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 : 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, 2 Department of Community Health, UKM Medical Centre 3 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 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 . 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 . 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 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 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 study were; 1). To determine protection from climate-related risks and to the epidemiology and the dengue vector substantially reduce health systems‟ ecology in relation to climate variability, 2) To greenhouse gas emissions and iii) to ensure that assess the community vulnerability towards health concerns are addressed in all decisions dengue from climate variability 3) To identify on reducing risks from climate change taken by the adaptive measures in dengue control and 4) other key sectors. Current dengue fever and To assess the effectiveness of COMBI for dengue haemorrhagic fever epidemics have dengue control. The hypotheses of this study resulted in the loss of lives. Political and were; 1) There is an association between financial commitments are needed to ensure a climate variability and dengue epidemiology sustained, integrated dengue control and and dengue vector ecology and 2) COMBI is prevention strategies to be implemented. effective in controlling dengue. Countries in this region need to develop a comprehensive national dengue integrated plan that includes surveillance, case management, RESEARCH METHODOLOGY social mobilization and communications, integrated vector management, outbreak Various research methodologies were applied in responses and operational researches. Dengue this research project. Study locations transmission relies on a complex combination comprised of urbanized and rural localities; the of multiple risk factors and calls for an Langat river basin, Seremban and Ledang intersectoral approach. Stakeholders‟ actions districts. The selection of the study locations is need to cut across sectors for an effective based on concurrent research projects dengue prevention and outbreak response. managed by the research team members. Research activities include site visits to collect The increasing morbidity, mortality and health detail information on area and the community costs on dengue and dengue haemorrhagic study is based. Review of the 2003- 2008 fever are escalating at an alarming rate. The surveillance data on the DF/DHF incidence economic impact of DF/DHF is enormous, cases were carried out to determine the placing significant burdens on affected dengue epidemiology in the study locations. communities. The impact varies and can Community surveys on the knowledge include loss of life. Medical expenditures for prevalence, opinion and practice (KOP) on hospitalization of patients, loss in productivity Aedes, DF and DHF were carried out in the of affected work force, strain on health care Ledang district. services due to sudden, high demand during epidemic. Considerable expenditures for scale The ecology of mosquitoes was studied in emergency control actions incur and also the Seremban and Ledang districts which include loss of national income from tourism as a result the determination of the species composition,

Malaysian Journal of Public Health Medicine 2010, Vol. 10 (2): 25-34 peak biting time and its population density. The next phase of this project will be on Four sampling methods were adopted; the bare geostatistical modeling, analysis and mapping leg catching and the CDC (Centers for Disease applying ArcGIS 9.3.1 software to evaluate the Control) light trap, the ovitrap and the larva interrelationship between Aedes population, survey. Abiotic parametes such as ambient DF/DHF incidence, land use activities and temperature, relative humidity and rainfall climate variability. Computer simulation distribution were analysed to identify the models and global change scenarios will be correlations between these variables with the incorporated to explore the risks of the public Aedes mosquito population and distribution. health. The GIS mapping on the dengue risk The Aedes population density based on the zones and the factors contributing to its burden ovitrap, Aedes and Breateau indexes were will be applied to assess the community obtained from the health facilities in the study vulnerability towards Aedes. The information locations. The community survey and mosquito gathered on the community vulnerability and ecology were carried out during pre- and post their capacity to respond will support the intervention phases. proposed adaptation measures towards effective dengue control as response to climate A series of workshops, group discussions and change. This project is currently in progress. activities such as COMBI activities to promote Aedes control were conducted regularly in the Ledang and Seremban communities in RESULTS AND DISCUSSION collaboration with the health and district officers. COMBI in the Hulu Langat communities This paper reports on preliminary findings of were carried out by the other researchers in our study. In the dengue epidemiology, the UKM. The above mentioned are considered as highest incidence of dengue cases recorded in our intervention activities. The processes Seremban was in 2003. The dengue cases during these activities were documented to decreased between 20-40% since 2005 (Figure provide information on the community 1). The locations of the reported uncontrolled responses and their adaptive capacities towards dengue cases were reduced. The breeding dengue. habitats of Aedes were diminished if the community took care of their environment. The trends on Aedes population, dengue cases Reduction of the breeding habitats leads to the and community surveys pre and post- reduction in the density of Aedes population interventions, the processes for dengue control which could then reduce the transmission of activities were analysed. dengue.

