Fatal Lassa Fever Case Confirmed in Iowa

The Iowa Department of Health and Human Services (IDHHS) today announced the death of an Iowa resident from Lassa fever, a rare, often fatal, viral hemorrhagic fever.

There have been eight travel-associated cases of Lassa fever in the U.S. in the past 55 years.

If confirmed, the Iowa case would be the ninth known occurrence of travelers returning to the U.S. since 1969.

This individual had recently returned from travel to West Africa, where ISHHS believes the person contracted the virus. About 5,000 Lassa fever-related deaths occur in West Africa each year.

Dr. Robert Kruse, State Medical Director of the IDHHS, stated in a press release on October 28, 2024, "I want to assure Iowans that the risk of transmission is incredibly low in our state. We continue investigating and monitoring this situation and are implementing the necessary public health protocols."

Lassa fever is carried by rodents and is transmitted to humans who may come in contact with the urine or feces of the infected rodents. Approximately 80% of Lassa fever patients have mild or no symptoms.

The U.S. Centers for Disease Control and Prevention posted a statement emphasizing that the overall risk to the public from this case is very low. 

Lassa is included in the World Health Organization's R&D Blueprint of priority pathogens, for which there is an urgent need for accelerated research, vaccine development, and countermeasures. 

As of October 2024, several Lassa fever vaccine candidates are conducting research, but the U.S. FDA has approved none.