Bangladesh confirmed its first case of Zika virus infection in an old blood sample of a 67-year-old man who had not been overseas, Reuters reported. The man reportedly lives in the southeastern port city of Chittagong.

"He was well. None of his relatives had tested positive," Zahid Maleque, Bangladesh's junior health minister, was quoted by the news agency as saying.

"The virus was found in the man as we tested old blood samples of nearly 1,000 people afflicted with fever in 2014 and 2015," Mahmudur Rahman, director of the ministry's Institute of Epidemiology, Disease Control and Research, said

Meanwhile, South Korea has also confirmed its first case of the Zika virus in a 43-year-old man who travelled to Brazil, its centre for disease control said, according to the Reuters.

The Zika virus, transmitted by the Aedes aegypti mosquito, has caused alarm in Brazil, the Caribbean and many Latin American countries. China has also reportedly confirmed the presence of the Zika virus in the country, and has started an extensive public cleaning campaign to stop the virus from spreading.

Scientists are studying the links between the Zika virus and two neurological disorders — microcephaly and Guillian-Barre Syndrome.

Brazil, which has seen a sudden spike in microcephaly cases, has been one of the worst-hit countries in the world. Over 500 cases of microcephaly have been confirmed since the start of the outbreak and an additional 3,900 suspected cases are being investigated.

The World Health Organisation declared the Zika virus a public health emergency Feb. 1, 2016. The Zika virus is likely to affect 4 million people in America, according to the WHO.

India's Health Minister JP Nadda said no case of Zika virus infection has been confirmed in the country yet, although states have been put on alert.