With the rampant hot and humid weather in Singapore, dengue fever/dengue hemorrhagic fever has been on the rise with five times the total number of reported cases this year as compared to last year. A total of 11,490 dengue cases have been reported this year, as of September 7, 2019).

So what exactly is dengue fever and why this yearly rise in numbers? Dengue is a mosquito-borne viral infection that causes a severe flu-like illness. In some cases, it develops into severe dengue. The full life cycle of dengue fever virus involves the role of mosquito as a transmitter and humans as the main victim and source of infection. The Aedes aegypti mosquito is the main transmitter that spreads dengue viruses. The viruses are passed on to humans through the bites of an infective female Aedes mosquito, which mainly acquires the virus while feeding on the blood of an infected person.

Once infected, humans become the main carriers and multipliers of the virus, serving as a source of the virus for uninfected mosquitoes. The virus circulates in the blood of an infected person for 2 to 7 days, at approximately the same time that the person develops a fever. Those already infected with the dengue virus can transmit the infection via Aedes mosquitoes after the first symptoms appear, usual during 4 to 5 to a maximum of 12).