(Des Moines, IA) Effective immediately, the beach at Lake of Three Fires in Taylor County will be closed temporarily for swimming. The closure is a precautionary response to a confirmed infection of Naegleria fowleri in a Missouri resident with recent potential exposure while swimming at the beach at Lake of Three Fires State Park.

Testing to confirm the presence of Naegleria fowleri in Lake of Three Fires is being conducted in conjunction with the CDC and could take several days to complete. The Iowa Department of Health and Human Services is working closely with the Department of Natural Resources to share information about this rare infection and will provide additional updates as test results become available.

Naegleria fowleri is a microscopic single-celled free-living ameba that can cause a rare life-threatening infection of the brain called primary amebic meningoencephalitis (PAM). The ameba is commonly found in warm freshwater such as lakes, rivers, and ponds; however, PAM is extremely rare. Since 1962, only 154 known cases have been identified in the United States. No additional suspected cases of PAM are currently being investigated in Missouri or Iowa.

While Naegleria fowleri can be present in any body of warm freshwater across the United States, infections as a result remain rare. Infection by Naegleria fowleri can occur if water containing the ameba enters the body through the nose. The Naegleria fowleri ameba then travels up the nose to the brain where it destroys the brain tissue. This infection cannot be spread from one person to another, and it cannot be contracted by swallowing contaminated water.

People can take actions to reduce the risk of infection by limiting the amount of water going up the nose. These actions could include:

• Hold your nose shut, use nose clips, or keep your head above water when taking part in water-related activities in bodies of warm freshwater.
• Avoid water-related activities in warm freshwater during periods of high-water temperature.
• Avoid digging in, or stirring up, the sediment while taking part in water-related activities in shallow, warm freshwater areas.

(These recommendations are best practices but not based on scientific testing since the low numbers of infections make it difficult to show effectiveness.)