Lassa fever was confirmed on Sunday at Emory University Hospital in Atlanta, Georgia. The Centers for Disease Control and Prevention (CDC) confirmed that one patient tested positive for the virus. Lassa fever is not common in the United States, and local Atlanta residents are wondering if the virus is contagious.
This is only the seventh case of Lassa fever to ever hit U.S. soil since it was first discovered in 1969 in Nigeria. Lassa fever is most common in Africa, more specifically West Africa, where hundreds of thousands of people are infected every year.
According to CNN, Lassa fever infects an estimated reported 300,000 people yearly in West Africa, and has already proven to be fatal in at least 5,000 of those reported cases. The CDC came out publicly on Sunday saying that one male patient with confirmed Lassa fever was being treated at Emory University Hospital, a nearly 600-bed facility in Atlanta, Georgia, that specializes in caring for acutely ill adult patients.NBC affiliate 11Alive in Atlanta reports that Emory University officials first broke the news on Saturday morning. Around 11 a.m. on Saturday, officials reportedly announced that a patient suspected to have the Lassa virus had arrived at Emory University Hospital early Saturday morning from West Africa.
The CDC then confirmed on Sunday that the unidentified patient's test results had come back positive for Lassa fever. Until that time, Emory would only say that they were treating a patient for symptoms of febrile illness, which means a fever is present but the cause is not known. CNN reports that the U.S. State Department requested the patient be transported from West Africa where he was working as a physician's assistant with a missionary organization in the Togo nation of West Africa.
The Lassa fever patient is said to be an American and is currently being treated at Emory for a "serious communicable disease." But how serious is Lassa fever, and is the virus contagious?
Even though the Lassa fever patient is being treated inside Emory's Serious Communicable Diseases Unit, NBC News reports that the virus is not easily transmitted from person to person. People usually become infected with Lassa fever through inhalation or direct contact with the excrement of infected rodents.
"The risk of getting Lassa fever in the United States from someone who has traveled to West Africa is extremely low," according to a spokesman with the CDC.
In fact, there's only one specific rat that transmits the Lassa virus. One specific type of rat, called the Natal multimammate mouse, is responsible for infecting up to 500,000 people annually in Africa mainly in the countries of Nigeria, Sierra Leone, Liberia, Guinea, and the Central African Republic.Some symptoms of Lassa fever include fever, muscle fatigue, nausea, cough, and conjunctivitis. These symptoms present as soon as six days from infection or as late as 21 days from initial infection and mimic the symptoms of other more common viruses. But Lassa fever is considered a viral hemorrhagic fever, where hemorrhaging from the mucous membranes accompanies the fever.
Hemorrhaging only occurs in roughly 20 percent of Lassa fever cases. Eighty percent of Lassa virus infections never even result in symptoms.
Lassa fever is similar to the Ebola virus, which also causes hemorrhagic bleeding and is common in Africa. But the Ebola virus is contracted from primates, not rodents, and is much more deadly because there is no specific treatment or vaccine. Ebola is also extremely contagious among groups of people through casual day-to-day contact with bodily fluids, unlike the Lassa fever. Casual contact includes shaking hands, drinking from a water fountain, sneezing, or kissing an infected person.
Officials at Emory say there is a slight possibility that Lassa fever can be transmitted from human to human, but only through direct contact, not casual contact.
"It cannot be transmitted through casual contact, and is not an airborne virus," according to Emory.
Lassa fever can be fatal if not treated, but Emory officials say Lassa fever can be successfully treated with the antiviral drug Ribavirin.
The sixth case of Lassa fever in the U.S. occurred in May, 2015, and was ultimately fatal. The patient traveled to the U.S. from Liberia and went to a New Jersey hospital on May 18, 2015, complaining of a sore throat, fatigue, and fever. After being sent home, the patient began hemorrhaging three days later and died. Lassa fever was confirmed after the patient's death.
But, according to the CDC, death is rare in Lassa fever patients, saying only one percent of Lassa fever cases result in fatality, compared to 70 percent for Ebola cases.
Even so, Lassa fever has been known to cause deadly outbreaks. In 2011, three people died and 10 family members were infected with the Lassa virus after a 78-year-old Bauchi, Nigeria, man did not seek proper medical treatment and died of Lassa fever.
Death and outbreaks are certainly not the norm, though, with Lassa fever. Dr. Colleen Kraft, who works at Emory inside the Serious Communicable Diseases Unit, assures the public that Lassa fever is much harder to contract than Ebola and not nearly as lethal. Kraft also said that herself and her colleagues at Emory have strict protocols to follow to protect themselves and the public from contracting Lassa fever.
[Image by Kelly, et al/Wikimedia Commons]