Community Vulnerability on Dengue and Its Association with Climate Variability in Malaysia: a Public Health Approach
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Malaysian Journal of Public Health Medicine 2010, Vol. 10 (2): 25-34 ORIGINAL ARTICLE COMMUNITY VULNERABILITY ON DENGUE AND ITS ASSOCIATION WITH CLIMATE VARIABILITY IN MALAYSIA: A PUBLIC HEALTH APPROACH Mazrura S1, Rozita Hod2, Hidayatulfathi O1, Zainudin MA3, , Mohamad Naim MR1, Nadia Atiqah MN1, Rafeah MN1, Er AC 5, Norela S6, Nurul Ashikin Z1, Joy JP 4 1 Faculty of Allied Health Sciences, National University of Malaysia, Jalan Raja Muda Abdul Aziz, 50300, Kuala Lumpur 2 Department of Community Health, UKM Medical Centre 3 Seremban District Health Office 4 LESTARI, National University of Malaysia, Bangi 5 Faculty of Social Sciences and Humanities, National University of Malaysia, Bangi 6 Faculty of Sciences and Technology, National University of Malaysia, Bangi ABSTRACT Dengue is one of the main vector-borne diseases affecting tropical countries and spreading to other countries at the global scenario without cease. The impact of climate variability on vector-borne diseases is well documented. The increasing morbidity, mortality and health costs of dengue and dengue haemorrhagic fever (DHF) are escalating at an alarming rate. Numerous efforts have been taken by the ministry of health and local authorities to prevent and control dengue. However dengue is still one of the main public health threats in Malaysia. This study was carried out from October 2009 by a research group on climate change and vector-borne diseases. The objective of this research project is to assess the community vulnerability to climate variability effect on dengue, and to promote COMBI as the community responses in controlling dengue. This project also aims to identify the community adaptive measures for the control of dengue. Various research methodologies were applied in this research project in different localities. Site visits, review on surveillance data and mapping on Aedes population, dengue cases and climate variability, community survey on the knowledge prevalence , opinions and practices (KOP) and mosquito ecology were carried out during pre- and post intervention phases. Community vulnerability towards Aedes and dengue were mapped out applying GIS. A series of workshops, group discussions and activities such as COMBI activities to promote Aedes control were conducted involving the Ledang communities, the health district officers and UKM researchers. These activities also included interventions and documentation of community responses and their adaptive capacities towards dengue. Trends on Aedes population, dengue cases and community surveys pre and post-interventions, the processes for dengue control activities were analysed. The research findings could provide understanding on the community vulnerability to dengue against climate variability, their responses and adaptive measures. The community advocacy on combats against Aedes is a possible effective solution in dengue control. This research could provide other dimensions in public health management to address the impacts of climate change on vector-borne diseases. Key words: Dengue, climate, community vulnerability, participation, adaptation INTRODUCTION Dengue is one of the main vector-borne scenario without cease. Dengue in Asia has diseases affecting tropical countries and been reported since 1770 and in Malaysia since spreading to other countries at the global 1901 in Penang. Climate change has been Malaysian Journal of Public Health Medicine 2010, Vol. 10 (2): 25-34 closely associated to the occurrence of diseases In Malaysia, dengue has been endemic since its such as those spread by arthropods. The rainfall first description by Skae in 19023. The annual and temperature patterns and changes have incidences of dengue in Malaysia are about 367 impacts on the river flows and breeding areas. cases in a „quiet‟ year to more than 10,000 Infections that are influenced by climate cases in a „busy‟ year. Similar to other change share certain common features. They countries within the region, all four dengue are localized, and their distribution may be virus serotypes have been associated with confined within the ecology of their reservoir. dengue fever (DF) and dengue haemorrhagic Some may have life cycles that involve more fever. Dengue virus type 4 (DENV-4), the once than one host. Other than infecting humans, predominant (40 to 64%) serotypes isolated they may also infect a vector, such as the from DF patients in Malaysia during the period Aedes mosquito and sometimes a wild 1967 to 1969 has, however, been isolated in vertebrate animal host. Both, or either the less than 5% of DF cases for almost a decade vector or the host, act as reservoir. The habitat with no reported isolation in the last 