Survivors of Cyclone Nargis are seen in Tontay, 15 miles from Rangoon, 17 Jun 2008

The United Nations is launching a massive campaign in Burma this week to fight the spread of dengue fever in areas hard-hit by last month's deadly cyclone.

Starting Tuesday, hundreds of volunteers will begin fanning out across the main city of Rangoon and into the Irrawaddy Delta, where the U.N. estimates more than two million people have been affected by the storm.

The groups will be looking for mosquito larvae that breed in pools of standing water during the monsoon season.  That season began early last month when Cyclone Nargis ripped across the delta, leaving more than 130,000 people dead and missing.  

U.N. officials fear the number of cases of the mosquito-borne disease could be higher than usual this year because many people have lost their homes and are more exposed to mosquitoes. 

Some information for this report was provided by AP.