Eighteen soldiers were infected with swine flu after coming in contact with fifteen teens in the Birthright Israel program who were diagnosed with the virus. The teens have been quarantined in Israeli hospitals while the soldiers were released in good condition in recent days. The IDF indicated that the medical conditions of the soldiers were being closely followed. Greg Harnage, 19, from Roseville, California, was one of the unfortunate teens who caught the virus. He was "a little surprised, a little upset" when he first found out he had swine flu. "I thought it was just a cold," he said on Monday. Harnage spent 10 days touring the country this month and felt a bit sick after the journey, experiencing a runny nose, cough and fever. After a visit to the doctor, he tested positive for the disease. The group leader told the supervisor, who passed on the information to other groups within birthright. Harnage was quarantined in the Judaean Guest House in Jerusalem to prevent the spread of the virus. He experienced a full recovery and is expected to return to the United States in a day or two. "I feel 100% better," explained a still bed-ridden Harnage. "I'm just trying to get out of here as soon as possible." The other students who contracted the disease had similar experiences. Birthright organizers said that they were "immediately quarantined" and treated according to Health Ministry standards. The treatment paid off - those who were ill are now "in good health" and their condition is "defined as good." The organization noted that the teens who got sick represented only a fraction of the many birthright participants who traveled the country this year. None of those who contracted swine flu are sure exactly how they got it or why particular students contracted it while the rest on the trip were fine. "We went to all the same places," said Harnage. They took the same plane to Israel, sat in the same buses, and saw the same sites. The source of the swine flu continues to be a mystery. Taglit-Birthright Israel is a Zionist organization that sponsors free 10-day trips to Israel for Diaspora Jews, ages 18 to 26, who have neither traveled to Israel before on a peer educational trip or study program nor have lived in Israel past the age of 12.