Scientific Working Group Report on Dengue

This document provides an overview of dengue research and recommends a global "priority research agenda" aiming to provide information for policy and practice that can facilitate evidence-based decisions about dengue control. The strategies shared emerged from a meeting held in Geneva, Switzerland, from October 1-5 2006 that was organised by The Special Programme for Research & Training in Tropical Diseases (TDR), which is sponsored by the United Nations Children's Fund (UNICEF), the United Nations Development Programme (UNDP), the World Bank, and the World Health Organization (WHO). An estimated 50 million dengue infections occur annually, and approximately 2.5 billion people live in dengue-endemic countries. In recognition of the public health importance of dengue hemorrhagic fever (DHF), the Dengue Scientific Working Group (SWG) of 60 experts from 20 countries met to review existing knowledge on dengue and establish priorities for future dengue research aimed at improving dengue treatment, prevention, and control.

Communication-centred elements highlighted in a section of the paper reviewing ongoing dengue research include:

• The role of information and communication technology (ICT) in improving vector control: "the usefulness of new information technology (IT) tools for decision-making, such as spatial analysis of vector breeding using geographical information systems (GIS) and determination of dengue vector threshold levels using mathematical modelling, will be explored by the IVCC [Innovative Vector Control Consortium]."
• The role of ICT in improving epidemiological surveillance: The example offered here is DengueNet, an open-access web-based information system that allows public health officials and researchers to share a common database and foster collaboration. It was created by the WHO unit of Epidemic and Pandemic Alert and Response (EPR) for collecting and analysing global standardised epidemiological data on dengue and DHF cases and deaths, and circulating virus serotypes, by geographical area and time.
• The role of community participation, described here as "a vital component in the delivery and sustainability of effective dengue vector control". WHO "commissioned the development of a step-by-step guide on social mobilization and communication for dengue prevention and control....This communication-for-behavioural impact (COMBI) approach to social mobilization has been field tested in several countries in Asia, Latin America and the Caribbean, where it contributed to the challenging task of engaging communities in more focused application of vector control measures against Ae. aegypti and other important vectors."
• The role of networking in improving case management: "Establishment of laboratory networks in South-East Asia and Latin America, and field trials of the performance of selected tests, are under way."
• The role of research capacity-building: "While capacity strengthening components are an overarching theme in most research programmes, more systematic approaches to individual and institutional capacity building for dengue research is desirable."

Going forward, the SWG recommends priority dengue research areas organised around the following four research streams: research related to reducing disease severity and case fatality (one communication-related element: process and impact evaluation of staff training); research related to transmission control through improved vector management (one communication-related element: analysis of the contribution of IT to decision-making); research related to primary and secondary prevention (including vaccines); and health policy research contributing to adequate public health response.

Annexes to the report include working papers that were prepared for the October 2006 meeting. One of them (beginning on page 140 of the report) is "Achieving Behaviour Change For Dengue Control: Methods, Scaling-Up, And Sustainability" by John Elder and Linda S. Lloyd. The foundation for this paper was built on a review of 11 WHO-supported dengue communication and mobilisation programmes using the COMBI planning tool in 6 South Asian and Latin America/Caribbean countries. All programmes included behaviour change efforts at the household level; some focused on the broader community and other partners (schools were the most common partner). Elder and Lloyd point out that multi-level, vertically, and horisontally integrated programmes offer the best solution to dengue control. "For optimal effects, such programmes would include not only community-wide (e.g. mass media) and house-by-house efforts, but also those efforts of schools, worksites and other organizations within the community."

Reviewing the WHO-sponsored programmes through the COMBI lens, Elder and Lloyd assert that, at the community and regional levels, responsible agencies may need to identify "programme champions"; at other levels, they say, groups of individuals may share responsibility for maintaining programme momentum and integrity. While neither model seemed to have an advantage over the other, sustainability is always a challenge (enthusiasm will at some point die out), and the authors suggest strategies to optimise commitment. They note that there are few examples of incorporation of social marketing principles in dengue prevention and control programmes.

Elder and Lloyd suggest that, regardless of the framework, "operationalisation" of behaviours (examining and defining the frequency, duration, or strength of the behaviour) is essential to understand prior to the development of any community-based approaches to dengue control. In Ae. aegypti control efforts, it may be difficult to observe the nature of the "behaviour" (knowledge of breeding cycles or fear of mosquito contamination), and, therefore, for monitoring purposes, it is often necessary to select physical by-products of the behaviour rather than an observation of the behaviour itself. Further complicating the task is the fact that "When using the COMBI planning tool, programme planners must focus on target behaviours that will have a measurable impact on the specific component of dengue prevention and control being addressed through the communication/social mobilization plan; the target behaviours, however, are the result of a community-based process through which the target population and the programme planners identify and test behaviours for feasibility and effectiveness....Planners should focus on what is truly practical for modest or resource-poor environments (resource-poor referring to both the programmatic environment and the target community)."

As the authors of this working paper explain, in addition to the integration of efforts and the operationalisation of specific, observable "target" behaviours, there is a need to emphasise information sharing and feedback loops through monitoring and evaluation. They note that few studies reported in the literature on dengue indicate that systematic monitoring and evaluation have been carried out, and that a weakness of all programmes examined to date is the lack of behavioural indicators that have been tested and validated for routine field use within the context of national dengue programmes. However, "[i]n the Nicaragua programme, maps with colour-coded pins used to track neighbourhood outbreaks of dengue and malaria provided feedback to all staff and community health volunteers regarding epidemiological markers for programme progress, and pinpointed specific blocks in the neighbourhoods where more intensive education and behaviour change work were needed. Staff and volunteers met each month to discuss the neighbourhoods and specific challenges, so that staff and volunteers received continuous feedback and reinforcement for their work..."

In outlining key issues for consideration in behaviour change interventions in the dengue context, Elder and Lloyd emphasise: programme leadership and planning for sustainable community participation and involvement; transfer of technical knowledge and skills in planning participatory behavioural interventions to health workers, community volunteers, and other partners at the local level; creation and maintenance of monitoring and feedback systems at the local and national levels, including the development of behavioural indicators; and judicious mix of communication channels (interpersonal, mass media, publicity, etc.) to support programme behavioural goals over time, based not just on available funding but also on effectiveness for the local context.