One of Vietnam's top health officials says neither of its two confirmed Zika patients had recently traveled abroad.
The country's health ministry confirmed its first two cases of the mosquito-borne Zika virus on Tuesday, announcing that a 64-year-old woman in the popular beach resort of Nha Trang and a 33-year-old pregnant woman in Ho Chi Minh City tested positive for the Zika virus in late March, after they were both hospitalized with fevers, eye strain and rashes.
"[They were infected with the virus] by mosquitoes. However, it’s unclear where and how, since the number of tourists coming to Vietnam and the number of Vietnamese traveling abroad are huge," Dr. Tran Dac Phu, who heads the tropical country's preventive health department, told VOA. "So up to now we have not yet determined where and how they got the virus from mosquitoes."
Tran also said Vietnam is raising its virus alert system to level 2, which indicates there have been confirmed cases but has not yet issued travel restrictions. He said the country was launching a Zika prevention campaign including educating pregnant women, raising awareness, and expanding measures to protect against mosquitoes.
He also said Hanoi officials are working closely with the World Health Organization and the Centers for Disease Control and Prevention in monitoring and sharing information on Zika, which has been linked to increased rates of microcephaly — a birth defect in which babies born to infected mothers have unusually small heads and brains.
Tran said both patients are in stable condition with mild symptoms and could be discharged in several days, adding that it is unlikely either had spread the virus to others.
"One of them came from a clean working environment and the other, upon developing symptoms, was hospitalized immediately and actively quarantined," he said.
Brazil, which has been hardest-hit by Zika, has reported more than 4,000 cases of microcephaly since October.
The World Health Organization has declared the Zika outbreak an international health emergency.
This report was produced in collaboration with VOA's Vietnamese Service.