The Global Elimination of Lymphatic Filariasis the Story of Zanzibar
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The Global Elimination of Lymphatic Filariasis The Story of Zanzibar WHO/CDS/CPE/SMT/2002.15 ACKNOWLEDGEMENTS The lymphatic filariasis (LF) elimination programme in Zanzibar is the story of the hard work and commitment, primarily of the people of Zanzibar. This document is an attempt to portray the dedication of the many people who were convinced of the importance of the LF programme and made the campaign a success. WHO is indebted to those who are mentioned within the pages of this publication, and also those not mentioned who nevertheless saw a vital role for themselves in making a difference to the health of their communities. This publication has been made possible by a contribution from the Bill and Melinda Gates Foundation. © World Health Organization 2002 This document is not a formal publication of the World Health Organization (WHO), and all rights are reserved by the Organization. The document may, however, be freely reviewed, abstracted, reproduced or translated, in part or in whole, but not for sale or for use in conjunction with commercial purposes. The views expressed in documents by named authors are solely the responsibility of those authors. The Global Elimination of Lymphatic Filariasis The Story of Zanzibar WORLD HEALTH ORGANIZATION WHO Tanzania Country Office WHO AFRO Regional Support WHO HQ Social Mobilization Team (CPE/SMT) WHO HQ Country Technical Support Team (CPE/CEE) Contents Letter from the WHO LF Support Team (HQ) 4 Lymphatic filariasis and the strategy for its elimination 6 Living with lymphatic filariasis 8 The partnership 9 Zanzibar profile 11 What is the value of eliminating LF? 12 The plan 14 The cost/value calculation 16 Personal sellers 18 Whose campaign is this? 20 Supporting the personal sellers 21 Radio script 23 The best laid plans... 24 Decision to postpone or continue 26 Politics 28 The vital link 30 F-Day 32 The Mop-Up Day 35 Keys to success 36 Partnerships: thinking global... and acting local 38 The future 40 Letter from the WHO LF Support Team (HQ) Zanzibar was a challenge. Almost everyone in prevalence of LF parasite in the country is one Zanzibar, nearly a million people, needed to be of the world’s highest. Around 15% of people convinced that they had to swallow free but carry the parasite. In some villages, infection potent drugs. And they all had to do it on the rates were well over 30%. The social environ- same day, Saturday, 27 October 2001. It would ment also presented special challenges to a be one of the largest mass drug administrations drug distribution programme. Prior to October, ever attempted. And if it worked, then 27 research revealed the presence of widespread October would be the beginning of the end for misconceptions about LF — that the disease the stigmatizing and incurable parasitic disease was caused by witchcraft or eating green coco- known as lymphatic filariasis (LF), the world’s nuts. Once the campaign was launched, second leading cause of disability. And with the rumours began circulating that the free tablets elimination of LF, elephantiasis, the disfiguring were a form of birth control or had disease caused by the filariasis parasite, would unknown side-effects. If this wasn’t enough, vanish over time as well. logistical and financial problems arose that threatened to sink the entire effort. In fact, the No longer would people be anchored in life by drugs themselves arrived in Zanzibar too close giant legs or other horrors of the disease. to 27 October, "F-Day". If the majority of the population did take the What follows is the story of the LF campaign in drugs once a year for at least five years, then Zanzibar. It is one of the most unusual health transmission would essentially be stopped. campaigns ever. The risk was that if the target was not reached, the exercise would largely be a waste of time, In Zanzibar, we were reminded again that effort and money. WHO is a technical agency. We supply, primarily, expert advice. But no matter how good our The challenges in Zanzibar were enormous and, advice is, if a health campaign is to be success- quite frankly, more than we expected. The ful it is because thousands of ordinary people 4 work very hard to improve the health of their neighbours. It is also because a few people, like senior political and religious leaders, com- mit themselves in a public way to personally improving the nation’s health. These personal commitments were abundant in Zanzibar. So, although the programme did not go entirely the way it was planned, the success was more than was hoped for. Given all the frantic activity and eventual success in Zanzibar, we should not lose sight of how special this moment is. After 4000 years of physical and psychological suffering inflicted by LF, we now have the tools to eliminate this disease. If nations seize this opportunity with vigour and commitment, in the way that Zanzibar did, we not only can put an end to this terrible affliction, but also can break the chains that have bound millions of people to poverty. Zanzibar shouts at us that this can be done. But it can be done only if we work hard, work in partnership and, now with the example of Zanzibar, work with the certainty that we all can make a difference. 