Abstract
Seroepidemiologic studies, which measure serum antibody levels produced in response to infection and/or vaccination, can be valuable tools for gaining insight into population level dynamics of infectious diseases. However, because seroepidemiologic studies are expensive and logistically challenging, they are not routinely conducted for surveillance purposes. We have identified a novel venue, state fairgrounds, in which annual sera samples from a population may be rapidly collected with minimal recruitment expenses. We conducted a pilot pertussis seroepidemiologic study over the course of 3 days at the 2016 Minnesota State Fair to determine if this setting, which hosts nearly 2 million visitors over 12 days each year, is viable for facilitating larger seroepidemiologic studies. A total of 104 adults and children were enrolled to provide a finger stick blood sample for serologic testing and to take a written survey regarding recent cough illness and pertussis vaccination. The survey was used to distinguish between antibodies induced by vaccination and pertussis infection. Elevated antibodies suggestive of recent infection were found among two adults. The prevalence of undetectable antibodies, suggestive of susceptibility, was 72.3% (95% CI 59.6, 85.1%) among 7-17 year olds, 53.8% (95% CI 26.7, 80.9%) among 1-6 year olds, and 23.3% (95% CI 8.2, 38.5%) among adults. Our ability to rapidly enroll participants and collect satisfactory specimens suggests that seroepidemiologic studies with 1000-2000 participants could efficiently be completed over the 12-day course of the Minnesota State Fair. This setting raises the possibility of efficiently conducting annual population-based seroepidemiologic studies to supplement traditional public health surveillance in estimating disease prevalence, monitoring vaccine impact, and identifying at-risk groups.