Earlier, the German woman was mistakenly reported by Japanese media as a 40-year-old Vietnamese visitor to Japan. After recovering in Japan, the woman has come back to Ho Chi Minh City's District 2 to work, said the ministry's Preventive Medicine Department, Xinhua news agency reported.
Besides the Zika-infected German citizen, Vietnam has so far detected three other patients who live or work in Ho Chi Minh City and the two central provinces of Khanh Hoa and Phu Yen.
Zika virus is acquired through bites from infected Aedes aegypti mosquitoes. Common symptoms include fever, skin rash and joint pains.
It can also cause microcephaly, brain malformations and other birth defects if a pregnant woman is infected.
