Preventing COVID-19 spread in closed facilities by regular testing of employees - an efficient intervention in long-term care facilities and prisons

Background: Draconic control measures were introduced to contain the global COVID-19 pandemic, many of which have been controversial, particularly the comprehensive use of diagnostic tests. Regular testing of high-risk individuals (pre-existing conditions, older than 60 years of age) has been suggested by public health authorities. The WHO suggested the use of routine screening of residents, employees, and visitors of long-term care facilities (LTCF) to protect the resident risk group. Similar suggestions have been made by the WHO for other closed facilities including incarceration facilities (e.g., prisons or jails), where in parts of the US, accelerated release of approved inmates is taken as a measure to mitigate COVID-19. Methods and findings: Here, the simulation model underlying the pandemic preparedness tool CovidSim 1.1 (http://covidsim.eu/) is extended to investigate the effect of regularly testing of employees in order to protect immobile resident risk groups in closed facilities. The reduction in the number of infections and deaths within the risk group are investigated as well as the potential economic gain resulting from savings in COVID-19 related treatment costs in comparison to costs resulting from the testing interventions. Our simulations are adjusted to reflect the situation of LTCFs in the Federal Republic of Germany. The probability is nearly one that COVID-19 spreads into closed facilities due to contact with infected employees even under strict confinement of visitors in a pandemic scenario without targeted protective measures. Regular screening of all employees by PCR tests provides a significant reduction of COVID-19 cases and related deaths in LTCFs. While the frequency of testing (testing rate) and the quality of tests have noticeable effects, the waiting time for obtaining test results (ranging from 12 up to 96 hours) hardly impacts the outcome. The results suggest that testing every two weeks with low-quality tests and a processing time of up to 96 hours yields a strong reduction in the number of cases. Rough estimates suggest a significant economic gain. Conclusions: The introduction of COVID-19 in closed facilities is unavoidable without thorough screening of persons that can introduce the disease into the facility. These measures provide an economically meaningful way to protect vulnerable risk groups characterized by an elevated risk of severe infections in closed facilities, in which contact-reducing measures are difficult to implement due to imminent unavoidable close human-to-human contacts.