2023-03-24
It is essential to understand the latest situation regarding avian coronaviruses in Asia, commonly
referred to as the well-known avian infectious bronchitis virus (IBV), given that new and diverse
types of IBV are continually being identified worldwide, particularly ones that are isolated from
commercial poultry and associated with a wide range of disease conditions. The existing IBVs
continue to evolve in various geographic areas in Asia, which results in the recombination and co
circulation between IBV types. This makes it increasingly difficult to prevent and control IBV
infections, despite routine vaccination. Some IBV have also been identified in other avian species
and they may pose a threat of cross-transmission to commercial sectors.
Medion also monitors the incidence of IB in several countries in Asia such as Malaysia, Thailand,
Vietnam, Cambodia, China, Korea, India, Pakistan, Iran and Saudi Arabia. In these countries, several
strains of the IB virus were found, both classic, such as Mass41 and variants, such as 793b, 4/91
and QX. For several countries such as Malaysia, Thailand and China, IBV strain QX was most widely
reported from 2022 to early 2023 using the PCR method. Many farms still use only the classic IBV
vaccine for their vaccinations, which can actually use the already available QX vaccine as a
homologous vaccine with field challenges.
These reports provide an overview of IBV circulation and the emergence of dynamic new variants
found throughout Asia through recombination of IBV strains, but it is necessary to emphasize the
most dominant and dangerous QX strain for commercial poultry. In addition to commercial poultry,
backyard poultry and free-ranging birds may serve as a ‘hub’ for IBV transmission within a
particular area. These birds may be capable of spreading viruses, either to areas of close proximity,
or to remote places via migration and trade.
Yonatan Dimascahyo Budianto
Technical Education and Consultation
Artha Vena International Pte. Ltd
