Three premature babies at the Rambam Medical Center in Haifa were found on Thursday to be carrying the swine flu virus. The H1N1 virus has remained dormant in all three infants, who have been isolated from the other newborns while the hospital conducts an investigation to determine the source of the virus.

So far this winter, two Israelis have died as a result of swine flu. A 3-year-old boy succumbed in mid-January, marking Israel’s first swine flu death since 2009. Two weeks later, a 28-year-old woman died as well.

Health Ministry officials said last month that there were currently no special safeguards prepared against swine flu in Israel, but that the flu vaccine administered this year includes immunization against the life-threatening virus.

Children, the elderly, patients with chronic illnesses and pregnant women are considered to be at high risk of contracting the disease.

Hundreds of cases of the H1N1 virus were recorded in the West Bank in recent weeks, with at least 10 people dying as a result of the illness, according to Israel Radio.