Protecting families from contaminated food and water
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Protecting families from contaminated food and water
Posted in cryptosporidium,Cyclospora,Our Blog on July 28, 2025
Parasites in flood water are some of the lesser-known dangers during flooding events like hurricanes and the current Kerr County flood. These intestinal parasites can cause serious damage and are often difficult to get rid of.
What parasites can be found in flood water? How can you avoid these parasites? What to do if you get sick?
Follow along for this and more as we explore the topic of parasites in flood water!
As if you don’t have enough to worry about during flooding events, we had to unlock a new fear.
Parasites.
There are the more commonly known microbes like Giardia, Cryptosporidium, and Cyclospora. As well as some that you may not have heard of before.
Giardia lamblia is the most commonly found intestinal parasite in the United States. Or in the world for that matter. This parasite is often detected in raw (untreated), under-chlorinated water, and groundwater contaminated with surface water. All of which commonly occur during flooding events.
This parasite forms protectives cysts that can survive in food and water as well as its journey through the digestive tract.
When these giardia cysts reach the acidic environment of the stomach (and duodenum), they awaken and begin to reproduce themselves. Once these harmful parasites make it to the colon, they reform their protective cysts and pass back into the environment, where they may infect another host to start the whole process over again.
Symptoms of Giardia infections can take around a week or two. The worst symptoms usually last for three to four days.
Early Giardia symptoms often include:
As the infection develops, additional symptoms may include:
Several treatment options are available for Giardia infections. Medications like quinacrine, furazolidone, and paromomycin are commonly used treatments for giardiasis.
Cryptosporidium parvum, or simply “Crypto” is one of the more undiagnosed parasites in flood water. However, it can also be found in untreated or undertreated water, well water, and spring water.
Most people treat symptoms on their own without medical intervention and therefore are not tested for the intestinal germ. In some cases, people experience no symptoms at all but continue to shed the parasite into the environment.
The specific life cycle of this parasite requires it to pass through the body and into the environment for a time before it can become infectious again to humans, making it one of the more concerning parasites in flood water.
If symptomatic, the most common symptoms associated with Crypto infection is watery diarrhea. This is the biggest clue that prompts healthcare providers to test for this specific parasite (among other common parasites in flood water).
Other common Crypto symptoms include:
Most people begin feeling sick somewhere between two and ten days after exposure, with illness lasting for a week or two. Some may experience prolonged infection or relapses.
Additional complications may occur in people with a weakened immune system. In some cases, the parasite can leave the small intestine and digestive tract to enter other parts of the body (including the respiratory tract).
In most cases, there is no specific treatment prescribed for Cryptosporidium infection. Unless immunocompromised or during pregnancy, the infection is not treated with specific medication. The patient is generally advised to manage symptoms by keeping hydrated.
Anti-diarrheal medication is not advisable, as it may prolong illness.
Cyclospora cayetanensis infections are another one of the concerning parasites in flood water. These microorganisms also have an oocyst life-cycle, requiring them to pass through the body and into the environment for a time to become infectious to others.
Symptoms of Cyclospora infection do not begin immediately. It often takes about a week from exposure to begin feeling sick.
The most common symptom of Cyclospora infection involves watery diarrhea, with frequent, sometimes explosive bowel movements.
Other common Cyclospora symptoms include:
Some people with cyclospora infection have no symptoms at all.
If not treated, illness can last anywhere from a few days to a month or longer, with several relapses before the infection runs its course.
Most people treated for Cyclospora infections are prescribed Trimethoprim-sulfamethoxazole (TMP-SMX). Symptoms generally resolve within a few days of starting this treatment protocol.
In addition to the more common Giardia, Crypto, and Cyclospora parasites in flood water, a few other microsporidia make the list.
Ingestion is the most common way to become infected with parasites in flood water. There are a few things you can do to reduce your risk of infection.
If you do not need to be out in flood water, it is best to avoid it.
It may be tempting to venture out to explore the area. However, exposure risk is not worth the curiosity. Keep yourself and your family safe by avoiding flood water if possible.
If your water supply is potentially contaminated with parasites, boiling it can kill those harmful microbes.
Bring water to a full rolling boil for at least one minute.
Be sure to not only boil drinking water, but also water used to wash your hands, cook, and bathe.
If you cannot avoid flood water, be sure to wash your hands and clothes after exposure. Especially prior to eating, drinking, or touching your mouth. Use boiled water if necessary.
Even contact with a small number of parasites in flood water can cause serious infection.
If you begin experiencing symptoms of these parasites or other microbes from flood water, seek medical attention. Notify your healthcare provider that you have been exposed to parasites in flood water to expedite specialized testing that can lead to faster diagnosis.
Appropriate medication can improve recovery time.
If you’d like to know more about food safety topics in the news, like “Parasites in Flood Water,” check out the Make Food Safe Blog. We regularly update trending topics, foodborne infections in the news, recalls, and more! Stay tuned for quality information to help keep your family safe, while The Lange Law Firm, PLLC strives to Make Food Safe!
By: Heather Van Tassell (contributing writer, non-lawyer)