Volume 67. Number 3Print<d in tio U.S.A.

(ISSN 0148-916X)

INIE RNAI IONAI. JOURNAI. OP LEPROSY

Comparison of Two Methods of Leprosy Case Finding inthe Circle of Kita in Mali 1

A. Tiendrebéogo, S. O. Sow, M. Traore, K. Sissoko, and B. Coulibaly'

Leprosy is still an endemic disease in themember states of the Organisation pour lalutte contre les Grand Endemies (OCCGE),with a prevalence rate of 1.45 per 10,000inhabitants in December 1996 (`). OCCGE,thc coordination and cooperation organiza-tion for the control of major endemics, cov-ers eight French-speaking countries of WestAfrica, including Mali. In Mali, a nacionalleprosy control program (NLCP) has beencarried out since 1992 ( 5). This NLCP, us-ing the World Hcalth Organization's recom-mended multidrug thcrapy (WHO/MDT),treated about 15,000 leprosy patients be-tween 1992 and 1996. The WHO/MDTcoverage rate reachcd 90% of registeredcases in 1996. The prevalence rate of lep-rosy fell from 18.48 to 3.57 per 10,000 in-habitants during 1992-1996. Nevertheless,the detection rate remained at almost thesame levei, ranging between 1.37 and 2.11per 10,000 inhabitants (5 `').

Meanwhile, in the countries of Beninand Burkina Faso, other member states ofthe OCCGE, active case finding of leprosywas set up in some arcas ( 1 . 9). This resultedin a two- or threefold increase in the detec-tion rate. So, we thought that the same leveiof the detection rate in Mali could be attrib-uted to the passive case finding donethrough the NLCP. The poor effectivenessof that case-finding method could result in aconstant and low detection rate. Mass cam-paigns for detection and treatmcnt of lep-rosy patients during the dapsone monother-apy period (1960-1975) have been aban-

' Received for publication on 22 March 1999. Ac-cepted for publication on 16 June 1999.

' A. Tiendrebéogo, M.P.H.; M. Traore, M.D.,Observatoire de Ia Lcpre en Atrigue, P.O. Box 251,Bamako, Mali. S. O. Sow, M.D., Institut Marchoux,P.O. Box 251, Bamako, Mali. K. Sissoko, M.D.;B. Coulibaly, M.D., District Health Center, Kita, Mali.

Reprint requests to A. Tiendrebéogo at the aboveaddress or FAX: 223-22-95-44.

doned (7) because they were not cost effec-tive and were opposite to thc integration ofleprosy control into the peripheral healthservices.

In 1997, we decidcd to carry out a com-parative study of the passive and activemethods of leprosy case finding. Our objec-tives werc to measure the costs and resultsof these strategies and to propose recom-mendations to the OCCGE member statesfor the climination of leprosy.

MATERIALS AND METHODSOur study was a survey comparing thc

detection rates of two case-finding methods(passivo and active). We estimated the de-tection rate with the passive case findingmethod at 1 case per 10,000 inhabitants andthe detection rate with the active method at4 cases per 10,000 population. The samplesize for cach method, in a one-tailed com-parison test of two proportions and equalgroups with an a risk of 5% and a powcr(1 — (3) of 90%, would reach 65,000 persons.

We chose the Circle of Kita to carry outour study. Kita is a health district in thesouth of Mali. Total population of the Cir-cle was about 274,000 inhabitants. We in-volved ali villages of more than 1000 in-habitants in our survey. The villages wererandomly separated roto two groups. Thepassive detection method was allocated to agroup of 37 villages with a total of 80,135inhabitants. The active detection methodwas carried out in a group of 32 villageswith 69,518 inhabitants.

The passive case-finding method con-sisted of: a) health education sessions aboutleprosy signs presented in villages by thenearest health center nurses; b) counsellingof people with suspect signs of leprosy, re-ferring them to the peripheral health center;c) examination of suspicious cases bynurses at the peripheral levei of the healthsystem; and d) confirmation of the leprosy

237

238^ International Journal of Lepros_v^ 1999

THE TABI.E. Contparison of the results and costs of ttt'o case-/inding ntethods in Kitacircle (Mali).

