South Korea has confirmed a woman who returned from a trip to Vietnam has been infected with the Zika virus, the country's ninth such case, health authorities here said Friday.

The 40-year-old woman, whose identity has been withheld, tested positive for the mosquito-borne virus after traveling to Ho Chi Minh City from July 11-15, according to the Korea Centers for Disease Control and Prevention.

The KCDC said she had been infected with the virus after being bitten by a mosquito during her trip to the Southeast Asian country.

She has shown symptoms of rash, muscular pain, joint pain and conjunctivitis since July 19 and went to a hospital on Monday to receive an examination, health authorities said.

The latest case raises the number of confirmed infections in South Korea to nine, since the country reported its first Zika patient in March.

The virus, first discovered in Africa, has been linked to thousands of birth defects in newborn babies like abnormally small heads and improperly developed brains in Brazil. (Yonhap)