Health officials have expressed fears, that the virus causing the current Ebola epidemic in West Africa has not evolved as quickly as some scientists had suggested quelling fears of developing into even more virulent and contagious form of the virus.
A newly published research in the journal Science suggests, however that the virus is undergoing contained mutational changes.
Thomas Hoenen, lead study author and virologist at the National Institute of Allergy and Infectious Diseases wrote “Despite the extensive and prolonged human-to-human transmission in this outbreak, the virus is not mutating as rapidly as expected.”
The findings had been received with relief as earlier reports had suggested that the Ebola virus was mutating twice as fast in previous outbreaks, raising fears it could become more lethal. If it were mutating rapidly, health experts have expressed concerns that a rapidly mutating virus could acquire skills of evasion of diagnostic tests or develop protections against experimental vaccines and treatments. As of the moment, there is no known cure for Ebola.
A study backed by the U.S. National Institutes of Health and published in the journal Science concluded that the virus was altering at about the same rate as in previous outbreaks.
The authors wrote, “Our data suggest that Ebola virus is not undergoing rapid evolution in humans during the current outbreak.”
There are no approved vaccines or medicines for Ebola. There had been concern that a rapidly mutating virus could present a tricky moving target that could complicate efforts to develop ways to prevent and treat the virus.
An international team of researchers arrived at this conclusion after genetic sequencing samples of Ebola were extracted from patients in Mali. The samples were taken from a toddler who died from the virus in October and from three other patients who were infected in November.
The researchers were surprised to discover that the virus sample from the toddler showed only nine nucleotide differences against another sample taken in Sierra Leone six months earlier. The Ebola genome consists of a single strand of RNA made up of almost 19,000 nucleotides.
The biggest Ebola outbreak so far, centered in the African countries of Liberia, Guinea and Sierra Leone, has caused the death of 10,326 and infected 24,907 people, according to the WHO.
Ebola viruses have been reported to undergo only limited genetic changes during outbreaks, a phenomenon that also seems to be true in the current outbreak, in the past,” authors of the study wrote.
“Whereas from a public health perspective the current Ebola virus outbreak in West Africa continues to be an extremely pressing emergency, it is doubtful that either virulence or transmissibility has increased in the circulating Ebola virus strains.”