This article is more than 5 years old. Information may no longer be current.
Imported cases of Lassa fever often missed for days
Click Here to Manage Email Alerts
From 1969 to 2016, 33 cases of Lassa fever were diagnosed in travelers from West Africa to nine other countries, according to a new report. Researchers suggested that the “ease and frequency of international travel” means health care providers will continue to see Lassa fever cases in areas where the disease is not endemic.
Writing in Emerging Infectious Diseases, Aaron Kofman, MD, an Epidemic Intelligence Service officer in the CDC’s Viral Special Pathogens Branch, and colleagues noted that 80% of patients with Lassa fever either have a mild or no manifestation of the disease, whereas approximately 20% experience severe symptoms, including facial swelling, hepatic and renal abnormalities, pulmonary edema, and hemorrhage. Lassa fever carries an approximately 1% overall case-fatality rate, but among hospitalized patients, that rate increases to 15% or more, according to the report.
“While Lassa fever is a rare cause of illness in returning travelers from West Africa, imported cases have important implications for medical and public health providers,” Kofman told Infectious Disease News. “From a clinical standpoint, many cases share common clinical features which may be useful for providers to be aware of when considering travel-related diagnoses.”
Kofman and colleagues conducted a retrospective review of all 33 reported cases imported from seven West African countries, intending to “quantify the frequency of case-patients having distinctive clinical features, time from patient presentation to clinical suspicion of a Lassa fever diagnosis, and the risk for secondary Lassa virus transmission.”
There were distinctive clinical features in only half of the cases, and it was common to find delays in clinical suspicion of Lassa fever, they reported. In the destination country, the median time from patient presentation to clinical suspicion of Lassa fever was 5 days. Secondary transmission of the disease only occurred in contacts with high-risk exposures, such as direct contact with patients or patient body fluids, and was rare, occurring in only two instances.
It is critical that future responses to imported cases of Lassa fever include “timely recognition of distinctive clinical features, earlier treatment of patients, and targeted public health responses focused on high-risk contacts,” according to Kofman and colleagues.
“Because Lassa fever is uncommonly seen outside of West Africa, all imported cases represent opportunities to learn more about its clinical manifestations and epidemiological implications in non-endemic settings,” Kofman said. – by Marley Ghizzone
Disclosures: Kofman reports no relevant financial disclosures.
Click Here to Manage Email Alerts