Dengue epidemiological characteristic in Kuala Lumpur and Selangor, Malaysia

In the last few decades, dengue remains a leading public health problem in Malaysia. The problem persists with increasing trend of cases despite implementation of various interventions by the Ministry of Health Malaysia. The difficulty in eradicating dengue disease throughout the world is related to the complexity of the dengue phenomena. With no access to a safe, effective and affordable dengue vaccine, the only intervention strategy is to control the mosquito vector. In reality, data on mosquitoes is limited, and in most cases, the dynamic of mosquito is unobservable. In this study, based on the dengue incidence data in Malaysia-Kuala Lumpur and Selangor-from the year 2011 to 2014, a transmission model of type SI-SIR is constructed. Transmission rates in the two locations are estimated from the data fitting of the dynamic of infected human to dengue incidence. The average infection rate and the estimated average reproduction number for Selangor are estimated to be 0.1674 week-1 and 1.025, respectively. An enclave in Selangor, the capital city Kuala Lumpur has slightly lower average dengue infection rate of 0.1656 week-1 and estimated average reproduction number of 1.014. Further sensitivity analysis indicated that the dengue infection rate is the critical parameter of dengue transmission in Kuala Lumpur and Selangor. This implies that dengue control strategies should focus on reducing the dengue infection rate. Numerical simulations are also performed to validate the estimated dengue infection rate, to illustrate the dengue dynamics and to determine the effects of dengue control strategies in the two selected locations. The predictive test results of this method also provide good results in capturing the pattern of dengue cases both in Kuala Lumpur and in Selangor. Numerical simulations on instantaneous reproduction number reveal that the instantaneous reproduction number of Kuala Lumpur varies between 0.8 and 1.28 while the instantaneous reproduction number of Selangor varies between 0.7 and 1.2. The insights and results presented in this paper are useful to the relevant authorities in analyzing the effect of mosquito intervention for reducing the prevalence of dengue in Malaysia. (c) 2021 International Association for Mathematics and Computers in Simulation (IMACS). Published by Elsevier B.V. All rights reserved.

Automated summary

Despite various interventions by the Ministry of Health Malaysia, the number of dengue cases in Malaysia continues to increase. This study constructed a transmission model based on dengue incidence data and estimated the transmission rates in Kuala Lumpur and Selangor. The results indicate that the dengue infection rate is a critical parameter for dengue transmission, and control strategies should focus on reducing this rate. The predictive tests and numerical simulations in this study provide useful insights for analyzing the effect of mosquito intervention in reducing dengue prevalence in Malaysia.