Portable HEPA Purifiers to Eliminate Airborne SARS-CoV-2: A Systematic Review.

OBJECTIVE: Current epidemiologic predictions of COVID-19 suggest that SARS-CoV-2 mitigation strategies must be implemented long-term. In-office aerosol-generating procedures pose a risk to staff and patients while necessitating examination room shutdown to allow aerosol decontamination by indwelling ventilation. This review summarizes the current state of knowledge on portable high-efficiency particulate air (HEPA) purifiers' effectiveness in eliminating airborne SARS-CoV-2 from indoor environments. DATA SOURCES: Medline, Embase, Cochrane Databases, and the World Health Organization's COVID-19 Global Literature on Coronavirus Disease. REVIEW METHODS: Data sources were systematically searched for original English-language published studies indexed up to January 14, 2021 per the following search strategy: ("HEPA" OR "High-efficiency" OR "High-efficiency particulate air" OR "Efficiency particulate" OR "Purifier" OR "Filter" OR "Cleaner" OR "Filtration") AND ("COVID" OR "COVID-19" OR "SARS-CoV-2" OR "Coronavirus"). Additional relevant studies were identified by searching the reference lists of included articles. RESULTS: Eleven published studies have evaluated the effectiveness of portable HEPA purifiers in eliminating airborne SARS-CoV-2 with relevantly sized surrogate particles. Ten studies evaluated aerosols and submicron particles similar in size to SARS-CoV-2 virions. In all studies, portable HEPA purifiers were able to significantly reduce airborne SARS-CoV-2-surrogate particles. The addition of portable HEPA purifiers augmented other decontamination strategies such as ventilation. CONCLUSION: Experimental studies provide evidence for portable HEPA purifiers' potential to eliminate airborne SARS-CoV-2 and augment primary decontamination strategies such as ventilation. Based on filtration rates, additional air exchanges provided by portable HEPA purifiers may be calculated and room shutdown times potentially reduced after aerosol-generating procedures.

Olfactory Dysfunction: A Highly Prevalent Symptom of COVID-19 With Public Health Significance.

OBJECTIVE: Coronavirus disease 2019 (COVID-19) is a global pandemic affecting millions of individuals, killing hundreds of thousands. Although typically described with characteristic symptoms of fever, cough, and shortness of breath, greater understanding of COVID-19 has revealed myriad clinical manifestations. Olfactory dysfunction (OD)-hyposmia and anosmia-has recently been recognized as an important symptom of COVID-19 and increasingly gained traction as a public health tool for identifying COVID-19 patients, in particular otherwise asymptomatic carriers who, unawares, may be major drivers of disease spread. The objective of this study is to review the scientific evidence about anosmia in COVID-19. DATA SOURCES: PubMed, Google Scholar, and Web of Science. REVIEW METHODS: Comprehensive literature search of primary studies pertinent to the objectives of this review using the chosen data sources. CONCLUSIONS: Current evidence shows that OD is highly prevalent in COVID-19, with up to 80% of patients reporting subjective OD and objective olfactory testing potentially showing even higher prevalence. OD is frequently accompanied by taste dysfunction. Up to 25% of COVID-19 patients may experience sudden-onset OD as the first symptom. A large proportion of COVID-19 OD cases may resolve over the period of a few weeks. IMPLICATIONS FOR PRACTICE: Sudden anosmia should be considered a symptom of COVID-19. Assessing for sudden-onset anosmia may increase sensitivity of COVID-19 screening strategies, in particular for identifying patients at the earliest stages of disease. Since many cases of OD due to COVID-19 may resolve in the short term, conservative management, including observation, is reasonable, while advanced imaging is unnecessary.

Mood, Anxiety and Olfactory Dysfunction in COVID-19: Evidence of Central Nervous System Involvement?

OBJECTIVE: The objective of this study was to determine the burden of depressed mood and anxiety in COVID-19, and associated disease characteristics. MATERIALS AND METHODS: This is a prospective, cross-sectional study of 114 COVID-19 positive patients diagnosed using RT-PCR-based testing over a 6-week period. The two-item Patient Health Questionnaire (PHQ-2) and the two-item Generalized Anxiety Disorder questionnaire (GAD-2) were used to measure depressed mood and anxiety level, respectively, at enrollment and for participants' baseline, pre-COVID-19 state. Severity of smell loss, loss of taste, nasal obstruction, rhinorrhea/mucus production, fever, cough, and shortness of breath (SOB) during COVID-19 were assessed. RESULTS: PHQ-2 and GAD-2 significantly (P < .001) increased from baseline to enrollment. PHQ-2 was associated with smell loss (adjusted incidence rate ratio [aIRR] = 1.40, 95% CI, 1.10-1.78, P = .006), age (aIRR = 1.02, 95% CI, 1.01-1.04, P = .006), and baseline PHQ-2 score (aIRR = 1.39, 95% CI, 1.09-1.76, P = .007). GAD-2 score was associated with smell loss (aIRR = 1.29, 95% CI, 1.02-1.62, P = .035), age (aIRR = 1.02, 95% CI, 1.01-1.04, P = .025) and baseline GAD-2 score (aIRR = 1.55, 95% CI, 1.24-1.93, P < .001). Loss of taste also exhibited similar associations with PHQ-2 and GAD-2. PHQ-2 and GAD-2 scores were not associated with severities of any other symptoms during the COVID-19 course. CONCLUSIONS: Despite the occurrence of symptoms-such as SOB-associated with severe manifestations of COVID-19, only the severities of smell and taste loss were associated with depressed mood and anxiety. These results may raise the novel possibility of emotional disturbance as a CNS manifestation of COVID-19 given trans-olfactory tract penetration of the central nervous system (CNS) by coronaviruses. LEVEL OF EVIDENCE: 3 Laryngoscope, 130:2520-2525, 2020.

