ABSTRACT
ObjectiveTo evaluate the benefits and risks of any type of zinc intervention to prevent or treat SARS-CoV-2. DesignA living, systematic review and meta-analysis, incorporating rapid review methods. Data sources17 English and Chinese databases and clinical trial registries were searched in April/May 2020, with additional covid-19 focused searches in June and August 2020. Eligibilitycriteria and analysisRandomized control trials (RCTs) published in any language comparing zinc to a control to prevent or treat SARS-CoV-2. Other viral respiratory tract infections (RTIs) were included, but the certainty of evidence downgraded twice for indirectness. Screening, data extraction, risk of bias appraisal (RoB-2 tool) and verification was performed by calibrated, single reviewers. RCTs with adult populations were prioritised for analysis. Results123 RCTs were identified. None were specific to SARS-CoV-2 nor other coronaviruses. 28 RCTs evaluated oral (15-45mg daily), sublingual (45-300mg daily), or topical nasal (0.09-2.6 mg daily) zinc to prevent or treat nonspecific viral RTIs in 3,597 adults without zinc deficiency. Compared to placebo, zinc prevented 5 mild to moderate RTIs per 100 person-months, including in older adults (95% confidence interval 1 to 9) (number needed to treat (NTT)=20). There was no significant difference in the rates of non-serious adverse events (AE). For RTI treatment, a clinically important reduction in peak symptom severity scores was found for zinc compared to placebo (mean difference 1.2 points, 0.7 to 1.7), but not average daily symptom severity (standardised mean difference 0.2, 0.1 to 0.4). 19 fewer per 100 adults were at risk of remaining symptomatic over the first 7 days (2 to 38, NNT=5) and the mean duration of symptoms was 2 days shorter (0.2 to 3.5), however, there was substantial heterogeneity (I2 = 82% and 97%). 14 more per 100 experienced a non-serious AE (4 to 16, NNT=7) such as nausea, or mouth or nasal irritation. No differences in illness duration nor AE were found when zinc was compared to active controls. No serious AE, including copper deficiency, were reported by any RCT. Quality of life outcomes were not assessed. Confidence in these findings for SARS-CoV-2 is very low due to serious indirectness and some concerns about bias for most outcomes. ConclusionsZinc is a potential therapeutic candidate for preventing and treating SARS-CoV-2, including older adults and adults without zinc deficiency (very low certainty). Zinc may also help to prevent other viral RTIs during the pandemic (moderate certainty) and reduce the severity and duration of symptoms (very low certainty). The pending results from seven RCTs evaluating zinc for SARS-CoV-2 will be tracked. Systematic review registrationPROSPERO CRD42020182044
ABSTRACT
BackgroundCoronavirus disease 2019 (COVID-19), the respiratory disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was first identified in Wuhan, China and has since become pandemic. As part of initial response activities in the United States, enhanced contact investigations were conducted to enable early identification and isolation of additional cases and to learn more about risk factors for transmission. MethodsClose contacts of nine early travel-related cases in the United States were identified. Close contacts meeting criteria for active monitoring were followed, and selected individuals were targeted for collection of additional exposure details and respiratory samples. Respiratory samples were tested for SARS-CoV-2 by real-time reverse transcription polymerase chain reaction (RT-PCR) at the Centers for Disease Control and Prevention. ResultsThere were 404 close contacts who underwent active monitoring in the response jurisdictions; 338 had at least basic exposure data, of whom 159 had [≥]1 set of respiratory samples collected and tested. Across all known close contacts under monitoring, two additional cases were identified; both secondary cases were in spouses of travel-associated case patients. The secondary attack rate among household members, all of whom had [≥]1 respiratory sample tested, was 13% (95% CI: 4 - 38%). ConclusionsThe enhanced contact tracing investigations undertaken around nine early travel-related cases of COVID-19 in the United States identified two cases of secondary transmission, both spouses. Rapid detection and isolation of the travel-associated case patients, enabled by public awareness of COVID-19 among travelers from China, may have mitigated transmission risk among close contacts of these cases.
