocercj-asis Control programne Volta Rive:: Basin Arca in the Epidemiologival ilv._:luation llnit ocP/EPT/7 6.tt i/orking Paper ,'**"1{=*Xl9pi{o.r-9.q-r9j'J,.*u.[J1urr-f r-oJu.0.qc-q0-qpJrc.rl.FJ.s*.cLrF.t1-Ol.nqcltr_r{E FOR IIT]Efli GIIIiNX, - P/rlU,Sfl;i0t0cY _ U.K. BRr}IM,MI,N{(wuor/oci,-nlt) Paper presen-ied a-b t]:e Meeting of the }trationalOnchocerciasis Conmittee in BJ1gat""g"l j"iy-ZO 4- L.-L , ,y' -'-{ . }A$IgBUHo-WJoI--TliE -0twllg.clActui.s*ri"c jlllFg!*sgq$lq{p,_ul-qrrua - PAPuISITOI,OGY - l4ryd$s.!,i"Et a I'lre ir:nportance of onchoccrciasj-s in l,iorthcrn Ghana j"s knovrn since a long time. Thc prevalencc of the d.j-sease and. thc prcvalence of blind.ness lrcsulting from it have becn determined by extensivc surveys of l4edical Field Units of the Ghanaian rlublic I-IcaItir Sorvice and ind.ivid.ual workers. ll-rhe resul-ts have been summarizeit ard collcctod, in the Rcport of tirc PAG-Mission (1II,H.O. 1971 a'). ft is the aim of thc 0choccrciasj-s Con-Lrol Pr.oject to iirtcrmpt thc transmission of the disease by vec-;or con-brol operations, and. thus achieve a prosrcssivi: d.ccline in thc incid.ence of oucbooorcal losions. Changes in incid.ence howcver can only be measured. against suitable baseline data. Evaluating existing information available iir -the s.)ven 1,,/est-Afri-can countries concerned. rtith -bhe projcct, the PAG-I,lission stated that such d.ata clid. not cxist. In thcir absence a sample of villages had. to be choscn -bhroughout the projcct aTea, in which d.ata rclating to thc epid.enniolory of the cliscase would. be col-Icc-fgd. Age - rmil scx-sPecific prevalence ratios obtained. with stand.ardizcd methods would. then scrve as baselinc d,ata for thc longitud.inal stucly (w,H.o. LgTl h). thc tasks for the first cycle of survcys orLhe baseline study were outlined by thc above n,cntioned docunent (UHO lg7lh)e - id.entif)' village s selec'[ed for sye,fua'Uionz - take thc populati.on census in those villagcsr - coll-cc'b andl. proccss baseline d.ata relating to sex - and age-specific prevalcnce ra'bios, - carry out in-bcnsive stud.ics in a small number of vilIagcs. arr/2 t.a -2- Ita:EsLigIE - ql4-Irs.ttlo-ds. Thc sel-ection of vill-ages as well as tirc method.s to bc usec] d.uring the actual examinations harrs 5..n d,escribcd. in detail in 'Lhc Report of the 1'AG-t4issior: (tmO f975t), and again with somo modifications and a critic.rl evaluation, after the first cxpgricnces in the project hat1 bccn gathcrecl (rnosr ct aI, lg75). Itor Ghana a lis;-b of randomly selccted. villagcr: s-bratified. for end.emicity had bcen prepared. by the P/rG-Mj-ssion. As ii turrred out, not a]1 villages cxistcd. anymore and othcrs r*ere unsuitable -bo be included. in the sanple, because of socially unstablc populations. Iurthcrmoro, alnost thc whole of the Northern Rcgion had not bcen includ,eri in 'i;hc sampling frame. Thereforc finally only 11 of 'the original 12 vil-lagcs lrere includ.ed. in the evaluations. The PAG-Mission had. also recommended to axamine about 41800 pcople in G.hana and. to choose clusters of about J00 persons. This woul-d. havc 6i-ven 16 villages which was insufficicnt to cover a}l river basins thqt contain importan'b brecd.ing site s of [1p;+_13Lqr. *d-q4g.o5-ugr.. Population movemonts are a not negli.geable factor iri l$orthern Ghana. tlhen d.ecid.ing on the number of oersons and clusters to be exarnincd. d.uring thc basic evaluations, i-b lras nccessary to a1low for the possibility tirat villages may be d.eserted., or may change in a way that they nay have to be d.ropped. from the sample. llith rcgard. to tirnc and. manpowell available, it was finally d.ccid.cd. to increase the number of villages to zio, and thc number of ind.ivid.ual examinations to abotit 121000, Thc add.itional clustcrs l{ere scfcctcd accord.ing to thc criteria of PROST et aI . 