The man, who came to Vietnam in March and has since worked in Binh Duong province, was diagnosed with mild coronavirus symptoms at a Family Medical Practice clinic in Ho Chi Minh City on June 30 before leaving for Indonesia.
He was immediately transferred to the Binh Duong Provincial General Hospital for medical observation. Authorities also quarantined a total of 145 people who had close contact with the Indonesian man.
Latest RT-PCR tests conducted by the Ho Chi Minh City Pasteur Institute showed the man had not contracted the virus, and he is now in stable condition. All 145 people having close contact with him have also tested negative.
With the Indonesian confirmed negative, Vietnam has gone through 77 days without new locally transmitted coronavirus infections.
The country has so far recorded 335 cases, of which 326 cases have been discharged from hospital after making a full recovery. Of the remaining 19 patients, 8 have tested negative for the virus at least once.
According to the Ministry of Health, Vietnam is one of the four Southeast Asian nations that have recorded no deaths so far alongside Cambodia, Timor-Leste and Laos.
In Southeast Asia, the epidemic is evolving in a complex manner, with Indonesia topping the list of hardest hit countries with nearly 58,000 positive cases and close to 3,000 deaths.