MANILA, July 10 (Xinhua) -- Dengue cases this year could reach a "phenomenal" number in the Philippines and might even surpass the country's worst outbreak in 1998, media reports said on Thursday.

    No less than 12,000 dengue cases have been reported from January to May, said Health Secretary Francisco Duque III, quoted by the Manila Bulletin.

    "There has been an increase of about 36 percent over last year," Duque said.

    "Our highest (number of cases) was in 1998. Let's cross our fingers and hope we don't reach that, but there are indications it could reach, even surpass (the record)," said the health chief of the country.

    In 1998, close to 40,000 cases of dengue, 500 of them fatal, were reported.

    "Let's brace for the worse but we are not helpless," he added.

    Duque said that the trend of the mosquito-borne disease is going up since 2005 because global warming causes the mosquitoes carrying the dengue virus to become extremely hyperactive.

    "Because they are hyperactive, they have to feed more and bite more," Duque said.

    He added that apart from global warming, the increase of dengue cases could also be attributed to urbanization and congestion.

    "We now have more people, more congestion so mosquitoes do not have to travel far to transmit their virus," he said.