Accepted for publication 7 December Introduction

Transcription

1 Lepr Rev (2005) 76, Progress towards the elimination of leprosy in Nigeria: a review of the role of policy implementation and operational factors OSAHON I. OGBEIWI Leprosy Mission International, Africa Monitoring and Evaluation Service, Tract House, PO Box 8083, Benin City, Nigeria Accepted for publication 7 December 2004 Summary The annual reports of the national leprosy control programme in Nigeria were reviewed to study the trends of the indices of leprosy control from 1992 to 2003 and determine the influence of operational and policy factors. By 2003, both national prevalence and case detection rates had reached below 0 5 per 10,000. Sub-nationally, all except three contiguous States in the Southeast, had prevalence rates below one case per 10,000. Over the 12 years, the prevalence rate decreased by 94 1%, from 7 14 to 0 42 per 10,000, with two periods of rapid decline: and Remarkable surges of discharges from multi-drug therapy (MDT) occurred in these same periods. The period corresponds to the years of introduction of MDT, case reviews, and clean-up of leprosy registers nationwide, while 1998 corresponds to the year the programme adopted the shortened 12-month MDT regime for multibacillary (MB) leprosy. The overall trend of case detection since 1992 was relatively stable, but had three significant periods of initial increase ( ), stability ( ) and recent decline ( ), apparently related to the changing levels of activeness of the national programme. The pattern of new cases detected revealed increasing MB classification and lower disability, but a relatively stable child rate since The trend of MB proportion was also related to the years of MDT introduction and the adoption of a new leprosy case definition and classification policies. Thus, Nigeria has attained a low leprosy endemic status mainly through operational and policy influences. The challenges that remain include reducing the relatively high leprosy burden in the Southeastern States and evolving effective case detection interventions that will make an observable impact on the incidence of leprosy. Introduction Before 1998, Nigeria was one of the most leprosy endemic countries in the world. Surveys in the 1940s and 1950s found prevalence rates ranging from 16 to 390 per 10,000, while the most recent survey in 1990 estimated a countrywide leprosy prevalence of 360,000, or 30 3 per 10,000. Multi-drug therapy (MDT) was introduced to Nigeria in 1985 and was launched Correspondence to: O. I. Ogbeiwi ( osahonjio@yahoo.co.uk) /05/ $1.00 q Lepra 65

2 66 O. I. Ogbeiwi with the National Tuberculosis and Leprosy Control Programme (NTBLCP) for implementation nationwide in ,2 Then, MDT covered only 4 3% of leprosy patients. Leprosy control areas were separate, distant and operated isolated individual vertical poorly funded strategies. 2,3 From inception, therefore, the national programme aimed to reduce the prevalence of leprosy to a level where it was no longer a public health problem by the year 2000, detect leprosy patients in the early stages of the disease and provide MDT for all patients as recommended by World Health Organization (WHO). It also aimed at preventing or reducing disabilities associated with leprosy and reducing social and psychological stigma associated with the disease. 3 With the assistance of international donor agencies and WHO, the national programme employed strategies such as capacity building, procurement of logistics, development of uniform health information formats, review of existing patients, clean up of old leprosy registers, implementation of monthly MDT at PHC level and case holding. 2,4 Between 1996 and 1998, the control effort was on increasing the geographical coverage of MDT services, early case finding, and creating awareness of leprosy. It was during this time that a Special Action Programme for the Elimination of Leprosy (SAPEL) was done in some fishing villages in Akwa Ibom State, in South East Nigeria, and Leprosy Elimination Campaigns (LEC) were carried out in six States: Jigawa, Kano, Sokoto and Zamfara, Benue in the North and Enugu in the South-East. The SAPEL had good case holding results, and those of the LEC in Table 1 indicate that, overall, the campaigns found untreated leprosy in about 1 in every 450 persons examined. Almost three-quarters of diagnosed cases were multibacillary (MB) and one-fifth were children. In addition, the disability proportion of detected new cases was relatively low. Thus, the LEC programmes carried out in Nigeria were successful as cases of consequence were detected as expected. 5 However, the increased case detection experienced during the campaign was not sustained in the subsequent years, raising questions about the long-term benefit and cost-effectiveness of special programmes such as SAPEL and LEC in Nigeria. Details of the experience, outcome and recommendations of these programmes have been published by other authors. 6 9 In addition, the NTBLCP adopted a simplified case definition and classification of leprosy in 1996, carried out a tripartite evaluation of the national leprosy control programme in 1997 and in 1998, the shortened treatment regime for MB leprosy as recommended by the 7th WHO Expert Committee. 1 Compared with the years before, the national leprosy control programme was relatively inactive during years after Table 1. Results of Leprosy Elimination Campaigns (LEC) carried out in Nigeria New cases (NC) detected State Year Duration (months) Population examined Total NC % MB% Child% G2% Suspect cases Enugu , Zamfara/Sokoto , Benue , Jigawa , Kano , Total ,

