Background Chagas disease (CD) is a neglected parasitic disease that affects >6 million people in the Americas, including >200,000 people in the United States (US). Medical provider knowledge of CD is key to decreasing morbidity and transmission; however, few studies have assessed diagnostic practices in US health systems serving at-risk patients. Our study aimed to describe existing provider approaches to diagnosing CD in California and Texas. Methods Site-based research teams at four hospital systems (the University of California [UC] San Francisco [UCSF], San Diego [UCSD], Irvine [UCI], and the Harris Health System [HHS] in Houston, TX) retrospectively identified patients ≥18 years old tested for CD between 2016-2019 and systematically extracted electronic medical record data using complementary electronic data entry forms. Specifically, eligible patients were identified using laboratory orders at UCSF and UCI, while the remaining sites employed SlicerDicer (Epic Systems). This study was approved by institutional review boards at each site. Results We identified 333 patients tested for CD, including 109 from UCSF, 88 from UCSD, 25 from UCI, and 111 from HHS. These patients had 125, 99, 31, and 181 tests sent to commercial laboratories, respectively. Test reactivity varied by system with the greatest percent reactivity among tests ordered at UCI (23%) followed by UCSD (16%), HHS (15%), and UCSF (10%). Among patients who screened positive for CD by commercial assays, confirmatory testing through the Centers for Disease Control and Prevention was sought for 100% at UCI; 59% at HHS, 55% at UCSF, and 40% at UCSD. The medical specialty that most often ordered CD testing was Cardiology at all UC sites (UCSF, 50%; UCSF, 55%; UCI, 35%) and Internal Medicine at HHS (46%; Cardiology ordered 13%). Only one recorded CD test was ordered by an Obstetrics/Gynecology service at any site. Conclusion These early results report positivity rates between our healthcare systems and demonstrate inconsistency in attaining recommended confirmatory testing, as well as a paucity of CD testing ordered through Obstetrics/Gynecology despite risk of congenital transmission. These findings suggest areas of opportunity to improve provider awareness and lay a foundation for standardizing CD diagnostic practices in the US. Disclosures Caryn Bern, MD, MPH, UpToDate (Wolters Kluwer) (Other Financial or Material Support, Author Royalties)

Eating a high fat diet can lead to obesity, type 2 diabetes, and dopamine system dysfunction. For example, rats eating high fat chow are more sensitive than rats eating standard chow to the behavioral effects (e.g., locomotion and yawning) of dopaminergic drugs (e.g., quinpirole and cocaine). Daily dietary supplementation with 20% (w/w) fish oil prevents high fat diet-induced enhanced sensitivity to quinpirole-induced yawning and cocaine-induced locomotion; however, doctors recommend that patients take fish oil just two to three times a week. To test the hypothesis that intermittent (i.e., 2 days per week) dietary supplementation with fish oil prevents high fat diet-induced enhanced sensitivity to quinpirole and cocaine, rats eating standard chow (17% kcal from fat), high fat chow (60% kcal from fat), and rats eating standard or high fat chow with 20% (w/w) intermittent (e.g., 2 days per week) dietary fish oil supplementation were tested once weekly with quinpirole [0.0032–0.32 mg/kg, intraperitoneally (i.p.)] or cocaine (1.0–17.8 mg/kg, i.p.) using a cumulative dosing procedure. Consistent with previous reports, eating high fat chow enhanced sensitivity of rats to the behavioral effects of quinpirole and cocaine. Intermittent dietary supplementation of fish oil prevented high fat chow-induced enhanced sensitivity to dopaminergic drugs in male and female rats. Future experiments will focus on understanding the mechanism(s) by which fish oil produces these beneficial effects.