Study: MERS virus in Korea mutated to become less virulent
In a surprise finding, South Korean researchers observed point mutations in MERS-CoV isolates that rendered the virus less virulent as the outbreak in that country spread last year, a finding that may have ramifications for vaccine development, according to a study today in mBio.
The scientists isolated 13 viral genomes from 14 patients infected with MERS-CoV (Middle East respiratory syndrome coronavirus) in late spring through July last year in South Korea. They found that 12 of the genomes had two specific mutations (I529T and D510G) in the receptor-binding domain (RBD) of the virus's spike protein.
They also determined that the mutations impaired viral fitness and virulence, rather than making the virus more virulent, or capable of causing severe disease.
"This is an interesting strategy of coronavirus evolution to survive in nature and live together with the new host. The virus may tune down its power to attack for the sake of longer survival in the new host," said principal investigator Nam Hyuk Cho, PhD, in a news release from the American Society for Microbiology (ASM), which publishes mBio.
He added, "The unexpected findings suggest that MERS-CoV adaptation during human-to-human spread may be driven by host immunological pressure such as neutralizing antibodies, resulting in reduced affinity to the host receptor."
Most MERS vaccines now undergoing trials use the spike antigen to generate an immune response, a factor that may render them less effective if the study's results prove true. "Strategies for vaccine development also need to consider the chance of emergence of neutralizing antibody-escape mutants," said Cho. "Vaccines for MERS need to target the more stable and conserved region of the spike."
South Korea had 186 confirmed MERS cases and 38 deaths in last year's outbreak.
Mar 1 mBio study
Mar 1 ASM news release
China confirms H5N6 avian flu outbreak in Guizhou province
China yesterday reported an H5N6 avian flu outbreak on a farm in the south-central province of Guizhou that affected more than 20,000 poultry, according to a report posted by the World Organization for Animal Health (OIE).
Of 20,121 susceptible birds, 3,258 developed symptoms and 3,120 died from the infection. The remaining 17,001 were euthanized to prevent disease spread, Chinese agriculture officials said in the update. The outbreak began on Feb 20.
Last month a farm with swans and peacocks was affected by H5N6 in Hunan province.
Feb 29 OIE report
Study finds placement of hospital hand sanitizer matters greatly
Placing alcohol-based hand sanitizer dispensers in the middle of a hospital lobby floor just inside the visitor entrance more than quintupled its use among visitors, researchers noted in a study today in the American Journal of Infection Control.
The investigators conducted a 3-week observational study at Greenville Memorial Hospital in Greenville, S. C., during which they observed more than 6,600 visitors using hand sanitizers. They found that hand sanitizer use was 5.28 times higher when the dispenser was in the middle of the entrance versus near the information desk on the side of the lobby.
The team also found that children and young adults were 47% more likely to use the hand sanitizer than were older adults. Also, people entering the hospital in groups were almost 39% more likely than those arriving solo to use the sanitizers.
"Visitors represent an additional vector by which healthcare-associated diseases can be transmitted to patients, and thus visitor hand hygiene is an opportunity to further improve patient safety," the authors said in a press release from Elsevier, which publishes the journal.
Mar 1 Am J Infect Control abstract
Feb 29 Elsevier press release
