Worries increase that some of the 25,000 people that attended Bieber’s concert in Chiba Prefecture may have brought back an unpleasant “souvenir” with them.

This week a male Justin Bieber fan was diagnosed with the measles and presumed to have been highly contagious at the time he attended the singer’s large-scale concert, held at Chiba Prefecture’s Makuhari Messe on August 14.

Worried about a possible epidemic, the Disease Control and Prevention Center (DCC) and other medical organizations have been alerting the public about the situation.

“This is a message from the city of Chiba to the Aichi Pediatric Association. A patient suffering from the measles was found in attendance at the Justin Bieber concert held at Makuhari Messe. Since the measles is an airborne virus, it’s possible that other concertgoers may be infected. Those who develop a fever are urged to visit and consult with their doctors.”

“There’s fear that the measles outbreak in the Kanto region might spread to the rest of the country. It should be noted that the virus has a much higher rate of infection than the flu. Infection might be a low concern for some, however, risk of death is six times higher for women who are pregnant.”

The attached image goes on to outline the concert victim’s schedule leading up to the concert and his subsequent diagnosis:

August 9: Developed a fever of 39.1°C (102.4°F)
From August 13: Developed a full body rash
August 13-15: Visited the Tokyo and Kanagawa areas
August 14: Attended a concert at Makuhari Messe
August 19: Diagnosed with the measles

While dire concern might be warranted, Japan has continued to struggle with random measles outbreaks since the mid-90s, when changes to the country’s laws on childhood immunization gave parents the choice of deciding when or if to vaccinate their child(ren). Many parents have particularly opted out of the measles, mumps, and rubella (MMR) vaccine over the years, due to some of the serious side effects in one of the previous strains used in the vaccine. As a result, the country is often prone to measles outbreaks, like the most recent major one back in 2014.

According to the Centers for Disease Control, links were made between measles outbreaks in Japan and measles exportation to the United States, identifying Japan as the country most responsible for Stateside breakouts.

Since the measles has around a 90 percent transmission rate for anyone unvaccinated that comes in contact with the disease, and almost 100 for unvaccinated, pregnant women, it’s highly recommended that those who haven’t already been vaccinated against the measles, or who are showing symptoms of an outbreak, make an appointment with their doctor as soon as possible.

Luckily the patient in question seems to be recovering normally, but others who could have been infected may not be so fortunate.

Source: Twitter/@pediat_mama, Twitter/@tabitora1013 via My Game News Flash, Centers for Disease Control (MMWR Weekly)
Feature/top image: Flickr/Lou Stejskal via Wikipedia