LOUISA COUNTY, Va. (CBS19 NEWS) -- The Virginia Department of Health is investigating several illnesses among people who were recently in the Lake Anna area.

According to a release, there is a cluster of gastrointestinal illnesses among people who were there for the Memorial Day weekend.

Some of the sickened people have been diagnosed with E. coli infections, which can cause stomach cramps and diarrhea as well as vomiting, fever and chills.

In severe cases, VDH says the infection can cause organ damage and lead to hemolytic-uremic syndrome, which affects the kidneys and platelet levels.

The release says there have been several reports of gastrointestinal illnesses, mainly in children, who have similar symptoms. Some of those infected have been hospitalized.

Officials are looking into all potential causes of the illnesses, including lake water and food exposure.

“We hope that those hospitalized continue to recover and can return home to their families soon,” said Rappahannock Health District Health Director Olugbenga O. Obasanjo, MD. “This is an ongoing investigation with the health department, and we will likely continue to learn about the situation in the coming days.”

VDH says all of the sickened people have confirmed swimming or other water exposure in Lake Anna, but officials say they do not have enough information at this time to confirm that as the cause of the illnesses.

Water testing is underway to evaluate the concentration of bacteria in the water and to see if there is a public health risk.

These illnesses are not suspected of being related to a harmful algae bloom because this particular pathogen is not associated with those.

While there are indications of algae activity in the lake, which is typical for this time of year, there is no ongoing harmful algae bloom event.

While no swimming advisory has been issued at this time, officials are encouraging people to use caution when they go swimming in Lake Anna.

“As we head to pools, lakes, and beaches to enjoy the warmer weather and spend time with our families, it is important to remember to take precautions to prevent illness,” Dr. Obasanjo said. “Showering before and after swimming, washing your hands before eating, and being sure not to drink the lake water are some of the ways to stay healthy this summer. It is also important not to swim if you have diarrhea. Children may need extra monitoring and reminders to follow these precautions.”

Anyone who was in the Lake Anna area over the Memorial Day holiday weekend or since and who has experienced symptoms should contact their local health department and seek medical care if those symptoms have not eased.