The H5N1 strain of avian influenza has been tested for in at least 12 people in Cambodia, according to the health ministry, after an 11-year-old girl passed away this week from the disease in the nation’s first known human transmission in almost ten years.

According to a statement from the health minister on Friday, the victim’s father, who was a member of the group the victim had contact with in a province east of the capital Phnom Penh, tested positive for the virus but showed no symptoms.

The statement did not disclose the test results of others in the group and did not specify how the victim’s father had contracted the virus, commonly known as bird flu.

The girl’s case was the first known human infection with the H5N1 strain in the Southeast Asian country since 2014, Bunheng had said on Thursday.

The girl from Prey Veng province was diagnosed with bird flu after falling sick with a high fever and cough on Feb. 16, the statement said.

When her condition deteriorated, she was transferred to the National Children’s Hospital in Phnom Penh but died on Wednesday, the health ministry said.

Since early last year, bird flu has ravaged farms around the world, leading to the deaths of more than 200 million birds because of the disease or mass culls, the World Organization for Animal Health (WOAH) recently told Reuters.

The H5N1 influenza has expanded to mammals, according to the World Health Organization (WHO), but the risk to humans is still minimal.

According to WHO Director-General Tedros Adhanom Ghebreyesus, H5N1 has been spreading among domestic and wild birds for 25 years, but recent reports of infections in mink, otters, and sealions “need to be followed cautiously.”

Health officials in Cambodia advised people to avoid handling sick or dead animals and birds and to call a hotline if they had any suspicions that they had become ill.