ROLL BACK MALARIA Specifications for NE T T I N G M AT E R I A L S Roll Back Malaria Cabinet Project World Health Organization 20 Avenue Appia, CH-1211 Geneva 27, Switzerland Tel: (+41) 22 791 3606, Fax: (+41) 22 791 4824 E-mail: [email protected] Web site: http://www.rbm.who.int/ WHO/CDS/RBM/2001.28 © Copyright 2001 by Roll Back Malaria/World Health Organization This document is not a formal publication of the World Health Organization 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 nor for use in conjunction with commercial purposes. The designation employed and the presentation of the material in this publication, including maps and tables do not imply the expression of any opinion whatsoever on the part of the secretariat of the World Health Organization concerning the legal status of any country, territory, city or area of its authorities, or concerning the delimitation of its frontiers or boundaries. Dotted lines on maps represent approximate border lines for which there may not yet be full agreement. The mention of specific companies or certain manufacturers’ products does not imply that they are endorsed or recommended by the World Health Organization in preference to others of a similar nature that are not mentioned. Er rors and omission excepted, the names of pro p ri e t a ry products are distinguished by initial capital letters. CONTENTS Part 1 The importance of setting specifications for netting materials 1. Introduction 3 2. Role of ITNs in disease prevention 3 3. Prospects for use of ITNs in Africa 4 4. Why having specifications for netting materials is necessary 4 5. Interactions between fabrics and insecticide formulations 5 6. Netting materials 5 6.1 Cotton and polyester 6.2 Polyethylene 6.3 Polyamide/nylon 6.4 Polypropylene 7. Quality of nets 6 8. Other insecticide-treated materials 6 8.1 Curtains: 8.2 Tents 8.3 Treated clothing and bedding 9. Long-lasting insecticide-treated nets 7 10. Conclusion 7 Part 2 Existing specifications applicable to netting materials 1 Introduction 9 2 Fibre composition 9 3 Air permeability 9 4 Tear resistance 9 5 Bursting strength 9 6 Flammability 9 7 Minimum specifications for polyesterc 11 8 Other tests related to strength and possible duration 12 9 Minimum specifications for cotton 12 10 Minimum specifications for polyethylene 13 11 Specifications for other materials 13 Part 3 Net design, labelling and packaging 1 Introduction 14 2 Size 14 3 Door 14 4 Border 15 5 Label 6 Net attachment 16 Annexes 1 List of participants 17 2 Intermin minimum specifications for polyester and proposed design of nets and labelling for institutional buyers 20 1 Specifications for Netting Materials 2 Part 1 The importance of setting specifications for netting materials 1. Introduction Ins e c t i c i d e - t r eated nets (ITNs) are an important component of current efforts to Roll Bac k Mal a r ia (RBM) since, in addition to developing new cost-effective interven t i o n s , RBM intends to make existing tools, including ITNs, more widely avai l a b l e . ITNs are known to protect against a range of vec t o r- b o r ne diseases (leishmaniasis, filaria s i s , as well as malaria) and can red u c e over all childhood mortality by about 20%. They are theref o r e seen as one of the main tools of achieving RBM’s objective of halving the world’s malaria burden by the year 2010. RBM strat e g y calls for a 30-fold increase in the purchase and use of ITNs, especially in Afric a . Among RBM partners USAID has already initiated the “NetMark” project in Africa and UNICEF has established support systems targeting country-level ITN interventions. RBM is now catalysing the development and strengthening of global, regional and country-level partnerships among governments, the private sector, UN agencies and NGOs in order to support ITN implementation. RBM’s strategy for ITNs emphasises the importance of compliance (regular use) and re- treatment. Retreatment issues, the need to move from efficacy (well-established through several randomised field trials) to large-scale implementation; and developing technical guidelines are among the main challenges to “going to scale”—making ITNs available, affordable and sustainable. WHO will support ITN implementation research, further develop insecticide-treated materials and investigate related aspects such as pyrethroid resistance (mechanisms, dynamics and impact). To achieve RBM’s objectives, a mosquito net culture in which owning ITNs and using them properly is the social norm, has to be created, especially in Africa. Expansion of a mosquito net culture to national scale will require partnership between the public and private sectors in which the public sector must reduce taxes and import tariffs, ensure standards, promote