Cambodian has confirmed its eighth case of H1N1, sometimes called swine flu, with a young Australian woman testing positive for the illness, health authorities said Wednesday.

Ly Sovann, deputy department of communicable disease control for the Ministry of Health, said the 15-year-old girl had flown in from Bangkok on Thai Airways and was red-flagged by scanners at Phnom Penh International Airport.

“She was taken to the local hospital, Calmette, on Tuesday night, for a health checkup,” he said, adding that her health had improved.

Authorities are now looking for people who may have been sitting near her on the plane.

“We’ve already searched their homes and the hotels where they are staying, but until now we have not found such cases,” he said.

The H1N1 virus, which spread from Mexico earlier this year but appears to be less deadly than initially feared, appeared in Cambodia in June, when four American students tested positive. In subsequent days, two Cambodians and one Filipino also tested positive.

The World Health Organization has declared a global epidemic of the disease, which authorities had first attempted to contain. Worldwide, the illness has killed more than 250 people, but it has infected tens of thousands.