Zika infection during pregnancy can cause a serious birth defect called microcephaly that is a sign of incomplete brain development.
The Zika virus has now been found in 17 Alabama counties, including Marshall County, and a second travel-related case has been confirmed in Mobile County.
The on-site workers quarters at two other dormitories at Senoko South and Kranji were also inspected on August 27.
"It's quite frightening, because I thought Zika is something happening on the other side of the world".
Zika can be passed along by sex, but the bigger threat is that some kinds of mosquitoes can carry it.
"MCHD will continue to monitor the situation and assist the community in identifying other possible cases", Eichold said in the statement.
As of last Thursday, the Alabama Department of Public Health (ADPH) reports there have been a total of 29 travel-associated positive tests for the Zika or Flavivirus (unspecified but likely Zika) among the 241 state residents who have been tested.
Pregnant women and their partners are urged not to travel to some four dozen countries - a lot of them in the Caribbean and Latin America - where Zika virus is now active.
They included a pregnant 32-year-old.
This "vertical transmission" from female mosquito to her eggs may help the virus survive even when conditions are poor, such as during the dry season in the tropics.
Ellyadi's mother, Lela Noordin, said: "We have to take care now that this virus is around", said Noordin.
Taiwan on Monday issued a travel advisory for Singapore, urging travellers to watch out for mosquito bites and cautioning pregnant women and those planning to conceive to postpone trips to all areas with Zika cases.
Singapore authorities have continued to inspect thousands of homes around the country, spraying insecticides and removing potential mosquito breeding habitats.
As of Monday, the MOH says that they have completed testing of foreign workers at a Sims Drive construction site, who previously showed symptoms of fever or rash.
The latest global outbreak of the disease began in Brazil in early 2015.