3 Elimination of leprosy in Nigeria 67 The programme achieved 100% MDT coverage by December 1995, completed the establishment of Leprosy Control Programmes in all States of the country by the end of 1996, and attained the WHO elimination target of less than 1 case per 10,000 population at the national level by end of This paper reviews the influence of the operational and policy aspects of MDT implementation on the trends of the basic indicators of leprosy control in Nigeria. Materials and methods The author examined past NTBLCP annual reports prepared by the Central Tuberculosis and Leprosy Unit of the Federal Ministry of Health as available at May These reports are compiled annually from quarterly periodic reports from the States. The objective of the review was to describe the trends of leprosy control indicators up to end of 2003 and to analyse the influence of operational factors on these trends. Reliable and complete data was found from 1993 after the national programme was launched and a uniform recording and reporting system was introduced nationwide. Based on available data, this review presents prevalence and annual case detection trends for 12 years from 1992, the trends of case detection indices, including proportions of children and disability grade II among new cases for 11 years from 1993, and the trend for patients released from treatment (RFT) for 13 years from The indicators studied are the main ones that the NTBLCP collects data on periodically from the State Leprosy Control Programmes, using the quarterly statistical reporting format (code: NTBLCP/LEP5). The prevalence indicators are the registered prevalence number and rate at the end of each year. The case detection indicators include the number of new cases detected, case detection rate and the proportions of new cases that were multi-bacillary (MB) leprosy, children under 15 years and grade II disability. Also included is the number of patients released from treatment at the end of year. Even though recent NTBLCP reporting forms now collect data of the sex of new cases, the other cases removed from the registers annually (died, transferred out and treatment not completed) and reaction cases detected and treated, these indicators were excluded for reason of their absence in the NTBLCP annual reports of the earlier years reviewed. All rates are expressed as per 10,000 population. Apart from the population figure given by the NTBLCP Central Unit in Table 2, all population figures used in the analysis of rates were projected annually from the 1991 census population figure (88,514,501) using a 2 83% growth rate. 10 All proportions are expressed as percentages. It should be noted, however, that the 2001 data does not include the figures from Osun and Oyo States, two of the least endemic States (see Table 2), whose annual reports for 2001 did not reached the NTBLCP as at the time of this review. Nigeria has six geo-political zones as named in Table 2. However, the middle belt States of Kwara, Kogi and Benue, politically classified as North, are in this analysis included in the South because of their cultural proximity to the South and being located below the two major rivers, Niger and Benue that divide the country into three major geographical parts. In the analysis of trends, significance was assessed using the Chi-square for trend in the STATCALC EPI 6 04 programme. In this review, only trends with P-value, 0 05 are regarded as statistically significant.

