Health officials in Sweden reported one confirmed case of meningitis and two probable cases among Swedes who attended a recent scout jamboree in Japan, a day after urging all 1,900 Swedish participants to consult a doctor.
"We have one confirmed case of meningitis. It's a young girl who is being treated here," a spokeswoman for Stockholm's Karolinska hospital, Mirjam Kontio said.
Two other probable cases are currently being examined, Swedish Public Health Agency spokesman Christer Janson said.
Some 1,900 Swedes, most of them teens aged 14 to 17, took part in an annual scout jamboree in Japan from July 28 to August 8, attended by some 30,000 people from more than 150 countries.
Health authorities urged Swedes who went on the trip to get antibiotics to prevent the spread of the highly contagious disease, after the three suspected cases emerged.
Meningitis is an acute inflammation of the protective membranes covering the brain and spinal cord and can be life-threatening. Symptoms include high fever, a stiff neck, vomiting and severe headaches.
Several European participants have displayed symptoms, and three cases have been confirmed in Scotland, the health agency said.