Q How does the Zika virus spread?

A The Zika virus is transmitted when an Aedes mosquito, which also transmits diseases such as dengue, bites someone who is already infected.

When that mosquito bites a second person, he may then be infected with the Zika virus.

The virus can also be spread through sex.

Q What are the symptoms of Zika?

A Zika symptoms are similar to those of dengue fever. They include fever, rashes, joint or muscle pains, and headaches.

However, Zika symptoms tend to be milder than those of dengue. Those with Zika also tend to have red eyes or conjunctivitis.

On average, only one in five people infected with Zika actually falls ill - the rest may not have any symptoms at all.

People who have Zika do not usually need to be hospitalised, and deaths are rare.

Q Is there a vaccine or any kind of treatment for Zika?

A No, there is currently no vaccine for Zika. Only the symptoms can be treated.

To avoid getting infected, take precautions to avoid mosquito bites. This includes wearing clothing that covers as much of the body as possible and sleeping under mosquito nets or in rooms with wire mesh.

Q Is the virus really linked to birth defects and other disorders?

A Preliminary research has led the World Health Organisation (WHO) to conclude that Zika causes microcephaly and Guillain-Barre syndrome.

Microcephaly is a condition where a baby is born with an unusually small head, while Guillain-Barre syndrome is a rare condition in which a person's immune system affects the nerves.

The WHO began to investigate the link between Zika and these two medical conditions after reports from Brazil showed an unusual increase in both conditions following a Zika outbreak there.

Q How many countries are affected by the Zika virus?

A Currently, Singapore's Ministry of Health (MOH) has named more than 30 countries - including Brazil and Mexico - where Zika outbreaks are ongoing.

A place is considered to have an outbreak when it has a relatively high number of cases, with widespread transmission or transmission for more than eight weeks.

MOH has also named 14 other countries where Zika transmission is ongoing. These countries, including the Philippines and Vietnam, have relatively fewer cases and transmission is not as widespread.

Linette Lai