Joey Colby Bernert

West Virginia University, USA

Abstract Title:

Surveillance Bias and the Hidden Burden of Community Q Fever Exposure in the United States

Research Interests:

Background: Q fever, caused by Coxiella burnetii, is conventionally characterized as an occupational disease affecting agricultural workers. However, the pathogen's environmental resilience and airborne transmission capacity suggest broader community exposure.
Objective: To assess whether U.S. surveillance systems systematically undercount community Q fever exposure by optimizing for occupational case detection. Methods: We synthesized four independent data sources: CDC National Notifiable Disease Surveillance System data (2000-2019), National Inpatient Sample hospitalizations (2010-2019), National Health and Nutrition Examination Survey serology (2003-2004), and a global systematic review of 81 Q fever outbreaks. We compared geographic, demographic, and temporal patterns to identify surveillance gaps. Results: CDC surveillance identified approximately 200 annual cases with peak incidence at ages 60 to 64 years (occupational pattern) and clustering in livestock-dense states (South Dakota: 12.43 per million; Iowa: 5.71 per million). However, NHANES serology revealed 3.0% population seroprevalence (6.2 million exposed), with 87% reporting no agricultural work history. National Inpatient Sample data showed 46% of Q fever hospitalizations occurred in large metropolitan areas, with a four-fold increase in inpatient frequency from 2010 to 2019. Global outbreak data demonstrated 53% of outbreaks were community-acquired with indirect transmission predominating.
Conclusions: U.S. Q fever surveillance captures occupational cases while systematically missing community exposure, resulting in a 99.7% detection gap. Surveillance systems optimized for occupational reporting fail to detect environmental and urban community transmission. Policy recommendations include expanding case definitions to include residential proximity to livestock, enhanced urban surveillance, clinician education on non-occupational presentations, and environmental sampling at urban-rural interfaces.