Active case finding Passive case finding p Value

No. villagesPopulationPeriod of case findingPrevalence of cases of leprosyPrevalence rate per 10,000 inhabitants

3269,518

May—June 199740

5.75

3780,135

June 1997—May 199815

1.87 0.0001New cases of leprosy 30 12Detection rate per 10,000 inhabitants 4.31 I.50 0.001

MB new cases 40 58.3 NS'Disahled new cases 0 16.7 NS

% Children among new cases 40 0 0.009% Single skin lesion in new cases "'0 O NS% New cases living at less than

15 km from nearest health center 6.7 66.7 0.0001Total cost of case-finding method 2 ,150 US$ 432 USSCost for each new case found 72 USS 36 USS

"NS = Not statistically signilicant.

diagnosis by a nurse specialized in leprosyat the district levei.

The active case-finding method con-sisted of: a) health eduction sessions aboutleprosy signs presented in villages by a mo-bile team composed of a doctor and twonurses; b) nurse's examination of suspi-cious cases of leprosy immediatcly after theeducation session; and c) confirmation ofthe leprosy diagnosis by the mobile teamdoctor.

The WHO definition of a case of leprosy(a person with clinicai signs of leprosy andrequiring MDT) was used ("). A case ofleprosy actively found was a person con-firmed to be leprous after examination inhis village by the mobile toam membcrs. Acase of leprosy passively found was a per-son living in a village of the passive case-finding group and diagnosed as a leprosypatient in a health center during the 12months following the education session.

The mobile team visited by car the 32villages of the active case-finding group inMay and June 1997. Nurses presented edu-cation sessions about the signs of leprosy inthe 37 villages of the passive case-findingmethod during May 1997. Passive detectionof cases was carricd out in peripheral healthcenters from June 1997 to May 1998. Infor-mation on leprosy cases actively or pas-sively found was written on questionnaires,and the data collected were analyzed withEpi-Info software. To estimate the costs ofeach method, we took account of the costs

for the transportation of the mobile team bycar and per diem of the team membcrs dur-ing May and June 1997. For passivo detec-tion, we only took account of the costs ofthe nurses' trips by motorcycle to the vil-lages of passivo detection for the health ed-ucation sessions.

RESULTSActive case-finding results and costs.

In the 32 villages with 69,518 inhabitants,the mobile team found 40 cases of leprosy.Four of them were already on MDT, 36were requiring treatment and 30 were newcases of leprosy never treated before. Therewas no disabled patient among the newcases. Multibacillary (MB) patients were40% of the new cases and children (lessthan 15 years old) also represented 40% ofthe new cases. Six patients (20% of newcases) had a single skin lesion; 93.3% of thenew cases were living in villages more than15 km from the nearest health center. Thedetection rate was 4.31 per 10,000 inhabi-tants and the costs to find a new case wereestimated at 72 USS.

Passive case-finding results and costs.In the 37 villages with 80,135 inhabitants,peripheral health center nurses found 15cases of leprosy betwcen Jungi 1997 andMay 1998. Twelve of thcm were new casesof leprosy and the detection rate was 1.5 per10,000 inhabitants. The percentages of MBleprosy and disabled cases were, respec-tively, 58.3% and 16.7%. There was no

67, 3^Tiendrebéogo, et al.: Ttt'o Methods of Case Finding^ 239

18 —

16 —o

2-

▪

^—

Ca.

O 12 —v)

^ 10

• 8 —

C 6

• 4 —E

2 —

0

0-15 km^ 16 -30 km^ >30km

Distance to the nearest health center

FIG. 1. Number of new cases of leprosy actively and passively found according to distance from closesthealth center. • = passive case Finding; = active case finding.

child or single lesion patient among the ncwcases of leprosy passively found. Passivecase-finding costs were about 36 US$ perpatient; 66.7% of the cases were living invillages less than 15 km from the closesthealth center (The Table).

Comparison of results and costs of thetwo methods. Comparing the results of thetwo methods, indicators showed that activecase finding found earlier cases of leprosywith no disabilities, fewcr MB patients andmore cases among childrcn. Active detec-tion appeared more efficient, with a detec-tion rate higher than the passivo detectionrate (p <0.001). Active case-finding al-lowed us to detect cases in remote arcas; theproportion of new cases living near hcalthcenters was higher with the passive methodand the differencc with the active methodwas statistically significant (p <0.0001)(Fig. 1).

