Hurricane Harvey: The hidden health dangers of floods

Even after Hurricane Harvey's immediate flooding threat goes away, Texas residents will still face a host of potential health problems from the water -- and from what the water leaves behind.

Health and Human Services Secretary Dr. Tom Price declared a public health emergency in Texas on Sunday. That means the department has put additional medical personnel from around the country on alert, ready to provide help when they are needed.

The health concerns that floodwater can bring include physical and mental challenges.

Unhealthy floodwater

Floodwater is more than simple rain. It's often contaminated with sewage and chemicals and can hide sharp objects made of metal or glass.

Floodwater can also carry disease. That's a serious problem in developing countries where cholera, typhoid or yellow fever are already present, according to the World Health Organization. None of those diseases are common in Texas, so an outbreak is highly unlikely.

What may be more common will be people getting a bout of diarrhea or other stomach problems if they come into contact with contaminated water or if they consume food or drink that has. Using items that have been submerged in the water can also cause stomach problems. To cut down on infection, the CDC reminds parents not to let their children play with toys that have been in the water, unless the toys get washed thoroughly first.

Exposure to floodwater can increase a person's risk for skin rashes, ear, nose and throat problems and conjunctivitis, but the World Health Organization says that none of these are epidemic prone. Of 14 major floods between 1970 and 1994, the WHO said the only major epidemic of diarrhoeal disease happened in Sudan in 1980. American disease control is much more advanced than Sudan's. The other major risk is drinking contaminated water -- but again US disease surveillance is likely to minimize that risk.

The occasional stomach bug or respiratory infection may more likely result from people having to stay in close quarters with large groups. With a flood it is hard for people to keep up their usual healthy hygiene standards. When people stay together in shelters with large groups it's easy to spread germs.

The CDC highly recommends people who are staying at shelters be extra careful to wash their hands or to use an alcohol hand gel to try and prevent the spread of any disease. People with open wounds also need to take extra care to keep them covered. Floodwater can easily cause a wound to become infected.

Health-related clean up challenges

Doctors often see more patients with respiratory infections after the floodwaters recede and people are allowed to return to their homes. Contamination from the floodwaters and the mold that quickly grows in a warm environment like Texas can exacerbate asthma or trigger allergies.

The CDC advises people to wear rubber boots and gloves when they clean up their homes. That way they can avoid direct contact with any item that has come into contact with floodwater.

Walls, floors, and anything with a hard surface that has come into contact with floodwater -- like stoves, refrigerators, counter tops, children's play areas, all need to be cleaned with soap, water and disinfected with a bleach solution. Fabrics should be washed in hot water or dry cleaned. Furniture like beds and upholstered sofas and chairs that can be saved should be dried out in the sun and then sprayed with a disinfectant. Carpets should be steam cleaned.

Food and beverages that have come into contact with floodwater should be thrown away. The Food and Drug Administration suggests people should also throw away any prescription drugs, even drugs that are in their original containers or with screw tops should be thrown away since they may no longer be safe if they've come into contact with contaminated water.

Standing water

Floods typically flush out mosquitoes and interrupt their breeding, but when the flooding stops, there is an increased risk for infection from a mosquito born illness like Zika or West Nile. Mosquitoes that carry disease thrive in standing water and breed quickly when there is a lot of it.

After Katrina, studies show areas that were directly impacted by that hurricane did see an increase of cases of West Nile.

The CDC suggests people who are near the standing water should take extra care to use bug spray with DEET to keep the bugs away.

Mental health concerns

The biggest health concern from a flood, other than the immediate dangers of rushing waters, may be mental, studies show.

Hurricanes and flooding generate additional anxiety, depression and stress. The storms can exacerbate existing mental health problems or lead to new ones.

Stress is common both during and after any natural disaster. That means tears may come easier, sleep may be a challenge, excessive worry or a desire to be alone may be really strong, thinking may become muddled and it may be hard to remember things or to listen to people. And it may be hard to even accept help, the experts say.

Some people may develop problems related to the lingering challenges associated with post-traumatic stress disorder, but the majority of those affected should recover in time. People who have strong bonds with family, friends and co-workers tend to recover best, so the experts suggest paying close attention to those relationships to help speed recovery.

For those who do have lingering mental challenges, counseling is recommended. If people need immediate help, the Health and Human Services Department set up a Disaster Distress Helpline to help those struggling with any mental health problems resulting from the storm. That toll-free number, staffed by mental health professionals, is: 1-800-985-5990.