Malaysian Journal of Medicine and Health Sciences (eISSN 2636-9346) ORIGINAL ARTICLE Study on the Distribution and Abundance of Aedes aegypti and Aedes albopictus in Different Environment Settings for High- Rise Buildings Zuhainy Ahmad Zhaki1,3, Nazri Che Dom1,2, Ibrahim Ahmed Alhothily1 1 Centre of Environmental Health and Safety, Faculty of Health Sciences, Universiti Teknologi MARA Selangor, Malaysia 2 Integrated of Mosquito Research Group (I-MeRGe), Faculty of Health Sciences, Universiti Teknologi MARA, Selangor, Malaysia 3 Vector Control Unit, Kuala Langat District Health Office, Ministry of Health, Kuala Langat, Selangor, Malaysia ABSTRACT Introduction: Vector surveillance in high-rise buildings is important to predict and monitor the presence of vectors regarding their abundance and distribution. In this study, the infestation profile of Aedes aegypti and Aedes albopic- tus species in different environmental settings were investigated. Methods: Four high-rise apartments in four differ- ent localities were selected for ovitrap surveillance. Fifty ovitraps were placed in semi indoor and outdoor settings. Results: A total of 507 (42.8%) from ovitraps showed the presence of the Aedes species larvae. Out of these, 170 (33.5%) of the positive ovitraps were those placed in semi indoor and 337 (66.5%) in outdoor. Of the total 16,613 Aedes larvae found, 4,130 (24.9%) were from semi indoor, and 12,483 (75.1%) from outdoor. In terms of distri- bution, Ae. albopictus was predominantly found in outdoor environments (POI=87.5%; MLT=36.45 larvae). Ae. aegypti was also found in outdoor environments (POI=14.89%; MLT=8.26 larvae). There was a significant difference in POI for both Ae. aegypti and Ae. albopictus in the two different environments but no significant difference was observed in MLT, indicating that the density of the Aedes species in both environments was well distributed. Con- clusion: In this study, the patterns of Aedes habitat in high-rise apartments were observed. This study has shown an invasion and adaptation of Aedes mosquitoes into the ecosystems of high-rise buildings. It can be concluded that housing designs and the condition of the surrounding environment affects the infestation profile and the distribution of Aedes mosquitoes. Keywords: Aedes aegypti, Aedes albopictus, High-rise buildings, Ovitrap surveillance Corresponding Author: contributing in the epidemiology of the dengue fever Nazri Che Dom, PhD disease is the behavior of mosquitoes within the field Email: [email protected] itself (3). A difference in pattern of habitat preference Tel: + 603-32584447 can be seen between these species as certain studies revealed a higher abundance of Ae. aegypti in indoor INTRODUCTION areas while Ae. albopictus shows a higher occurrence in outdoor areas (5,6,7). Dengue fever is an urban viral disease. The virus is carried by female Aedes mosquitoes and can be transmitted to Dengue cases have also been reported in high-rise humans through the bites of these infected mosquitoes buildings that offer places of residence in the form of (1,2). The vector that causes dengue fever consists of flats, apartments or condominiums (1). Human activities two species of Aedes mosquitoes namely Ae. albopictus and poorly-maintained sanitation in the surrounding and Ae. aegypti. The abundance of these species is area can trigger the breeding of mosquitoes. High-rise influenced by the preference and inherent behaviors in buildings designed with rain gutters that make cleaning oviposition of these female mosquitoes, as well as biotic almost impossible offer the best breeding conditions and abiotic factors (3). Environmental factors such as for mosquitoes as regions with improper drainage and relative humidity, wind and temperature influence the piping systems show high potential in becoming Aedes occurrence and density of these species. Anthropogenic habitats (1). Essentially, there are a lot of potential changes in the environment will influence the breeding spots in high-rise buildings, including the areas abundance and distribution of Ae. aegypti whilst Ae. surrounding it. It is very difficult to control and monitor albopictus will mainly be influenced by the presence of the prevalence of these mosquitoes as checking and vegetation in the surrounding area (4). The main factor cleaning activities in these areas are usually limited and Mal J Med Health Sci 15(SP4): 91-98, Dec 2019 91 Malaysian Journal of Medicine and Health Sciences (eISSN 2636-9346) not thorough. Aedes larvae are usually found breeding in both natural and artificial containers and they do not necessarily breed independently; both species can be found simultaneously within the same breeding container (8,9). High-rise buildings offer the perfect ecosystem for