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 behind an outbreak in Nigeria, where a total of 9,500 suspected and confirmed cases were reported this year.
Health officials from the CDC and Iowa Department of Health said the patient had no symptoms while traveling, adding the risk of transmission was 'extremely low' as people are only contagious when they have symptoms.
They did not reveal when the patient started to suffer symptoms, or when they returned to Iowa, and did not say whether there were any close contacts.
However, the Iowa case still sparked concerns among health experts.
Below, DailyMail.com details everything you should know about Lassa fever:
What is Lassa fever?
Lassa fever is a severe viral illness that leaves patients suffering from symptoms within a week to three weeks of infection.
The disease is endemic to West African countries including Guinea, Sierra Leone, Liberia and Nigeria – where it is spreading.
Experts say this may be due to a proliferation in the number of rodents in the country that carry the infection, called Mastomys rats, raising the risk of a human infection.
But there are also sporadic cases recorded outside of Africa, which are linked to people traveling from the region.
Lassa Fever was first discovered in 1969 after two missionary nurses died in the Nigerian town of Lassa from a mysterious illness.
There have been nine cases recorded in the US to date, with each linked to recent travel from another country.
How do you catch Lassa fever?
Lassa fever is a virus carried by Mastomys rats, a species of rodents common across sub-Saharan Africa, and it causes no symptoms in the rodents.
People catch the disease by touching surfaces contaminated with the urine, droppings or saliva from the rats and then touching their mouths.
They can also become infected after eating foods contaminated by rats or if the virus gets into an open cut or sore.
Human-to-human transmission can occur only if someone starts to show symptoms of the virus, which tend to begin within a week of infection.
It can be passed on via 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 they are showing no signs of infection.
How deadly is it?
Around 15 percent of patients with severe disease die from Lassa fever, the World Health Organization suggests.
But Dr Robert Garry, a professor at Tulane Medical School in New Orleans, suggested to STAT News the fatality rate in severe cases can be as high as 70 percent in some areas where it is difficult to get adequate treatment.
Dr Garry was basing his higher estimation on his experience working in Sierra Leone, where the virus is endemic and where he has several research projects.
Scientists warn children under 10 years old and pregnant women are particularly at risk of the disease because they have weaker immune systems. For pregnant women, data shows more than 95 percent of them miscarry their fetus.
In an infection, Lassa fever attacks multiple organ systems in the body, including the liver, spleen, kidneys and lining of blood vessels.
This can cause inflammation in the organs and stop them from working properly, leading to the death of the patient.
What are the symptoms?
The World Health Organization says about 80 percent of people infected with the virus have no symptoms, meaning can not spread it.
Warning signs tend to begin about a week to three weeks after infection.
In the early stages, patients may suffer from a slight fever, feeling tired and weak and a headache — similar to other hemorrhagic fevers like Ebola and malaria.
But in later stages, especially if a patient is not treated, the individual may suffer from 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 diagnosing Lassa fever can be difficult to diagnose because symptoms vary and are similar to those caused by other diseases.
In the early stages, symptoms may appear similar to those for malaria, shigellosis, typhoid fever and yellow fever.
To diagnose an infection, the World Health Organization says samples from the patient need to be tested in a high level bio-safety lab to confirm — and contain — the infection.
Bodily fluids, such as saliva, blood or urine, are tested for the virus, and in some cases, fluids taken via spinal tap are also tested.
Is there a vaccine?
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 anyone diagnosed with the disease receives rest, hydration and other drugs to manage their symptoms.
The World Health Organization says there is currently no vaccine against the virus, and that efforts should instead focus on prevention.
This relies on 'good hygiene' and discouraging rodents from entering homes, the agency said.
This may include storing food in rodent-proof containers, disposing of garbage far from the home, maintaining a clean home and keeping cats, which prey on rats.
Can Lassa fever lead to complications?
The CDC says about one of three people infected with the virus are left with hearing loss after the initial infection resolves.
The agency warns this can happen in both mild and moderate cases of the disease.
The CDC also warns that if a pregnant woman is infected, there is a high risk of a miscarriage and about 95 percent of fetuses do not survive.
Am I at risk of catching Lassa fever?
There have been nine cases of the disease recorded in the US since 1969, including the Iowa patient this week.
Each was linked to recent foreign travel, with patients becoming ill soon after they returned to the US. There was no subsequent transmission.
The case before the latest was recorded in May 2015 in a New Jersey resident who had recently traveled to Liberia. The patient also died.
Overall, out of the nine patients diagnosed in the US at least three have died.
Others survived but reported being left partially deaf and regularly suffering from bouts of pain and severe fatigue.
Experts say the risk from Lassa fever to Americans is low, and there are no signs it 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.
