INDIANAPOLIS | State health officials are urging Hoosiers to use caution during the cleanup of their flood-damaged homes because dangers remain even after the floodwaters recede.

Although homeowners are often tempted to begin cleaning out their homes and salvaging possessions as soon as possible, it's wise to wait until floodwaters fully recede, said Jennifer Dunlap, a spokeswoman for the state Department of Health.

Pools of water in and outside flooded homes can harbor waterborne diseases and pathogens such as E. coli bacteria that floodwaters swept out of swamped septic systems, she said.

"There's a lot in those floodwaters. A lot of stuff from septic systems have washed up and you're getting your hands and yourself in the same thing that's in the sewers," she said.

Because a small cut or scratch can make people more susceptible to diseases like tetanus -- an acute, often fatal, disease -- state health officials recommend that people in flooded areas make sure they are up-to-date on their tetanus immunizations.

In the coming days, homeowners returning to flooded homes should also remember that their private wells may have been tainted by floodwaters, state health officials said.

In fact, any well in a flooded area should be assumed to be contaminated with sewage that washed into it during the flash flooding, the health agency said. Residents should not use those wells until they are inspected by a professional well contractor and treated.

In the next few weeks, areas that were flooded may see a growing number of mosquitoes if the weather turns hot and dry because that creates ideal mosquito breeding conditions, Dunlap said.

"Stagnating water is where they breed, so once it's safe to get out in your yard, that's something to watch out for," she said.

The state's health department's Web site -- http://www.in.gov/isdh/ -- has added tips on how homeowners should approach the cleanup work on their property once floodwaters recede.

Those include first turning off a home's electricity and cleaning and drying wet light fixtures before turning the electricity back on.

Any items that cannot be salvaged should be thrown away, such as wet ceiling tiles, paper products, baseboards, dry wall and insulation.

Carpets may be saved by wet vacuuming, shampooing, and ensuring that it's dried completely.

But most mattresses or other large items soaked with floodwaters will probably have to be discarded. Some mattresses can be salvaged after disinfecting and air-drying.

If possible, homeowners should open windows and doors during the cleanup process and leave them open for at least 24 hours.