In an editorial in the July12th 2024 edition of Science Dr. Nicola Lewis Director of the Worldwide Influenza Center, at the Francis Crick Institute in London and Dr. Martin Beer Head of the Institute of Virology, Friedrich-Loeffler Institute in Germany expressed their concern over the diagnosed incidence rate of bovine influenza-H5N1. Essentially the specialists warned of emergence of a potential zoonotic strain given the changes in the genome of the H5N1 avian virus to become infectious to dairy cattle.
It is evident that cases of H5N1 among workers involved in depopulating impacted egg production complexes in Weld County, CO. showed both conjunctivitis and respiratory tract involvement, denoting increased pathogenicity for humans. Comparison of avian, bovine and human strains applying whole genome sequencing is in progress but the inference of human susceptibility to a mammalian-adapted H5N1 avian influenza virus raises concerns. As yet there is no evidence of contagion, but obvious animal-to-animal transmission occurred among mink on a farm in Spain in 2023 and among marine mammals along the Pacific coast of South America from 2022 onwards.
The authors urge action expressed in the title of their editorial entitled Stop H5N1 influenza in U.S. cattle now. Suggested action included:
- Intensify surveillance incorporating as many U.S. dairy farms as is possible by sampling bulk milk. This has been initiated in Colorado.
- Enforce strict quarantine for infected herds and restrictions on both interstate and within-state transport
- Introduce biosecurity and hygiene precautions including the supply of PPE and decontamination of vehicles and equipment.
- Initiate surveillance for human cases including characterization of viruses from influenza cases and sampling of wastewater.
The authors urged global surveillance with real-time release of information concerning swine and fur-animal farms to detect any mutation that may predispose to a zoonotic strain or resistance to current antiviral drugs. Human clusters of infection should be investigated to determine source and mode of transmission.
Drs. Lewis and Beer stressed the need for a One Health approach with cooperation among the Food and Agriculture Organization, the United Nations Environment Program, the World Health Organization and the World Organization for Animal Health.