Sinonasal pathophysiology of SARS-CoV-2 and COVID-19: A systematic review of the current evidence.

OBJECTIVE: The ongoing pandemic of coronavirus disease (2019 coronavirus disease [COVID-19]), caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) virus, is highly contagious with high morbidity and mortality. The role of the nasal and paranasal sinus cavities is increasingly recognized for COVID-19 symptomatology and transmission. We therefore conducted a systematic review, synthesizing existing scientific evidence about sinonasal pathophysiology in COVID-19. STUDY DESIGN: Systematic review. METHODS: Systematic searches were performed of all indexed studies in PubMed/Medline and Cochrane databases through 28 March 2020 and studies searchable on preprints.com (including ArXiv and Scilit repositories) through 30 March 2020. Data extraction focused on sinonasal pathophysiology in COVID-19. RESULTS: A total of 19 studies were identified. The sinonasal cavity may be a major site of infection by SARS-CoV-2, where susceptibility genes required for infection are expressed at high levels and may be modulated by environmental and host factors. Viral shedding appears to be highest from the nose, therefore reflecting a major source for transmission. This has been highlighted by multiple reports of health care-associated infection (HAI) during rhinologic procedures, which are now consequently considered to be high risk for SARS-CoV-2 transmission to health care workers. While sinonasal symptomatology, such as rhinorrhea or congestion, appears to be a rarer symptom of COVID-19, anosmia without nasal obstruction is reported as highly specific predictor of COVID-19+ patients. CONCLUSION: Sinonasal pathophysiology is increasingly important in our understanding of COVID-19. The sinonasal tract may be an important site of infection while sinonasal viral shedding may be an important transmission mechanism-including HAI. Anosmia without nasal obstruction may be a highly specific indicator of COVID-19. LEVEL OF EVIDENCE: 2a.

Olfactory Dysfunction and Sinonasal Symptomatology in COVID-19: Prevalence, Severity, Timing, and Associated Characteristics

OBJECTIVE: Olfactory dysfunction (OD)-hyposmia or anosmia-is a symptom of coronavirus disease 2019 (COVID-19), caused by the novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We sought to better determine prevalence, severity, and timing of OD in COVID-19 relative to other sinonasal and pulmonary symptoms. STUDY DESIGN: Prospective, cross-sectional. SETTING: Regional/cantonal hospital. SUBJECTS: In total, 103 patients diagnosed with COVID-19 with reverse transcription polymerase chain reaction (RT-PCR)-based testing. METHODS: All patients testing positive for COVID-19 at Kantonsspital Aarau over a 6-week period were approached. Timing and severity (at its worst, on scale of 0 [none], 1 [mild], 2 [moderate], and 3 [severe]) of OD, loss of taste, nasal obstruction, rhinorrhea/mucus production, fever, cough and shortness of breath (SOB) were assessed for each patient. RESULTS: Prevalence of OD was 61.2%, and severity of OD was strongly correlated with severity of loss of taste experienced (ρ = 0.87, P < .001). OD was experienced on the first day of COVID-19 by 8.7% and overall occurred at median infection day 3 (mean, 3.4;range, 0-12). Most experiencing OD reported anosmia, and mean severity of all with OD was moderate to severe (mean [SD], 2.7 [0.6]). Nasal obstruction (49.5%) and rhinorrhea (35.0%) were frequently reported but not correlated with OD. SOB was more severe in patients with OD. OD was associated negatively with older age (OR, 0.96;95% CI, 0.93-0.99;P = .007) and positively with female sex (OR, 2.46;95% CI, 0.98-6.19;P = .056). CONCLUSIONS: OD is highly prevalent during COVID-19, occurring early and severely, often in conjunction with loss of taste. OD is associated negatively with older age and positively with female sex. Patients with OD may also experience more severe SOB.