4 68 O. I. Ogbeiwi Table 2. Distribution of leprosy in Nigeria in Source: NTBLCP Central Unit Registered prevalence New cases detected Geo-political zone State Population 000 Total Rate Total Rate MB% Child% G2% North Central Kano Jigawa Katsina Kaduna Plateau Nasarawa North East Bauchi Gombe Borno Yobe Adamawa Taraba North West Zamfara Kebbi Sokoto Niger Fct.Abuja South East Benue Ebonyi Akwa-Ibom Abia Enugu Anambra Imo Cross / R South South Edo Delta Rivers Bayelsa South West Kogi Ondo Lagos Ogun Kwara Oyo Ekiti Osun Total 126, Results SITUATION REGARDING NATIONAL LEPROSY CONTROL IN 2003 Both prevalence and case detection rates have reached below 0 5 per 10,000 population at the national level by the end of Table 2 shows this was the situation in 20 of the 37 States. In another 14 States, these rates were between 1 and 0 5 per 10,000. Only three contiguous States in South Eastern Nigeria, Cross River, Ebonyi and Benue, still have both rates above one per 10,000 (see map of Nigeria in Figure 1). Besides these three States, leprosy prevalence and case detection rates are significantly lower in the South than the North. While 14 (70%) out of the 20 Southern States had both prevalence and case detection rates below

5 Elimination of leprosy in Nigeria 69 Figure 1. MAP of Nigeria showing the 37 States (source: per 10,000 by 2003, in the North, only six (35%) of the 17 States had this low endemic level (P, 0 05). Table 2 also shows that States in the Eastern zones of the country (Southeast, South-South, Northeast and North Central) had significantly higher leprosy rates than those in the Western zones (Southwest and Northwest). Sixteen (66 7%)of the 24 States in the Eastern zones had either one or both rates higher 0 5 while one (7 7%) of the 13 States in the western zones had this level (P, 0 01). Of the total 4647 new cases detected during 2003, 87% were classified as MB. Less than 10% were children and grade II disability rate was 12 4%. The MB proportion of new cases

6 70 O. I. Ogbeiwi was above 60% in all 37 States and above 80% in 30 States. The proportion of children among new cases was less than 10% in 17 States, and the disability rate was above 10% in 22 States. Disability rate is below 5% in only four States. There were no significant regional or zonal differences in the rates of MB, children or disability in the country (P. 0 05). TRENDS IN NATIONAL LEPROSY CONTROL INDICATORS Prevalence Figure 2 shows the registered prevalence decreased by 91 9% between 1992 and The prevalence rate fell significantly from 7 14 to 0 42 per 10,000 during the 12-year period (x 2 =1479; P, 0 01). This fall in registered caseload seemed to have occurred in four stages. It was a rapid fall during the 3 years from 1992 to 1994 (from 7 14 to 2 02). It was a more gradual fall during the 3 years 1995 and In 1998 alone, there was a 41 5% decrease in the registered prevalence from 12,878 to 7534 cases. The registered prevalence rate fell below the WHO elimination target of less than one case per 10,000 inhabitants at the national level by the end of the same year. Between 1998 and 2003, registered prevalence rate decreased slightly but steadily from 0 7 to 0 42 per 10,000, and this is statistically significant (x 2 =10 0; P, 0 01). Case detection Figure 3 shows that case detection rates varied from 0 23 in 1992 to 0 38 per 10,000 in The 12-year trend is not statistically significant (x 2 =2 09; P=0 15). However three definite periods of change of case detection trend are shown in figure 2: a significantly increased number and rate of case detection from 2105 (0 23) in 1992 to 7827 (0 81) in 1994 (x 2 =30 2; P, 0 01); a more or less stable case detection rates ranging from 0 62 to 0 81 between 1994 Figure 2. Trends of registered prevalence and prevalence rate in Nigeria

