The northern Thai city of Chiang Mai, whose metropolitan area contains almost a million people, is at risk from the Zika virus, according to provincial authorities.
Chiang Mai-based City News reported that provincial governor Pawin Chamniprasart has designated a control zone for the Zika virus in the San Sai Luang District of Chiang Mai Province, in order to contain the spread, after several cases were identified in the district.
Seven people have reportedly been infected so far in the province, which is also at risk of a dengue outbreak.
The mosquito-borne Zika virus has been known to occur largely in tropical regions of Africa and Asia, and is related to dengue fever, Japanese encephalitis and yellow fever.
A widespread Zika epidemic began in Brazil early last year, spreading to other parts of South and North America and to some Pacific islands. It has since been detected in Southeast Asia, in Singapore and Thailand.
The symptoms of Zika infection are generally mild, although in pregnant women in can cause brain malformations and other defects in unborn children. There are no vaccines or specific treatments.