5 years. A of the reservoir is determined by the total of 7103 cases DF/DHF were notified in temperature and the locality water. If the 2000. The number had markedly increased to agent and the reservoir survived under given 48,845 cases in 2007. In 2006, the incidences of global climate change, the agent will multiple DF were 64.37 and DHF was 4.1 per 100,000 more rapidly. The reservoir such as the populations. The incidences increased to 144.7 mosquito will also develop more rapidly. For per 100,000 populations in 2007. example, it may have a shorter life cycle. Malaysia has an equatorial climate which is The concept of vulnerability is useful for very conducive for the breeding of dengue assessing risks to human societies from vector- reservoirs. borne diseases. It is applied in the scientific and policy communities in investigating the Climate change is likely to increase the acreage likely threats from climate change1,2. that is conducive for dengue fever Vulnerability is a measure of the potential transmission. Some countries such as Australia impacts of a given change, taking into account have reported increasing number of dengue the adaptive capacity which is available to the cases reflecting such global trend this affected system or community to respond to situation. In the coming years, there will be an that change. In other words, it describes the increasing number of people who live in these sensitivity of the particular system of interest dengue risk regions. An estimated 50 million to vector-borne diseases, taking its adaptive dengue infections occur every year, including capacity into account. Adaptive capacity 500 000 cases of DHF that require consists of the adaptation technologies and hospitalization which is equivalent to cultural tools and the public health approximately one DHF case every minute. At infrastructure and resources that are available least 21 000 deaths from DHF occur every year, to implement appropriate management mostly among children –equivalent to one responses. young life lost to DHF almost every 20 minutes. These statistics will become worse unless More user-friendly GIS softwares and other urgent and effective actions to be undertaken emerging mapping technologies, such as Google to avert from such risks. Some 40% of the Earth and Microsoft Virtual Earth, provide new world‟s population (2.5 billion people) now live opportunities to visualize spatial and space- in areas where transmission occurs1. It‟s time patterns for entomological and important to develop public health sectors epidemiological data, and to generate risk corresponding of a 30-fold increase in models for vector and dengue virus incidence following the geographical expansion exposure1,2,3. Key benefits of adopting GIS of its main vector, Aedes aegypti, since the based approaches include the capacity to link 1960s2 and to the accrued co-circulation of different types of information for a given multiple serotypes, which increase the risk of spatial location or area (e.g., land cover, sequential infection with the dengue virus and climate factors, socioeconomic variables, and severity of disease. entomological and epidemiological data), potential for spatial statistical analysis, and development of spatial databases which could Malaysian Journal of Public Health Medicine 2010, Vol. 10 (2): 25-34 be used in formulating a wide range of public of negative publicity. Numerous efforts were health programs. Another practical application taken by the authorities such as the health is ongoing mapping of dengue case locations in ministry and local authorities to prevent and relation to spatial coverage of implemented control dengue; however dengue has been vector control. This mapping will provide continually to be the main public health assessment on the vulnerability of the threat in Malaysia. communities to these global changes that depends on their adaptive capacity, which A project is undertaken by a research group on requires both appropriate technology and climate change and health specifically on responsive public health systems. The vector-borne diseases in UKM since October availability of resources in turn depends on 2009 to address the above WHO regional action social stability, economic wealth, and priority plan. The objective of this research project is allocation of resources to public health. to assess the community vulnerability from climate variability towards dengue, and to WHO regional action plan to protect human promote COMBI as the community responses in health from climate change has three broader controlling dengue. This project also aims to objectives; i) to increase awareness of the identify the community adaptive capacity and health consequences of climate change; ii) to control measures for dengue. The specific strengthen health system capacity to provide objectives of this