The Tokyo Metropolitan Government said Thursday that a 3-year-old boy died of influenza-related brain fever after being infected with swine flu. He became the youngest, and 29th, fatality of the H1N1 epidemic in Japan.

The boy went to see a doctor Monday evening after coming down with a 38-degree fever, coughs and mucus. He went to the same doctor when his temperature hit near 40 Tuesday morning. In abbreviated tests, he was confirmed to have the Type A H1N1 influenza virus, and was administered Tamiflu.

His condition worsened Tuesday evening and he was taken to another hospital, where he soon died.