Chicken farm in Brazil under a sky patterned with viruses, representing the threat of IBV.

Is Your Flock at Risk? Understanding Avian Infectious Bronchitis in Brazil

Lena Kashyap in Health & Wellness August 2025 • 4 min read.

"A deep dive into the complexities of infectious bronchitis virus (IBV) in Brazil, its impact on poultry, and what it means for your farm."

Infectious Bronchitis (IB) is a major threat to poultry farms worldwide, causing significant economic losses due to illness and reduced productivity. The Avian Infectious Bronchitis Virus (IBV), which causes IB, is particularly challenging to control because it can change and adapt, leading to different strains that affect chickens in various ways. Understanding these strains and how they spread is crucial for protecting your flock.

In Brazil, IBV poses unique problems. The virus has a high ability to mutate, and the primary method of defense, vaccination, faces limitations. The most common vaccine uses only one serotype, Massachusetts, which doesn't always protect against the diverse range of IBV strains found in the country. This gap leaves Brazil's large chicken population vulnerable to outbreaks.

This article breaks down the complexities of IBV in Brazil, drawing on research from the Coronavirus Research Group at the University of São Paulo. We'll explore how IBV affects Brazilian poultry, the challenges in controlling the virus, and what steps can be taken to better protect your chickens. Whether you're a poultry farmer, a veterinarian, or simply interested in poultry health, this guide offers valuable insights into navigating the world of IBV.

Why is IBV Such a Problem in Brazil?

Chicken farm in Brazil under a sky patterned with viruses, representing the threat of IBV.

To grasp the impact of IBV, it’s important to understand how widespread it is. A study by Sandri et al. (2009) revealed that a significant 73.5% of poultry flocks tested positive for IBV. This included broiler, layer, and breeder chickens. What's more concerning is that the predominant strains were not the Massachusetts type, which is what the standard vaccine targets. These 'variant' strains accounted for over three-quarters of IBV cases, highlighting a major gap in protection.

The virus doesn't discriminate when it comes to affecting different parts of the chicken. IBV RNA has been detected in various organs, including the lungs, trachea, kidneys, and even reproductive organs. This widespread presence contributes to a range of symptoms, from respiratory issues to problems with egg production. The ability of IBV to affect so many areas makes it particularly difficult to manage.

High Prevalence: IBV is widespread across Brazilian poultry farms.
Variant Strains: Most infections are caused by strains different from the vaccine target.
Multi-Organ Impact: The virus affects various organs, leading to diverse symptoms.

Understanding the genetic diversity of IBV is crucial for developing effective control strategies. Researchers have been working to map out the different strains and their relationships to each other. This involves analyzing the virus's genetic code to understand how it evolves and spreads. By tracking these changes, scientists can better predict which strains are most likely to cause problems and develop more targeted vaccines.

What Can Be Done to Protect Brazilian Poultry?

Addressing the challenge of IBV in Brazil requires a multi-pronged approach. More research is needed to fully understand the diversity of IBV strains circulating in the country. This knowledge will help in developing vaccines that offer broader protection. Additionally, improving biosecurity measures on farms can help prevent the spread of the virus. This includes strict hygiene practices, limiting contact with other farms, and carefully monitoring the health of flocks. The aim is to empower poultry farmers and veterinarians with the knowledge and tools necessary to combat this persistent threat.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1590/s1516-635x2010000200008, Alternate LINK

Title: Avian Infectious Bronchitis Virus In Brazil: A Highly Complex Virus Meets A Highly Susceptible Host Population

Subject: Animal Science and Zoology

Journal: Revista Brasileira de Ciência Avícola

Publisher: FapUNIFESP (SciELO)

Authors: Pe Brandão

Published: 2010-06-01

Everything You Need To Know

What exactly is Avian Infectious Bronchitis Virus (IBV), and why is it a problem in Brazil?

Avian Infectious Bronchitis Virus (IBV) is a significant threat to poultry in Brazil because it causes Infectious Bronchitis (IB), leading to illness and reduced productivity in chickens. The virus's ability to mutate and adapt into different strains makes it difficult to control. In Brazil, the situation is exacerbated by the limitations of the primary defense, vaccination, which often doesn't protect against the diverse range of IBV strains found in the country.

How widespread is IBV among poultry farms in Brazil?

The study by Sandri et al. (2009) revealed that a significant 73.5% of poultry flocks in Brazil tested positive for IBV. This high prevalence indicates the widespread nature of IBV across various types of chickens, including broilers, layers, and breeders. The fact that the predominant strains were not the Massachusetts type, the target of the standard vaccine, underscores the vulnerability of the poultry population and the need for improved control strategies.

What parts of a chicken's body can Avian Infectious Bronchitis Virus (IBV) affect, and what are the implications?

The impact of IBV in chickens is multifaceted. IBV can affect multiple organs, including the lungs, trachea, kidneys, and reproductive organs. This widespread presence leads to a range of symptoms, from respiratory issues to problems with egg production. The multi-organ impact of IBV makes it particularly challenging to manage because it can cause diverse and complex health problems in infected chickens.

Why isn't the current vaccination strategy fully effective against IBV in Brazil?

The primary limitation of the current vaccination strategy in Brazil is that the standard vaccine typically uses only one serotype, the Massachusetts strain. However, the majority of IBV infections in Brazil are caused by variant strains that are not covered by this vaccine. This mismatch leaves a significant portion of the chicken population vulnerable to outbreaks. Addressing this requires developing vaccines that offer broader protection against the diverse range of IBV strains.

What can be done to better protect poultry from Avian Infectious Bronchitis Virus (IBV) in Brazil?

Protecting Brazilian poultry from IBV requires a multi-pronged approach. This includes conducting more research to understand the diversity of IBV strains circulating in the country. This knowledge will help develop vaccines that offer broader protection. Additionally, improving biosecurity measures on farms is crucial. This includes strict hygiene practices, limiting contact with other farms, and carefully monitoring the health of flocks. These measures aim to empower poultry farmers and veterinarians to effectively combat the persistent threat of IBV.