1t975). The number of villages ruas stil1 too sna1l to be abl-e io ranclomize as well- as to achj-evc ad.equate geographical coverago. Thc latter was decmed. more important r^riih regard to the task to evaluate voctor control me-bhod.s. The collection of d,a-ba in the villages again foIlor+ed the outlines provided by PAG-Mission (rnIo r97lb) and PnOS'll et a1 . (t975). In 34 villagcs trSii,rple Evaluations rr wcre performed. .. rf 1 t. -1- Tlro skin snips from the iliac crcsts vrerc taken r^riLh sclcral- punch-instrumcnts aftcr uALilER, and examined, for microfilariac of .Q3r.c*\9-c*c;gg1v-o-I.gq1.-qg aftcr thcy had bccn covcrecl witj: dcstitlcd watcr lor J0 minutes. Tlrosc tha't remainecL ncga-bive were placcd. in the wc-l-1s of nicrotitrc-plates and. covcrccl with norraal saline for at r-east another J r,ourt beforc r:e-examination. Grcat carc r/as talccn to clcan thr.. sl<in of thc pai;ients with alcohol sr'rabs befo::e .the snip was takerrr and to disinfect tlie p'urrch-inst:rrmcnts, each timc -bhcy had bcen usec)., in glutaraldchydc. Every per.son iras weighccr. &nfl mcasured r.rith a Srlcli-balancc and scal-c. rrinal-Iy thc binocular visi-on was tested with an abbrcviatcd. vcrsion of sj6grcns hand-test (turlnron,.) t976). Iind.ings were recordcd on form S 602 (r.inncx 1). ';Dc'Lailed. Evar*ationsir \,trere carri.,d. out i_n 6 virlag.cs (pis. r). Thoy inclucicd. a furl inr,;i-rcction of the slcin for onchocercal_ lesions, palpation for nodulesr, and. cxamina-bion for hanging groins and onchocercal olcphantiasis of the scrotum. Again everybod.y was roeig{'rccl and. rneasurod. Two sJ:in snips }rcre taken an6 examincd. as in r?Si-mplc L.lvaluations!?. Ad.d.itional1;r a snip at flre outer canthus of thc eye was tal;en if hcad.-nod.ules were founcl . fn two villagcs (rr7, sabon Gida; !J, \Jidenaba) a canihr-rs snip was taken frorn evcrybody over I ycar. Af i;er tire parasitolog:i-cal examination the visus of each eyo 1,Ias -bes'i;cd scpana.Lcfy rui bh the S j6gren hand._tcs;t. Iinally bo.bh eyes of all persons ovcr ! were cxarained bJ, the Ophthalmologist. A11 findings were r:ccorcr-cri. on form s dor (Annex 2). A description of forms S 60] and S 602 an,l the coclcs usede can be found in 1tr.I{.g.(t975 ").Afi;er preparatorJ. vicits to thc Nationar onchocerciasis Cornmittce in -Iiccra, and through i'i; to Ghanaian Heal-,uh Au-i;horities in Sep'bcmber, 1975, thc survey work started in l{id._0c_tober, \975 and lasi;ed until /,p=il r5th, 1976. By 1;hen 12, r!1 pcrsons in 40 villages had bccn exanined-. onc villagc (91, lliacnaba) rras exanined twicc in orcler to see horu pcople wiII react to fu'Lur.e re-exanipations, and to corilparc thc results of repeated s:-rrvG3rsr ../ls -4- A11 examina-bion forms wcre copied in Ouagaoou-3ou and. the copies sont for. elec'uronic d"a'ba proccssint to the statistician in W,I'i.0 lIcad-quarters, C-enevao !p"s*u_IJs.:_ fn thc Uppcr i.i.eplion 22 vi-).lages wcre examined.. 