7 Elimination of leprosy in Nigeria 71 Figure 3. New cases detected and case detection (CD) rate in Nigeria and 1999 (x 2 =0 57; P=0 45), and then a significantly decreased case detection from 0 72 in 1999 to 0 38 in 2003 (x 2 =13 7; P, 0 01). Multi-bacillary new cases Figure 4 reveals that in 11 years the MB proportion increased significantly from 56% to 86% between 1993 and 2003 in a stepwise fashion (x 2 =58 9, P, 0 01). The line graph shows the two stages of increase of the MB proportion: first, sharply from 56% in 1993 to 75% in 1996, and second, steadily from 75% in 1998 to 86% Proportion of grade II disability and children among new cases Figure 5 shows that the proportion of new cases with grade 2 disability decreased from 20 2% to 12 4% during the 11-year period reviewed. The fall in grade 2 proportion occurred principally in 1994 and It continued to fall from 1998 to This trend is significant (x 2 =36 5; P, 0 01). Similarly, the child proportion among new cases reduced from 12 5% in 1993 to 9 3% in 2003, a significant decrease in 11 years (x 2 =10 12; P, 0 01). Figure 4 shows the main fall in child proportion occurred in Before and after this year, the trend of child proportion was relatively stable. Cases released from MDT A total of 96,455 patients were released from MDT between 1991 and As the statistical format does not report on cohorts, analysis of treatment completion rates at the national level is not practicable. Figure 6 shows that the two periods with a remarkable surge of discharges from treatment correspond to 1993 and 1994, and The sum of 31,641 patients

8 72 O. I. Ogbeiwi Figure 4. Proportion of new MB cases detected in Nigeria Figure 5. Child and disability rates of new cases detected annually in Nigeria discharged during these three years amount to 32 8% of the total released from treatment since Figure 6 also shows a decreasing trend of the number of discharges from MDT annually since 1998, corresponding to the overall decreasing registered prevalence of leprosy in the country.

9 Elimination of leprosy in Nigeria 73 Figure 6. Leprosy patients released from treatment annually, Discussion This review confirms the decline of registered prevalence of leprosy in Nigeria and the attainment of the WHO elimination target of less than one case per 10,000 inhabitants by year 2000 at the national level. Thus, Nigeria is one of the 110 endemic countries (out of 122 in 1985) that had reached the elimination goal at the national level by the beginning of The past trends of leprosy in Nigeria are similar to those reported from many other formerly endemic countries across the globe. For example, a 20-year review in ALERT, Ethiopia found a 30-fold reduction of leprosy prevalence and an 80% increase in MB proportion of new cases. Unlike in Nigeria, however, the ALERT review reported a 6-fold decrease in case detection rate and 60% reduction of child proportion of new cases. 12 For Nigeria, this feat is a major landmark in the nation s effort to bring the scourge of leprosy under control since 1930s. 1 This trend generally underscores the success of the tripartite cooperation of the Federal Government of Nigeria, the WHO and the international donor organizations, members of International Federation of anti-leprosy Associations (ILEP), that been involved in the funding, direct resource support and development of the national programme since its inception. There is no evidence of an impact on the national leprosy control programme by the civil unrest that occurred in Nigeria during the period reviewed. With both prevalence and case detection rates below 0 5 per 10,000 inhabitants since 2002, Nigeria could now be considered a leprosy low-endemic country. 13 Sub-nationally, the majority of the States have achieved the WHO elimination target, and more than half of them also have a low endemic status. There is, however, still a cluster of endemicity in the Southeastern corner of the country, where the national programme should now target its strategies to reduce the caseload of leprosy to elimination level in all parts of the country. In addition, there are significant geographical differences in the distribution of leprosy in Nigeria. Registered leprosy is significantly more prevalent in the North than in the South, and more in the East than in the West. While the review did not investigate for the reasons for these differences, the author speculates religious and ethnical bases. The North,

