Qa'dah 16, 1435, Sep 11, 2014, SPA -- More than 100 people have contracted dengue fever in Japan, in the first domestic outbreak of the disease in 70 years, dpa cited the government as saying Thursday. There were now 103 confirmed cases, the Health Ministry said, almost all of whom had visited the apparent centre of the outbreak, Yoyogi Park in central Tokyo. A large portion of the park has been closed to visitors while health authorities investigate the origins of the outbreak and catch mosquitoes carrying the virus. Dengue, more commonly found in less-developed tropical countries, causes a flu-like illness, including headaches, fever and joint pains, according to the UN's World Health Organization (WHO). There is no specific treatment, but proper medical care can reduce fatality rates to under 1 per cent, according to the WHO.