'r'hey cover the Black Volta (3), the Kamba (1), the liulpaun (f ), the Sissili (l) , 'bhe l,r/hite Vol'ba i1) the iled Volta (6 ) , and the l,lorago (f ). Two villages r.relre not neal any big rivcr. Fifteen villages were chosen close to entomolo3ical catchiu6; points. liurvcy-worli concentrated somewhat on the Sissili and the Red Vol-i;a, thcrc are a nrurrbcr of development projects. fn three clusters a DeLailcd llvaluation was carried. out. The llor-i;hcrn licgion is reirrescn-bed by 17 village s focated. on thr-- slack \ror ta (2), thc MoIc (r), blie Kul-da (r ), the tr'Ihite volta (5), the Kul-Dauil. (r), the Nasia (1), thc Oti (l), and. the Daka (l), iIo vil-lages r,rithout rc.Lation -bo a river werc sel-ected. and no clusters in the arca of '-t-'arnalc a,r-c includ.ed. in the sample. It is knor,rn tha-b there is no onchocerciasis around. Tanale (CUllt 1975). Detailed. Evalua'bions tlcrc dnne in Lhrec viIlagcs. Fourteen of -i;he villagcs in thc l,ior'[]rcrn Rcllion are closc to lln-bor,ro]ogical catching poi.nt s. Onc vill-ag;c was cxamincd, 'chat lics al::cady in Srong-Ahafo Rc54ion. It is situated. on thc Black Vol-ba and. in l;hc vicini-by of two rcgrrlar catchinli points. Figure 1 shor,is thc location of thc villagcs in relation to tirc main rivcrs.. ilhc villagcs that sar,v Ic'La.iled. Ilvaluations were spccially marl<ed. Thc cxact gco;ralhical coorclinates, village na"mes and i;]rc adninistrat:'-vc units undcr whose jur-i-sdiction thoy fall can bc'barlccir from tablc 1. To provide a finlc to ccnsus infor- matj-onr the coclc numbcr of thc res,)ecti-ve cnumeration arca has been addod. Table 2 establishes 'birc relati-on to cntomol o$r. f'or al} yiflages not morc d.isi;ant than 10 km a-b thc rrost froin a Sinulium- catclriirg point, its name anil scria] nunber arc statcd.. /r^ -5- '1'hc total nuu:bcr of examinations uas 121111 or l-lr95B, if thc rc-cxamination of one villagc is sltb'cract':il. Tile avcragc cluster sizc si.zc is 2)) witb' a rangc fron 99 to B!8. Betwecn 2OO and. J00 pcoplc wcrc exarninecl in thc r.rajori'uy of viIIages. The ovcrall sex-ratio i.s practical.ly I with 5987 males and 5971 fcmalcs. If ho,rrcvcr age-specific scx-ratios aIe calculated, one observes a surplus of fernalos in thc agc of 20 to 40 years and a d,cficit of thcm bcti+een 10 and 20 ald fron 40 to 50 yealrs (:rig' 1), rn gencral very fcw of the pcople actuellly prcscnt in the villagc or section to be examincd, rofuscd.'co conc or failccl to appcar for other rcasons' 0n averagc 95,296 werc snippcd. The nurnbcr of pcolle who happened to be temporarily absent co8. huntingr on a marlret or visiti,ng, does not amount to more than / .2)/o of all persons cxamined. When th<; villa,ge rdidenaba (91) was rc-examincd six months aftcr the first survcy, 55 of th<-. original 225 persons did not shovr up. Thc majority of these clrop-outs (51) naa left thc village tcmporarily. Another 1, did not cone because thcy were sick, { hcrd. died., } refused. to be snipped, agaiir and,2 iracl movcd to a d.iffcrcnt viI1age. If one looks at the agc-distribution of thcse drop-ou'Ls (nig. 4), it is evident tha'b womcn betrueen 20 and40 ycars ancl childrcn lcss than 10 ycars forrn -bire largest group anong them" The figures of person:i prcscnt, examinerl ancl temporarily absent for cach village are con taincd. in tablc J. .P,ge.v-a,]*ep-cp-g{.onc}_o.cer_c--i31sis"s lilos'L of the villages exanined are situated in hypcr- and meso- end.cmic onchoccrciasj-s areas. the prevalencc ratcs rn table { and' in fiLlr-r.re ! have beon ad.jur.r-bed. for a61e and- sex by applying the actual- sex- ancl age-spccific rates of each clus'ber to a stand.ard population. Even thcn sor;Ie commllnibres show prevalence rates