Active case finding looked more expen-sive than passive case finding. Neverthe-less, it was a faster method of case finding,allowing the detection of more cases in^1month than the passive method found in 12months. Elsewhere, unlike thc passive de-tection, thc histogram of actively foundnew cases by age showed two spikes (ninenew cases at 10-14 years and nine new

cases at 35-39 years) (Fig. 2). Those spikescorrespond to the ages of great incidente inleprosy classically described in the naturalhistory of the disease ( 2').

DISCUSSION

The active detection rate was 2.5-foldhigher than the national detection rate inMali in 1997 ( 8). The effectiveness of theactive case finding of leprosy by a mobileteam confirms the findings of olhei studiesdone in Benin and Burkina Faso ('•`'). It alsoconfirms the effectiveness of the leprosyclimination campaigns (LEC) supported byWHO in Madagascar and Guinea in WestAfrica. Leprosy at its heginning is a pain-less disease and its skin lesions do not makepeople go for a medicai examination. Thisis particularly truc when thc hcalth ccntcr isfar from villages. In our survey, we foundthat less than 25% of passively found newcases carne from arcas more than 30 kmfrom a hcalth center. In a village 60 kmfrom the nearest health center, we activelydetected 15 ncw cases of leprosy. None ofthem had tried to travel to the hcalth ccntcrfor a medicai visit. We think that when thedistances between villages and hcalth cen-ter are more than 15 km, only active casefinding detects new cases of leprosy.

I

35to39

25to29

20to24

30to34

240^ International Journal ofLeprosy^ 1999

9—

8o 7 —C.

4. 6 —o

5 -

v 4

o3

z

o^I

0^5^10^15to^to^to^to4^9^14^19

4o^45^

50^

55^

60^

65to^to^to^to^to

^to

44^

49^

54^

59^

64^

69

Cases years old

2

1 –

II {

70to75

2. Number of cases of leprosy actively and passively found according to age. • = passive case finding;11 = active case linding.

An advantage of active case finding ofleprosy is earlier detcction, with more pau-cibacillary (P13) cases requiring short treat-ment and more single-lesion cases that canbe treated by a single dose of rifampin-ofloxacin-monocyclinc (ROM). An earlieractive detection also prevents the occur-rence of disabilities and leprosy rcactions.These advantages could compensate for themore expensive active case finding com-pared to the passive method. For bettercost-effectiveness of active case finding,this method could be applied in reniote ordifficult-to-access arcas and only repeatedevery 2 or 3 years rather than yearly.

A criticism of active case finding in lep-rosy is based on the risk of intake of self-healing cases. These self-healing cases-indeterminate form of leprosy—could leadto an overdiagnosis of new cases. However,the safety of current treatments of leprosywith WHO/MDT ('°) makes acceptable thatoverdiagnosis. it is better to overdiagnosesome self-healing cases than to have a fewpaticnts become disabled.

Passivo detcction of leprosy is a betterstrategy for health services integration. Itcould easily be combined with other com-ponents of primary health care (extend pro-gram of immunization, tuberculosis controlprogram, etc.). For a better quality of lep-

rosy diagnosis and considering the mobilityof health staff at the peripheral levei, pas-sive detcction requires a program of train-ing and rctraining of nurses and permanentsupervision of the peripheral health staff atthe district levei. To be efficient, passive de-tection should be preceded by informationand education campaigns about the signs ofleprosy. When considering the costs of in-formation campaigns, training, retrainingand supervision activities, the low cosi ofpassive case finding could reach the cost ofactive case finding.

The costs, advantages and inconve-niences of each method made us propose aflow chart for the choice of a case-findingmethod (Fig. 3). This chart is based uponthe prevalence rate of leprosy, MDT cover-age, and the average radius of the attractioncircle of each peripheral health center. Weproposed the flow chart to the NLCP man-agers of each member state of the OCCGEand hope that it could be used in settingplans for the elimination of leprosy.

CONCLUSIONOur comparative study of two methods

of case finding in leprosy showed that ac-tive detection is more efficient, allowingtreatment of earlier cases of leprosy and theprevention of disabilities. The more expen-

Prevalence rateMore than 1/10,000^Equal or lesa than 1/10,000

MDT coverage of^MDT coverage of

peripheral^ peripheral

Health centers^Health centers

80^ 80%^X80%^80 %

1center area

)10 km•(10 km

V

AC+PCAC

Average radius of

peripheral health

center area

PC

Average radius of

peripheral health

67, 3^Tiendrehéogo, et al.: Two Methods of Case Finding^241

Fic. 3. Proposed flow chart for choosing a leprosy case-finding method in integrated health systems. AC =active case finding; AC + PC = combined active and passive case finding; PC = passive case tinding.

sive active method could be compensatedby carrying out active case finding in onlyremote and isolated arcas and repeatingthese activities at intervals of 2 or 3 years,according to the prevalence of leprosy. Pas-sive detection of leprosy cases should beaccompanied by education sessions. For theelimination of leprosy, the two case findingstrategies should be combined in mostcountries endemic for leprosy.

