A stretch of Orchard Road and a surrounding area in Somerset is now a red zone for dengue. Any area with more than 10 dengue cases is considered a red zone or a high risk area.

Some 18 cases have been reported at the cluster. Of the cases, 15 are construction workers at the Orchard Gateway Construction while the other three cases are individuals working nearby, the National Environment Agency told the Straits Times on Tuesday.

The Orchard dengue cluster includes teenage hangout area Scape Skate Park and shopping malls Triple One Somerset and 313 Somerset.

There were 18,153 dengue cases as of last week.