of almost go%. the basins of tiie Sissili, tjrc ltcd and.'Lhe lJhitc Volta and. the I(ulpawn account for 14 of 18 v:'-l]ages r,,rith a prevalcnce higher than 7q6. Gepcrally lorvcr rates ruere for.rnd in'i;he villages along the Oti aird the naka. ,..f5 -6- tr?hen i.nfectlon rates of mal-es and females are compar€d, one finds that they do not tliffer to a great deg::ee, and that there is a signlficant comelation between then (see the scatter dla6ran in the lower part of figure 5). tn area"s with less than 5O/" endenicity. the rates of women tend. to be lower than those of the males. rable 4 contai.ns the onchocerciasis prevalence rates for each rriIlage. In villages with prevalence rates of 60/" and more practl- cal-ly all aduLts urere found infected. At the age of 10 years uicrofilrriae can be d.emonstrated i-n the skin srulps of about 5O/". The differences betrryeen sexes are small. (p:-g.6). The nr:nber of mi crofilariae that were eor.rnted in sing] s snips passed. somotimes welI. above JOO. Lfost srrips contaj.necl fron 10 to 2O nlcrofilariae. This skew d.lstributj_on may best be approximated by a log-norma-l, Consequently the geometric meaJl lvas used to characterize microfilartal_ densities of popuJ-atlons. the mean d.ensities are generaEy high if the prevalence is h-lgh and the eorrelation of 1:revalence rates and geometrie mean d.ensitles is statistlcally signiflcant. rremafes show usually lovrer densities than men, but rise comespondingly to td.gher means of the mal-es (see the scatter of male and fmaale densities in the diagram in the ]ower part of figure T). a€airt n:icrofilaria-l- d.ensities change lvltir age as j-s demonstrated in figure B. Mean densities for all villages are given in the ].ast three colu-urrs of table 4. lYhen the village Wi<lenaba (gf) *s.. re-surrreyed after 6 months, 170 persons were rs-sxqmined. During thls second. survey 140 j-nstead of 121 were positive. 27 positive durlng the seoonfl passage had been negative the flrst time and g that had been posi-tive on the jJritial examination rirere found. negative t}:e second time. Nobody of the people had received. treatrnent agai.nst onchooerciasis betvleen the su:rreys. . ../'l -7 - Prevalence of bLindness Prevalence rates of bl-indness were ad.justed for age and sex as d.eserlbed above. The denom:inater here is not as in a]-I_ othor rates the population exanlned. but the inhabitants of the trillage ire. the mm,ber present plus those temporari-Iy absent. fhe. highest percentage of blindness was for.md in Sogo (fO7) vtit}e 61611. In 19 v:illages blindness rates exceed.ed, 2%. Thlrteen of then Iay in the basins of the SissiJi, the Kulpawn, the Red. and the l'f'hite Yo1ta. In two of the six rrill-ages near the 3lack Volta more than 2/, of the inhabitants were blind, In the others from t% to 4, could not see, No blind people were seen 1n fuvo villages on tire Oti and in one village on the Daka. fhe bllndness rates ln the other three villages near these rivers ditt not pass 2%, Dinlnished. vision was fotmd about as often as blindness but as in this ease the denominator vras tho population snAmingfl, the rates are nlrmerically slightly h-lghcr than bllndness rates. The pattern of geographical distributj-on is ginifsr to bllndness : high prevalence of dininishcd vision was founcl in the villages along the Sisslli, the lfu1paurn, thc Red and !