Are we overlooking the role of environment and location in cystic fibrosis?

Cystic fibrosis (CF) care has changed dramatically over the past decade. Advances in diagnosis, multidisciplinary care, and new treatments have improved both life expectancy and quality of life for many people living with CF. Yet respiratory infections remain a common and challenging aspect of the condition.

Not everyone experiences these infections in the same way. Some people develop recurrent respiratory infections throughout their lives, while others are affected less frequently. While we know that genetics, age, disease severity, and treatment influence infection risk, emerging evidence suggests environmental conditions and geography may also contribute. 

This raises an important question: are we overlooking factors outside the individual?

How location impacts cystic fibrosis respiratory infections

Many of the bacteria and fungi associated with CF respiratory infections are commonly found in the environment. The air we breathe, the water we use, the climate we live in, and even the characteristics of our local communities may influence our exposure to these microorganisms. Geographic location can also shape environmental exposures and access to health care. 

These ideas are not new, but they have received relatively little attention in CF research. As people with CF live longer and spend more time engaging in work, travel, and community life, understanding the role of environmental conditions and geography may become more important in explaining why some people experience respiratory infections more frequently than others.

The evidence so far 

To better understand the relationship between the environment, geography, and respiratory infections in CF, we conducted a systematic review and meta-analysis. We reviewed 43 studies that examined whether environmental conditions or location were associated with respiratory infections in people living with CF.

The studies investigated a diverse range of exposures. Some focused on environmental conditions such as temperature, humidity, air pollution, and vapour pressure. Others examined where people lived and where they received care. Together, these studies explored whether differences in environmental exposures and geography could help explain variation in respiratory infections between individuals and populations.

While the studies varied considerably in their design, methods, and outcomes, several consistent themes emerged. We found evidence that environmental conditions, including time of year, air pollution, vapour pressure, and chemical characteristics of water and soil, were associated with bacterial respiratory infections in people with CF. We also found evidence that where people lived and where they received their care were associated with both bacterial and fungal respiratory infections.

One of the key strengths of this review was its comprehensive approach. By systematically identifying, assessing, and synthesising the available evidence, we were able to provide a broader picture of a research area that has historically been fragmented across different pathogens, environmental exposures, and settings.

However, important gaps remain. Many studies focused on a single pathogen or exposure, and there was variation in how environmental and geographic factors were measured. Most studies were observational, meaning they could identify associations but could not determine whether these factors directly caused infections. We also found relatively little research from Australia, despite the country's diverse climates, environments, and population distribution.

Why the environment and geography matter 

For many years, research into respiratory infections in CF has understandably focused on genetics, clinical care, and new therapies. These remain central to improving outcomes. However, our review suggests that environmental conditions and geography may be an important piece of the puzzle that is often overlooked.

This does not mean clinicians should start making decisions based solely on where a patient lives. Rather, it highlights the need to consider respiratory infections within a broader environmental and community context. Understanding why infections occur is a critical first step towards understanding how they might be prevented.

There is a clear need for more Australian research in this area. Australia's vast geography and diverse climate provide an opportunity to better understand how place-based factors influence infection risk. 

Future studies should also move beyond bacterial infections. Fungal and viral pathogens remain comparatively under-studied, despite their potential impact on respiratory health. Consistent methods and larger studies will be needed to strengthen the evidence base and determine which environmental exposures are most relevant to clinical practice.

As people with CF continue to live longer and healthier lives, the factors influencing respiratory health are likely to extend beyond the clinic walls. Genetics and treatment will always remain important, but understanding the role of the environment and geography may help us better understand why respiratory infections affect people differently and identify new opportunities to improve respiratory health in the future.

Brittnee Bryer is a PhD candidate at The University of Queensland. 

Jialu Wang is a PhD candidate at Queensland University of Technology. 

Associate Professor David Reid is a respiratory physician at The Prince Charles Hospital, the lung inflammation and infection group lead at QIMR Berghofer Medical Research Institute, and is affiliated with The University of Queensland. 

Dr Darsy Darssan is a Senior Lecturer at The University of Queensland.