Zika arrives in Bangkok's central business district

Bangkok's Sathon and adjacent districts are under close watch for possible Zika virus transmission after 21 people were diagnosed with the disease in Sathon. (Photo by Pattanapong Hirunard)

Twenty-one cases of the Zika virus have been reported in Bangkok's Sathon central business district, and officials are now watching for more possible infections in several adjacent districts.

Dr Wantanee Wattana, deputy permanent secretary for the Bangkok Metropolitan Administration (BMA), said those infected included a formerly pregnant woman whose husband had just returned from Singapore, local media reported on Saturday.

The woman had a high temperature, rashes, joint pain and red eyes. She contracted the virus in the 37th week of her pregnancy but has since given birth and both the mother and her newborn are safe.

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A survey found many mosquito-breeding areas within a 100-metre radius of the family's residence. Health surveillance of infected people will remain active in the area for the next 30 days and in districts adjacent to Sathon.

Sathon borders Bang Kholaem, Bang Rak, Khlong Toei, Pathumwan and Yannawa districts. Infected people are being advised to stay home for 30 days.

The Public Health Ministry reported earlier that there had been five Zika patients a year on average in the country from 2012 to 2015. Zika is of particular concern because it has been linked to birth defects, with cases of microcephaly widespread in Central and South America.

About 20 other cases of the mosquito-borne virus have been reported recently in Bung Kan, Chanthaburi, Chiang Mai and Phetchabun provinces but control operations have proved effective, authorities said.