the use of ITNs and ensure protection of high-risk groups, while the private sector must advertise the product, create and meet demand through producing, wholesaling and retailing nets. ITNs are currently sold and distributed through the public sector (governments), the private sector and a mixture of the two (governments, international organisations and NGOs). ITNs might be distributed free (e.g. by NGOs in emergency situations), subsidised, or with full cost recovery (e.g. China, Gambia). Although a large number of bednets have already been purchased globally by various institutional buyers—NGOs or other agencies such as UNICEF, UNHCR and WHO belonging to the UN system— there is as yet no consensus on specifications for netting materials and, as a result, it is difficult for buyers to compare offers and control quality. It is also difficult for manufacturers to cope with the requirements of separate agencies who request different, sometimes conflicting, specifications. Setting minimum specifications for bednets will also help to promote quality products, which is likely to improve their community acceptance. 2. Role of ITNs in disease prevention The use of ITNs has been shown to be very cost-effective and resulted in a 20% reduction in overall child mortality in Africa, equivalent to six deaths averted per year per 1000 children protected, at a cost of about US$ 5 per child. A total of 80 million children in Africa are currently at risk, and the use of ITNs would prevent 480,000 deaths per year. A meta-analysis Specifications for Netting Materials 3 s h owed that under stable malaria transmission (EIR<1) in Africa and PNG, ITNs provide 46% p rotection against Plasmodium falciparum and under unstable transmission in Asia and Latin America, they provide 60% and 45% protection against P. f a l c i p a r u m and P. v i va x re s p e c t i ve l y. In holoendemic areas of Africa, it is not yet entirely clear whether ITNs provide personal protection to users or mostly protect communities through a “mass effect” on the population s i ze and lifespan of mosquitoes. In some areas (especially in West Africa), py re t h ro id resistance is already at high levels and to what extent this might reduce the impact of ITNs is not yet known. 3. Prospects for use of ITNs in Africa The task of scaling-up of ITN use from trial (efficacy) to national level (effectiveness) is a difficult one. In 1998 WHO started providing technical and financial support to popularise ITNs. Three intercountry workshops have already been organised by the WHO Regional Office for Africa (AFRO) to prepare national action plans to promote large-scale use, and 30 countries h a ve attended. WHO will now concentrate on monitoring and evaluating country programmes. In Fe b ru a ry 1999 a consultation was organised to develop the necessary tools and indicators for monitoring such programmes. ITN promotional activities are currently being assessed in five countries, and by the end of 2000, 20 countries will have been assessed (with recommendations for discussion during future workshops). In the five so far reviewed, 30-60% of households had at least one net, but only 13% of nets were treated and less than 5% had been retreated. Most of the time, treatment took place at fixed treatment centres, and this seems to contrast negatively with the household dip-it-yourself approach developed in East Africa. This monitoring data will be used to sensitise African leaders to some of the challenges to the concept of “going to scale” with ITNs. 4. Why having specifications for netting materials is necessary Specifications exist primarily to protect and benefit consumers. However, certain qualities are culture-specific, and attempts to standardise colour or shape, for example, are undesirable. Neither WHO, UNICEF or any other agency should see themselves as final arbiters in such matters; that is for the user, and market forces or social marketing may lead to a broad range of net sizes, shapes and colours. However, at the moment, some standardisation on size makes procurement simpler for institutional buyers. While social research on preferences is needed, there is insufficient time when needs are pressing, for example in emergency situations. In the longer term, social research for the procurement of acceptable nets will prove to be essential for community-based interventions. Criteria to define netting materials are as essential as quality control. Test methods and standards should meet ISO (International Standards Organisation) criteria. First it must be defined what the material is expected to do, then the necessary parameters or criteria must be selected, the specification range or limits must be set, and then the test method decided upon.