Screening Nursing Homes for COVID-19 by the Combination of RT-PCR, Clinical History and Rapid Point-of-Care Serology: Results of a Pilot Italian Study in a Hotspot of Lombardy

Abstract

Background: COVID-19 outbursts have been registered worldwide within care homes with asymptomatic transmission combined with shortage/inaccuracy of diagnostic tests undermining the efforts at containment of the disease. Nursing facilities Lombardy (Italy) were left with no, or limited, access to testing for eight weeks after the outbreak of COVID19. Methods: This study includes 246 residents and 286 workers of three different nursing homes in Brescia-Lombardy. Clinical questionnaires and rapid serology tests were devised to integrate the data of the first available RT-PCR screening. Follow-up serology after 60-days was performed on 67 of 86 workers with positive serology or clinically suspicious. Findings: 36 residents and 18 workers had previous positive RT-PCR. Thorough screening disclosed two additional RTPCR-positive workers. Serology screening revealed antibodies in 59 residents and 48 workers, including 32/36 residents and all workers previously positive at RT-PCR. Follow up serology disclosed antibodies in two additional workers with recent symptoms at the time of screening. The professionals in close contact with residents had more infections (20·79% vs 1.66%; p=0·00013 Fisher exact test). A suspicious clinical score was present in 48/63 residents and in 40/48 workers who tested positive with either method with asymptomatic disease more frequent amongst residents (28·5% vs 10·4%; p=0·032). Interpretation: Integration of RT-PCR testing with clinico-serological screening provided additional information useful to implement protective measures. Rapid serology tests demonstrated efficient and particularly suited for elderly persons less able to move/cooperate. Funding: The cost for serology tests has been met mostly from voluntary donations. Some residual funding from previous different research studies was also used. The authors received no other financial support for their research, authorship, and/or publication of this article.Declaration of Interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article. Ethics Approval Statement: Formal review and approval by the ethic committee of Spedali Civili of Brescia (NP 4378) was obtained for this study. Informed consent was obtained from all workers and residents or their representatives.