Many of them are living in Ho Chi Minh City, and Ba Ria-Vung Tau and Binh Duong provinces, where Zika infections were detected, he added.
Therefore, the province is coordinating with the labour federation and the management board of industrial parks to increase communication campaigns, he said.
The health sector warned workers who regularly travel to disease-affected areas to visit medical facilitations for a check-up.
The province also held training courses on Zika detection for nurses and doctors.
A number of campaigns have been launched to kill mosquito larva in 171 communes and wards.
Vietnam detected 65 Zika cases by November 19, including 62 in Ho Chi Minh City.
The Zika virus is transmitted to humans primarily through Aedes aegypty mosquito bites and sexual intercourse.
The symptoms of Zika infection include fever, conjunctivitis, headaches and muscle pains. Zika infection during pregnancy may lead to microcephaly in babies, which is responsible for incomplete brain development and an unusually small head.
Currently, there is no vaccine for the virus.