Singaporean environmental authorities checked and sprayed chemicals every residential apartment in Aljunied district, where 41 Zika virus-positive patients were reported, including 36 foreign construction workers. Most of the patients have been recovered.
However, five more suspected cases have been discovered, including one foreign worker.
On August 27, the health ministry of Singapore confirmed first locally-transmitted case of Zika in the area, a 47-year-old Malaysian woman who lived and worked in Singapore.
In May, Singapore confirmed the first Zika virus injection, brought in by a 48-year-old man who returned from Brazil.
Since early this year, the nation has reported over 10,000 cases of dengue fever, of which seven died.