Browsing by Author "Yoon Ling Cheong"
Now showing 1 - 3 of 3
Results Per Page
Sort Options
- PublicationAwareness of body mass index and its associated factors: A cross-sectional study(2022)
;Yong Kang Cheah ;Kuang Kuay Lim ;Hasimah Ismail ;Ruhaya Salleh ;Chee Cheong Kee ;Kuang Hock LimYoon Ling CheongThis study explores the correlates of sociodemographic factors, smoking, and caloric knowledge to body mass index awareness with a focus on Malaysia. Logistic regressions were estimated to examine sociodemographic factors associated with body mass index awareness. More than half of respondents were unaware of their body mass index (54.8%). Age was negatively associated with body mass index awareness. Adults without formal education were less likely to know their body mass index than those with tertiary‐level education. Adults were less likely to be aware of their body mass index if they engaged in smoking. Adults with knowledge of the definition of calories were more aware of their body mass index than others. The findings emphasize the urgent need for a forthcoming sociodemographic factors‐specific policy directed toward improving body mass index awareness to lower the prevalence of obesity in Malaysia. - PublicationCharacterization of Sodium Channel Mutations in the Dengue Vector Mosquitoes Aedes aegypti and Aedes albopictus within the Context of Ongoing Wolbachia Releases in Kuala Lumpur, Malaysia(2020-08-13)
;Noor Afizah Ahmad ;Nancy M. Endersby-Harshman ;Nur Ruqqayah Mohd Mazni ;Nur Zatil Aqmar Mohd Zabari ;Siti Nor Syazwani Amran ;Muhammad Kamarul Ridhuan Ghazali ;Mohd Arif Abdul Karim ;Yoon Ling Cheong ;Steven P. Sinkins ;Nazni Wasi AhmadAry A. HoffmannSpecific sodium channel gene mutations confer target site resistance to pyrethroid insecticides in mosquitoes and other insects. In Aedes mosquito species, multiple mutations that contribute to resistance vary in their importance around the world. Here, we characterize voltage sensitive sodium channel (Vssc) mutations in populations of Aedesaegypti from Kuala Lumpur, Malaysia, and look at their persistence in populations affected by ongoing Wolbachia releases (a dengue control measure). We also describe a Vssc mutation in Aedesalbopictus (F1534L) found for the first time in Malaysia. We show that there are three predominant Vssc haplotypes in Aedesaegypti in this region, which all persist with regular backcrossing, thereby maintaining the original genetic composition of the populations. We identify changes in genotype frequency in closed populations of Ae. aegypti maintained for multiple generations in laboratory culture, suggesting different fitness costs associated with the genotypes, some of which may be associated with the sex of the mosquito. Following population replacement of Ae. aegypti by Wolbachia in the target area, however, we find that the Vssc mutations have persisted at pre-release levels. Mosquitoes in two genotype classes demonstrate a type I pyrethroid resistance advantage over wildtype mosquitoes when exposed to 0.25% permethrin. This resistance advantage is even more pronounced with a type II pyrethroid, deltamethrin (0.03%). The results point to the importance of these mutations in pyrethroid resistance in mosquito populations and the need for regular backcrossing with male mosquitoes from the field to maintain similarity of genetic background and population integrity during Wolbachia releases. - PublicationModelling the Effectiveness of Epidemic Control Measures in Preventing the Transmission of COVID-19 in Malaysia(MDPI, 2020)
;Balvinder Singh Gill ;Vivek Jason Jayaraj ;Sarbhan Singh ;Sumarni Mohd Ghazali ;Yoon Ling Cheong ;Nuur Hafizah Md Iderus ;Bala Murali Sundram ;Tahir Bin Aris ;Hishamshah Mohd Ibrahim ;Boon Hao HongJane LabadinMalaysia is currently facing an outbreak of COVID-19. We aim to present the first study in Malaysia to report the reproduction numbers and develop a mathematical model forecasting COVID-19 transmission by including isolation, quarantine, and movement control measures. We utilized a susceptible, exposed, infectious, and recovered (SEIR) model by incorporating isolation, quarantine, and movement control order (MCO) taken in Malaysia. The simulations were fitted into the Malaysian COVID-19 active case numbers, allowing approximation of parameters consisting of probability of transmission per contact (β), average number of contacts per day per case (ζ), and proportion of close-contact traced per day (q). The effective reproduction number (Rt) was also determined through this model. Our model calibration estimated that (β), (ζ), and (q) were 0.052, 25 persons, and 0.23, respectively. The (Rt) was estimated to be 1.68. MCO measures reduce the peak number of active COVID-19 cases by 99.1% and reduce (ζ) from 25 (pre-MCO) to 7 (during MCO). The flattening of the epidemic curve was also observed with the implementation of these control measures. We conclude that isolation, quarantine, and MCO measures are essential to break the transmission of COVID-19 in Malaysia.