Health risks of flood go beyond just drowning

As the tragedy of Hurricane Harvey continues to unfold in Texas and Louisiana, US public health officials are already alerting people about the suite of ills that come along with flood waters, woes that are common to floods the world over.

The most immediate health risk, of course, is from drowning, especially for people trapped in vehicles, Renee Funk, associate director for emergency management of the Centers for Disease Control and Prevention, told Reuters on Monday.

Waters that rise rapidly and flow can also be filled with debris that can too easily snag and drag along, even if the water is not too deep. Continued exposure to water, even if it is not especially cold, can lead to hypothermia, bringing to mind that alarming picture of wheelchair bound seniors sitting half submerged in their den.

Carbon monoxide poisoning from portable generators is another threat that has officials worried. "Unfortunately, we expect there will be people who die from that and people will be poisoned from it," Funk said.

Floodwaters also pick up dangerous toxic chemicals from submerged storage units and vehicles and swamped tool sheds and garages, not to mention human waste. Exposure to skin through wading or swimming in the waters can cause rashes or respiratory problems.

"The No. 1 thing we're concerned with in a flood is chemicals," said Funk, who advised people to shower and wash their hands immediately after contact with floodwater.

The rising waters can also flush snakes out of their usual habitats and force them into places they might not normally be seen or expected. I know from having lived in Houston from age 3 to 8 that diamondback rattlers and water moccasins were one of the reasons you kept away from the bayous and every bayou in east Texas has got to be overflowing beyond belief.

My sister, who still lives in Houston, told me a friend of theirs just yesterday opened the front door of his house to find an alligator in his driveway. She lives on San Felipe Street, which she tells me has been renamed Lake San Felipe.

An image of swarms of stinging fire ants clinging to a floating raft in Houston went viral on Monday. A bite from one of those will never be forgotten.

Standing water is also a breeding ground for mosquitoes, even though flood waters wash away many of their breeding sites. Funk said floods typically cause a rise in nuisance mosquitoes, such as the Culex variety, and these, too, can carry disease, and the effects can be delayed.

A year after Hurricane Katrina in 2005, regions in Louisiana and Mississippi affected by the flood reported a doubling of cases of "neuroinvasive" West Nile virus, that is, cases in which the virus caused severe inflammation in the brain or spinal cord, Dr. Peter Hotez, dean of the National School of Tropical Medicine at Baylor College of Medicine, told Reuters over the phone from his home - his lab at Baylor was closed.

"A year from now, we'll have to look very closely at West Nile and other mosquito-borne viruses," Hotez said.

In the immediate aftermath of Harvey, bacterial diseases are a concern, although cholera, a scourge in the wake of many natural disasters in developing countries, is likely not a worry in Houston, he said.

"Bacterial infections are really important, such as salmonella and E. coli infections," Hotez said.

"Certainly the conditions here could promote cholera," Hotez told The Washington Post, "but you'd have to have somebody infected with cholera coming into the area."

The Centers for Disease Control and Prevention is warning parents not to let their children play with any toys that have been exposed to floodwater until the objects are thoroughly washed with clean water.

The CDC is also advising people to wear rubber boots and gloves when they return to their homes and begin the cleanup.

Also, in a climate like Texas, mold grows quickly in damp, dank places and problems with asthma and allergies typically send people to the doctor after the waters recede.

Contact the writer at chrisdavis@chinadailyusa.com.