In Brazil, the virus has been linked to a rare birth defect, microcephaly, which causes small head size.
Those infected in Singapore include 36 foreign construction workers employed at a site near Aljunied, in the southeast of the island, the health ministry and the National Environment Agency (NEA) said yesterday.
On Saturday, authorities had confirmed Singapore’s first case of a local transmission of the virus, to a 47-year-old Malaysian woman, also from the Aljunied area.
“MOH (the ministry of health) cannot rule out further community transmission in Singapore, since some of those tested positive also live or work in other parts of Singapore. We expect to identify more, positive cases.”
The authorities have tested 124 people, primarily construction workers. Seventy-eight tested negative and five are pending. Thirty-four have recovered.
It was not said where the foreign workers were from, but Singapore hosts a large contingent from the Asian sub-continent.
“All the cases are residents or workers in the Aljunied Crescent/Sims Drive area. They are not known to have travelled to zika-affected areas recently, and are thus likely to have been infected in Singapore. This confirms that local transmission of zika-virus infection has taken place,” the authorities said.
Dozens of NEA staff cleaned drains and sprayed insecticide in the mainly residential area early yesterday, and volunteers and contractors handed out leaflets and insect repellent.
The NEA workers had by then accessed 1,800 premises of a total of 6,000 in the area to check for mosquito breeding.
Residents welcomed the clean-up. “I’m very scared of mosquitoes, because they always seem to bite me. They never bite my husband,” Janice, 31, who gave only her first name, told Reuters.
“This concerns me, because, maybe, in a couple of years, I want to have another (child).”
Zika was detected in Brazil last year and has since spread across the Americas. The virus is a risk to pregnant women. It can cause severe birth defects. It has been linked to 1,600 cases of microcephaly in Brazil.
The Singapore government said there were “ongoing local transmission” cases in Indonesia, Thailand, and Vietnam.
Other countries in the region to have detected the zika virus since 2013 include Bangladesh, Cambodia, Laos, Malaysia, Maldives, and the Philippines, according to the World Health Organization (WHO).
Malaysia has stepped up surveillance at main transit points with Singapore.
Health director-general, Noor Hisham Abdullah, said leaflets on zika-prevention were being handed out and paramedics were at entry points to handle visitors with potential symptoms.
As of this month, Malaysia has screened two million visitors at air, sea, and land entrances, and has found no zika infections.
In Thailand, where 100 cases of zika have been recorded this year, the Department of Disease Control (DDC) is screening all athletes returning from the Olympic Games in Brazil, but is not otherwise changing its prevention measures.
“Every country in this region has zika-transmission cases,” said Prasert Thongcharoen, an adviser to the DDC.
“Thailand has, however, managed to contain the problem through early detection.” In Indonesia, the health ministry said there had been no recent cases.