A middle-aged Iowa resident who recently traveled to West Africa has died of Lassa fever, state health officials confirmed Monday.

“I want to reassure Iowans that the risk of transmission is incredibly low in our state,” said Dr. Robert Kruse, medical director of the Iowa Department of Health and Human Services, said in a news release. “We continue to investigate this situation and monitor and implement the necessary public health protocols.”

The Centers for Disease Control and Prevention and local public health partners are working to identify anyone “who may have been in close contact with the patient, out of an abundance of caution, for monitoring,” the release said.

What is Lassa fever?

Lassa fever is a virus that mainly occurs in Sub-Saharan Africa. It is spread by West African multi-tamed rats, which are currently the only species known to carry the Lassa virus, health officials say.

The viral disease can develop quickly once someone is infected, with an incubation period of two to 21 days, the World Health Organization says.

In the past 55 years, only eight travel-related cases of Lassa fever have been reported in the US. a New Jersey man died after the virus has been diagnosed.

About 100,000 to 300,000 cases of Lassa fever occur in West Africa each year and the CDC estimates it kills about 5,000 people.

How is Lassa fever spread?

People can contract Lassa fever by having contact with infected rats or their saliva, urine, or feces, which can happen through contaminated food or household items.

Infections can also spread between people after contact with bodily fluids from an infected person. It is not spread through casual contact, such as hugging, shaking hands or sitting next to someone.

“People with Lassa fever are not contagious until their symptoms begin,” the CDC notes.

The University of Iowa Health Care System, where the resident was treated, said the patient was being cared for in the Special Pathogen Unit, a locked unit designed to safely treat infectious diseases, and assured the public that the hospital “remains a safe place ‘. receive care.”

The CDC said the person “was not ill while traveling, so the risk to fellow passengers is extremely low.”

Although person-to-person transmission has not previously been reported in the US, the CDC urges increasing isolation precautions for viral hemorrhagic fevers such as Lassa virus.

Symptoms of Lassa fever

Although Lassa fever can be fatal, most people experience only mild symptoms, including low-grade fever, feeling tired and weak, and headache. These common symptoms are similar to many other conditions, and health officials say most people with mild cases are never diagnosed.

About 1 in 5 infected people will develop a severe case of the disease, the WHO says.

Some people may experience bleeding, vomiting, difficulty breathing, facial swelling, and pain in the back, chest, or stomach.

The overall mortality rate for the disease is about 1%, “but may be as high as 15% or more among patients hospitalized with severe illness,” according to the WHO.

Health officials say treatment options may include an antiviral drug called ribavirin, which is most effective when given early, and supportive therapy such as painkillers and rehydration to help relieve symptoms.

Alexander Tin contributed to this report.