A recent study from Columbia University, published in the open-access journal PLOS Water, investigates how weather conditions, climate, and water sources affect hospital admissions for waterborne infectious diseases in the United States. The study examined 12 years of data from 516 hospitals in 25 states.
Key findings on biofilm-forming bacteria
Biofilm-forming pathogens, such as Legionella, Pseudomonas, and Nontuberculous mycobacteria (NTM), thrive in biofilms within water distribution systems and are responsible for respiratory infections, especially among vulnerable populations like individuals over 55 or those who are immunocompromised. During the study period, biofilm-forming bacteria were responsible for 81% of all waterborne disease hospitalizations.
- Legionella: Hospitalizations due to Legionnaires’ disease increased by 124% as soil moisture increased by one standard deviation. Unlike other biofilm-forming bacteria, Legionnaires’ disease had a higher hospitalization rate in urban settings.
- Pseudomonas: Pseudomonas species were the most significant contributors, accounting for 66% of all hospitalizations linked to waterborne pathogens, primarily causing respiratory infections.
- NTM infections: NTM infections accounted for 9.6% of hospitalizations and are often linked to plumbing systems with biofilm growth.
Geographical and environmental influences
- Urban vs. rural: The study found a 16% decrease in hospitalizations due to bacterial pathogens in urban areas compared to rural ones. However, for biofilm-forming pathogens like Legionella, the rates were notably higher in urban areas.
- Drinking water source: Groundwater was associated with higher hospitalization rates for biofilm-forming bacteria. This trend was evident across multiple biofilm-forming pathogens, emphasizing the role of water infrastructure and water sources in causing illness.
- Meteorological factors: The study highlighted the role of soil moisture in biofilm-forming bacterial infections, with increased soil moisture levels corresponding to higher hospitalization rates. This suggests that wet conditions may facilitate the proliferation of biofilm-forming bacteria in water systems, subsequently leading to higher infection rates.
Conclusion
The study identifies a clear link between meteorological conditions, drinking water sources, and hospitalization rates for waterborne diseases. With climate change potentially leading to more extreme weather events, the study highlights the need for improved water infrastructure and water management practices to mitigate the risk of these waterborne infections, particularly in urban areas and regions dependent on groundwater sources.
