Singapore's National Environment Agency (NEA) said on Tuesday that a new Zika cluster has been confirmed at Highland Road and Jansen Close near Kovan, with two cases of locally transmitted infection.
NEA said both are residents in the area. The agency has already started its operations to kill mosquitoes in the area. At present, there are three active Zika clusters in Singapore around the same neighbourhood.
On Monday, NEA said that an additional case was confirmed at the Glasgow Road cluster and another new case at the Poh Huat Road West/Poh Huat Terrace/Terrasse Lane cluster on Tuesday.
Meanwhile, the authorities also said that the cluster at Flower Road/Hendry Close was closed on Tuesday and has been kept under surveillance.
NEA urged residents to be vigilant and continue to eliminate mosquito breeding habitats, as there could still be "asymptomatic or mild, undiagnosed cases which might result in further transmission of the virus if there are mosquitoes in the vicinity".
According to NEA, the precaution methods are quite similar to its approach to dengue cases. It has also requested residents to let NEA officers carry out inspections and indoor spraying of their homes.
Zika is a mosquito-borne virus that was first identified in Uganda in 1947. It can be passed from a pregnant woman to her unborn baby. Zika virus can cause birth defects and can also result in microcephaly in which the baby's head is smaller than expected.
In cases of adults, Zika infections have been linked to a rare neurological syndrome known as Guillain-Barre and other neurological disorders as well.
The World Health Organisation said people infected with Zika can have symptoms including mild fever, skin rash, conjunctivitis, muscle and joint pain, malaise or headache. These Zika symptoms normally last for two to seven days.
NEA advised the members of the public to seek medical attention if they are unwell, especially with symptoms such as fever and rash.
There is no treatment or vaccine for Zika infection yet. Companies and scientists are working to develop a safe and effective vaccine for the virus. Zika is commonly said to be a close cousin of dengue and chikungunya.