An Iowa resident is dead after federal and state health officials suspect the person contracted a rare case of Lassa fever, a viral disease similar to Ebola that's rarely seen in the U.S.

The Iowa Department of Health and Human Services said on Monday that it had confirmed a middle-aged, unnamed eastern Iowa resident had died from Lassa fever, though the Centers for Disease Control and Prevention is investigating to confirm the diagnosis.

Officials believe the individual contracted the virus after traveling to West Africa early this month, but since the person wasn't sick while traveling, the CDC says the risk to fellow airline passengers is "extremely low." The patient was also under isolation at the University of Iowa Health Care Medical Center — where they died early Monday afternoon — but Iowa HHS along with the hospital, the CDC and local health partners are continuing to monitor anyone who had been in close contact for 21 days to ensure their health.

"This is a difficult time for the family of this individual, and I want to express our deepest condolences," said Dr. Robert Kruse, state medical director of the Iowa Department of Health and Human Services. "I want to assure Iowans that the risk of transmission is incredibly low in our state. We continue to investigate and monitor this situation and are implementing the necessary public health protocols."

RELATED STORY | Nearly 30 million Americans are impacted by a rare disease

Lassa fever is a common viral disease in West Africa, where infected rodents carry and spread it to humans through contact with urine or droppings, the CDC says. Infected humans can also transmit it to other humans in rare cases once they have active symptoms and only through direct contact with their bodily fluids, including blood or mucus, or through sexual contact.

In West Africa, there are 100,000 to 300,000 cases and 5,000 deaths related to Lassa fever each year. But if the case is confirmed in the Iowa resident, it will be only the ninth known U.S. occurrence since 1969, each appearing in an American who traveled to a place where the disease is commonly found, the CDC says.

It takes one to three weeks after a person is infected with Lassa fever to see signs, and about 8 in 10 who are infected will have mild symptoms and go undiagnosed, the CDC says. Those who do have symptoms may feel a slight fever, fatigue, weakness and headache. Other serious symptoms can include vomiting, difficulty breathing, bleeding and swelling.

Both mild and severe symptoms can lead to complications, such as with hearing and pregnancy. About 1 in 3 cases of Lassa fever result in some level of deafness — permanent, in many cases — and if a person is pregnant while infected, about 95% of fetuses do not survive, per the CDC.

An antiviral drug named Ribavirin has been used to successfully treat people who are infected with Lassa fever. The organization says it's most effective when given soon after a patient becomes ill.