SUMMARY

%

Kita is a health district of Mali, a lep-rosy-endemic country in West Africa. Weconducted a comparative study of passiveand active case finding of leprosy in thisdistrict in 1997. In May and June, a mobileteam realized active case finding by visiting32 villages of more than 1000 inhabitants.For 12 months, peripheral health center

242^ International Journal of Leprosy^ 1999

nurses did passive detection aftcr informa-tion and education sessions about the signsof leprosy in the other 37 main villages ofKita. The active detection rate (4.31 per10,000) was threefold highcr than the pas-sive rate (1.5 per 10,000) and allowed us tofind earlier cases of leprosy. Active casefinding identificd children and single-lesiondiscase; the passive method did not. Costfor finding a new case was estimated at 72US$ by mobile team detection and 36 US$by passive case finding. Although the activemethod looked more expensive than thepassive one, it was the only effective strat-egy to detect leprosy patients in rcmote anddifficult-to-access arcas. Based upon the re-sults of the study, a flow chart is proposedfor the choice of case-finding method whendesigning a leprosy elimination program.

RESUMENKita es un distrito de Mali, un pais con lepra

endémica dei Africa occidental. En este distrito, en1997 se hizo un estudio comparativo sobre la detec-ción pasiva y activa de nuevos casos de lepra. En mayoy junio, un equipo móvil realizó la detección activa decasos visitando 32 poblaciones de más de 1000 habi-tantes. Durante 12 meses, enfemeras de centros desalud periféricos realizaron la detección pasiva de ca-sos después de varias sesiones infomrativas y educa-cionales sobre los signos de la lepra, en ontras 37poblaciones de Kita. La tasa de detección activa de ca-sos (4.31 pr 10,000) fue 3 vetes más alta que la tasa dedetección pasiva (1.2 por 10,000) y permitió encontrarlos casos de manera más temprana. El corto para el hal-lazgo de un nuevo caso fue de 72 dólares americanosen la detección activa y de $36 en la detección pasiva.Aunque el método activo resultó más costoso que el pa-sivo, fue la única manera efectiva de detección de ca-sos en regiones remotas y de dificil acceso. Basados enestos resultados se propone un diagrama de Ilujos paraescoger el método de detección de casos cuando sedisena un programa de eliminación de la lepra.

RÉSUMÉLe district de Kita est une zone de santé du Mali,

un pays 00 la lepre est endémique en Afrique del'Ouest. Dans ce district, nous avaons mené en 1997une étude comparative de détection de nouveaux casde lèpre, l'une passive et I'autre active. Durant lesmois de mai et de juin, une equipe mobile a recherchéactivement les cas en visitant 32 villages de plus de1000 habitants. Pendant 12 mois, de infirmières decentres de soins périphériques á la région ont réaliséune détection passive de nouveau cas après avoir menédes sessions d'infomration sur les signes de la lèpredans 37 autres villages principaux du district de Kita.Le taux de détection par la méthode active (4,31 per10 000) a été trois fois plus élevé que le taux obtenupar la méthode passive (1,5 pour 10 000) et nous a

permis de trouver des cas plus précoces de lèpre. Lecan pour trouver un nouveau cas a été estimé à 72$US pour l'équipe mobile de détection et à 36 $USpour la détection passive de nouveaux cas. Bien que laméthode active ait semblé plus chère que la méthodepassive, la première est la scule qui puisse efficace-ment détecter les patients souffrant de lepre dans leszones reculécs et difficiles à atteindre. Basé sur les ré-sultats de cette étude, un organigramme est proposé pouraider au choix de la méthode de détection lors de l'élab-oration d'un programme d'élimination de la lèpre.

Acknowledgment. This study received financialsupport from the Francophone Research Fund (FFR)through the Associated Francophone Laboratory no.304 of AUPELF-UREF. We gratefully acknowledgethe FFR and the peripheral and district health staff ofKita Circle in Mali who made this study possible.

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