Trends of case detection and prevalence of leprosy in VietNam since 1983

Nội dung text: Trends of case detection and prevalence of leprosy in VietNam since 1983

1. SCIENTIFIC RESEARCH TRENDS OF CASE DETECTION AND PREVALENCE OF LEPROSY IN VIETNAM SINCE 1983 Tran Hau Khang*,** KHOA NGHIÊN CỨU VÀ ỨNG DỤNG CÔNG NGHỆ TẾ BÀO GỐC Đánh thức vẻ đẹp tiềm ẩn ABSTRACT Background: Leprosy is one of oldest diseases in recorded history caused by Mycobacterium leprae. The disease mainly affects the skin, the peripheral nerves and it can cause disability if left untreated. Leprosy was common in many countries, especially those with tropical or subtropical climates. However, NÂNG CƠ - TRẺ HOÁ DA with the implementation of Multi Drug Therapy (MDT), leprosy is becoming very rare disease in several GIẢM BÉO 3 TRONG 1 countries in the world. BẰNG MÁY Vietnam has seen a highly significant decrease in the prevalence rate (PR) of leprosy since the HIFU introduction of multidrug therapy (MDT) in 1983. It is clear that over the past 35 years, the profile of leprosy in Vietnam has been changed significantly. Sử dụng sóng siêu âm hội Objective: This study was conducted to present and to analize the trends in case detection and tụ cường độ cao kết hợp prevalence of leprosy in Vietnam from 1983 to 2018. với công nghệ laser 19006951 CÔNG NGHỆ Method: Individual records and annual reports were collected to analyze information of the MỚI NHẤT prevalence of registered cases, the numbers of new cases detected yearly, their sex, age, classification and disability status. • Tăng sinh collagen, tái tạo và trẻ hóa da • Làm thon gọn khuôn mặt Results: Prevalence rate has dropped significantly from 6.78 per 10,000 population in 1983 to 0.01 • Loại bỏ vết chân chim, nếp nhăn, làm sáng • Giúp tiêu mỡ hông, đùi, bụng, bắp chân,... per 10,000 in 2018. While the case detectionrate (CDR) has shown a smaller fall, from 3.74 per 100,000 da và mượt mà population in 1983 to 0.10 per 100,000 in 2018. The proportion of grade 2 disability among new cases from 1983 to 2018 fluctuated a lot depending on the trend in case detection. Conclusion: With the introduction of MDT in 1983, the epidemiology of leprosy in Vietnam has dramatically improved with the prevalence rate declined significantly and majority of the patients are now able to lead normal lives in the community without being stigmatized and discriminated. Keywords: leprosy, multidrug therapy, disability, prevalence rate, detection rate. * Hanoi Medical University ** National hospital of Dermatology and Venereology No. 29 (September 2019) DERMATOLOGY 5
2. SCIENTIFIC RESEARCH 1. INTRODUCTION It is clear that over the past 35 years, the profile of leprosy in Vietnam has been changed Leprosy is one of oldest diseases in recorded significantly. history caused by Mycobacterium leprae. The This study was conducted to present and disease mainly affects the skin, the peripheral to analyze the trends of case detection and nerves and it can cause disability if left untreated. prevalence of leprosy in Vietnam since 1983. Leprosy was common in many countries, especially those with tropical or subtropical 2. MATERIALS AND METHODS climates. However, with the implementation of Multi Drug Therapy (MDT), leprosy is becoming New cases were detected through voluntary very rare disease in several countries in the world. reporting, mass survey and contact examination. In Viet nam, leprosy was a major public A diagnosis of leprosy was made of a person with health problem. In the past, many patients were definite loss of sensation in a pale or reddish skin ostracized by their communities as the disease patch or a thickened peripheral nerve with loss was considered incurable, disfiguring and wrongly of sensation and/or weakness of the muscles thought to be highly infections. Due to the strong supplied by that nerve or the preserve of acid – fast stigma attached to this disease, patients who have bacilli in a split skin smear. The bacterial study was successfully completed