5 1. The vector 2. Microfilariae Lymphatic filariasis 3. Adult worm and the strategy for its elimination M ore than 120 million A thread-like worm causes the disease reproductive organs and lower limbs people are infected with the lymphatic that is spread by mosquitoes. which are characteristic of hydrocoele filariasis parasite. The lives of 40 mil- LF parasites are found in more than and elephantiasis. lion people are limited and disfigured 80 countries around the world, which by the disease. For them, there is no means that 1000 million people are at As this process of destruction conti- cure. The remaining 80 million infected risk. nues, the mature worms produce off- people risk the same fate. These spring. It is these immature parasites people have impaired immune systems Efforts to eliminate the disease began (microfilariae), which circulate freely in and are at risk of developing the gross with an understanding of the parasite the blood, that are picked up by a deformities. itself. Once injected by the mosquito mosquito and passed to the next into a human victim, the adult worm person. The efficiency of transmission Lymphatic filariasis does not kill, but lives for several years, producing is quite low in LF. One bite from a in most countries of the world it millions of immature worms called malaria-carrying mosquito can trigger inflicts an enormous physical and microfilariae. The worms can lodge in the disease, but it takes several hun- psychological destruction. LF hits the lymphatic system, a network of dreds of bites to infect someone with hardest among the poorest people nodes and vessels that delicately LF. Once the infection is established, and, because its victims are rendered regulate the fluid balance between the the cycle continues endlessly, from unable to work, they are shackled in tissues and blood. Damage to the person to person, forever. even more desperate poverty. lymph system causes the swelling of 6 Young boy with LF (elephantiasis) No drug exists to cleanse the body of The theory was so sound that in 1997, all the adult worms, but some WHO committed itself to eliminating veterinary drugs were known to block LF. the reproduction of the parasite. Scientists established that the co- The Chinese validated the concept administration of these drugs was safe when they mixed one of the drugs, and effective in humans. In fact, diethylcarbamazine (DEC), with This saturation level would need to be a single dose of the drugs blocked the ordinary table salt and distributed it maintained year after year for production of microfilariae for a year. to the population. Over a period of the level would need to be maintained time, LF disappeared. China, however, for the entire reproductive lifespan of These findings sparked enormous was a unique situation. Elsewhere, the worm. But when the last adult interest because they suggested a public health workers do not have worm died in the last infected person, public health strategy that could such direct influence over a popula- the mass drug administration could be eliminate LF. In theory, if the drugs tion. Another approach was required, stopped, and LF would be eliminated. could block the creation of the young and subsequently WHO developed microfilariae in an infected person, the mass drug administration (MDA) The challenge is in implementing such they would not be available to be strategy. a large-scale intervention. It is not sucked up by mosquitoes. This would known whether such a large stop transmission. And if the microfila- MDA is built around dosing entire percentage of a population – both riae were blocked year after year, until populations at risk with LF drugs once those infected and not – could be the mature parasite lived its full five a year for five years. To be successful, convinced to commit themselves to years of reproductive lifespan, the risk it requires that a substantial propor- take drugs, with potential minor side- of LF would evaporate. tion of a population participate for at effects, for so many years. least five years. 7 Living with LF Jaku Hassan Ali is a fishmonger and estimates he is about 65 years old although he is not certain. He has had elephantiasis since he was a child and believes he acquired the disease while playing in muddy water.