-,Ilelte Vo1ta. ?revalence ratcs for blindness and fliminfshsd vision for each village are to be found in table 4. Discussion V/lth 40 villages and. 1l-e958 people seen j-:: Northezn Ghana the target set by the PAG-IIission (,nUO Lg7lb) has been met with more than twice as Bqny slemirls'1;ions. 0n1y in t[[s way it waS possible to fulfiI1 the criterla set doln by PROSI et a1. (3OlS). The srimFle as it is, covers all major rivers breeding Sj-uur1ium i"z:. Itrorthern Ghana and at the sane tj-me most regular entomological catching poi^nts. fhis - eventua-1Iy - should enable the llnking of medical- and entomological. data so that conclusions may be dravrn frou it, .. ./B -B- clusters are concentrated 1n the basins of the sissili, the YItr-ite and Red volta becausc this area is the site of agricultural devel0pment projects *ndertaken by national, lnternational and bilateral agencies. In the future it vrllI be important to prove that the oncl:.ocerciasts control project was successfuLl here. The prevarence ra'bes tha.t were found, fo,Iow in gen*al thopattern Ia:own from previous surveys. For 21 vl11ages a direct coro.parison to figures eollected soue 15 yems ago is possible (1rurc rszz a). rhen prevalence was in most cases only half of the present rates. Blifudness rates on the other hardare praotically identlca-l. fhts suggests that more sensitl'e techniqr-res to evaluate skin snips may be responsibre for tirts d'ifference rat.er than an increase in the endemicity of onchocerciasis, U/lth the i:resent sur,\rey, some gaps in the mapping of the d.lstribution of onchocerciasls were filIed in the riorthern Region. Hi-gh lnfection rates and irigh blindness rates were fo*nd i.n turo vi1la6es of sparsery poprlated country in and around the l,Iol-e Game Reserye (vi11ages 122 and. 128). f t shows that this h:ltherto unh:ovm focus - etmost inacessable by Cor _ 1s as badly affected by the crisease as the varleys of the sissir-i and. the Red Volta. The re-exq4i::.ation of y/idenaba (gl) may give an imr:ression of what to e4pect during a second. passage. If the sane drop-out_ rate - 24/. - applies to a1r- rnillages in iriorther, Ghana, the sam;,'Ie vl'j.I1 decrease to about 91100 persons at the second passage and to T rooo at a fifth passage. The greatest losses wil] occurin the groups that are econonrcarly the most i,terestin6: yor,lg adults and cirildren. In tire report of the pAC_I{ission (vfUO ]971 b) it has been reoonrne;ac.ed to give medicar treatment to the people during the sulrveys. ff this was d.one during the fut*re re-examinations the drop-out-rate may be less. RSfereS::s r GRANT F,c PROST A, tB. iitr.H. O. (tgl>) -9- (lglS) The epidelrlology of onchoeerclasis in Ghana w:ithspecial emphasis on its soclo_economic aspects, unpublished clocunent), \r{.H. 6., ONCHOfigp/TD.L3 THY]TEFORS, c. pArnq,utrr (tglS) Methods evaLuation of onchocereiasis. vector control progra.nue. of mass epidemlological Their utillzatlon 1n a (nnpublished docr;ment), r/,H.0., oNCHo/v{p/TD.l4 rHY,EroRSr B (rgzo) vision screen-Lng of ilriterate populations. The problem of untestability. (unpulished. document)UIHO, \Torklng paper ocp/ml/76.+. t IY.H.O, (tgZl'.a) preualenee ef onchocerciasls and..bllndness 1n theprogramme area, baselj_ne data and data sotrrces, Report ofthe ?reparatory Asslstance I\tfssion to The Goverr:nent,Annex ,y_2t vI.H.o. , ocp/77,1. y" 17'H'0. (tglz r) Estrmated. coet of the epidemiol0gicar- evaluation component of the onchocereiasis contror- programme lnthe Velta_river basin area, Report of the preparatoryAsslstance ],[lssions to the Goverr:ments, Arrnex V_4, ril.g.6,, ocp/73.1. Detailed examination for S 601, w:Lth record description ;Ekpert Cornrnittr (,rnpubr i sb.u u:",*;:;T::]:T#rff#;:;:."'", yILIAGES EII1I.