treatment and have been judged as positive if in 100 oil - immersion fields cured were found to be leading a segregated life. there was one or more Mycobacterium leprae Some of them are being congregated in places bacilli and the bacterial index (BI) was 1+ or greater such as leprosy villages/colonies where persons on the Riddley scale 1,2. All patients with positive affected by leprosy (PALs) facing similar social skin smear were classified as multibacillary (MB) problems have been staying for a long time. whatever the number of the skin lesion. Those with In order to change the situation of the disease, negative skin smear, the classification was decided in 1982 the national leprosy control program by the number of skin lesion: Paucibacillary (PB) if (NLCP) was established and MDT was implemented cases have up to five skin lesions and MB if cases one year later (1983). It has to be admitted that have six or more skin lesions (2). since the introduction of MDT, there has been a All were treated and followed by the health remarkable improvement in the epidemiology worker. The supervisions for every 3 months were with MDT making an enormous effect upon the carried out by the dermatologists. program of controlling the disease. As a result, Individual records and annual reports were Vietnam has achieved the elimination target at analyzed to collect information on the prevalence the national level in 1995 with the prevalence of registered cases, the number of new cases rate of 0.7 per 10,000 population. Since then detected yearly, their sex, age, classification, and the prevalence rate continued to decrease at all disability status. provinces. At the end of the year 2000, the sub- The prevalence rate was expressed as the national target has been reached. Partially, the number of the registered patient at the end of the new case detection rate has declined (1,2). year per 10,000 population. New case detected 6 DERMATOLOGY No. 29 (September 2019)
3. SCIENTIFIC RESEARCH rate was expressed as the number of new cases elimination at the national level in 1995 reporting detected during the year per 100,000 population. a prevalence rate of 0.70 per 10,000 population. In order to promote community awareness 3. RESULTS AND DISCUSSION and to increase case-finding activities in some selected parts of the country, several special 3.1. Trend in prevalence of leprosy projects were carried out such as health Table 1 shows a decreasing trends in the educational campaigns, special action project absolute numbers and rates of registered for elimination of leprosy (SAPEL), leprosy prevalence cases at the end of each year as well elimination campaign (LECs) and mini-LECs. As as the annual newly detected cases from 1983 to shown in table 2, these activities were conducted 2018. As a result of the efforts undertaken by the during the years 1991 to 1997. national program, Vietnam reached the goal of Table 1. Prevalence and case detection in Vietnam, 1983-2018 Prevalence Cases detected Year n Per 10,000 n Per 100,000 1983 38,652 6.78 2,021 3.74 1984 36,226 6.14 2,103 3.77 1985 32,483 5.36 2,062 3.59 1986 29,219 4.79 2,292 3.88 1987 27,401 4.42 2,183 3.61 1988 24,570 3.90 1,847 2.98 1989 23,612 3.69 2,073 3.26 1990 24,081 3.65 1,995 3.47 1991 18,418 2.71 2,500 3.69 1992 9,245 1.36 3,142 4.53 1993 7,090 1.01 3,185 4.38 1994 7,104 1.00 3,173 4.29 1995 5,277 0.70 2,591 3.45 1996 4,827 0.68 2,883 3.83 1997 4,665 0.61 2,808 3.65 1998 3,482 0.44 2,162 2.74 1999 2,087 0.27 1,795 2.35 2000 1,718 0.23 1,477 1.94 2001 1,532 0.2 1,336 1.73 2002 1,269 0.16 1,158 1.44 2003 1,204 0.15 949 1.18 2004 828 0.1 858 1.04 No. 29 (September 2019) DERMATOLOGY 7
