BANGKOK (Reuters) - Thailand should not worry about the Zika virus, its Public Health Ministry said on Tuesday (Feb 1), just a day after the World Health Organization (WHO) declared the virus an international emergency and the second case of the virus in the country this year was reported by a Bangkok hospital.

"Thais should not worry. Thailand has no outbreak of this disease," the Ministry of Public Health said in a statement. "We have asked everyone to monitor and prepare measures to look after this disease ... Thais should not panic. Mostly if patients get this disease they recover," the ministry said.

Thailand is the worst-hit country in South-east Asia, with an average of five cases a year since 2012, according to the Ministry of Public Health.

Two cases of the virus have been confirmed this year, after Bhumibol Adulyadej Hospital in Bangkok announced that it treated a man "about 20 years old" infected with the Zika virus on Jan 24. He has since recovered.

In addition, last month, Taiwan reported one case of Zika infection in a man from Thailand after he set off a temperature scanner at Taiwan's Taoyuan International Airport.

The WHO on Monday declared the mosquito-borne Zika virus an international public health emergency due to its link to thousands of birth defects in Brazil.

Neighbouring Malaysia and Singapore have said they are at high risk for the spread of Zika if the virus is imported.

The WHO said last month the rapid spread of Zika in the Americas was due to a lack of immunity among a population that had not been previously exposed to the virus.

Thailand's Public Health Ministry has said there was "no technical evidence" of in-built immunity to Zika in Thailand.

According to a June 2015 article in The American Journal of Tropical Medicine and Hygiene there have been "several cases reported in travellers returning from Thailand".

Seven cases of Zika infection were found between 2012 to 2014 in Thai residents, it said. "These endemic cases, combined with previous reports in travellers, provide evidence that Zika is widespread throughout Thailand," the journal said.

Sill, the ministry said it was not overly concerned. "I ask you to have confidence in Thailand's surveillance system," Dr Amnuay Gajeena, director-general of the Disease Control Department, said in a statement.

The ministry has asked members of the public to help eliminate mosquitos around their homes and in their communities and has advised those travelling back from Zika-affected areas to report any symptoms.