Chicken infectious anemia (CIA) is a vertical transmission infectious chicken disease caused by the chicken infectious anemia virus (CAV). The disease can induce stunting and immunosuppression in chicks by infecting bone marrow-derived stem cells, causing huge economic losses for the poultry industry. To determine the prevalence of CIA in Shandong Province, China, 854 suspected CIA samples were collected and analyzed in 13 cities in Shandong from 2020 to 2022. The PCR results showed that a total of 115 CAV were isolated. The CAV-positive rates were 17.21% (26/151) in 2020, 12.23% (35/286) in 2021, and 12.94% (54/417) in 2022, with severe mixed infections. Among them, CAV and fowl adenovirus (FAdV) were the most common, accounting for 40.86%. VP1 gene homology analysis showed that isolated strains shared 96.1–100% homology with the previously reported CAV strains. Genetic variation analysis showed that most of the isolated CAV strains were located in genotype A. These results indicate that CIA infection in Shandong chickens in recent years has been prevalent and mixed infections are common, but there were no significant genetic variations. Our results extend the understanding of the prevalence and genetic evolution of CIA in Shandong Province. They will offer new references for further study of the epidemiology and virus variation and the prevention and control of this disease.

Particulate matter (PM) and the microorganisms of duck houses may have negative impacts on animal and human health. During 2021‐2022, PM2.5 and PM10 inside and outside the duck house were sampled with a built‐in air sampler in Tai’an City, Shandong Province, and the diversity and abundance of microorganisms within the PM were analyzed by macrogenomic and absolute sequence analysis. The results showed that PM2.5 and PM10 concentrations in the house and at downwind points exceeded the short‐term (24 h) guideline of the global air quality guidelines (AQG). Macrogenome sequencing showed that the microbial composition of the PM2.5 samples was dominated by bacteria (exceed 85%); a total of 1316 bacterial genera and 110 fungal genera were identified in PM2.5 samples from duck house 1 in winter, which were much higher than the results of amplicon sequencing method reported before, and relatively high levels of the pathogenic bacteria (Coccidioides immitis, etc.) and the conditionally pathogenic bacterium (Rothia nasimurium) were identified at the species level. Absolute quantitative sequencing detected conditionally pathogenic bacteria and allergens at high levels in PM10 samples: Corynebacterium (5.6 × 10⁷ copies/g), Aerococcus (9.9 × 10⁶ copies/g), Alternaria (3.3 × 10⁶ copies/g), and Aspergillus (8.3 × 10⁵ copies/g). Moreover, Corynebacterium was the highest content of PM10 in summer and PM2.5 samples in winter, and its pathogenicity and potential threat should be noted. The diversity and relative abundance of microorganisms were similar in the duck house and at the downwind point. The results showed that the microorganisms in the house environment have a greater influence on the air environment around the downwind point and may pose a public health risk to the staff and the surrounding area.