4. SCIENTIFIC RESEARCH Prevalence Cases detected Year n Per 10,000 n Per 100,000 2005 642 0.1 746 0.9 2006 572 0.1 666 0.75 2007 510 0.1 552 0.66 2008 540 0.1 530 0.62 2009 350 0.04 413 0.48 2010 318 0.04 359 0.41 2011 322 0.04 374 0.43 2012 265 0.03 296 0.34 2013 260 0.02 294 0.29 2014 187 0.02 227 0.2 2015 178 0.02 168 0.19 2016 138 0.02 153 0.15 2017 109 0.01 112 0.12 2018 96 0.01 77 0.1 Table 2. Special projects implemented from 1991-1997 Number of new Project Number Population covered cases detected LEC 8 1,100,200 603 SAPEL 6 872,000 154 Others 18 1,030,000 663 Total 32 3,002,200 1,420 During the nineteen eighties the caseload in terms of registered prevalence was very high in the country. This was mainly due to re-registration of a large number of patients who were previously treated with dapsone. These patients were again treated with MDT. Moreover, during this period, MB patients were treated for a period of 24 months or until the bacteriological index (BI) became negative. This explains why the prevalence rate from 1983 to 1991 was very high in the country. However, starting from 1992, the number of registered cases declined dramatically. The rapid reduction in prevalence was due to factors such as: increase MDT coverage in the whole country which quickly cleared up the backlog cases, following a standard case definition for treatment and improving registration practices (removing from the treatment registers patients who have completed treatment, dead, migrated and defaulted). The prevalence rate continued to decline remarkably after the introduction of 12 months fixed-duration treatment in 1998 for MB patients. 8 DERMATOLOGY No. 29 (September 2019)
5. SCIENTIFIC RESEARCH 8 7 6 5 4 PR (Prevalence rate) DR (Detection rate) 3 In percentage 2 1 0 Year Figure1. Prevalence rate (PR) and detection rate (DR) of leprosy (1983-2018) Analysis of data from 1983-2018 revealed of new case detected annually increased and this that the prevalence rate has dropped significantly was mainly due to the acceleration of various from 6.76 per 10,000 in 1983 to 0.01 per 10,000 in activities for case detection that was carried out 2018. It is clear that over the past 35 years, leprosy in the country. Many activities were implemented prevalence rate has declined dramatically by in certain areas especially to promote case- around of 99% finding. A total of 32 special projects such as Since the introduction of MDT, a health education campaign, a special project for remarkable improvement was also observed elimination of leprosy (SAPEL), leprosy elimination in the epidemiological situation. MDT had an campaign (LEC), mini-LEC were implemented, enormous effect in reducing the disease burden. covering more than 3 million inhabitants (Table The prevalence rate continued to decline in all 2). These projects led to an increase in new case the provinces and at the end of the year 2018, detections and helped to clear up the remaining the elimination target was also reached at the undetected (backlog) cases in endemic pockets provincial level in the country. which were mainly in the High Plateau areas and some places in the Southern Provinces. 3.2. Trend in case detection This probably explained why the case As seen in table 1, new case detection in detection peaked during the period of 1991-1997. Vietnam from 1983 to 2012 fluctuated a lot. However since then, in parallel with the decline During the period 1983-1990, case detection in prevalence the annual new case detection also remained relatively stable with only slight declined. With sustained case-finding efforts, changes. However, during 1991-1997 the number No. 29 (September 2019) DERMATOLOGY 9
6. SCIENTIFIC RESEARCH the number of new cases detected annually Grade 2 disabilities Year continues to decline and in 2018 it was reported Number Proportion(%) to be 96 cases with a case detection rate of 0.10 2011 80 21.39 per 100,000 population. 