{rNED rN G}IA-llA : LOCATION ApMINISTRATTVE UNIT ANp RIIATTON TO 1g7o cENSrrs Table Vi1l,age I{o Geographical Coordinate N l,J Naue Local Council District Regloa Ceagus Enuneratlon Area e1 1 0290 1 090 10.49 2.50 OuugEfiPE LN-I{BUSSIE-NANDOM IAIIRA II.R.091 10.53 0.34 TILT KI]SAN/EA-ZEBILLA BAI,IKU U.R. 8500 1 I092 10.48 o.37 SEKOTI BONOO.ltrBDA!{ B0LGATiTNGA u.R. U.R. 841006093 10.51 o.34 LIIDENABA KIISA}I]IBA-ZEBTLLA BA-!rlKI, 094 10.43 8500360.2,1 APODABOGO KUSAI,IABA-ZEBILLA BAI,,KU u.R. 850630 841045 095 10.55 o.45 ASBUGA BONGO-NMDAM BOLGATA},IG.I], U.R096 10.44 0.14 DANUGU TEMPANE4ARU BAI{KU u.R. 85101 101097 10.56 ,.18 KAYORO-WIJRU CHI.TUIA-P.IGA NAVRONGO u.R. B3264000098 10.59 1.19 KAYONO CHT.IN,'I-P.O.GA NAVRONGO U.R. 83276000099 10.48 1.28 NIKONG CHIANA.PAGA NAVRONGO u.R. 832001100 101 10.50 1.24 N.II(oNG.S.'EORO CHIA$A-PAGA I{IIVRONGO u.R. 83?00210.39 1.27 BECHAUNSI S,INDEMA NAVRONGO u.R. 830039102 10.21 1,20 L'IASI S.U{DEMA SAI\IDEMA 103 NAVRONGO u.n. 83000210.26 1,n FI'Ii{BISI NAVRONGO u.R. 830007104 10.36 1.13 KADEMA S,TNDE}IA 105 10.36 NA',IRONGO u.R. 8300201.02 NAGA NAVRONGO 106 NAVRONGO u.R. 831030 1 0.02 0.58 JII{G]I 107 WA.L!;WAIE GAJ'IBAGA I[.R. 740500009.51 0.58 s0Go SAVETI]GU Tli$hIE N.R. ?3004602108 10.43 2.43 LISSA LAITIRAJIRAPA L,llrat u.R. 81079000109 10.19 2.47 SIJI NltllDxLI-FITNSI 1,rA u.R. 80 103111C 9.4e 2.44 KP.IXF,]I lfA (URBJN coUNcrL) WA U. R. 8000002 VTLLAGES EXAMIIIED I]I GHINA : lncATI0N, ADMINISTRATTYE UNIT qIID BXLIITIoN T0 12?9 !E!!q! Table 1 Geographlcal Coor<linate Nane Local Councll District Region Census Enuleratlon Area N Iil 1i1 10.05 1,54 KI'LUN Ni'.1,1D/r-LI-FUNSI WA u.R. 80 104 1 112 10.26 0.53 NAB,IRI lLlJ,EWJTLE G.I,MB,l,GA N.H. ,140o39 113 1 0.30 0.59 DIIU WALEWIJ,E GIUBAGA N.R. 14Oo41 114 9.53 2.24 T1NINA UA (URB.X COUNCIL) ldi\ u.R. 800033 WILEM.IE GTWBAGA N.R. 7 4003401115 10.26 1.03 PASINKPE 116 10.14 1.16 Y,tGiA-t WALEl{;l.LE GAI'IBAGA N.R. 740007 11? 8.18 0.17 SABON-GIDI, SrlL\GA JillJ.iiUl\ }I.R. 7100 1701 118 9.17 0.16 E SiiBr,RI SISOBA.ZABZIJGU YENDI I{.R. 121O1e01 119 9.3,6 o.22 E KENGUA SABOBA-IABZUGU YENDI N,R. 721o31 12t) 10.1 2 o.'t7 ZINDUA GUS,EIEGU-CHEREPO}iI YENDI N.R. 723045 121 1 0. 0/r 0.19 E T1IMBO GUSHIEGU-CI{EREPONl YENDI N.R. '123035 122 g.o1 0.11 YAPAI.A BIMBILA TENDT N.R. '120050 123 9.o5 0.11 YAPALA.BAGGYO BN{BILA IENDI N.R. 720050 124 9.06 236 BAIE BOLE DAMONGO N.R. 70004501 125 s.56 2.32 BUANFO BOtE DAUONGO N.R. 70oo 370 1 126 8.16 2.16 BIrI-AIil'IMfAImOM l,IENCHI IJENCHI B.A 63ooa9 1 2'.1 9.19 1 "41 MURUGU DI,I{ONGO DA}IONGO N.R. 70101801 128 9.45 1 ,21 COBEBA.SOMUN DJJ,IONGO DAMONGO N.R. 701 03901 129 10.4) o..39 DATOKO BOIGATANGA-TONGO B0LG/tTANGA u.R. 84056000 I/ILL,ctrS jtL\illllED TN GII':I,!,'. : ;IELi'II0U fC IlM;l illLSIjiS ',I'!D f,i'lI0iICLC61n-'1 Q-.fC;iIi{G POniTS Table 2 Vl1lage No Name Rlver Systen Eatouological Catchlng Polnt Nu.aber c9,j GE}IGEM(PE BL:CK VOLTA KAI:B.I BRIDOE 1307 091 TTLI R8D VOLTJ\ I{AFOODI 1 401 092 SEI(OTI RE' VOLTI SEKOTI 1402 093 ..IIDENABA ITED TCLT-i. N.:NGODT 1401 c9+ :1F0DABOGO RED VOLT::. siti(oTI 1402 naE -{SBUGA DJD V0LT:1. 1I'.TGCDT 1401 c96 D/NI]GU 50t,1,G0 i{.;l(Pi-ilDt RI 15o5 i.97 KAI0RO-'rtlIRU SISSILI l{ i(c][G 't408 (98 K"rY0.R0 SISSTTI a o.: Nirf0NG srssILr 1I ''XOHG 1408 N.