Pic: AP.

TOKYO (AP) — Japan has reported 19 new cases of dengue fever, most of them thought to have been contracted during visits to popular Yoyogi Park in downtown Tokyo.

The cases announced Monday raise to 22 the number of dengue infections thought to have been contracted locally. The health ministry earlier reported three local cases, the first in nearly 70 years.

Japan sees dozens of imported cases of dengue fever each year, mostly in tourists who catch the illness while traveling in tropical regions. The disease, which is transmitted by mosquito, was common in Japan during World War II but was locally eradicated for decades.

Dengue causes symptoms including fever, severe joint pain and headaches. There is no treatment, and in a small number of cases patients can suffer severe and life-threatening bleeding.