1.Dengue Vector Control in Malaysia- Challenges and Recent Advances
Lee HL ; Rohani A ; Khadri MS ; Nazni WA ; Rozilawati H ; Nurulhusna AH ; Nor Afizah AH ; Roziah A ; Rosilawati R ; Teh CH.
The International Medical Journal Malaysia 2015;14(1):11-16
Dengue is a serious mosquito borne disease common in tropical and sub-tropical countries including Malaysia.
There is at present a lack of specific treatment and an effective tetravalent vaccine against dengue. The control
of dengue depends solely on the suppression of the two most important vectors namely, Aedes aegypti and Ae
albopictus. Despite intensive and extensive control efforts by health agencies, the disease continues to spread.
This paper updates various innovations on control of dengue vectors. Gene-based sterile insect technique
using the RIDL technology for both Aedes aegypti & Ae albopictus control has now been actively researched and
field trials are pursued to evaluate the effectiveness of the technology. The release of Wolbachia-infected Ae
aegypti is another dengue control innovation. The infected mosquito cannot support development of dengue
virus and has shorter life span. Other innovations include: auto-dissemination of insect control agents using
ovitrap, autocidal adult and larva trap, outdoor residual spraying, insecticidal paint and biocontrol agent. In
other innovation, outbreak prediction capability is enhanced by developing model based on environmental data
and analysis utilising neural network.
2.Aedes larval population dynamics and risk for dengue epidemics in Malaysia
Rohani, A.* ; Suzilah, I. ; Malinda, M. ; Anuar, I. ; Mohd Mazlan, I. ; Salmah Maszaitun, M. ; Topek, O. ; Tanrang, Y. ; Ooi, S.C. ; Rozilawati, H. ; Lee, H.L.
Tropical Biomedicine 2011;28(2):237-248
Early detection of a dengue outbreak is an important first step towards implementing
effective dengue interventions resulting in reduced mortality and morbidity. A dengue
mathematical model would be useful for the prediction of an outbreak and evaluation of
control measures. However, such a model must be carefully parameterized and validated
with epidemiological, ecological and entomological data. A field study was conducted to
collect and analyse various parameters to model dengue transmission and outbreak. Dengueprone
areas in Kuala Lumpur, Pahang, Kedah and Johor were chosen for this study. Ovitraps
were placed outdoor and used to determine the effects of meteorological parameters on
vector breeding. Vector population in each area was monitored weekly for 87 weeks. Weather
stations, consisting of a temperature and relative humidity data logger and an automated rain
gauge, were installed at key locations in each study site. Correlation and Autoregressive
Distributed Lag (ADL) model were used to study the relationship among the variables. Previous
week rainfall plays a significant role in increasing the mosquito population, followed by
maximum humidity and temperature. The secondary data of rainfall, temperature and humidity
provided by the meteorological department showed an insignificant relationship with the
mosquito population compared to the primary data recorded by the researchers. A well fit
model was obtained for each locality to be used as a predictive model to foretell possible
outbreak.