SINGAPORE - Singapore must assume that Zika is no longer confined to the clusters of Aljunied and Bedok, Prime Minister Lee Hsien Loong said in his first remarks on the Zika outbreak in Singapore.
"The cases so far have been in Aljunied and Bedok, but we must assume that Zika is elsewhere in Singapore too," he said in a post on Facebook on Thursday (Sept 1).
He urged everyone to do their part to wipe out mosquitoes, which can be vectors for both Zika and dengue viruses.
"Our best defence is to eradicate mosquitoes and destroy breeding habitats, all over Singapore. Do the 5-step Mozzie Wipeout. Let's all do our part to fight Zika, and dengue as well," he said.
He also said in his post that it was only a matter of time before Zika reached Singapore.
"Do take precautions and get tested if you show symptoms," he advised.
On Thursday, authorities announced that a second pregnant woman was found to be infected. She was among 31 new cases confirmed, of which three had no links to the existing clusters of Aljunied and Bedok.
The three live in Tagore Avenue, Yishun Street 81 and Harvey Crescent. Including five more look-back cases identified, there were 151 locally-transmitted cases of Zika in Singapore.
Of the 115 people who tested positive for Zika virus infection as of Wednesday (Aug 31), 57 are foreigners who live and work in Singapore, the Ministry of Health (MOH) said.
Seven nationalities are affected, including 23 mainland Chinese.
There are 15 Indian nationals, 10 from Bangladesh and six from Malaysia. One individual is affected from Indonesia, Myanmar and Taiwan.
"All had mild illness. Most have recovered while the rest are recovering well," said MOH.
A Malaysian woman living and working in Aljunied was identified as the first known case of a person being infected locally on Saturday.
A pregnant woman who lives in the Aljunied Crescent and Sims Drive area was among the cases confirmed on Wednesday.
While the symptoms of Zika - fever, rash, joint or muscle ache, red eyes or a headache - are mild for most people, it can cause birth defects in babies if their mothers are infected during pregnancy.
Inspection and outreach efforts have already started in a potential new cluster of infection in Bedok North Avenue 3.
They are to start in Joo Seng and Punggol Way, where isolated cases were found, NEA said. Control operations are ongoing in Aljunied.
One of the control measures is the roll-out of Gravitraps, which trap female mosquitoes - 30,000 have been rolled out since the start of the year and another 20,000 are being set up.
NEA is also assessing high-risk areas based on data from the Gravitraps, but did not specify where these areas are.
A strategy to keep the incidence of the disease low was shared at a briefing on Thursday afternoon by the Ministry of Health (MOH) and NEA.
Efforts to keep the mosquito population low and break the disease's chain of transmission will be carried out.
Prevention and control measures are important as it may take many days before an infected person sees the doctor, said Mr Derek Ho, NEA's director-general of public health.
Symptoms generally manifest three to 12 days after infection sets in, and some who contract the disease may not present any symptoms.
Professor Leo Yee Sin, Director of the Institute of Infectious Diseases and Epidemiology at Tan Tock Seng Hospital, said that active case finding, which is what the authorities are doing currently, is the reason that new cases have been uncovered.
If the authorities had not actively looked for the cases, they may have never come to light as symptoms are too mild, said Dr Derrick Heng, group director of public health at MOH.
MOH is analysing the strain of Zika virus to determine its origin, but this may take a few months to verify, they added.