2012 44 14.86 Table 3. Proportion of grade 2 disabilities 2013 45 17.31 among new cases, 1983-2018 2014 20 10.7 Grade 2 disabilities 2015 31 17.42 Year Number Proportion(%) 2016 33 23.91 1983 825 40.82 2017 26 23.85 1984 625 29.70 2018 18 18.75 1985 655 31.77 3.3. Grade 2 disability among new cases 1986 683 29.80 As shown in table 3 the proportion of grade 2 1987 605 27.70 disabilities among new cases was highest in 1983 1988 517 27.99 (40.82%). However, it declined in 1984 and reached 1989 577 27.83 a level of 17.86% in 1993. It then increased again 1990 551 27.62 reaching a level of 31.59% in 1996. This increase 1991 606 24.20 could be due to the intensive case-finding 1992 685 21.80 efforts that were carried out between 1991 and 1993 569 17.86 1997. These case-finding efforts (table 2) have 1994 641 20.20 detected a large number of back-log cases most 1995 789 30.50 of whom were probably having a high proportion 1996 909 31.53 1997 854 30.40 of disabilities as a result of delayed diagnosis. It 1998 626 28.95 could also be due to re-registration (recycling) 1999 450 25.07 of old patients as a new case especially those 2000 309 20.92 with disabilities. However, the grade 2 disabilities 2001 267 19.99 proportion among new cases started to decline 2002 225 19.43 from 1997 onwards and in 2018 it was 18.75%. 2003 179 18.86 The declining trend observed is a good indication 2004 145 16.90 but it needs to decline further. The delay in case 2005 121 16.22 detection as reflected by high grade 2 disabilities 2006 108 16.20 proportion among new cases could be due to 2007 101 18.30 high stigma in the community and low awareness 2008 86 16.23 about the disease in the general public. 2009 78 18.89 2010 67 18.66 10 DERMATOLOGY No. 29 (September 2019)
7. SCIENTIFIC RESEARCH 50% 45% 40% 35% 30% 25% In percentage 20% 15% 10% 5% 0% 1983 1985 1987 1989 1991 1993 1995 1997 1999 2001 2003 2005 2007 2009 2011 2013 2015 2017 Year Figure 2. Proportion of grade 2 disability among new cases 3.4. Female and children among new cases Table 4 shows the proportion of female among new cases detected from 1983 to 2018. The proportion of female among new cases has increased to around 27-38% especially since 1995. Similar findings were also seen in some countries in the region such as Thailand (3,7,8). As shown in table 4, the child proportion among new cases has always been below 10%. The child proportion has been fluctuating between 3.95% and 9.57% during the years 1983 to 1995. However, following the declining trend in the number of new cases detected annually, a similar decline was also observed in child proportion from 1995 to 2018. The proportion of children among new cases fell gradually from 9.57% in 1995 to 3.38% in 2012, a decrease by around 65%. More interesting, there was no child with leprosy was detected in the year 2018. No. 29 (September 2019) DERMATOLOGY 11
8. SCIENTIFIC RESEARCH 45 40 35 30 25 20 Female In percentage Children 15 10 5 0 1983 1985 1987 1989 1991 1993 1995 1997 1999 2001 2003 2005 2007 2009 2011 2013 2015 2017 Year Figure 3. Proportion of female and children among new cases Assuming that case-finding activities carried out especially among school children remain stable, the reduction in the proportion of children among new cases indicates that the transmission of the disease may be decreasing. However, as no serological tools are available at present to measure the transmission of the disease in the community this phenomenon can’t be validated. Similar observations of a decrease in the case detection rate along with a decrease in the proportion of children among new cases have been seen in several other countries in South East Asia such as Myanmar, Bhutan, and Thailand (4,5,6,9). 12 DERMATOLOGY No. 29 (September 2019)
9. SCIENTIFIC RESEARCH Table 4. Propo female, children and MB patients amon newly detected cases, 1983-2018 Under 15 years old Female MB cases children Proportion Proportion Proportion Year Number Number Number (%) (%) (%) 1983 612 30.28 169 8.59 811 40.10 1984 622 29.50 83 3.95 651 31.13 1985 504 24.40 141 7.84 804 39.10 1986 646 28.20 185 8.07 802 35.20 1987 642 29.40 157 7.21 1009 46.24 1988 509 27.60 141 7.63 738 39.60 1989 466 22.50 120 5.79 932 45.56 1990 463 23.20 130 6.52 798 39.40 1991 494 19.80 120 4.96 1075 43.40 1992 739 23.50 241 7.67 1413 45.50 1993 1114 35.00 231 7.25 1496 47.20 1994 872 27.50 151 4.76 2062 65.20 1995 926 35.70 222 9.57 1632 62.68 1996 1017 35.20 211 7.32 