The man, 28, who resides at Golden City Building of Nghi Phu commune, Dien Chau district, tested positive on June 16 evening after having close contact with his brother, a COVID-19 patient.
The patient, a member of a local ID card working team, was said to have contacted many people in seven communes of Dien Chau district.
The Nghe An provincial administration moved to mobilise hundreds of healthcare workers and police officers to Dien Chau to carry out contact tracing and quarantine.
Preliminary epidemiological investigations show more than 6,000 people had come into close contact with the patient.
Nghe An also decided to impose social distancing on Dien Chau district, starting from 00.00hrs on June 17.
At present, Nghe An province has recorded five COVID-19 cases, including four in Vinh City which is also under a social distancing order.