Malaysian Journal of Public Health Medicine 2010, Vol. 10 (2): 25-34

Figure 1. Dengue cases in Seremban district, 2003-2008.

For Hulu Langat, the dengue cases showed a sharply in 2005 and remained high in 2008 decreasing trend in 2004. However, it increased (Figure 2).

Figure 2. Dengue cases in , 2004-2008.

Malaysian Journal of Public Health Medicine 2010, Vol. 10 (2): 25-34

The study on the mosquito ecology was The containers with positive Aedes larves were conducted every two weeks since early October plastic, polystyrene and water containers, 2009 till end December 2009. We found some ground water wells, flower pot saucers, and differences in the type and distributions of coconut shells The vector for Japanese species in our initial mosquito surveys from Encephalitis which is the species (Culex October to November 2009 at Seremban and sitiens, Culex vishnui and Culex sinensis) were Ledang districts. also present which could be related to the pigfarming activities in this area. At Felda Ledang the main mosquitoes that were trapped and caught were Armegeres We found a sudden increased of the Aedes subalbatus, Aedes albopictus and Culex albopictus population, from 22.7% (during the quinquefasciatus with a total of 54.1%, 22.7% dry season) to 53.0% (during the rainy season). and 10.8%. From the CDC light trap, we found During the dry season, the sampling period was that the majority of the vectors were in October 2009. For the rainy season, the Armigeres subalbatus (32.0%) followed by sampling period was during November 2009. Culex quinquefasciatus, Aedes albopictus, Culex sitiens, Culex vishnui, Anopheles kochi Post community intervention at Felda Ledang and Culex sinensis of 28.1%, 16.4%, 7.8%, 5.4%, using a COMBI approach (which is explained in 1.54 and 0.78% respectively. However, from the later section) showed a significant decrease the BLC, we found 65.2% Armigeres subalbatus in the mosquito population density in the area and 34.8% Aedes albopictus. (p<0.05) (Table 1).

Table 1. Mosquito ecology (pre and post intervention)

Mosquito species No. of mosquito (%) No. of mosquito (%) p value

(pre-intervention) (post-intervention)

Ae. albopictus 44(22.70) 1(0.50) p<0.05

Ae. pseudoalbopictus 2 (1.03) 0(0.00) p<0.05

Ar. subalbatus 105(54.12) 2(1.03) p<0.05

Cx. gelidus 2(1.03) 1(0.50) p>0.05

Cx. vishnui 2(1.03) 0(0.00) p<0.05

Cx. pseudovishnui 0(0.00) 2(1.03) p<0.05

Cx. Quinquefasciatus 21(10.80) 5(2.60) p<0.05

Cx.sinensis 0(0.00) 2(1.03) p<0.05

An.kochi 1(0.50) 0(0.00) p<0.05

At Seremban, the mosquito ecology was Our mosquito ecology findings above indicated conducted in . Majority of mosquito that the abundance of Aedes albopictus could catched were Aedes albopictus (98.04%) from lead to high risk of dengue and chikunyunga at both CDC light traps and BLC. Senawang in the Seremban district. In the Ledang district, with the presence of Aedes

Malaysian Journal of Public Health Medicine 2010, Vol. 10 (2): 25-34 albopictus and its sharp increment during rainy mosquito breeding places within their season, could lead to higher risks for dengue immediate surrounding areas. The Seremban and chikunyunga. The presence of the Culex COMBI has established an organizing team that species could give rise to Japanese holds regular meetings and map out their Encephalitis. action plans. Their COMBI programs depend on the management of which involves planning, Community involvement on a program for implementation and performance evaluation dengue control was implemented using COMBI21 (i.e. the reduction in the dengue cases). The approach at the study locations; the Hulu monitoring of these performances need to be Langat (the Langat river basin), Seremban and conducted regularly in order to evaluate the Ledang districts. effectiveness of the COMBI program. The sustainability of their COMBI program relies to COMBI in Seremban district was initiated since a great extent on the approaches of the COMBI 2002. In this COMBI program, each individual program for dengue control as shown in Figure spent 10 minutes to search and destroy any 3.

