South Korean health authorities said Wednesday that they are conducting tests on nine additional suspected cases of swine flu amid a heightening alert against the deadly virus that is rapidly spreading across the globe, according to Yonhap News Agency.
The Korea Centers for Disease Control and Prevention (KCDC) said in a statement that the nine individuals being tested recently returned from trips to Mexico and the United States and showed flu-like symptoms such as coughing and fever.
On Tuesday, the KCDC said that a 51-year-old woman had been quarantined at a state-designated hospital after being identified as the nation's first probable case of swine flu.
Patients are identified as "probable" when they test positive for type-A influenza that regularly causes outbreaks among pigs and is transmittable to humans, but negative for human variants of the virus.
The report on the suspected patients comes as governments worldwide are struggling to control the spread of the highly infectious virus, which has reportedly killed over 150 people in Mexico alone.
Human cases have also been reported from the United States, Canada and some European countries, according to media reports, raising concerns that the virus is spreading at a faster-than-expected pace.
The disease control center raised its alert level Tuesday by one notch to "Yellow" from the previous "Blue," a move aimed at intensifying cooperation to stem the outbreak of swine influenza.