The UK also recorded two cases of the disease in February 2022 in travelers who were returning from Mali.
There was another case in the UK in 2009, in a 66-year-old man who had recently returned to Britain from Abuja in Nigeria.
How is the US managing the recent case?
Officials in Iowa isolated the patient at a specialist disease hospital after they came forward with their symptoms.
The individual was described as only having a 'short illness' before dying.
No further details have been revealed, and the CDC says the risk the virus has spread is 'low.'
News
A Single Enzyme Could Hold the Key to Treating a Devastating Brain Disorder
Blocking an enzyme’s production restored brain growth and healthy behaviors in mice engineered to develop Angelman syndrome, pointing to a possible treatment target. Children with Angelman syndrome begin to show difficulties with thinking and [...]
Scientists Develop a Clever New Way To Kill Cancer Cells From the Inside
Scientists have developed an experimental strategy that exploits a chemical byproduct of cancer cells to produce anticancer drugs directly inside them. Scientists in Japan have developed an experimental method that uses a chemical produced [...]
Our books are available worldwide!
Online Sellers other than Amazon, Routledge, and IOPP Indigo Global Health Care Equivalency in the Age of Nanotechnology, Nanomedicine and Artifcial Intelligence Global Health Care Equivalency In The Age Of Nanotechnology, Nanomedicine And Artificial [...]
After only a short training, people in a coma managed to send targeted signals
Researchers have succeeded in communicating with brain-injured patients who are unconscious. They see enormous potential in this for future treatments. Patients who lie motionless in bed after a severe brain injury and do not [...]
MIT Scientists Reprogram Immune Cells Inside the Body To Destroy Cancer
Natural killer cells reprogrammed inside mice eliminated lymphoma tumors and helped damaged livers heal, though whether this approach could help people with cancer or autoimmune disease remains unknown. To make a cancer treatment from [...]
Melanoma mRNA Vaccine Shows Promise in Preventing Disease Recurrence
Key takeaways: Phase 3 trial finds personalized intismeran plus pembrolizumab may better prevent high-risk melanoma recurrence after surgery The trial enrolled 1,137 patients and builds on phase 2 results showing about half the recurrence [...]
Scientists Discover a Powerful New Weapon Against a Dangerous Gut Infection
The promise of an experimental treatment for C. difficile gut infections lies partly in the bacteria it leaves alive, according to early laboratory and mouse research. Broad-spectrum antibiotics can disrupt the gut’s microbial community, [...]
Your Bones May Hold a Hidden Clue to Blood Cancer Survival
For people with blood cancers called myelodysplastic syndromes, osteoporosis may hold an overlooked clue to survival, a three-year observational study suggests. In blood cancers that develop in the bone marrow, an important clue to [...]
Researchers Discover What Reading for Pleasure May Be Doing to Your Brain
Reading for pleasure may offer surprising benefits for the brain, with research linking the habit to better mental health, stronger cognitive abilities, and a lower risk of dementia. Reading for pleasure may do far [...]
Scientists Discover a Hidden Trigger That Keeps Inflammation Alive
Inflammation persists after proteins detach from immune receptors, revealing a potential target for autoimmune treatments. Since a Nobel Prize-winning discovery in the 1990s identified molecules called Toll-like Receptors as the guardians of the human [...]
A Virus Gives Itself Away the Moment It Attacks
Researchers have found the trigger behind a powerful bacterial defense against viruses. Viruses that prey on bacteria could become an increasingly important tool for treating bacterial infections, particularly as antibiotic resistance makes some infections [...]
Scientists Discover Aspirin May Slash Dementia Risk by 70% – but Only for Certain People
Aspirin was linked to a sharply lower dementia risk in some older adults, and their genes may hold the clue. A Monash University analysis found that older adults with a particular genetic profile had [...]
Inflammation May Awaken Dormant Cancer Cells Years After Treatment
The body’s response to inflammation may disturb cancer cells that have been lying silent for years, giving them an opportunity to grow again. Researchers at the Francis Crick Institute have found that gut inflammation [...]
Where do nanoparticles go once they enter the body?
New international best practice guidance, co-written at ANSTO, sets out how to measure where nanoparticles like titanium dioxide end up in the body and how long they remain. The guidance has been shared by [...]
Long-Acting HIV Shots Could Solve a Major Treatment Challenge for Young People
A major African trial suggests that changing how HIV treatment is delivered could significantly improve viral suppression in adolescents. Young people with HIV were more likely to keep the virus suppressed when they received [...]
WHO Factsheets – The top 10 causes of death
In 2023, the 10 leading causes of death accounted for 33 million deaths, or 54% of the total 61 million deaths worldwide. The top global causes of death, in order of total number of lives lost, [...]