10 74 O. I. Ogbeiwi having a larger population of adherents of Islam (with alms giving as one of the five pillars) than the South, is more accepting of leprosy disabilities; and so has a generally lower leprosy stigma, favouring a higher reporting of leprosy cases for treatment. Communal fear of leprosy is still relatively high in the South, especially in the Southeast where is begging is social taboo. Ethnically and culturally, the States in the Southwest and Northwest are more homogenous, having, respectively, mainly the Yoruba and Hausa-speaking tribal groups. The States in the South-south, Northeast and Southeast with higher leprosy rates have multiples of tribal ethnicities with varied cultures. However, the definite role of religion and ethnicity in the distribution of leprosy in Nigeria still has to be proved. There appears to be an obvious relationship between the periods when particular leprosy control activities were carried out and the trends of registered prevalence and discharges of leprosy cases. The significant fall of registered prevalence during the early years of the national leprosy control programme ( ) was due to the implementation of MDT nationwide and the resulting massive discharge of inactive or wrongly diagnosed cases from leprosy registers. Secondly, the attainment of the WHO elimination target in the year 1998 was the result of the programme s adoption of the new WHO 12-month MB regime in mid and the subsequent massive discharge of all patients on the former 24-month regime that had received more than 12 doses. The peaks of MDT discharges during these same years confirm the direct influence of these events on the registered prevalence rates in Nigeria. Overall, the range of case detection rates between 1992 and 2003 implies a generally stable case detection trend in Nigeria. While the initially increased case detection during the early years could be mostly due to increased awareness creation during MDT introduction, 1 they stabilized relatively after the attainment of 100% MDT coverage between 1996 and 1999, even though WHO-funded SAPEL and LEC programmes were carried out during this period. This stability of case detection possibly indicates that these special leprosy elimination programmes, carried out to rapidly increase geographical coverage and passively mop up the backlog of old cases, 5 did not make a significant impact on the trend of case detection rates at the national level. The decline of case detection rates in the last 5 years may be the effect of the relative inactiveness of the national program or possibly an indication of the ineffectiveness of passive case finding approach, that was the background strategy in the programme, in a post-elimination phase. However, in spite of the stable case detection, the trends of the indices suggest a changing pattern of the new cases detected, especially the rising trend of multibacillary rate and falling disability rates. Since 1992, new cases have been increasingly classified as MB, the infectious leprosy. The increasing MB proportion before 1996 could have been the result of increasing diagnostic awareness and skill of leprosy workers who were actively being trained during that period. Since 1998, it seems related to changes in the national policy made in 1996 regarding the classification of leprosy, which conformed to the new case definition and the simplified and flexible field classification of leprosy introduced by WHO. The new classifications were reflected in the Workers Manual released in and 1998, 16 and divided leprosy into the WHO s two field types, pauci-bacillary (PB) and MB, using the number and distribution of lesions and smear result as basis but with a waiver: to classify all doubtful cases as MB. 17 The falling disability rate of new cases shows that new cases were increasingly diagnosed before they developed visible deformities. This represents an improving earliness of case detection. 18 The programme, therefore, in spite of the stability and passiveness of case detection, seems to be making significant strides of progress towards elimination of leprosy related disabilities in the country. However, the grade 2 disability rates of new cases in 2003

