Swimming advisory issued for Lake Anna in Louisa County due to algae bloom

The Virginia Department of Health issued a swimming advisory late Friday for the Upper section of the North Anna Branch of Lake Anna in Louisa County.

The section of the lake is experiencing a harmful algae bloom, and the public is advised to avoid contact with this area of the lake until algae concentrations return to acceptable levels.

The North Anna Branch includes the upper waters of the North Anna arm including the sandbar of the lake and downstream to the Route 522 bridge.

Harmful algae, called cyanobacteria, can cause skin rash and gastrointestinal illnesses, such as an upset stomach, nausea, vomiting and diarrhea. Cyanobacteria have the potential to produce toxins. One cyanotoxin was detected at both Upper North Anna and Pamunkey Branch sites, but below levels of health concern.

People visiting Lake Anna are advised to avoid discolored water or scums that are green or bluish-green because they are more likely to contain toxins.

People and pets are advised to avoid swimming, windsurfing and stand-up-paddle-boarding, as well as other activities that pose a risk of ingesting water.

Activities such as boating may continue with proper precaution in advisory areas.

Follow-up monitoring above Route 208 on the lake is planned for the week of July 15.

Visit SwimHealthyVA.com to learn more about harmful algae blooms or to report an algae bloom or fish kill.

Update on Memorial Day weekend outbreak

The Virginia Department of Health provided an update Friday on the outbreak of the Shiga toxin-producing Escherichia coli, or STEC, in people who were in the Lake Anna area around Memorial Day weekend.

The number of STEC cases remains at 25 and has not changed.

People who have been exposed to STEC typically develop symptoms within three to four days, but it can take up to 10 days.

Among the 25 cases, 23 patients reported visiting the lake between May 24 and May 27, and the most recent illness onset date is June 4.

Two patients did not visit the lake but had close contact with a person with a STEC infection.

VDH continues to investigate reports of ill patients and closely monitor the situation.

It is possible that more outbreak cases will be identified.

For the most current information about this outbreak, visit VDH’s website or call the VDH Call Center at (877) 829-4682.