The number of cases of the mosquito-borne Zika virus in Singapore reached 258 on Monday, with health authorities warning it is no longer contained in one part of the city-state and likely to spread further.
In a joint statement, the Ministry of Health and the National Environment Agency confirmed 16 new cases, four of which were not linked to existing cluster areas.
"Over time, we expect Zika cases to emerge in more areas given the presence of the Aedes mosquitoes here," the statement said.
Zika is spread by the Aedes mosquito, which also spreads dengue fever.
"MOH and the National Environment Agency (NEA) will therefore adjust our strategies to manage Zika in the same way that we deal with dengue."
Despite having one of the highest standards of healthcare in Asia, dengue is endemic in tropical Singapore which sees high rainfall and humid weather, ideal mosquito-breeding conditions.
Most of the confirmed Zika cases have been centred around the adjacent suburbs of Aljunied and Paya Lebar.
Many of those initially infected were foreign workers on a condominium construction project, whom health authorities say are more suspectible because they live and work in close proximity.
The health ministry also said on Monday it would no longer isolate patients because of its "limited effect".
"As more cases emerge, there is evidence that there is transmission in the community with the presence of infected mosquitoes," said the health ministry.
Authorities are working to control the mosquito population, the ministry said, fumigating the affected areas and checking for breeding sites.
Those found with mosquito larvae in their homes can be fined up to Sg$5,000 ($3,700).
Zika causes only mild symptoms for most people such as fever and a rash but pregnant women who catch it can give birth to babies with microcephaly, a deformation marked by abnormally small brains and heads.
The virus has been detected in 67 countries and territories including hard-hit Brazil.
Several countries including Taiwan and Australia have warned pregnant women against travel to Singapore.
The Philippines on Monday reported the country's first locally-transmitted case of Zika, while Malaysia confirmed its first locally-transmitted case on Saturday.
The first case on Malaysian soil was reported in a woman who is believed to have contracted it while visiting her daughter in Singapore.
A member of a pest control team inspects drains at a Zika cluster in Singapore.