The Health Hazards of Severe Flooding

— -- Deadly floods in West Virginia have already killed at least 23 people and officials fear the heavy rains could put others in danger. But floodwater can be noxious even after it recedes, according to medical experts.

Standing water can contain harsh chemicals as waters wash over roads and other industrial areas. Bacteria can infect open wounds, causing dangerous infections, and infectious diseases including E.coli, norovirus and tetanus can spread easily in areas with flood damage, according to the U.S. Centers for Disease Control and Prevention. Those who escape their homes amid standing water or who go back to their homes to deal with flood damage should be extra vigilant about the safety risks.

“Disease producing bacteria are often carried by flood water and sewage,” Dr. Rahul Gupta, commissioner of DHHR’s Bureau for Public Health and State Health Officer, said in a statement last week. “These bacteria can remain alive and dangerous for long periods of time on items covered or exposed to flood water or sewage.”

Bleach and other cleaning supplies should be used to kill bacteria that can build up after a flood.

“It is important to remember that clothing and some furniture and household furnishings can be salvaged by cleaning and disinfecting,” Gupta added. “However, residents should discard whatever item cannot be cleaned and dried. Mattresses, for example, should be discarded.”

Dr. William Schaffner, an infectious disease expert at Vanderbilt University Medical Center, said in an earlier interview that mold or debris left behind due to muddy water can exacerbate asthma or breathing problems.

"You can get mold growing up on things that you’re then trying to clear out," Schaffner said.

As mud dries, it can turn into dust and affect the lungs, said Schaffner, who recommends wearing a surgical mask during cleanups.

Anyone who had a wound exposed to floodwaters should seek medical attention to determine if a tetanus booster shot is necessary, he said.

In addition to short-term problems, Schaffner said, there's another hazard that could last long after the floodwaters recede. He said he's concerned that standing water could mean in increase in the West Nile virus carried by mosquitoes.

"All this floodwater is going to leave puddles and pockets of water that will be great breeding grounds of mosquitoes," Schaffner said. "If there are a lot of mosquitoes, more mosquitoes will bite birds and then bite people," spreading the virus.

A list of ways to stay safe after a flood can be found here.