METHODS: Individuals of An. balabacensis were collected in the field in Ranau district, Sabah to establish a laboratory colony. Induced mating was used, and the life history parameters of the progeny were recorded. The age-stage, two-sex life table approach was used in the analysis. The culture conditions in the laboratory were 9 h light:15 h dark, mean temperature 25.7 °C ± 0.05 and relative humidity 75.8% ± 0.31.
RESULTS: The eggs hatched within 2 days, and the larval stage lasted for 10.5 days in total, with duration of instar stages I, II, III and IV of 2.3, 3.7, 2.3, 2.2 days, respectively. The maximum total fecundity was 729 for one particular female, while the maximum female age-specific mean fecundity (mx) was 142 at age 59 days. The gross reproductive rate or number of offspring per individual was about 102. On average, each female laid 1.81 ± 0.19 (range 1-7) batches of eggs, with 63% of the females producing only one batch; only one female laid six batches, while one other laid seven. Each batch comprised 159 ± 17.1 eggs (range 5-224) and the female ratio of offspring was 0.28 ± 0.06. The intrinsic rate of increase, finite rate of increase, net reproductive rate, mean generation time and doubling time were, respectively, 0.12 ± 0.01 day-1, 1.12 ± 0.01 day-1, 46.2 ± 14.97, 33.02 ± 1.85 and 5.97 days.
CONCLUSIONS: Both the net reproductive rate and intrinsic rate of increase of An. balabacensis are lower than those of other species in published studies. Our results can be used to improve models of P. knowlesi transmission and to set a baseline for assessing the impacts of environmental change on malaria dynamics. Furthermore, incorporating these population parameters of An. balabacensis into spatial and temporal models on the transmission of P. knowlesi would provide better insight and increase the accuracy of epidemiological forecasting.
METHODS: A life table model was constructed using published Malaysian demographic and mortality data. Our analysis was limited to male smokers due to the low smoking prevalence in females (1.1%). Male smokers aged 15-64 years were followed up until 65 years or until death. The population attributable risk, health-related quality of life decrements and relative reduction in productivity due to smoking were sourced from published data. The analysis was repeated assuming the cohorts were never smokers, and the differences in outcomes represented the health and productivity burden conferred by smoking. The cost of productivity loss was estimated based on the gross domestic product per equivalent full-time worker in Malaysia.
RESULTS: Tobacco use is highly prevalent among working-age males in Malaysia, with 4.2 million (37.5%) daily smokers among men aged between 15 and 64 years. Overall, our model estimated that smoking resulted in the loss of over 2.1 million life years (2.9%), 5.5 million (8.2%) quality-adjusted life years (QALYs) and 3.0 million (4.8%) PALYs. Smoking was estimated to incur RM275.3 billion (US$69.4 billion) in loss of productivity.
CONCLUSION: Tobacco use imposes a significant public health and economic burden among working-age males in Malaysia. This study highlights the need of effective public health interventions to reduce tobacco use.