11 Elimination of leprosy in Nigeria 75 at the national level and in many of the States are still relatively high, indicating that the early case finding remains one of the key areas the national programme should still keep in strategic focus. The proportion of children among new cases, indicating the level of leprosy transmission, 18 seemed relatively stable before and after No explanation is possible for the reduction of the detection of child new cases in this year. In conclusion, the national leprosy control programme in Nigeria achieved the targeted prevalence level for elimination of leprosy before year 2000 and attained low endemicity, to a large extent, through effective implementation of leprosy elimination policies and strategies recommended by WHO. While these add to available evidence of the effectiveness of field based MDT, 19 this review clearly shows that the exercise of program policies directly contributed to the reported progress towards eliminating leprosy in Nigeria. The rising multibacillary rate also had an operational basis. Similar conclusions have been made by reviews of leprosy control trends in other countries, especially Myanmar 20 and Ethiopia. 12 However, in spite of special elimination campaigns and routine case finding activities, case detection has been relatively stable over the 12-year period. Despite the increasing earliness of new case detection, there is no sufficient evidence that any impact has yet been made on the level of transmission of leprosy in the country. The national leprosy control programme needs to pay strategic attention to leprosy control in the Southeastern States, and, nationally, evolve appropriate and more effective case detection interventions that will not only reduce the still relatively high new case disability rates but also make an observable impact on the incidence of leprosy, on which a true elimination of the disease ultimately depends. Acknowledgements The assistance and moral support of Dr (Mrs) T. O. Sofola, the former national coordinator of NTBLCP in Nigeria, especially in granting access to the annual reports of the national programme, is acknowledged with profound gratitude. The pre-review and comments on the first draft of this paper by the national coordinator together with medical representatives of the NTBLCP central unit, WHO, NLR, GLRA and TLMI, including Dr A. O. Awe, Dr Segun Obasanya, Dr Chukwu-ekezie, Dr Omoniyi, Dr Samson Kefas, Dr Patrobas, Dr Joe Chukwu, Dr Bassey Ebenso and Dr Mike Jose, is greatly appreciated. The author is most grateful for the co-operation given by the present national coordinator of NTBLCP, Dr Gwarzo, with whose assistance the updated and final version of this paper was possible. References 1 Federal Ministry of Health Dept of PHC and disease control. NTBLCP Revised Workers, Manual, 3rd edn, 1998, Part A p Benebo NS. National tuberculosis and leprosy control programme: the journey so far. Tropical Doctor, 1992; 22: Federal Ministry of Health, Department of Disease Control and International Health. NTBLCP Workers Manual, 1991, Part A, p Adeleye MO, National Leprosy Control Programme Broad Outline WHO, Nigeria 1989, p World Health Organization. Action Programme for Elimination of Leprosy. Guidelines for carrying out leprosy elimination campaigns Leprosy Review, 1999; 70:

12 76 O. I. Ogbeiwi 6 Ebenso BE. Results of a 1 year Special Action Project for the Elimination of Leprosy (SAPEL) in poorly accessible areas of Akwa Ibom State, Nigeria. Leprosy Review, 1999; 70: Sofola O. Leprosy Elimination Campaigns: the Nigerian Experience. Leprosy Review, 1999; 70: Ebenso BE, Tureta SM, Udo SO. Treatment outcome and impact of Leprosy Elimination Campaign in Sokoto and Zamfara States, Nigeria. Leprosy Review, 2001; 72: Namadi A, Visschedijk J, Samson K. The Leprosy Elimination Campaign in Jigawa, Nigeria: an opportunity for integration. Leprosy Review, 2002; 73: Federal Office of Statistics. Annual Abstract of Statistics 1996 Edition. Federal Republic of Nigeria, 1996, Chapter 2, pp World Health Organization. Report of Fifth Meeting of the WHO Technical Advisory Group on Elimination of Leprosy. Yangon, February 9 10, WHO/CDS/CEE/ section 3.1, pp. 1, 6 12 Groenen G. Trends in prevalence and case finding in the ALERT leprosy control programme, Leprosy Review, 2002; 73: Saunderson P. Workshop Reports, Workshop summaries, Opening and closing Ceremony Speeches. Workshop on Organization of leprosy services under low endemic conditions. XVth International Leprosy Congress, Sasakawa Memorial Foundation, 1998, p Federal Ministry of Health, Dept of Disease Control and International Health. NTBLCP Workers Manual, 1991, Part C, pp Federal Ministry of Health Department of PHC and disease control. NTBLCP Workers, Manual 2nd edn, 1997, Part C, pp , Federal Ministry of Health Department of PHC and disease control. NTBLCP Revised Workers, Manual, 3rd edn, 1998, Part C, pp World Health Organization. A Guide to Eliminating Leprosy as a Public Health Problem. Action Programme for the Elimination of Leprosy, 1st edn. WHO, Geneva 1995, WHO/LEP/95.1, pp International Federation of Anti-Leprosy Association. The Interpretation of Epidemiological Indicators in Leprosy. ILEP Medico-Social Commission, Technical Bulletin, 2001, p International Leprosy Association. Report of the ILA Technical Forum. Chemotherapy. Leprosy Review, 2002; 73: S27 S Tin Myint, Myo Thet Htoon. Leprosy in Myanmar, epidemiological and operational changes, Leprosy Review, 1996; 67: