Schistosomiasis and Neglected Tropical Diseases Control

Transcription

1 Schistosomiasis and Neglected Tropical Diseases Control S C I Children Boys 7 years Wanseko P/S Vector Control Division * Ministry of Health * Tel: * Fax: * Professor Joanne P. Webster Schistosomiasis Control Initiative Imperial College Faculty of Medicine, London, UK

2 Talk outline 1. What is schistosomiasis 2. Schistosomiasis Control SCI 3. Future directions Integrated NTD control

3 Talk outline 1. What is schistosomiasis 2. Schistosomiasis Control SCI 3. Future directions Integrated NTD control

4 What is Schistosomiasis? Blood-born fluke Endemic in 70 tropical and sub-tropical countries 5 species infect humans

5 Transmission

6 Schistosomiasis morbidity Total infected 200 million Mortality (annually) 150,000 due to kidney non function 130,000 due to portal hypertension Persons with associated morbidity: 70 million with haematuria 18 million bladder wall pathology 10 million hydronephrosis ! Chitsulo 2000, citing WHO 1985, 1993

7 Portal hypertension, hematemesis Serious consequences of schistosomiasis Hepatosplenomegaly and Hepatic fibrosis Gross hematuria and urinary obstruction Bleeding esophageal varicies and bladder cancer Anemia, inflammation and fibrosis of the bladder wall, colon, liver, spleen, lungs

8 The burden associated with infection is much greater than is visible Heavy infections cause acute and chronic morbidity (hepatosplenomegaly,, bladder pathology causing haematuria, renal pathology, severe anaemia, diarrhoea, ) is only the tip of the disease/disability iceberg Mild parasitic infections are associated with growth, body weight, calorie and cognitive deficits, chronic diarrhoea, chronic pain, chronic fatigue and exercise intolerance.

9 Talk outline 1. What is schistosomiasis 2. Schistosomiasis Control SCI 3. Future directions Integrated NTD control

10 There is a treatment Praziquantel Safe, effective, single oral dose after food 40 mg/kg body weight 600 mg tablets 10 years ago approximately $1 per tablet ($4 for an adult course) -= = now >7 cents - 93% cheaper!!!!

11 The Schistosomiasis Control Initiative (SCI) Mission SCI, in line with WHO S S resolution that all member state infected regions aims to reach 75% of all school-aged children by the year 2010 for schistosomiasis and intestinal helminths, Aims to encourage treatment of schistosomiasis in sub-saharan Africa by targeting those at high risk of developing severe morbidity, especially school-aged children, women and those in high risk occupations. By assisting selected countries to achieve successful national control c programmes,, SCI expects to create a SUSTAINABLE demand for treatment throughout Africa.

12 Countries receiving SCI support to control Schistosomiasis and intestinal helminths Niger Mali Burkina Faso Uganda Tanzania Zambia

13 Number of Treatments (millions) What we have done: 2002/3 2003/4 2004/5 2005/6 2006/7 0.1 Cumulative Treatment Total /3 2003/4 2004/5 2005/6 2006/7 SCI Treatment Years

14 Monitoring and Evaluation Pre-& Post-PZQ UC/SC Serology Questionnaires Liver/spleen palpations Heights/weights Kato-Katz/Filtration: p & i Etc..

15 Dramatic reductions in Prevalence have been observed Prevalence (%) GAÏK GOATA BOULOYE DORIB GOMPONSOM HITTE KALSAKA A KOUMBRI OUSRI NIESSEGA TORODI LERBOU BASELINE FOLLOW-UP YEAR E.g. Burkina Faso by school: S. haematobium pre- & 1-year post

16 E.G. Uganda - children Mean S. mansoni intensity pre-, Year 1 & Year 2. E.G. Burkina Faso children (n=1124) S. haematobium light & heavy intensities pre- & Year-1. Dramatic reductions in Intensity have been observed Mean Intensity (EPG) Lake Albert Albert Nile Lake Victoria Baseline Follow-up Year 1 Follow-up Year 2 Percentage (%) Negative: Lightly infected: < Heavily infected: >=50 Classes of intensity (e/10ml) Baseline Year 1 Time

17 Dramatic reductions in Morbidity have been observed

18 E.g. Reduction in severe Anaemia following chemotherapy

19 E.g. Reduction in Liver and Bladder pathology (as indicated by ultrasonography) following chemotherapy

20 SCI/ control Clinical Human perspective Parasitological Schistosome perspective

21 E.g. Monitoring for potential Drug resistance One drug, precise mechanism of action uncertain, no viable alternatives under development Random sampling of Schistosoma spp. population genetic structure. And Focal sampling of resistant-risk Schistosoma spp Baseline (12) months Parasitological status 6 months post treatment at Runga, Hoima District

22 Summary: 20 years ago, the WHO endorsed morbidity control as the key strategy for the control of schistosomiasis. At the same time, a strong plea was made for the integration of morbidity control due to schistosomiasis and soil-transmitted helminthaisis (WHA 54.19) for clinical cases and high morbidity-risk groups. Following the reduction in the prices of PZQ and other antihelminthic drugs, funding from the Bill and Melinda Gates Foundation, and the health- and poverty-related development targets embodied in the Millennium Development Goals: There is now compelling evidence that this strategy is feasible, significantly reduces morbidity and is cost effective.

23 Talk outline 1. What is schistosomiasis 2. Schistosomiasis Control SCI 3. Future directions Integrated NTD control

24 Schistosomiasis is one of a dozen Neglected Tropical Diseases Deaths DALYs Neglected Diseases 20% Other infectious diseases 29% Neglected Diseases 24% Other infectious diseases 30% HIV/TB/Malaria 51% HIV/TB/Malaria 46% Cause 20% of deaths and 24% of DALY s

25 The African Neglected Tropical Diseases Protozoan Infections Leishmaniasis (VL + CL + MCL) African Trypanosomiasis (Sleeping Sickness) Helminth Infections Soil-transmitted Helminth infections: Ascariasis-Trichuriasis Trichuriasis-Hookworm Lymphatic Filariasis (Elephantiasis) Onchocerciasis (River Blindness) Schistosomiasis (Bilharzia( Bilharzia) Dracunculiasis (Guinea Worm) Cysticercosis Bacterial Infections Leprosy Trachoma Buruli Ulcer

26 The main bottleneck in the past has been the "profit" motive with drug companies - having spent millions developing their drugs, they wanted to sell them to recoup R&D and make a profit. Sadly in the NTD world noone who needed the drugs could afford to pay from them. The mindset has now changed and a dual-pricing system exists with companies selling their products in the West and donating the same products for use by those in Africa infected with NTD's Onchocerciasis (Donation of Mectizan ) Lymphatic Filariasis (Donation of Mectizan and Albendazole) Soil-transmitted Helminths (Part donation/part purchase of Albendazole) Trachoma (Donation of Zithromax) Schistosomiasis (Part donation/part purchase of Praziquantel) Vitamin A Total estimated range of chemotherapy package per

27 Range of benefits to human health LF Oncho Schisto STH Vit A Trachoma Nets Anaemia Worm Control Growth Nutrition Skin Disease Blindness Prevention Community Treatment Transmission Control

28 Requirements Improve Global and National networking and interaction between compatible c partnerships Compartmentalized thinking from Global to National Disease-specific structures and task forces within agencies and country programmes Operational responsibility currently overburdened at district level Develop proposals for action orientated integration (and monitoring ing and evaluation) where technically and geographically appropriate Consideration of potential drug-drug interactions and appropriate distribution. Demonstrate the evidence base for cost effectiveness and cost benefit Demonstrate the advantages of chemotherapy based annual/biannual l treatments on improving health Research into development of developing alterative novel and inexpensive NTD drugs with excellent safety and therapeutic profiles Public-private partnerships Appropriate funding Appropriate funding E.g. Bill and Melinda Gates awarded $47.7 million to SCI, ITI, GAELF and WHO; DFID supports WHO and GAELF; USAID awarded a $100 million contract to control NTD s; Canadian donor support SCI with an annual donation of 12 million tablets of PZQ; Geneva Global has donated $8.9 million in for Rwanda and Burundi

29 Summary An estimated 500 million people in Africa alone are infected with one or more parasitic infections which cause NTDs. Neglected Tropical Diseases of the World s s most Neglected Populations are at least controllable or, in some cases, possibly eliminable/eradicable by safe and effective drugs, donated by, e.g., Merck, GlaxoSmithKine and Pfizer. With public and private partnerships the integrated control of NTDs can be implemented a marginal costs of $0.50 per person treated: Current and future programmes aim to combine low cost effective intervention with high coverage: Pro-poor strategies to reach the Millennium Development Goals.

30 However! We are only at the outset of these new broad-scale integrated control programmes. Despite all the funding generosity to date allows only 15% of the population in need within Africa to be treated. Chemotherapy-based morbidity control alone does not address the root behavioural and environmental causes of NTDs. Sound information, education and communication campaigns, as well as improving access to clean water and adequate sanitation, are also key factors for sustainable NTD control.

31 Thank you Prince Mahidol Award conference SCI staff and colleagues Bill and Melinda Gates Foundation.