1807 63.70 1997 1011 36.00 159 6.66 1687 59.11 1998 803 37.10 162 6.49 1189 54.67 1999 676 37.70 124 6.91 1071 61.27 2000 571 38.70 105 7.11 905 62.00 2001 497 37.00 77 6.00 822 61.74 2002 437 37.74 65 5.61 715 62.17 2003 339 35.72 52 5.48 616 65.27 2004 322 37.53 47 5.48 570 66.59 2005 269 36.06 39 5.30 492 66.71 2006 245 36.79 35 5.26 443 66.80 2007 178 32.25 25 4.53 377 68.30 2008 202 38.11 18 3.40 378 71.32 2009 144 34.87 12 2.91 295 71.43 2010 98 27.30 14 3.90 259 72.14 2011 121 32.35 11 2.94 269 71.93 2012 105 35.47 10 3.38 191 64.53 2013 82 31.54 14 5.38 180 69.23 2014 66 35.29 7 3.74 153 81.82 2015 53 29.78 5 2.81 143 80.34 2016 39 28.26 4 2.90 115 83.33 2017 38 34.86 2 1.83 91 83.49 2018 24 25.00 0 0 89 92.71 No. 29 (September 2019) DERMATOLOGY 13
10. SCIENTIFIC RESEARCH 3.5. Multibacillary (MB) among new cases mention should be made of the many motivated and dedicated field staff whose efforts and During the period 1983-1993, the proportion professionalism have resulted in an impressive of MB patients among newly detected cases impact on the leprosy epidemiology. Finally, increased slowly from 40% to 47%. However, the many donor agencies that have funded our from 1998 onwards the increase was found to programme, especially the members of ILEP such be more pronounced. In 2018 it was 92.71%. as NLR, DF, SMHF, GLRA,... need to be thanked. This increase in MB proportion could be due to Their generous support made possible the changes in the criteria for classification and to leprosy control work and its success. some extent, it could also be due to changes in the clinical presentations. However, by looking at REFERENCES the available data one is unable to differentiate the operational and the epidemiological factors 1. T H Ngoan. Leprosy. Medical Publishing that are contributing to the increase in MB House, Hanoi, 2002. proportion among new cases. 2. World Health Organization. A guide to 4. CONCLUSION eliminating leprosy as a public health problem. 21-26. 1995. It is clear that over the past 35 years, the profile of leprosy in Vietnam has changed 3. World Health Organization Epidemiological significantly. With the introduction of MDT in 1983, review of leprosy in the WHO Western Pacific the prevalence and case detection of leprosy has Region. 2008/3. dramatically declined and majority of the patients 4. Mgint T, Htoon MT. Leprosy in Myanmar, are now able to lead normal lives in the community epidemiology and operational changes 1958- without being stigmatized and discriminated. MDT 1992. Lepr. Rev, 67: 18-27. 1996. has made it possible to cure patients without any 5. Jakeman P, Jakeman NRP, Singay J. Trends sequelae in majority of the patients. It has renewed in leprosy in the kingdom of Bhutan, 1982-1992. the fight against leprosy in the country. Lepr. Rev, 66: 69-75. 1995. As a result of the remarkable reduction in the 6. Khang TH, Vijaykamar P, Lanh PH et al. magnitude of the disease in the country leprosy Treatment of leprosy with ofloxacin-containing is now becoming a rare disease in most parts of combined drug regimens in Vietnam. Madrigde the country. In spite of the success in reducing Journal of Dermatology and research. Vol 4, No 1, the disease burden, it is crucial that the activities May/2019. P: 96-99. of the National Leprosy Control Programme 7. Pirayyavaraporn C, Peerapakorn S. The (NLCP) are sustained and that the diagnosis and epidemiological impact of multidrug therapy treatment services are made easily accessible Lepr. Rev. 67: 18-27. 1996. to patients to ensure that the disease burden continues to decline further. 8. World Health Organization Weekly epidemiological record, No. 34, 24 August 2012. 5. ACKNOWLEDGEMENT 9. Khang TH, Thanh LT, Lanh PH. Predictive The author is grateful to all staff of the value of Gelatine Particle Agglutination Test Technical Guidance Department, NIDV who (GPAT) in leprosy detection. Indian Journal Lepr. contributed to the data collection. Special 2018, 90, 61-67. 14 DERMATOLOGY No. 29 (September 2019)