Aedes mosquitoes to breed, providing them the potential to create shelter and resting areas, breeding sites, and the benefit of access to humans as their blood meals (8). Thus, it is important to conduct a vector surveillance in high-rise buildings to predict the presence of these vectors, their changing density levels, the frequency of occurrence and any other epidemiological factors which relates to their vectorial capacity (10). It is important to have basic information on the density of these vectors, their abundance, as well as their distribution (10). Previous studies claim that ovitrap surveillance is a more efficient technique to measures the presence of Aedes vectors (9,11,12). This technique was used as a sampling method to determine the positive ovitrap index (POI) which serves as an indicator in evaluating the abundance Figure 1: Sampling sites: Four different locality of high-rise and distribution of the Aedes population within the apartment in Bandar Saujana Putra; (PI) Pangsapuri Impian (orange), (PSS) Pansgapuri Seri Saujana (blue), (B21) BSP 21 study area (3,9). This approach can also be used to (green) and (BSP) BSP Skypark (yellow). assess the fluctuation rates of the Aedes population over an extended period of time, especially in epidemiology of two blocks of apartments with six hundred and eighty studies. In this study, ovitrap surveillance through a nine units of houses. Both PI and PSS have been in series of ovitraps activities was conducted to identify the service for approximately eight years and the overall Aedes profile for both Ae. aegypti and Ae. albopictus surroundings seem poorly-maintained with unmanaged species in and around high-rise buildings apartments trash disposal, untidy communal yards and an overgrowth in Bandar Saujana Putra, Selangor. The outcome of this of vegetation. The surrounding area appears unclean study may provide a minimum information required to with piles of garbage randomly scattered at almost assess the problem arises in high-rise buildings. every floor. In contrast, the surrounding environment of B21 and BSP is well kept with planted trees, with the MATERIALS AND METHODS area looking cleaner and well maintained in terms of sanitation with proper waste management systems in Description of study sites place. However, certain areas in B21 was quite messy as The ovitrap surveillance was conducted in selected it still under construction works progress in that area. A high-rise apartments in four different localities; summary of the geographical and ecological description Pangsapuri Impian (PI), Pangsapuri Seri Saujana (PSS), of each locality is as shown in Table I. BSP 21 (B21), and BSP Skypark (BSP). Fig. 1 shows the location of these high-rise apartments. All four localities Study design are situated in Bandar Saujana Putra under Mukim The study aims to evaluate the infestation profile of Tanjung in Kuala Langat, Selangor. These four localities Aedes mosquitoes within selected high-rise buildings of high-rise apartments had been selected due to a series in Kuala Langat, Selangor. The profile of Aedes density of dengue outbreak incidences that had been reported was measured through data collected from conventional by the Vector Control Unit of the Kuala Langat Health ovitrap surveillance. Ovitrapping was done to obtain Office from 2014 to 2018. a baseline data of the infestation profile. Therefore, the sampling was conducted on three independent All localities were identified as sub-urban residential visits of all localities between 3rd December 2018 areas, where two of them are considered as low-cost to 4th March 2019 (14 weeks). The selected months apartments (PI and PSS) and the other two are serviced were chosen due to high Dengue Fever cases reported apartments (B21 and BSP). PI and PSS are located side to during that period. In this study, the ovitrap was placed side. PI is a five storey low-cost apartment with eighteen at places deemed as “semi indoor” and “outdoors”. blocks whereby each block consists of eighty houses Semi indoors would refer to areas inside the building and PSS is a low-cost apartment with five storey blocks itself, namely areas covered by the roof of the building consisting of ten blocks and each block has eighty whilst outdoors refers to areas outside the building units of houses. B21 consists of ten blocks of serviced area, including the surrounding environment (3,4). The apartments with eighteen and twenty-seven storey ovitrap containers were placed randomly near potential buildings while BSP is a serviced residence consisting breeding spots in order to capture more accurate results. 92 Mal J Med Health Sci 15(SP4): 91-98, Dec 2019 Table I: Geographical and ecological description of each locality recorded. Study sites Geographical