Lassa fever has reached the US for the first time in a decade, in a case that has surprised health officials.
The middle-aged patient in Iowa, who was not identified, died “a short time” after being hospitalized with the disease, which can cause bleeding from the eyes and seizures.
The patient had just returned to the US from West Africa, where the disease is endemic and was behind an outbreak in Nigeria, where a total of 9,500 suspected and confirmed cases have been reported this year.
Health officials from the CDC and the Iowa Department of Health said the patient had no symptoms while traveling, adding that the risk of transmission was “extremely low” since people are only contagious when they have symptoms.
They did not reveal when the patient began experiencing symptoms or when they returned to Iowa, and did not say if there were any close contacts.
However, the Iowa case still raised concerns among health experts.
Below, DailyMail.com describes everything you need to know about Lassa fever:
Health workers in protective gear are seen burying a 13-year-old boy who died of Lassa fever in Sierra Leone in 2014 (file photo)
An Iowa resident has died after contracting a terrifying viral disease, Lassa fever, which is similar to Ebola and leaves victims bleeding from their eyeballs
What is Lassa fever?
Lassa fever is a serious viral disease in which patients experience symptoms within a week to three weeks after infection.
The disease is endemic in West African countries including Guinea, Sierra Leone, Liberia and Nigeria, where the disease is spreading.
Experts say this could be due to an increase in the number of rodents in the country that carry the infection, called Mastomys rats, increasing the risk of human infection.
But sporadic cases have also been recorded outside Africa, linked to people traveling from the region.
Lassa fever was first discovered in 1969 after two missionary nurses in the Nigerian city of Lassa died of a mysterious illness.
There have been nine cases recorded in the US so far, with each case linked to recent travel from another country.
How do you contract Lassa fever?
Lassa fever is a virus transmitted by Mastomys rats, a species of rodent common in sub-Saharan Africa, and causes no symptoms in the rodents.
People contract the disease by touching surfaces contaminated with the rats’ urine, feces, or saliva and then touching their mouths.
They can also become infected after eating food contaminated with rats or if the virus gets into an open cut or sore.
Human-to-human transmission can only occur when a person begins to show symptoms of the virus, which usually begin within a week of infection.
It can be transmitted by touching the individual’s feces, blood, urine, or saliva and then touching your own mouth or eating contaminated food.
A person cannot spread the disease if he shows no signs of infection.
How deadly is it?
About 15 percent of patients with severe illness die from Lassa fever, the World Health Organization suggests.
But Dr. Robert Garry, a professor at Tulane Medical School in New Orleans, suggested they do so STAT news the mortality rate in severe cases can be as high as 70 percent in some areas where it is difficult to get adequate treatment.
Dr. Garry based his higher estimate on his experience working in Sierra Leone, where the virus is endemic and where he has several research projects.
Scientists warn that children under 10 and pregnant women are at particular risk from the disease because they have weaker immune systems. Data shows that in pregnant women, more than 95 percent of them suffer a miscarriage of the fetus.
When infected, Lassa fever affects multiple organ systems in the body, including the liver, spleen, kidneys and blood vessels.
This can cause inflammation in the organs and cause them to stop working properly, which can lead to the patient’s death.
What are the symptoms?
The World Health Organization says about 80 percent of people infected with the virus have no symptoms, meaning they cannot spread it.
Warning signs usually begin about one week to three weeks after infection.
In the early stages, patients may experience low-grade fever, feeling tired and weak, and headaches – similar to other hemorrhagic fevers such as Ebola and malaria.
But in later stages, especially if a patient is left untreated, the individual may experience more serious symptoms such as bleeding from the eyes, vomiting, difficulty breathing, facial swelling, and pain in the chest, back, and abdomen.
How is it detected?
Doctors say it can be difficult to diagnose Lassa fever because the symptoms vary and are similar to those caused by other diseases.
In the early stages, symptoms may resemble those of malaria, shigellosis, typhoid fever and yellow fever.
To diagnose an infection, the World Health Organization says patient samples must be tested in a high-quality biosafety laboratory to confirm — and contain — the infection.
Body fluids, such as saliva, blood or urine, are tested for the virus and in some cases fluids taken through a spinal tap are also tested.
Is there a vaccine?
The above map from the CDC shows the areas in West Africa where Lassa fever is endemic and has been detected
Doctors use the antiviral drug Ribavirin to treat patients suffering from the disease. It is most effective when administered shortly after a patient shows symptoms.
The CDC also recommends that anyone diagnosed with the disease receive rest, hydration, and other medications to control their symptoms.
The World Health Organization says there is currently no vaccine against the virus and efforts should instead focus on prevention.
This depends on “good hygiene” and discouraging rodents from entering homes, the agency said.
This includes storing food in rodent-proof containers, disposing of waste far from the home, keeping the house clean and keeping cats, which hunt rats.
Can Lassa fever lead to complications?
The CDC says about one in three people infected with the virus will experience hearing loss after the initial infection clears.
The agency warns that this can happen in both mild and moderate cases of the disease.
The CDC also warns that if a pregnant woman becomes infected, there is a high risk of miscarriage and about 95 percent of fetuses do not survive.
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Am I at risk of getting Lassa fever?
Since 1969, nine cases of the disease have been recorded in the US, including this week’s patient from Iowa.
Both were related to recent foreign travel, in which patients became ill shortly after returning to the US. No further broadcast took place.
The previous case was registered in May 2015 involving a New Jersey resident who had recently traveled to Liberia. The patient also died.
Overall, of the nine patients diagnosed in the US, at least three have died.
Others survived, but reported being partially deaf and experiencing frequent pain and severe fatigue.
Experts say the risk of Lassa fever to Americans is low, and there are no signs the disease has spread in the US.
But they warn there is a risk of infection if someone visits a West African country where the disease is endemic.
Britain also recorded two cases of the disease among travelers returning from Mali in February 2022.
There was another case in Britain in 2009, where a 66-year-old man had recently returned to Britain from Abuja, Nigeria.
How is the US dealing with the recent case?
Iowa officials isolated the patient at a specialty disease hospital after reporting their symptoms.
The individual was described as having only a ‘brief illness’ before dying.
No further details have been revealed and the CDC says the risk of the virus spreading is “low.”