Prevalence of SARS-CoV-2 Antibodies in a Multistate Academic Medical Center.

OBJECTIVE: To estimate the seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies in health care personnel. METHODS: The Mayo Clinic Serology Screening Program was created to provide a voluntary, two-stage testing program for SARS-CoV-2 antibodies to health care personnel. The first stage used a dried blood spot screening test initiated on June 15, 2020. Those participants identified as reactive were advised to have confirmatory testing via a venipuncture. Venipuncture results through August 8, 2020, were considered. Consent and authorization for testing was required to participate in the screening program. This report, which was conducted under an institutional review board-approved protocol, only includes employees who have further authorized their records for use in research. RESULTS: A total of 81,113 health care personnel were eligible for the program, and of these 29,606 participated in the screening program. A total of 4284 (14.5%) of the dried blood spot test results were "reactive" and warranted confirmatory testing. Confirmatory testing was completed on 4094 (95.6%) of the screen reactive with an overall seroprevalence rate of 0.60% (95% CI, 0.52% to 0.69%). Significant variation in seroprevalence was observed by region of the country and age group. CONCLUSION: The seroprevalence for SARS-CoV-2 antibodies through August 8, 2020, was found to be lower than previously reported in other health care organizations. There was an observation that seroprevalence may be associated with community disease burden.

The haphazard approach to the early detection of asymptomatic renal cancer: results from a contemporary executive health programme.

OBJECTIVE To compare the detection of asymptomatic renal cell carcinoma (RCC) in an executive health programme (EHP) that uses traditional methods of screening (history, physical examination and urine analysis) to programmes that screen by renal imaging. PATIENTS AND METHODS We retrospectively reviewed case records from patients undergoing executive health examinations at Mayo Clinic between 1 January 2002 and 30 September 2007. Results Of 32 310 patients, 18 RCCs were detected; of these, 13 (72%) were detected by the EHP and five (28%) were missed by the initial EHP screening process but subsequently discovered within 4-24 months. Of the 13 detected through the EHP, eight were discovered incidentally, two because of symptoms, and three because of asymptomatic microscopic haematuria (AMH). Of the 13, 12 were classified as early-stage cancers (Stage I). By contrast, of the five cancers missed by the EHP screening process, two were diagnosed because of the development of symptoms and only one was classified as Stage I. To date, two of these patients whose cancers were undetected by the EHP developed metastasis and one of them has died. Both had been followed in the EHP for years and neither had MH in multiple specimens. CONCLUSION Our EHP follows standard policy and relies on a history, physical examination and urine analysis to decide who to evaluate for asymptomatic RCC. This practice missed >70% of the potentially diagnosable cancers. The patients with RCCs that were discovered initially by the EHP fared better than those whose diagnosis was delayed. Our detection rate of four per 10 000 was only a fraction of those reported by programmes using imaging as a screening tool. The logic behind our current approach to the early detection of asymptomatic RCC needs to be reassessed. AMH is coincidental in most cases and patients could forego imaging if they are unsuitable candidates for screening. However, AMH will miss most treatable cancers and is not an appropriate screening test for an early detection programme. In the absence of reliable biomarkers, renal imaging should be the primary screening tool for detecting asymptomatic RCC in informed, clinically suitable individuals enrolled in an early detection programme.