North Korea did not immediately react to the report but it has previously called criticism over its human rights record a "plot to overthrow" its regime.
Nearly 19% of all people who came in contact with 10-19 year olds got infected, more than any other age group included in the study.
This year the city set up a large screen in a studio streaming images of hundreds of people, some with mud kits consisting of a mini-pool, mud packs, mud soaps and colourful mud powders.
In February and March, a massive outbreak among members of the Shincheonji Church of Jesus made South Korea the scene of the first large outbreak outside of China.
The apparent suicide came after one of Park's former secretaries filed a complaint on Wednesday alleging the 64-year-old had sexually harassed her, the Yonhap news agency reported.
After a search involving hundreds of police, Mayor Park Won-soon's body was found at Mount Bugak in northern Seoul around midnight, near where his phone signal had last been detected.
The 1950-1953 Korean War ended in an armistice rather than a peace treaty, leaving US-led UN forces technically still at war with North Korea.
North Korean leader Kim Jong Un presided over a video conference meeting of the ruling party's Central Military Commission, where members "took stock of the prevailing situation."
Enraged North Korean people across the country "are actively pushing forward with the preparations for launching a large-scale distribution of leaflets."