Infectious Diseases 2025

The severe case of H5N1 in Canada: more details

the New England Journal of Medicine | December 31, 2024 2 January, 2025 A new publication in The New England Journal of Medicine (NEJM) reports a case of critical illness caused by influenza A(H5N1) virus infection in a 13-year-old girl from British Columbia. She initially presented with conjunctivitis and fever and was discharged without treatment but later returned with respiratory distress and other severe symptoms.
Upon readmission, she was found to have a high viral load of influenza A, which necessitated her transfer to the pediatric intensive care unit. Despite treatment with oseltamivir and other antiviral medications, her condition worsened, requiring tracheal intubation and extracorporeal membrane oxygenation (ECMO). Read More

HPAI A(H5N1) virus infections in humans

the New England Journal of Medicine | December 31, 2024 2 January, 2025 A new publication in the New England Journal of Medicine examines the emergence and impact of highly pathogenic avian influenza A(H5N1) virus infections in humans and livestock in the United States, particularly from March to October 2024. During this period, 46 human cases were reported, primarily linked to occupational exposure to infected poultry and dairy cows. Most cases were mild, with symptoms such as conjunctivitis and respiratory issues, and none required hospitalization or resulted in death. The study highlights the importance of monitoring and preventive measures to address the risk of animal-to-human transmission.

The A(H5N1) infections in humans were predominantly mild, with no severe illnesses or fatalities reported among the 46 cases. Most patients experienced conjunctivitis and other mild symptoms. All but one case was associated with occupational exposure to infected animals, highlighting the risks faced by agricultural workers. Importantly, no evidence of human-to- Read More

Strategic challenges in the global control of HPAI

1 January, 2025 A recent scholarly review entitled "Strategic challenges in the global control of high pathogenicity avian influenza" presents a comprehensive analysis of HPAI management strategies. This authoritative publication, authored by leading experts in the field, examines the worldwide proliferation of the H5Nx lineage since 2005 and its consequent implications. The review addresses several critical aspects of HPAI control, including the documented ecological and epidemiological mutations of these viruses, their substantial impact on both wild and domesticated avian populations, and the associated risks of human transmission. Regarding prophylactic measures, the research presents substantial evidence supporting vaccination as an effective preventive intervention. Read More

APHIS updates indemnity program for avian influenza

1 January, 2025 The U.S. Department of Agriculture’s Animal and Plant Health Inspection Service (APHIS) is introducing an interim final rule aimed at curbing the spread of Highly Pathogenic Avian Influenza (HPAI) and providing farmers with additional tools to manage the disease. Under the new rule, poultry facilities must complete a biosecurity audit before restocking their flocks following an HPAI detection and before becoming eligible for future indemnity payments.
While APHIS, in collaboration with state and federal veterinary officials and industry partners, has worked extensively to address biosecurity challenges, some poultry farms continue to face difficulties, with some experiencing multiple outbreaks. Read More

Evolution of H5 and H7 HPAI virus cleavage site

1 January, 2025 A recent review examines the molecular evolution of highly pathogenic viruses, focusing on their natural history, biology, and the critical role of the haemagglutinin cleavage site motif.
The review offers a comprehensive analysis of the haemagglutinin cleavage site (HACS) motif in H5 and H7 avian influenza viruses (AIVs) and its implications for pathogenicity. It discusses the structural characteristics of the HACS motif, its function in the cleavage of the haemagglutinin protein, and the evolutionary dynamics that influence the emergence of highly pathogenic strains. The composition of the HACS motif, particularly the number of basic amino acids, is a primary determinant of the pathogenicity of H5 and H7 AIVs. Highly pathogenic avian influenza viruses (HPAIVs) typically possess multiple basic residues, allowing for cleavage by a broader range of host proteases, which facilitates systemic infection. Read More