NEW YORK (WABC) -- The CDC and the New Jersey Department of Health have confirmed a death from Lassa fever that was diagnosed earlier Monday in a person returning to the United States from Liberia.
The patient, 55, was admitted to a hospital on May 21 with fever and sore throat and was placed in isolation. Blood samples submitted to CDC tested positive for Lassa fever. The patient's condition continued to decline, and he passed away Monday evening.
Lassa fever is a viral disease that is common in West Africa, but rarely seen in the United States. It is not spread through casual contact or through the air. According to the CDC, there has never been person-to-person transmission of Lassa fever documented in the U.S.
In rare cases, it can be transmitted through direct contact with a sick person's blood or bodily fluids, or through sexual contact.
Despite the unlikelihood of person to person transmission, the Department of Health is working with hospital officials to identify all close contacts including health care workers, family members and anyone who may have come in contact with the patient out of an abundance of caution. They will be monitored for symptoms.
There have been five other cases of Lassa fever in travelers returning to the U.S. since 1969, including in a New Jersey patient who died in 2004 and a Minnesota case last year.
Although Lassa fever can produce hemorrhagic symptoms in infected persons, the disease is not related to Ebola, which is responsible for the current outbreak in West Africa. The patient tested negative for Ebola.
"This is not Ebola, it's different, it's not transmitted from person to person as easily and a much lower fatality rate," said Susan Boruchoff, M.D., Professor of Medicine and Infectious Disease Specialist at Rutgers Robert Wood Johnson Medical School.
It is because University Hospital in Newark has the expertise in treating patients with rare viruses and hemmorrhagic fevers like Ebola, that the man with Lassa fever was transferred there on Saturday.
"Obviously it's something we very rarely encounter in the U.S.," said Dr. Boruchoff. "It's a viral infection that is potentially transferred, though not commonly passed from person to person in medical settings."
According to the CDC and the New Jersey Department of Health, the patient flew from Liberia to Morocco to JFK on May 17.
On the 18th he went to St. Barnabas Medical Center in Livingston, New Jersey with a sore throat and fever. Sources say he did not let hospital staff know he had traveled to Liberia at the time.
On May 21, his symptoms got worse and he went back to the hospital. Then on May 23, he was transferred to UMDMJ in Newark and immediately placed in isolation. On Monday, the patient tested positive for Lassa fever and died that evening.
Now both agencies are trying to track down anyone who may have come in contact with the patient. "The incubation period is usually 1-3 weeks and most illnesses occur 10 after infection," said Dr. Boruchoff.
But ABC News chief health and medical editor Dr. Richard Besser says unlike Ebola, it is not highly contagious and is primarily spread through rodents.
"Patients are not very contagious. In Africa, they've seen some outbreaks in hospitals, but those hospitals that don't use sterile precautions with needles. In a Western hospital, you wouldn't expect to see any spread," said Dr. Besser.
In West Africa, Lassa virus is carried by rodents and transmitted to humans through contact with urine or droppings of infected rodents. 100,000 to 300,000 cases of Lassa fever, and 5,000 deaths, occur in West Africa each year.
"Given what we know about how Lassa virus spreads to people, we think the risk to the public is extremely low," State Epidemiologist Dr. Tina Tan said.
For additional information about Lassa fever, see the CDC website or the New Jersey Department of Health.
Person who traveled from Liberia to JFK died of Lassa fever