ACTION PLAN

PROMOTIONAL COMMUNITY CENTRE MOBILISATION

ACHIVEMENT PERSONAL/COMMUNICATION ADVERTISING INTERPERSONAL

Figure 3: COMBI approach for dengue control in Seremban district

The most established COMBI program in youths, residents, civil servants, private and Seremban district is at Perdana. They non-governmental organizations. This has have explored most of the opportunities in the shown favourable results due to the effective various events in mobilizing their local management of their activities as mentioned communities. In this community, various above. activities (Figure 4) were carried out such as COMBI on-call, Jalan-jalan Jom Cari Jentik- jentik, COMBI Youth Squad, Smart partnership, OPS Sikap, Discovery day of COMBI, Sepagi Jalinan Kasih di Apartmen, Family Day, Sport Carnival, Maulidur Rasul, and Sepetang COMBI Bersamamu (at the night market) and Eidulfitr Celebration (COMBI blog launching). There was active participation among the different community groups such as school children,

Malaysian Journal of Public Health Medicine 2010, Vol. 10 (2): 25-34

Figure 4: COMBI activities in Seremban districts.

In Hulu Langat district, the COMBI program was activities, 3K programs (Kebersihan, Keceriaan initiated in 2004 at Section 3 and Section 4 of dan Keselamatan) and dengue free campaigns Bandar Baru Bangi, in the district of Hulu at the Felda Sri Ledang Primary School. The Langatxiv. Here, Aedes breeding was found to COMBI workshop was organized by the Ledang occur mainly in water containers of semi Health office in collaboration with the UKM permanent nature (eg. „kolah‟, aquatic plant team on the 31st Oct 2009. The activities have jars, flower pot bases etc). A total of 172 lead to activation of the existing COMBI teams volunteers were recruited to disperse the at Felda Sri Ledang. Several health promotion message of “Suluh – Suluh, Basuh - Basuh” activities for the various community groups, whilst distributing leaflets and flashlights to i.e. the local residents, community leaders, 2666 homes. Residents were instructed to school children were planned. These activities eliminate such water containers twice weekly include regular educational activities on Aedes and scrub any containers found to contain and its transmission route, its risks to dengue larvae. The program commenced on 23/5/2004 and chikunyunga and their control programs, and lasted 16 weeks. During this period, the gotong royong etc. initial Aedes Index of 5 was reduced to 0.96. The COMBI approach in Hulu Langat The KOP (knowledge, opinion and practice) successfully demonstrated community surveys carried out at Ledang and the results involvement in dengue had reduced Aedes are shown in Table 2. It was found that their proliferation and dengue morbidity. There is no opinions improved significantly only after the information available on the COMBI activities in activation of the intervention programs. Hulu Langat after this period. The unavailability of information on COMBI The research findings of this study provide an activities in Langat after 2004 could indicate understanding of the vulnerability of the that the sustainability of such programs is community to climate variability and their important to ensure dengue control. responses and adaptive measures towards dengue. The community advocacy on their Another locality where a COMBI program was combats against Aedes is a possible effective reactivated in this project was the Ledang solution in the control of dengue. In addition, district. A few activities were organized with this research could provide other dimensions of the Ledang community such as the KOP survey public health management to address the (pre & post intervention), vector population impact of climate change on vector-borne survey as well as intervention programs. diseases. The intervention programs include COMBI This research toes the of recommendations awareness workshops, visits to Nilai Perdana made by WHO on the adaptation to climate COMBI in Seremban, gotong royong or cleanup change and the responses from science to

Malaysian Journal of Public Health Medicine 2010, Vol. 10 (2): 25-34 policy. The magnitude and character of global CONCLUSION climate change necessitates a community-wide understanding and responses, guided by Dengue vector ecology is important to policies well informed by good scientific understand the trend and distribution of advices. A successful policy-focused assessment dengue / DHF cases. Therefore we recommend of the potential health impacts of climate the dengue vector ecology at the district and change should include: i) a multidisciplinary state levels to be strengthened. We found assessment team; ii) responses to questions positive associations between the climate queried by all stakeholders; iii) evaluation of variability and the Aedes population density. risk management adaptation options; iv) Community plays important roles in controlling identification and prioritisation of key research dengue, for example via COMBI which enhances gaps; v) characterization of uncertainties and proper environmental sanitation. their implications for decision-making; and vi) tools that support decision-making processes. ACKNOWLEDGEMENT which is supported by the UKM research grant: UKM-AP-PI-18-2009 and UKM-GUP-KRIB-4/2008. This research is part of the research entitled “Climate resilience development-linking Special thanks to Dr Nihayah Mohamed (Head of science and governance for sustainability” Project for UKM-GUP-KRIB-4/2008).

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