{KoNG-S*30H0 STSSILI $_1.l(cMl 1 408 r1 BJ'OHI.IINSI SISSILT 1C2 I{L\SI SISJITI 143 Ftli,ttsISI SI JSILI 10/. KADEIIi 105 N:.Gri 1.TIIT9 VULI! iII?UGU 140'l 106 JTilSGA I,,'iIITE VOLT.1 '!.1-t lr-i 12o5 .)7 IIITE VCLTJ. SUGU l?o1 108 LISS,T K'rt{Bi. tlssA 1315 109 sll BL,JK VOLT*i 11C f,P.rri'lT'A BL,--CK VOI?A iiP NF:l 1301 VILIJ|GE S EXiII*1II{IED IN OII'1I{A : RELATION fO RIVEI1 BASINS AilD ENTOI'IoLOGICAI, cATCIlffi Table 2 Eotonologlcal Catchlog Point Nunber vlllage No I Name River S5rsteo KI'I,PAWN tfiIIlE VOLTA I{IIITE VOLTA KIIUIN DITI}SEIID 1413 111 KI'LIIN 1fr2 NABARI112 DIIII.rjLLAGE 1?o3 DW113 TANINA114 PAS},TPE 1n4 PASINKPE TIIITE VOLTA 115 YAGABA 1410 K]TPA}IN TAGABA116 SABON{}IDA 12J.3 SABO!$-GIDA DATA 117 SABARI-BRTDOE 1503 OTI 118 SABARI 1502 OTI SABOBA 119 KENOUA NASIA ZANDUA120 OTI TI'UBO1A YAP,II.A-CRO SSING 151 2 YAPALA DAIU\ 122 TAPALA-CROSSING 1512 YAPAI,A-BAE{}TO DAKA 1303123 CACI{E BAI,E BLACK VOLTA 124 TAGADI (IvorY coaat) 0901 BIIANFO BLACK VOTTA 16 AIGNYAKRO{ 1 309 BUI-AKATIYAKMU BLACK VOLTA1* MOONORI 1 216 UOI,E IIIIRI'GU1n GOREBA-$MIIN KIILDA 128 SEKOTI 1402 DAMI(O NED VOLTA 1D VILL,\GES EILUIINED IN GIIIN^ ! NWBER 0F PERS0NS E&${I}ilED Table 3 Village No Nane No of persons present - Total No of persons exaninecl Pre sentation % No of persons tenporarily absent M F TotaI 090 GEGENKPE 451 193 242 435 96.5 79 091 TlLI 323 133 152 285 88.2 20 092 SKOTI 1039 436 422 858 82.6 4? 093 WIDENABA 231 120 105 225 97.4 32 494 APODABOGO 245 109 116 225 91.8 14 095 ASBUGA 144 67 50 117 81 .3 24 096 D,IlNUGII 696 324 326 650 93.4 53 097 KAYORO-}'URU 373 181 174 351 94.1 15 098 K,".Y0R0 341 154 153 30'l 90.0 11 099 NAI(ONG 130 60 52 1't2 *.2 4 100 NAKONG.SABORO 165 72 72 144 87,3 39 101 BECHAIINSI 300 1fr 145 211 90.3 22 102 WITISI 328 140 14'l 28',1 87.5 23 103 r.I,}EISI 303 126 149 t75 90. B 21 104 KADEUA 311 142 150 292 93.9 22 105 lI riud 16'1 83 76 159 95.2 I 106 JANOA 421 21'.I u5 )92 93.1 95 107 s0G0 211 112 82 194 91.9 3 108 LlSSA 652 301 n6 6)'l 97.7 62 109 SAA 251 122 125 24? 98.4 n 110 KPiNFTI 393 185 164 350 89.1 44 VILLAGES EX,IMINED IN cH,'f{; ! NUI'fBER 0F PERSoNS EXTII,iINED Table 3 Village No Na^ne l{o of personspresent - Tota1 No of persong exarained Presentation /, No of persons tenporarily absentM F lota1 111 KIiLUN %9 123 123 246 91.5 5 112 NIB,lRI 431 199 216 415 96.3 24 113 DW 181 90 85 175 96.7 10 114 TANINA 100 50 43 93 93.0 7 115 PASINKPE 363 171 1Bg 360 99.2 9 116 YIIGr$"1 311 144 152 296 95.2 11 117 S,IBCN-GID,\ 331 162 168 330 99.1 7 118 S,lBriRI 296 171 12A 291 98.3 34 119 KENGUA 357 u5 163 338 94.',l 11 1n ZANDUT 317 158 155 313 98.7 1'.l 121 TUl,lB0 4D n3 2N 423 98.6 14 122 Y-\PALA 192 99 92 191 99.5 5 123 YAP,iLA.B.IGGYO 159 ?1 88 159 100.0 0 124 BAtE 6t 124 135 259 99.2 2 1D BUANFI] 248 1n 1n 240 96.8 13 126 BUI-iK;"J{Y.',KR0M 171 89 79 168 98.3 17 127 MTIRIJGU 338 176 153 3n g'1.3 B 128 COREBA-SOMI'N 258 130 128 258 100.0 4 1D Dir10K0 263 128 133 261 99.2 3 T0T,,ll, r\LL VILLTGES 12.150 5.9e7 5.971 1.958 93.8 859 ]II[t.cEs Etri';rllED rN GHr.N.i : pREv.'J,ENcE R,-TES ruD i'ircRoPrl-,ar,.L DitfsrrrEs Table 4 Village Nr Naae Prevalence Onchocerciasis Prevalencc Blindne s s Prevalence Diuinished Tlsion Georae tri cal lilea! Ivllorof l1arla1 Densily per SnipM F Total M F To tal \,' GEGT}KP5 6a.a 52.1 $.2 1.9 t.t 16.6 19.5 18.0 091 TILI BC.4 81 .8 81.1 3.3 5.c 22.8 l. I 71.8 iJ92 SK'TI na A ?c..i 7Q.9 =.o 9.c 1?.i 1e. i ilQ 1 TDtrN.3,T. 75.2 72.e 3.9 2.8 12.2 1 1.1 11 .7 ;.OD,3CGC )+ .,, ,9.8 57.2 0. 3.0 19.5 16,4 17 .9 095 -.SEBUG-r 67 ,7 :,3.2 55.o 1.5 )A 16.5 18.2 17.1 , a( D_-lruGu 55. j J 5+.6 1.8 5.2 11.1 10. 1 t..1 . 