Abstract:
Dengue disease, which is a mosquito-borne disease, has been an important public health
problem specially in the tropical and sub-tropical regions in the world. Neither vaccine
nor successful treatment has been found yet to dengue disease. Therefore prevention
and control play a vital role in minimizing the risk of dengue and its burden from the
vulnerable populations.
Mathematical models of dengue with fixed parameters do not completely describe the
dynamics of the dengue transmission since the dynamics of dengue depend on various
external factors such as climate, human mobility, geography and demography. We
wavelet and cross wavelet approach to understand the patterns of dengue outbreaks in
urban Colombo and their relationships with external factors such as climate and human
mobility. The rainfall is found to have a leading effect to dengue incidents in Colombo
with a lag of approximately eight weeks.
use
A climate risk Index Is developed using fussy set theory to investigate the risk from
rainfall and temperature to dengue. We validate the predicted risk by the fuss, model
with the reported dengue incidents in Colombo from year 2006-20U. The risk index is
found to be 80 percent accurate (error is less than 0.4) to predict the real risk of dengue in
72.28% of tile time. This climate risk index is used to model the nonlinear dynamics of the
dengue mosquito density. This model to mosquito density addresses both the biological
spread of mosquitoes and the climate f.vor.bility to their reproduction. The outcome
of this model is also validated with reported dengue incidents in Colombo. The level of
accuracy of the model is at kmst 90 percent accurate (error less than 0.25) in 74.19% of
the time and it is at letot 80 percent accurate (e„o, less than 0.4) in 94.77% of the time
We simulate the SIR (Susceptible, Infected and Recovered) model for dengue with climate
varying mosquito density. The simulated infected human distribution is observed to have
captured the signitamt properties such as trend, periodicity ,„d peaks in the reported
dengue incidents tune senes in Colombo. We fix the inBuence from temperature and the
iv
SIR model is simulated only considering the variation of rainfall. This dynamic model
can be used to set up an early warning system for dengue in Colombo with respect to
approximately two months leading rainfall.
We introduce two measures U\ and uz to control adult mosquitoes and growing juveniles.
We implement control measures with four combinations of u\ and uz. The numerical
results of the SIR model suggest that the dynamic of the infections has changed and the
number of infections is reduced as the efficiency of the control measures are increased.