To update, let's review some important statistics about Dengue in Singapore:


According to the graph above, the number of Dengue cases in Singapore peaked in 2014, and was closely matched by the number of cases in 2013. Though the number has subsided significantly in 2015, Dengue is still one of the main concerns among Singaporeans. Currently, the chance of Dengue virus transmission is higher due to the warmer weather, allowing the quicker breeding of mosquitoes while shortening the incubation period of Dengue virus. Yet, any major concern should be eradicated if safety precautions are carried out appropriately.

As mentioned in the previous post, Dengue virus is transmitted through the bites of female Aedes Aegypti and A.Albopictus mosquitoes. These species of mosquitoes are the vectors of Dengue virus. You may ask, what is a vector? A vector, in epidemiology term, refers to any agent, such as humans, animals or microorganisms, that are capable of carrying and transmitting infectious pathogens to other living organisms. The ability to infect is threatening, yet these arthropod vectors, upon acquiring the Dengue virus, are capable of transmitting the virus for the rest of their lives, to as many susceptible victims as they could find.

Dengue virus is an RNA virus with genome of 11 kilobases, some of which code for three different types of protein molecules that form the virus particle: core protein (C), membrane-associated protein (M) and envelope protein (E). In addition, there are 7 other essential proteins, namely NS1, NS2a, NS2b, NS3, NS4a, NS4b and NS5, that are active in infected host cells and bear the responsibility of viral replication. Classification of the serotypes of Dengue virus are according to difference in their antigenicity, with the four main strains being DENV-1, DENV-2, DENV-3, DENV-4. A new strain was discovered in 2013.

Unfortunately, Singapore is one of the countries where Dengue is endemic. Environmental factors such as climate and the failure to eliminate stagnant water provide the ideal breeding ground for Aedes mosquitoes. Dengue virus can be acquired via a single bite, with humans being the favorite target because they are the primary host of the virus.The virus lines gut of the infected mosquito, slowly spreading to different internal organs, such as the salivary gland, leading to the production of virus-containing saliva. All this happens within the infected mosquito while it is roaming around freely, feeding on blood meal while delivering the virus into susceptible, ill-fated targets. The minute size of this flying arthropod makes it hard to discover. Other modes of infection include organ donation from infected patient, blood transfusion and vertical transmission, in which the virus is passed from the mother to the fetus.

With each passing days, the number of Dengue cases continues to grow, both locally and around the world. Whether there is an efficient method of curbing the disease, it remains debatable. Taking safety precautions, such as removing stagnant water, can temporarily eradicate mosquito breeding spot, but surely, there are hidden places which they can grow as well. Another solution is applying insect repellent. Even so, one alarming fact about Dengue remains: the virus is completely harmless to infected mosquitoes, yet detrimental to us humans.  

References:
http://www.dengue.gov.sg/subject.asp?id=73
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3478998/