5 c97 iLY"rit:r-'.iirRu '1.,) 13.6 1a 5.1 1)-.2 9.0 Itr.3 2:_ z'.YC'10 ?a .2 55.1 5e.1 22 3.7 11..+ 13.o 1) a N. J:,NG ?3. 1 b u.l 69.5 3.4 4.8 11.9 t)t) 1t fi--',.'ir'G-S;.3'iitO Ai' t 75.2 5.3 4.j 10,3 16.1 1',l .2 'ir'\ i I BE3-].,UfiSI nl' '11., 75.3 4.' 19.8 14.9 1',l .0 ':.) 2 ill.sr Jo.-l 1.9 )t/ .i a 8.4 '12.2 1 i'3 -!-ui{BI,SI 53. t- 69.2 55.1 1t 5.2 rto ,n0.1 Ii, -J'.irr-I )). i ) t.o 53.8 L 2.1 ru. ) 4.8 t.) 1"5 II.C.. 53.7 58.1 40.8 '1 1C.',] 11 .6 11 .2 1'.,5 J ,IIG,! trl ,. 5!t .2 )i a LL< 1.4 17.9 OD ;;; 85.7 65.2 75.i o. f 3.9 lo 4,7 (t II.IU LIS S-i ',o Q) ) 80.8 4.O t.) 11 .1 13.2 12,2 1()9 55.1 55. z 6c. 8 6l.t 2.2 5.1 6.9 EN 5.9 11il KP.IJ{F'A 66.5 6e.e 1.8 3.6 14.6 13.? 14.2 ITLLIGES EXIJNIED T}I GiI..N.. 3 PRE'f.'J,ENCE .],TTES ,{TD }ITCROFIL;:RI.II DENSI?IES Table 4 Village l,l Nane Prevalance 0nchocerciasis Prevalence Bllnc1ne es 'rl Prevalence Dlnlnished Vislon Geonetric Mean,''iicrof ilarial _---Denslty per Snip_ M .t Total lil F TotaL 11" iilLU}I 77.9 79.4 78.? 4.8 '1,/, 18.5 15.3 16.9 112 I u'a-'. lr 72,2 75.9 71.1 1.1 >.1r 11.6 1J,4 in,9 113 DUU 73.1 75. 3 1.2 15,5 11.9 13.5 1 ,-; T llljri 11 .!, ,t1 L 34.1 c.c J.U 6.9 4,2 5.5 1.i I e-. s;r,nrr 4', 4 7/",2 .r,u c.7 1a I 12,' 12.3 116 : Yi-G.3' 89. I 89.9 3.3 7.9 12.5 14. B 11.lL ttl 1 i S...BO:{-GIDA 45.3 43.5 '2.3 1'.|.1 13.3 15 .0 6g.l bc. / 68,1 0.0 i.3 11,3 'l 1.8 11 ( )o.u lr n 50.j 1.0 2.O 12.5 11.4 la o 1n I z'.irou-- ol 5.5 nq lo 4.) ,.6 4.9 --'----.ffi121 , tmmo 34.3 38.2 ola 1.1 3.9 b.4 qrt 5.9 ,o. o 8.6 25.'.| nn 1.1 9.2 4.5 n( 123 Y. ?-,L'_-B.CGTo +)t'i 39.0 11 .1 1.5 3.9 15.9 11.1 124 B.{Lf '"3.0 69.4 /.< a 1.3 4.5 13.5 14.1 ,2 0 125 BU:i1'I.0 59..1 70,7 'lc-1 20.5 12.1 16.1 1% 6c.B 5t.7 1r. 1.3 19.6 12.8 16,) 1 r_7 ;;U?IIGU 1a,c '13.8 ?5.e 1.0 ).u 15.3 11 .4 13,9 128 Go;ultsi-sclflIN 73.1 75.0 74.8 2.1 ?.3 27.2 19.o ), A 14 D:TCiiD 75.6 55.5 10.e 1,6 8.2 1C r1 14 .1 14,9 3UI-.!Y'iigY-iltR0i'l -10- f llustrati-ons trigure I localizatlon of villages examined in Ghana Figure 2 Progress of basic epid.eniological evaluations 1n Ghana Iigure 7 Age-specifi4 sex-ratios in persons exa.rrlned J-n 12 villages)<. Figure 4 Age-specific drop-out-rates for m',les and females at the re-exa.mination of WldonaA" (gZ) Fisure ' I:"ffi3":l#"I"ff:T;:J:',ffi:";ffi'Il.ll"ll","-r, tr'lgure 6 Age-specific infection rates in villages on the Sissili. Figr-rre 7 l,ficrofi]-arla1 density in vi]lages (top) and comparison of male and fenale densities (Uetow). Figure 8 Age-specific nlcrofilarial rlensities in the onchocerciasls patients from Gengenkpe (go), LJ!!(,, *: .,y rj diJ0t:() (,() C) I . E-. ffi . :*r; ;i- i. -r ! ".-t.!,.c '-l i*i'*\ e-u - [-t .-F t:i i:- r-ll: .,() i-: '/ LJ ('-l ::H '4 r)e\': 'j- .:4r ) O . ; 'i1l { r:[ \'v ,'ir\ .'i.' 'LJ I -l *-" .t -[ -t I { -;rJ (, C} ('t a . n / -\(: t-,L*, t, HU t ,) "::u _!j :"-: i.t :,l "$ o ---#tur'r) /u i*{l,urt_) / t! \r#qlr L !T, iT 1l ' ('-tj ('"t ,r , I.I : u (()..* 11** *{} r qiYhr t)\-7 rr') C) 3 (tt\. ( O'-','{L, g'Ut r,t?t-! = c-)hi' c) -\ i.i'/\a / s-\. \ \* "/{)€ i.o -,(\l ,1-\ { \ t!,', e3v f!- $ -''a- rffi; Lr. - -;:5- { .,,\* ' i{ I tr t ,) ) -)l .) e -or. rr((.J L il .)) :1)(- {1 L c \\\\ \ C]((]),. 1( (.1(., ittr{, \, ) -l* , l'* I B L t, I I i I ,i c ! I \ ) I h t h I i d J( r-t. (: *\- d I '::a_ ,a,il\/ r.i*r'.1 :\ r! {";'"t. I ri / Proportion of Drop-outs ffig &' n 1 75 0 1 .75 5 10 20 30 40 s0 Nurnb€rs examined of 'f st passasa = | cge $,fl tJJ .,.' i{l ru za JU 4u 3u oge 2nd Possoge Widenobo (93) - Ferno/es t