On April 23, 68 students from a primary school in Longxi County, Gansu Province simultaneously exhibited various adverse symptoms including blurred vision, weakness in the limbs, headache, and abdominal pain. Later, patients with milder symptoms were sent to the local health center for observation and treatment, while more than 10 patients with more serious conditions were sent to Lanzhou for treatment. On May 2, the diagnosis from the Shouyang Town Health Center of Longxi County and the First Hospital of Lanzhou University was: collective hysteria.