The number of people suffering from the deadly Zika virus in Singapore increased to 242 a week after its detection in the country. The rapid surge of Zika cases in the island city-state greatly places the rest of Asia at risk.

CNN reported that around 2.6 billion people in Asia and Africa could contract Zika. The virus has since been found to be the main cause of microcephaly, which causes abnormalities in fetuses characterized by smaller heads and underdeveloped brains.

Experts have yet to determine the main cause of Zika's spread in Singapore, although transmission by the local Aedes aegypti mosquito has been referred to as the culprit in several cases.

The first internationally-transmitted case reported on May 13 involved a man who came from a trip to Sao Paolo, Brazil.

Malaysia reported its first Zika case on September 1 when a 58-year-old woman visiting from Singapore was found to have been infected by the virus. The first local transmission in the country was reported in September 3, prompting authorities to prepare against the virus' further spread.

Singapore's high population density, coupled by year-round humid weather conditions, makes it an ideal place for Zika-infected Aedes aegypti mosquitoes to thrive. With several of Asia's megacities reaching daytime populations beyond 10 million, many of them are vulnerable to the virus' onslaught.

More importantly, the Singaporean government's $72-million worth of efforts to curtail the spread of dengue fever - a disease also carried by Aedes aegypti mosquitoes, hasn't translated to further success in terms of stopping Zika from spreading. Such prompted officials to think of new ways to control the virus.

Other nations in Asia are touted for their vulnerability to Zika's potential spread in the continent. Asian megacities - many of which are suffering from overpopulation and poor sanitation, are particularly exposed to the virus' dangerous effects.