CDC Investigates Suspected Lassa Fever Death of U.S. Traveler
Public health officials are investigating a fatal case of Lassa fever in an Iowa resident who recently returned to the United States from West Africa. The patient, who died at the University of Iowa Health Care Medical Center, tested presumptively positive for the virus following their return earlier this month. According to the Centers for Disease Control and Prevention (CDC), the risk to the general public remains extremely low, as the patient was not symptomatic during travel.
Did You Know? If confirmed, this case would mark only the ninth known occurrence of Lassa fever in a traveler returning to the United States since 1969.
How Lassa Fever Spreads
Lassa fever is primarily transmitted to humans through contact with the urine or droppings of infected rodents, which are common in West Africa. The CDC reports that the virus is not spread through casual contact. Person-to-person transmission is rare and only occurs through direct contact with a sick person’s blood, body fluids, mucous membranes, or through sexual contact. Patients are not considered infectious until they begin to exhibit symptoms.
Public Health Response and Monitoring
The CDC is currently collaborating with Iowa state and local health officials to trace the patient’s movements and identify individuals who had contact with the patient after symptoms began. Those identified as close contacts will undergo active monitoring for 21 days to ensure public safety. While the patient’s death occurred in isolation, federal agencies have offered assistance to Iowa authorities to further investigate the circumstances of the infection, which early evidence suggests may have involved contact with rodents while the patient was abroad.
Expert Insight: The rarity of this disease in the U.S. necessitates a precise public health response. By focusing monitoring efforts on close contacts identified after the onset of symptoms, officials are applying standard protocols to contain a virus that, while common in West Africa with hundreds of thousands of cases annually, poses minimal threat to the general American population.
What May Happen Next
Health officials are awaiting confirmatory testing to finalize the diagnosis. Following this, the CDC and state partners will likely conclude their contact tracing efforts to verify that no secondary transmission occurred. Further details regarding the patient’s exposure history may be released as the investigation progresses. For additional technical information, the public can visit the About Lassa Fever | Lassa Fever | CDC page.
Frequently Asked Questions
Is there a risk to other passengers who traveled with the patient?
No. The CDC stated that the risk to fellow airline passengers is extremely low because the patient was not sick while traveling.
How is Lassa fever typically contracted?
The virus is most commonly spread to humans in West Africa through contact with the urine or droppings of infected rodents.
Are patients with Lassa fever contagious at all times?
No. The CDC notes that patients are not believed to be infectious before symptoms begin, and the virus does not spread through casual contact.
How can travelers to regions where Lassa fever is common better protect themselves against rodent-borne illnesses?