The outbreak of the Zika virus spread in Southeast Asia Thursday, after Singapore noted that total cases had risen to 115 while Malaysia confirmed that its first reported case was a woman who had traveled to the neighboring city-state.

The woman was diagnosed with Zika after she experienced rash and a fever for a week after her Singapore trip, Malaysia's Health Minister Subramaniam Sathasivam told Reuters.

The woman's child, who is in Singapore, and four other Malaysian nationals also tested positive for the virus, Reuters reported.

Malaysia, which shares a border with Singapore, has been taking precautionary measures since Monday such as scanning people to detect fever at major entry points and various airports, The Straits Times reported.

Singapore also announced late Wednesday its first case of a pregnant woman testing positive for locally-transmitted Zika virus, as a potential new infection cluster emerged.

The pregnant woman lived in the Aljunied Crescent or Sims Drive area, the first reported infection cluster, according to a joint statement by the Ministry of Health (MOH) and the National Environment Agency (NEA).

She will have a maternal-fetal medicine specialist's counselling and advice, the agencies said, while her doctor will closely monitoring both her health and her baby's development.

Meanwhile, a new group of infections were identified in Bedok North Avenue Three, east of the previously affected areas.

A further 33 locally-transmitted Zika cases were found, raising the total number of infections to 115. Nine of the new cases were detected as a result of the MOH's back-testing of patients who had shown signs of Zika symptoms.

India's foreign ministry confirmed that 13 Indian nationals were among those tested positive for Zika, while six Bangladeshi nationals diagnosed with the virus was confirmed by Bangladesh's foreign ministry, Reuters said.

The Chinese embassy in Singapore was informed that 21 Chinese nationals residing in the city-state had been affected by the Zika virus, China's Foreign Ministry told Reuters on Thursday.

Any disease outbreaks in Singapore, which has a tight system for containing disease, shows how difficult the disease is to control, Thomas Frieden, director at the U.S. Centers for Disease Control and Prevention, said in a Thursday NBC report.

The foreign ministry added that the 21 Chinese nationals' health was not under threat, and some had already recovered, Reuters reported.

"Over time, we expect Zika cases to emerge from more areas," Gan Kim Yong, Singapore's Minister for Health, said in the official statement. "We must work and plan on the basis that there is Zika transmission in other parts of Singapore and extend our vector control efforts beyond the current affected areas.