The floodwaters that inundated New Orleans after Hurricane Katrina forced many inhabitants to wade away from their ravaged homes in chest-high water. While the immediate dangers of the floodwaters were obvious, experts are now warning about the long-term risks for serious bacterial and viral infections.
The Environmental Protection Agency has found high levels of E. coli in sampled areas around New Orleans and are urging people to avoid contact with the water as much as possible.
Moreover, the temperature and humidity of the region, plus the crowded conditions in the shelters have caused some experts to worry about disease outbreaks normally found in Third World countries.
Why is New Orleans such a breeding ground for infectious disease?
In the 19th Century, New Orleans was well-known as a place for cholera. The region is considered the most tropical environment in the United States, and it has gone through cholera outbreaks; it has had typhoid fever; it has had salmonella and Campylobacter outbreaks. It has had epidemics in the past, but these epidemics have not occurred recently because of a better public health system.
What are some of the long-term health concerns in the regions affected by the floods?
The most immediate concerns are things that you can catch through contaminated water: typhoid fever, salmonella, cholera, etc. Since the entire city of New Orleans is underwater, there's clearly raw sewage there, too.
Hepatitis A is a food borne disease that you can get either through contaminated food or water, so it is also something these people have to worry about. Hepatitis A isn't a concern for those who have had the vaccine, but it is not a mandated vaccine in childhood. People are usually only vaccinated when they travel to countries where the risk is high, so I don't think the majority of Americans have received it.
What could be some of the potential contaminants of the water?
Animals and human feces are potential sources of bacteria, as well as pollutants and rotting, biological material.
At this point, what are some preventative steps people can take?
Well, if they don't have access to clean water, they need to boil their water for about twenty minutes. If they can't boil their water, there are tablets [available in many emergency kits] that precipitate out the organisms. If they can't get that, then they're at risk to catch these diseases.
Is drinking the water the only way to be exposed to the bacteria?
If people wade around in stagnant water, they could nick their skin or the skin may become edematous, like what happens when you stay in a pool or Jacuzzi too long. In this latter case, a bigger wound will occur more easily. Either way, a wound could become infected and start to fester.
How big is the risk?
You can treat all the things I listed with the exception of hepatitis A. So, rather than dying of dehydration, I think it would be better for people to drink some water.
One estimate puts 1.5 to 2 billion people in the world without access to safe, potable water. As a result, many people in the world drink contaminated water and risk contracting deadly diseases.
If somebody knows that they've come in contact with contaminated water, what should they look out for?
If they have drunk that water, they should clearly watch out for diarrhea—either severe, watery diarrhea or diarrhea where you produce painful, mucous-filled, slightly blood-tinged movements. Very frequently, the diarrhea is associated with cramps in your belly and fever. If people do get that, they should seek medical attention, especially if it lasts for more than two days.
How are these diseases treated?
In most cases, they would give a course of fluoroquinolone, an antibiotic. It is the same drug people would be advised to bring along with them when traveling to Third World countries. In most cases, bacterial diseases should respond to that.
What happens if an infected person is not treated immediately?
If you don't do anything, you can get into serious troubles, like dehydration. If the dehydration is severe enough, you can end up with renal failure.
Is there any way to ensure that the food supply is OK to eat?
Food is less of an issue because if you don't eat for two or three days, that's not as dangerous as not drinking water or getting fluids. People can safely survive not eating for a while, unless, of course, you're a diabetic.
Are there any other long-term concerns?
New Orleans is definitely a territory where, in the past, they had lots of malaria and dengue fever. The number of mosquitoes, which transmit those diseases, is going to increase with all the stagnant water.
There were ships that couldn't make it into New Orleans' ports that may have been from Third World countries. So, there's the danger in the southern United States that, if a person comes from the outside and has malaria or dengue virus infection in the blood, the mosquitoes are there to spread it.
However, America has been cleaned of these diseases and you'd need somebody who is infected to bring it to the local people. So, although this might not be an immediate threat, if the stagnant water festers for weeks, people need to be warned about the possibility of mosquito-borne diseases.