The H10 subtype avian influenza virus is widely present in wild birds, poultry, seals, and minks. With the emergence of H10, it poses an increasing threat not only to poultry farming, but also to human health. In 2021, there was a report of human infection with avian H10N3 influenza virus in Zhenjiang City, Jiangsu Province, China. The patient is a 42 year old male who sought medical attention at Jurong People's Hospital in Zhenjiang City, Jiangsu Province, China on April 26, 2021, due to fever, cough, fatigue, and shortness of breath. On June 18, 2022, a 32 year old man who raised poultry in Zhejiang Province was hospitalized due to coughing up blood and fever, and was finally diagnosed with H10N3 subtype influenza virus infection. In a 2022 paper co authored by Liaocheng University, Harbin Veterinary Research Institute, National Forestry and Grassland Administration, and East China Normal University

The epidemic and biological characteristics of H10 subtype avian influenza virus were studied separately, and the article title is "Emergence, Evolution, and Biological Characteristics of H10N4 and H10N8 Avian Influenza Viruses in Migratory Wild Birds Detected in Eastern China in 2020". Published in the Microbiology Spectrum journal on April 7, 2022, as shown in the following figure:

In the article, the author collected 23 types of influenza A viruses, including H1, H2, H3, H5, H9, and H10 subtypes, from waterfowl habitats in the Yellow River Delta of Shandong Province, black tailed gulls in the Swan Lake wetland, wild swans, and bone top chickens. Among them, there were 7 types of H10 subtype influenza viruses. See the table below:

Through evolutionary analysis of HA and NA genes, the HA genes of the seven isolated H10 subtype influenza viruses belong to the Eurasian lineage and are in the same branch as the H10 subtype influenza virus that infects humans, as shown in the following figure:

The NA gene of the isolated H10N4 subtype influenza virus belongs to the Eurasian branch, while the NA gene of H10N8 is derived from H5N8 in branch 2.3.4.4b and H3N8, H4N8, and H10N8 in wild birds, as shown in the following figure:

Based on the above findings, the author speculates that the evolutionary path of the virus is that the H10Nx virus of the North American lineage first spread to Alaska. In 2019, with the migration of migratory birds, it spread to South Korea and then to Bangladesh and eastern China. As shown in the following figure:

The author tested the receptor binding ability of the virus, and the results showed that although H10N4 and H10N8 subtypes of influenza virus preferentially bind to avian receptors, they already have the ability to bind to human receptors, as shown in the following figure:

The replication ability of H10N4 and H10N8 subtypes of influenza viruses is poor in chicken and mammalian cells, but they replicate efficiently in mice and can cause lung lesions and weight loss in mice. As shown in the following figure:

When H10N8 subtype influenza virus replicates in chickens, the main replication sites of the virus vary. Some viruses mainly replicate in the lungs and trachea, while others mainly replicate in the intestine and bursa of Fabricius.

For ducks, the virus has a higher titer in the trachea than in the lungs, and the virus has been detected in the entire intestine and bursa of Fabricius, with the rectal virus having the highest titer. The virus content in other organs such as the brain, liver, spleen, pancreas, and kidneys is relatively low, as shown in the following figure.

The article tested the replication and transmission of H10N4 and H10N8 viruses and found that the H10 subtype influenza virus can effectively replicate and spread in chicken and duck flocks. Especially, the H10 subtype influenza virus is more easily replicated in ducks than in chickens, indicating that ducks are susceptible hosts of the H10 subtype influenza virus. H10 subtype influenza virus infection cannot induce ducks to produce high levels of HI antibodies, while chickens have higher levels of HI antibodies than ducks. The final article concludes that the H10 subtype influenza virus prevalent in migratory birds has a high potential risk of spreading to poultry through fecal contamination of the environment.

Ruipu Biotechnology conducted H10 testing on 805 samples submitted for testing in various provinces of China in 2022, with a positive rate of 4% for the H10 pathogen; The detection rates of commercial geese, commercial ducks, yellow feathered broiler chickens, and white feathered broiler chickens are relatively high, and have been detected in various regions. In addition, the detection rate of waterfowl is high, mostly due to mixed infections. As shown in the following figure:

Chickens infected with H10 subtype avian influenza exhibit unexplained egg production decline. In the early stages of the disease, there are respiratory symptoms such as yellow green loose stools, and the egg production rate can decrease by more than 15% within 15 days. Antibiotic treatment is ineffective; The feed intake, mortality rate, egg quality, and hatching rate are all normal. The changes in autopsy are shown in the following figure:

Faced with the threat of H10 subtype avian influenza virus, colleagues in the breeding industry should be prepared for prevention and control. Establish a comprehensive biosafety system for breeding farms; Reduce stress and improve the health level of poultry populations; It is strictly prohibited to raise chickens, ducks, and geese together.