The number of confirmed dengue cases in West Bengal has shot up to 643 with 80 percent of the patients residing in Kolkata and its adjoining North 24 Parganas district the state health department said on Sunday. The disease has claimed three lives so far. The outbreak triggered a spat between ruling alliance partners Congress and Trinamool with the former alleging that the government was trying to suppress dengue figures. While 397 people were struck by the ailment in Kolkata 116 others fell sick in North 24 Parganas.The epidemic first struck in the second week of August. Hitting out at the Mamata Banerjee regime