When does Zika reach epidemic levels here?
Expert says Zika is new to Singapore, so we have not had enough experience to calculate the epidemic threshold
Another 31 new cases of locally-transmitted Zika infections were confirmed as of noon yesterday, including that of a second mother-to-be.
Perhaps more worrying, three cases not linked to any existing clusters have been identified. The three patients live at Tagore Avenue off Upper Thomson Road, Yishun Street 81 and Harvey Crescent near Simei.
As Prime Minister Lee Hsien Loong wrote on Facebook last evening: "We must assume that Zika is elsewhere in Singapore."
In his post, he reminded everyone to take precautions and get tested if they experience symptoms of the Zika virus.
He said Singapore has been tracking Zika for a while and knew that it was only a matter of time before it reached our shores.
ACTION: NEA started vector control operations and outreach efforts in Bedok North Avenue 3, Punggol Way and Joo Seng yesterday. TNP PHOTO: PHYLLICIA WANG
He said: "Scientists are still learning about this new disease. But we know that for most people, it is mild and often causes no symptoms at all.
"Pregnant women are at risk, as they are with other viral infections like dengue and chicken pox.
"The cases so far have been in Aljunied and Bedok, but we must assume that Zika is elsewhere in Singapore, too."
PM Lee added that our best defence is to eradicate mosquitoes and destroy their breeding habitats all over Singapore.
"Do the 5-step Mozzie Wipeout. Let's all do our part to fight Zika, and dengue as well."
The new cases confirmed yesterday raises the total to 151 since the first case was discovered on Saturday.
Like the first pregnant woman infected with Zika, the second mum-to be is also linked to the original Aljunied Crescent and Sims Drive cluster.
"Her doctor is following up closely with her to provide support and counselling," said a Health Ministry spokesman in a statement last night.
Apart from her and the three cases in new areas, MOH did not detail where the rest of the new cases were.
The existing Zika clusters include the Aljunied Crescent and Sims Drive cluster, which has now extended to Kallang Way and Paya Lebar Way, and a potential cluster at Bedok North Avenue 3.
Five other cases were detected as a result of MOH's look-back testing of previous cases, which is now complete.
In light of the rise in infections and the spread to new areas, perhaps it was inevitable this question was raised at the press conference yesterday: Is there a number for Zika to become an epidemic in Singapore?
Dr Derrick Heng, group director for Public Health at MOH, said that because Zika is new to Singapore, we have not had enough experience to calculate the epidemic threshold.
The Zika situation needs to be monitored to determine the calibration for an epidemic, added Professor Leo Yee Sin, director of the Institute of Infectious Diseases and Epidemiology at Tan Tock Seng Hospital.
She said: "At this point in time, we call it an outbreak because we've never had it before. We're seeing so many cases right now and we're actively dealing with the issues."
Going by the experience of Colombia, which had 6,000 cases of infection a week at its peak earlier this year, Singapore is some distance away from epidemic levels.
The South American nation declared an end to the epidemic in late July when the number of new infections dropped to 600 a week.
Singapore authorities said that as of Wednesday, two rounds of thermal fogging had been completed at the Aljunied Crescent and Sims Drive cluster, including the cluster in Paya Lebar Way and Kallang Way.
All drains have been flushed and another round of fogging will be conducted this week. A total of 49 breeding habitats - 26 in homes and 23 in common areas or other premises - have been detected and destroyed.
Indoor spraying, misting and oiling have also been conducted and daily misting of common areas is ongoing.
The National Environment Agency (NEA) started vector control operations and outreach efforts in Bedok North Avenue 3, Punggol Way and Joo Seng yesterday.
As of Tuesday, NEA has served notices on more than 500 inaccessible premises in the Aljunied Crescent/Sims Drive cluster to require the owners to contact NEA to arrange for an inspection, failing which NEA will proceed with forced entry.
The cases so far have been in Aljunied and Bedok, but we must assume that Zika is elsewhere in Singapore, too. Do the 5-step Mozzie Wipeout. Let's all do our part to fight Zika, and dengue as well.
- PM Lee Hsien Loong, in a Facebook post last night
Vector control efforts by the Inter-Agency Dengue Task Force
- National Environment Agency: Worked with the members of the Inter-Agency Dengue Task Force to step up vector control operations within the Zika clusters.
- Town councils: Stepped up their cleaning and larviciding of potential breeding habitats.
- Ministry of Education: Geylang Methodist primary and secondary schools activated their pest control operators and conducted fogging.
- Land Transport Authority: Stepped up vector control measures at all work sites and flushed the drains along the Kallang-Paya Lebar Expressway.
- Public Utilities Board: Conducted checking and sealing of chambers.
- National Parks Board: Cleared palm fronds and checking of tree holes at green verges.
- Housing Development Board, Singapore Contractors Association, Singapore Pest Management Association and Jurong Town Corporation: Sent advisories to all their contractors and members to step up vector control and preventive measures.
SPREAD OF ZIKA IN THE REGION
Of the 115 cases tested positive for Zika virus infection on Wednesday, 57 are foreigners who live and work here, the Ministry of Health (MOH) said yesterday.
Seven nationalities are affected, including 23 China nationals, 15 Indian nationals, 10 Bangladeshis, six Malaysians, an Indonesian, a Myanmar national and a Taiwanese.
"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.
The number of people who contracted Zika in Singapore has increased to 115 on Wednesday, MOH said.
A pregnant woman and her husband, who live in the Aljunied Crescent/Sims Drive area, were among the cases confirmed.
- The Straits Times.
Malaysia recorded its first case of Zika infection on Wednesday after a 58-year-old woman in Klang was suspected to have been infected by her daughter in Singapore.
She and her husband had visited their daughter on Aug 19 and returned on Aug 21. The daughter was confirmed as being infected on Aug 30.
The Health Ministry said the woman started exhibiting symptoms on Aug 28 and sought medical attention at a private clinic in Klang on Aug 30.
Full confirmation via blood tests is pending. - The Star.
An Indonesian woman has been infected with the Zika virus in Singapore, in the first case of the disease affecting an Indonesian, the Indonesian Foreign Ministry confirmed yesterday.
Foreign Ministry spokesman Arrmanatha Nasir said the patient had tested positive for Zika.
The woman, whose name and age were not disclosed by officials, is currently receiving treatment at a hospital in Singapore.
- Jakarta Post.