The man, 28, hailing from Dong Anh district, joined the Ha Nam patient in a wedding party in Ha Nam province on April 22.
The Ha Nam patient was confirmed on April 29 and the Hanoi man was taken for COVID-19 test together with those who had come into close contact with the patient.
The Hanoi Centre for Disease Control announced late on April 29 that the man had carried the SARS-CoV-2 virus.
Preliminary epidemiological investigations show more than 30 people had direct or indirect contact with the newly-detected patient.
Relevant agencies set up checkpoints around the patient’s residential area and disinfected his house and neighbours’.
Hanoi is the third locality in Vietnam that has recorded a community case during the day. Alongside Hanoi, Ha Nam reported five cases and Ho Chi Minh City had one case.
Hanoi ups COVID-19 arlet to highest
During a meeting held earlier on the same day, Hanoi authorities decided to raise its COVID-19 alert to the highest level.
They requested local administrations to suspend events of large gatherings, including a V.League football clash between Hanoi FC and Saigon FC at Hang Day stadium.
Policemen were asked not to travel to their hometowns for family reunion during the four-day public holiday, starting on April 30.
Those who return to Hanoi from other localities were required to make health declaration with local health facilities.
The city also decided to temporarily suspend non-essential services such as U-sing along (karaoke), bar clubbing, Internet gaming and discotheque, starting from 0.00hrs on April 30.