Commonground
Senior Moderator
Volume 51-4, April 2025: Challenges in Managing Gonorrhea and Prevention
Abstract
Background: The current avian influenza A(H5N1) epizootic poses a significant threat to public health, with sporadic infections in humans raising concerns about potential adaptation for efficient human transmission. Laboratory studies have provided evidence that the polymerase basic protein 2 (PB2) E627K mutation facilitates more efficient replication in mammals and humans. This mutation has been detected in Canadian poultry, wild birds and mammals.
Objective: Our objective was to summarize the current state of evidence on the impact of the avian influenza PB2 E627K mutation on human adaptation, transmission, epidemiology and clinical outcomes in natural human infections.
Methods: We employed a search strategy across MEDLINE, Embase, Scopus, Global Health and CAB Abstracts for articles published from each database’s inception until mid-May 2023.
Results: We identified nine eligible articles for review that addressed human transmission or adaptation (n=5), epidemiological or clinical implication (n=1) or both topics (n=3). Some studies suggested that the PB2 E627K mutation may play a role in zoonotic transmission from birds to humans, with studies indicating its association with parallel evolution and positive selection in A(H5) and A(H7) viruses. Other studies presented analyses that supported the notion of an increased fatality rate among cases with the PB2 E627K mutation, highlighting its potential role as a virulence factor.
Conclusion:
The association of the PB2 E627K mutation with human adaptation, transmission and increased fatality rates highlights the importance of genomic surveillance under One Health umbrella. Further research is warranted to explore the role of this mutation and determine how it interacts with other mutation
-snip-
Conclusion
To our knowledge, this is the first study to review the published literature for the impact of the avian influenza PB2 E627K mutation in humans. Findings suggest that the PB2 E627K mutation may be linked to increased virulence of the virus. Additionally, this mutation could have played a role in the virus transitioning from avian hosts to humans. However, a single PB2 E627K mutation may not be enough to enable sustained human-to-human transmission of avian influenza viruses A(H5) and A(H7). Our review provides public health authorities with the available evidence as of May 16, 2023, on the potential implications of this mutation for risk assessments, should it emerge in mammals or humans in their jurisdiction. The PB2 E627K mutation’s potential role in human adaptation, transmission and clinical implications underscores the significance of genomic surveillance in humans and animals and timely information sharing from a One Health perspective. Additional studies are needed on the avian influenza PB2 E627K mutation, including those that compare the clinical and epidemiological characteristics of cases with the mutation and those without. Further studies should also review other mutations, such as the PB2 D701K mutation, both independently and in conjunction with the PB2 E627K mutation, to better understand the dynamics of avian influenza mutations in human infection.
Continued: https://www.canada.ca/en/public-hea...2-e627k-mutation-human-infection-studies.html
Abstract
Background: The current avian influenza A(H5N1) epizootic poses a significant threat to public health, with sporadic infections in humans raising concerns about potential adaptation for efficient human transmission. Laboratory studies have provided evidence that the polymerase basic protein 2 (PB2) E627K mutation facilitates more efficient replication in mammals and humans. This mutation has been detected in Canadian poultry, wild birds and mammals.
Objective: Our objective was to summarize the current state of evidence on the impact of the avian influenza PB2 E627K mutation on human adaptation, transmission, epidemiology and clinical outcomes in natural human infections.
Methods: We employed a search strategy across MEDLINE, Embase, Scopus, Global Health and CAB Abstracts for articles published from each database’s inception until mid-May 2023.
Results: We identified nine eligible articles for review that addressed human transmission or adaptation (n=5), epidemiological or clinical implication (n=1) or both topics (n=3). Some studies suggested that the PB2 E627K mutation may play a role in zoonotic transmission from birds to humans, with studies indicating its association with parallel evolution and positive selection in A(H5) and A(H7) viruses. Other studies presented analyses that supported the notion of an increased fatality rate among cases with the PB2 E627K mutation, highlighting its potential role as a virulence factor.
Conclusion:
The association of the PB2 E627K mutation with human adaptation, transmission and increased fatality rates highlights the importance of genomic surveillance under One Health umbrella. Further research is warranted to explore the role of this mutation and determine how it interacts with other mutation
-snip-
Conclusion
To our knowledge, this is the first study to review the published literature for the impact of the avian influenza PB2 E627K mutation in humans. Findings suggest that the PB2 E627K mutation may be linked to increased virulence of the virus. Additionally, this mutation could have played a role in the virus transitioning from avian hosts to humans. However, a single PB2 E627K mutation may not be enough to enable sustained human-to-human transmission of avian influenza viruses A(H5) and A(H7). Our review provides public health authorities with the available evidence as of May 16, 2023, on the potential implications of this mutation for risk assessments, should it emerge in mammals or humans in their jurisdiction. The PB2 E627K mutation’s potential role in human adaptation, transmission and clinical implications underscores the significance of genomic surveillance in humans and animals and timely information sharing from a One Health perspective. Additional studies are needed on the avian influenza PB2 E627K mutation, including those that compare the clinical and epidemiological characteristics of cases with the mutation and those without. Further studies should also review other mutations, such as the PB2 D701K mutation, both independently and in conjunction with the PB2 E627K mutation, to better understand the dynamics of avian influenza mutations in human infection.
Continued: https://www.canada.ca/en/public-hea...2-e627k-mutation-human-infection-studies.html