Quarantine alone or in combination with other public health measures to control COVID-19: a rapid review.

BACKGROUND: Coronavirus disease 2019 (COVID-19) is a rapidly emerging disease classified as a pandemic by the World Health Organization (WHO). To support the WHO with their recommendations on quarantine, we conducted a rapid review on the effectiveness of quarantine during severe coronavirus outbreaks. OBJECTIVES: To assess the effects of quarantine (alone or in combination with other measures) of individuals who had contact with confirmed or suspected cases of COVID-19, who travelled from countries with a declared outbreak, or who live in regions with high disease transmission. SEARCH METHODS: An information specialist searched the Cochrane COVID-19 Study Register, and updated the search in PubMed, Ovid MEDLINE, WHO Global Index Medicus, Embase, and CINAHL on 23 June 2020. SELECTION CRITERIA: Cohort studies, case-control studies, time series, interrupted time series, case series, and mathematical modelling studies that assessed the effect of any type of quarantine to control COVID-19. We also included studies on SARS (severe acute respiratory syndrome) and MERS (Middle East respiratory syndrome) as indirect evidence for the current coronavirus outbreak. DATA COLLECTION AND ANALYSIS: Two review authors independently screened abstracts and titles in duplicate. Two review authors then independently screened all potentially relevant full-text publications. One review author extracted data, assessed the risk of bias and assessed the certainty of evidence with GRADE and a second review author checked the assessment. We used three different tools to assess risk of bias, depending on the study design: ROBINS-I for non-randomised studies of interventions, a tool provided by Cochrane Childhood Cancer for non-randomised, non-controlled studies, and recommendations from the International Society for Pharmacoeconomics and Outcomes Research (ISPOR) for modelling studies. We rated the certainty of evidence for the four primary outcomes: incidence, onward transmission, mortality, and costs. MAIN RESULTS: We included 51 studies; 4 observational studies and 28 modelling studies on COVID-19, one observational and one modelling study on MERS, three observational and 11 modelling studies on SARS, and three modelling studies on SARS and other infectious diseases. Because of the diverse methods of measurement and analysis across the outcomes of interest, we could not conduct a meta-analysis and undertook a narrative synthesis. We judged risk of bias to be moderate for 2/3 non-randomized studies of interventions (NRSIs) and serious for 1/3 NRSI. We rated risk of bias moderate for 4/5 non-controlled cohort studies, and serious for 1/5. We rated modelling studies as having no concerns for 13 studies, moderate concerns for 17 studies and major concerns for 13 studies. Quarantine for individuals who were in contact with a confirmed/suspected COVID-19 case in comparison to no quarantine Modelling studies consistently reported a benefit of the simulated quarantine measures, for example, quarantine of people exposed to confirmed or suspected cases may have averted 44% to 96% of incident cases and 31% to 76% of deaths compared to no measures based on different scenarios (incident cases: 6 modelling studies on COVID-19, 1 on SARS; mortality: 2 modelling studies on COVID-19, 1 on SARS, low-certainty evidence). Studies also indicated that there may be a reduction in the basic reproduction number ranging from 37% to 88% due to the implementation of quarantine (5 modelling studies on COVID-19, low-certainty evidence). Very low-certainty evidence suggests that the earlier quarantine measures are implemented, the greater the cost savings may be (2 modelling studies on SARS). Quarantine in combination with other measures to contain COVID-19 in comparison to other measures without quarantine or no measures When the models combined quarantine with other prevention and control measures, such as school closures, travel restrictions and social distancing, the models demonstrated that there may be a larger effect on the reduction of new cases, transmissions and deaths than measures without quarantine or no interventions (incident cases: 9 modelling studies on COVID-19; onward transmission: 5 modelling studies on COVID-19; mortality: 5 modelling studies on COVID-19, low-certainty evidence). Studies on SARS and MERS were consistent with findings from the studies on COVID-19. Quarantine for individuals travelling from a country with a declared COVID-19 outbreak compared to no quarantine Very low-certainty evidence indicated that the effect of quarantine of travellers from a country with a declared outbreak on reducing incidence and deaths may be small for SARS, but might be larger for COVID-19 (2 observational studies on COVID-19 and 2 observational studies on SARS). AUTHORS' CONCLUSIONS: The current evidence is limited because most studies on COVID-19 are mathematical modelling studies that make different assumptions on important model parameters. Findings consistently indicate that quarantine is important in reducing incidence and mortality during the COVID-19 pandemic, although there is uncertainty over the magnitude of the effect. Early implementation of quarantine and combining quarantine with other public health measures is important to ensure effectiveness. In order to maintain the best possible balance of measures, decision makers must constantly monitor the outbreak and the impact of the measures implemented. This review was originally commissioned by the WHO and supported by Danube-University-Krems. The update was self-initiated by the review authors.

[Quarantine Alone or in Combination with Other Public Health Measures to Control COVID-19: A Rapid Review (Review)]

BACKGROUND: COVID-19 (coronavirus disease 2019) is a new, rapidly emerging zoonotic infectious disease, that was reported to the World Health Organization for the first time on 31 December 2019. Currently, no effective pharmacological interventions or vaccines are available to treat or prevent COVID-19, therefore nonpharmacological public health measures are more in focus. OBJECTIVES: The aim was to assess the effects of quarantine - alone or in combination with other measures - during coronavirus outbreaks. METHODS: Because of the current COVID-19 pandemic, WHO commissioned a rapid review. To save time, the method of systematic reviews was slightly and with caution modified. This publication is a summary of the most important aspects of the rapid review, translated into German by members of the WHO Collaborating Centre at the Danube University Krems (Austria). RESULTS: Overall, 29 studies were included. Ten modeling studies focused on COVID-19, 4 observational studies and 15 modeling studies focused on SARS and MERS. The modeling studies consistently reported a benefit of the simulated quarantine measures. For example, the models estimated that quarantine of people exposed to confirmed or suspected cases of COVID-19 prevented between 44 and 81% of the cases that would otherwise have happened and 31 to 63% of the deaths, when compared to no such measures. In regard to costs, the earlier the quarantine measures are implemented, the greater the cost savings will be. CONCLUSION: Our confidence in the evidence is very limited. This is mainly because the COVID-19 studies based their models on the limited data that have been available in the early weeks of the pandemic and made different assumptions about the virus. The studies of SARS and MERS are not completely generalizable to COVID-19. Despite only having limited evidence, all the studies found quarantine to be important for controlling the spread of severe coronavirus diseases. Looking to the coming months, in order to maintain the best possible balance of measures, decision makers must continue to constantly monitor the outbreak situation and the impact of the measures they implement.