Infectious disease

Ancient origins of deadly Lassa Virus

Working as part of an international team in the United States and West Africa, a researcher at The Scripps Research Institute (TSRI) has published new findings showing the ancient roots of the deadly Lassa virus, a relative of Ebola virus, and how Lassa virus has changed over time.

Kristian G. Andersen is a biologist at The Scripps Research Institute.
Kristian G. Andersen is a biologist at The Scripps Research Institute.
Source: The Scripps Research Institute.

“This gives us a clear view of how the virus is evolving, which is important to know as we develop vaccines and therapies,” said TSRI biologist Kristian G. Andersen, a lead author of the new study.

At least 5,000 people die each year from Lassa fever. The virus is spread through contact with urine and droppings from infected Mastomys natalensis rodents (which are a natural “reservoir” of the virus) — and the disease can spread from human to human. In the new study, published in the journal Cell, the team—whose senior members included Pardis Sabeti and Joshua Levin of Harvard University and the Broad Institute, Robert F. Garry of Tulane University and Christian Happi of Nigeria’s Irrua Specialist Teaching Hospital and Sierra Leone’s Kenema Government Hospital—used a technique called next-generation sequencing to analyze genomes of Lassa virus samples taken from wild Mastomys natalensis and human patients in Nigeria and Sierra Leone.

The genomic data showed that far-flung strains of Lassa virus share a common ancestor that can be traced back more than 1,000 years to an area today known as Nigeria. This surprised the researchers, as Lassa fever was first described in Nigeria in 1969. “The virus has very ancient roots,” said Andersen.

The researchers found that the virus spread out of Nigeria about 400 years ago and over the past couple of hundred years moved into Guinea, Liberia and Sierra Leone—the same part of the world where the largest outbreak of Ebola virus has been raging since 2013. As Lassa virus spread, the virus mutated and seemed to better adapt to mammalian hosts.

The new data also show that most Lassa fever cases are caused by frequent “spillover” infections from the wild rodent reservoir to humans, rather than spreading from human to human. “The reason Lassa hasn’t yet grown into this huge epidemic is because there is limited transmission between humans,” said Andersen. “That’s a major difference between Lassa virus and Ebola virus.”

Andersen noted that local scientists in West Africa were key for this new study and will be crucial for future studies in the region. He views the next step in this research as understanding how the virus mutates within individual hosts as it confronts the immune system.

 

Source: Scripps Research Institute

01.09.2015

More on the subject:
Read all latest stories

Related articles

Photo

Rhinovirus

Common cold combats influenza

Rhinovirus, the most frequent cause of common colds, can prevent the flu virus from infecting airways by jumpstarting the body's antiviral defenses.

Photo

Coronavirus

“Hotspots” of a corona infection in the human body

An infection with the coronavirus SARS-CoV-2 can affect multiple organs. With this in mind, researchers of the German Center for Neurodegenerative Diseases (DZNE) and Cornell University in the US…

Photo

Re-evaluation of the coronavirus disease

COVID-19: A tale of two conditions

The SARS CoV-2 virus which causes COVID-19 may have been named prematurely. As more has become known about the infection, the severe disease does not appear to be a respiratory syndrome at all.…

Related products

Atlas Genetics - Atlas Genetics io system

Infectious diseases testing

Atlas Genetics - Atlas Genetics io system

Atlas Genetics Ltd
Siemens Healthineers – Versant HCV Genotype 2.0 Assay (LiPA)

Infectious Disease/Hepatitis

Siemens Healthineers – Versant HCV Genotype 2.0 Assay (LiPA)

Siemens Healthineers